Summer 2018 gave us all a sharp reminder about the value of a just-in-case silage forage reserve. Clearly, rebuilding this important home-grown bio asset is on this summer’s agenda for a good number of livestock farmers. In addition to growing more silage and harvesting more efficiently etc, minimising avoidable losses that occur once the clamp is sealed can also contribute. Research bean-counters say the loss can be 10% of harvested material even in well-managed systems, and as much as 25% on average!

So for everyone making silage this year, without exception, reducing this is equivalent to making extra tonnage at zero cost. Aside from effluent, which of course can be minimised by wilting grass to 25-30% dry matter, a significant but invisible cause of in-clamp silage losses is warming up. This can occur immediately after silaging, during storage, at the open clamp face and in the feed trough.

Warming up is caused by bio microns such as yeasts, moulds, fungi and pathogenic bacteria that are all unavoidably there on harvested grass. Against these, lactic acid is not particularly effective. Instead, it is acetic acid – yes, vinegar – that’s required, for exactly the same reason it’s used for pickling beetroot, onions, eggs etc to preserve them from rotting.

Independent research confirms that “acetic acid has been proven to be the sole substance responsible for increased aerobic stability, and this acid acts as an inhibitor of spoilage organisms“

The study also identifies that using inoculants producing lactic acid only “leads to silages which have low stability against aerobic deterioration” sometimes referred to as secondary fermentation.

To create the STAYCOOL effect inside the clamp, at the open face and in feed troughs, an inoculant is available with not one but three bio micro bacterial strains:

Lactobacillus plantarum to generate lactic acid for rapid preservation and optimize maximum capture of nutrients going into the clamp.

Two other Lactobacilli that generate acetic as well as lactic acid, to create the STAYCOOL effect.

The OptiSile Range

All the issues which apply to preserve grass silage also apply to Maize silage, Wholecrop silage and other ensiled crops. Therefore, the action of OptiSile is just as relevant on any crop which can be clamped and fermented. Our range includes OptiSile Wholecrop and OptiSile Maize.

Important Notice! Nine-out-of-ten UK dairy farms are thought to be missing out on optimizing the value of slurry at minimal cost. Among progressive RABDF members, of course, the picture is probably not this extreme. Nevertheless, there’s a long way to go before producing micron optimized enriched slurry even among this enlightened group.

As long ago as 2011, independent research by Kingshay found that treating slurry with five different forms of bio-logical slurry bugs increased total nitrogen by about 14%. For ammonium (NH4), which is readily available for plant uptake, the average was 12% higher than untreated. In both, these differences were statistically significant. The launch at 2017’s Grassland Event of AHDB’s updated Nutrient Management Guide (RB209) heralded a renewed focus on how to optimize the best use of home-grown organic fertilisers.

Right now, Liz Russell from Greenlands Nutrition Ltd says exploiting the full plant nutrient content of slurry for silage crops and grazing alike can help reduce fertiliser costs markedly. “One early adopter we know in north west Lancashire reduced their bagged-N use from 270 to 150kg/ha,” she says. “Financially, this saves £80/ha and a five-figure total annually.

“In addition, microbe enrichment reduces odours, digests stubborn crusts with minimal mechanical stirring, and inhibits new crust formation.”

“This is due to trillions of friendly bacteria that digest slurry’s fibre content, which otherwise floats to the surface and forms a crust. These bugs utilise nitrogen and sulphur, for example, converting them into available plant nutrients.”

The Kingshay study also found that treatment increased the ratio of aerobic-to-anaerobic bio-logical micron bacteria in slurry. Liz Russell says this makes it more friendly to soil microbes and thereby better for earthworms, soil health and productive capacity.

“For anyone thinking about trialling slurry bugs, this is a good time of year to start,” she explains. “In slurry stores less than half full, warmer weather gives bugs a chance to make a rapid visible impact, with the resulting material available for after-cut use this summer.”

“For maximum value and compliance with environmental limits, AHDB’s RB209 explains how to incorporate enriched slurry’s nutrients into fertiliser plans,” Liz adds. “To gauge the contribution of plant nutrients, we recommend and can provide laboratory analysis.”

“Amid the uncertainty that surrounds dairy farming right now, here is a way to make better use of material that is available in large quantities, and is already bought and paid for.” In 10 years time, this microbial revolution might just have become mainstream. Where innovative RABDF members lead today, others will surely follow…eventually.”

Imminent first cut silage quality is at risk where ground conditions remain poor due to recent high rainfall. In addition to raising cutting height to minimise soil pick up, farmers are being advised to use a combination inoculant that generates acetic acid as well as lactic acid.

To preview the Grassland UK event, micron biologist Dr David Adimpong from EnviroSystems says acetic acid inhibits soil-borne bacteria and moulds that otherwise can cause in-clamp spoilage. “Although no additive can handle heavy contamination, even low levels of soil can trigger a butyric fermentation,” he says.

To combat this, the company recommends a triple action inoculant with three bacterial strains, each with different but compatible modes of action. An example from EnviroSystems is OptiSile Extra, which contains the industry standard Lactobacillus plantarum, widely appreciated for rapid lactic fermentation and maximum capture of nutrients going into the clamp.

A second bacterial strain generates both lactic and acetic acid in the clamp, suppressing spoilage organisms throughout storage. The third activates when the clamp is opened to produce more acetic acid, keeping the clamp face and silage in the feed trough stable and cool.

“By inhibiting spoilage organisms, silage is protected not only from butyric fermentation but also heating up when exposed to air,” says Dr Adimpong. “Clearly, when silage heats up there is feed value and money are being lost into thin air.”

He adds that the research report supporting this advice states that using inoculants producing only lactic acid, “leads to silages which have low stability against aerobic deterioration.” [ref 1]

OptiSile EXTRA is made at Envirosystems’ manufacturing unit in Lancashire.

REFERENCE:

1 H Danner et al, 2003. Acetic Acid Increases Stability of Silage under Aerobic Conditions. Appl Environ Micro biol. 2003 Jan; 69(1): 562–567.

A biological treatment for unblocking slurry channels and liquifying dense sludge in hard to reach corners of slurry stores was launched at Dairy-Tech (Feb 2018, organised by RABDF).

According to Sally Russell from Envirosystems, Shift-It contains “a high concentration of sludge-digesting bacteria and fibre-melting enzymes.”

She says sludge blockages and residues are broken down and consumed as a nutrient source by trillions of vigorous friendly bacteria, converting nitrogen, sulphur and other plant nutrients into bacterial biomass.

“Farmers who understand how a cow’s rumen works can readily see the parallel,” she adds. “Starting with a serious problem, this produces high value, easy flowing, plant food. The bugs also oxygenate the slurry, making it much more friendly to soil microbes than typical anaerobic material.”

Sally Russell says it is not inevitable that slurry stores develop a sludge base, liquid middle and crust on top. Once de-sludging and unblocking problem situations has been achieved, she suggests that ongoing treatment with standard strength slurry bugs can prevent them recurring.

Shift It is available in 1.0kg pots and comes with comprehensive instructions for use. Tel 01772 860085.

Approval for use on organic farms as well as conventional has been awarded by the Soil Association to the OptiSile range of biological silage inoculants from Envirosystems. This adds to an existing Organic Farmers & Growers certification.

Variants in the range for grass, wholecrop and maize silages all employ a three-strain combination of Lactobacilli. One is the widely used L. plantarum, to promote rapid lactic acid fermentation and nutrient preservation at ensiling.

Two other strains not used in combination by other UK additives are included to generate acetic acid, a proven inhibitor of moulds, yeasts and Clostridia both during fermentation and at feed out.

This three-strain formula is effective over a wide range of dry matters, according to Envirosystems silage specialist Sally Russell. “For organic and non-organic farms alike, the lactic and acetic acid combination creates fast, stable preservation, and maximises palatability and nutrient availability,” she says.

Evidence that dairy farmers really care and prioritise cow comfort and health has been generated by a new survey. Organisers have given the findings to farming unions, Dairy UK and AHDB Dairy with permission to use the data if it helps them promote an accurate and caring image of farming, contrary to misleading propaganda put about all too often by the industry’s numerous critics.

The EnviroBed cubicle bedding study has found that cow comfort is farmers’ number one priority, rated ‘very important’ by 89% and ‘quite important’ by 9%. A close second, scoring 81% very and 13% quite important, is reducing mastitis bugs. Allied to this, number three is high absorbency, with 71% and 16% respectively. Farmers taking part used a variety of different bedding materials.

The importance of reducing humidity in cow housing is also well recognised. To improve ventilation, ridge tiles have been removed by 38% and fans installed by 9% of farmers. Another 18% and 10% respectively are considering these two options.

From the study sponsor, Sally Russell points out that keeping cows clean and comfortable doesn’t need be compromised by this winter’s shortage and high cost of bedding straw.

“Although this is driving up the cost of sawdust and some other materials, there are exceptions,” she says. “For example, some farmers with beef cattle and dairy replacements in straw yards are using a deep bed of EnviroBed Original, made from 100% dried recycled paper. Others place a 15cm layer on the floor and top it off with straw.

“For cubicles, the usual material of choice is EnviroBed Premium, a blend of dried paper and kiln dried virgin wood sawdust. Per cubicle, the recommended daily quantity and cost are just 1kg at less than 10p.”

Both materials are 95% dry matter and mildly alkaline 7.4 pH, helping create a dry and comfortable area that is unfavourable to disease organisms and fly eggs. They are also biodegradable and compatible with all manure systems. Sally Russell says prices remain where they were set in early July, long before the straw shortage came about.

The scientifically-attuned readers of this journal will be well ahead of the general public in awareness and understanding of the human microbiome. This life-sustaining population of micro-organisms is something that each of us carries round in our gut, body cavities and urogential tract. But word is spreading thanks to emerging coverage by lay media, including the recent BBC Radio 4 Food Programme’s ‘That Gut Feeling‘, presented by the elegantly surnamed Dan Saladino [1].

Over the period 2008-2012, the Human Microbiome Project [2[1]] has “characterized the microbial communities found at several different sites on the human body. The project has examined the role of these microbes in human health and disease.

“Over 1,300 reference strains isolated from the human body have been sequenced. Three hundred healthy adults between the ages of 18 and 40 were sampled at five major body sites: oral cavity, nasal cavity, skin, gastrointestinal tract and urogenital tract.” Since completion, this great work has spawned a new generation of research exploring the obvious question, what next?

Meanwhile, in the plant and soil science community, scientists setting out on a similar quest to their human health pathfinders have established the Earth Microbiome Project (www.earthmicrobiome.org).Its bold ambition is “to characterize global microbial diversity for the benefit of the planet and mankind“, no less. The immense scale of this project is outlined in a TEDx talk by University of Chicago Professor Rick Stevens [3[2]].

Meanwhile, writing in The Scientist, specialist science author Amy Coombs has said, “Like humans, with their complement of microbes that aid in everything from immune responses to nutrition, plants rely on a vast array of bacteria and fungi for health and defense… but plant biologists are only beginning to scratch the surface…”

Even so, it is known that just one teaspoon of soil contains up to 50,000 species of micro-organism: bacteria, fungi, protozoa, nematodes, mites and microarthropods. On a larger scale, Prof Stevens calculates that 1kg of soil contains more microbes than there are stars in the entire known universe.The numbers are colossal: 1030 microbes in 1kg soil, which is 106 (i.e. one million) times more than 1024 stars. Slightly more down to earth here in the UK, soil scientist Dr Martin Wood of Earthcare Technical Ltd says the typical total quantity of microbial biomass is the same as 12 adult sheep per hectare.

Simplistically, the larger any locality’s soil microbiome, the healthier the soil; or perhaps the healthier the soil, the larger the microbiome. Either way, healthy soil is more productive that unhealthy. Aside from nutrient content, Dr Wood suggests parameters that determine soil health include organic matter content (>3.5% organic carbon), no capping, no compaction, earthworms (c.25 per spadeful), porous, aerated and moist not waterlogged, all of which create the conditions required for a healthy and vigorous microbiome.

Based on all this, a reasonable hypothesis is that, in parallel with growing awareness of the human microbiome’s value to lay people, the same will happen in farming and agri-science about the soil microbiome. Even today, despite our lack of knowledge, one certainty is that there will be no catch all solution.

More relevant is the approach made so successful by Sir Clive Woodward with his 2003 Rugby World Cup squad or Sir Dave Brailsford with Team GB and Team Sky in cycling. Respectively, these are summarised as one per cent improvements in 100 areas or the aggregation of multiple marginal gains. And herein lies the direct relevance for this journal’s readers who, of course, are connected directly with soil health via manures from the animals they medicate or feed.

Some such connections are already well understood, particularly associated with anthelmintic (wormer) treatments for grazing livestock. In only about 17 days, grazing cattle produce their own weight in dung; for sheep, the figure is about 25 days [5[2]]. Of course, dung pats and sheep droppings decompose over time and make a worthwhile contribution to soil organic matter and nutrient content. But without the action of an invaluable group of insects, the breakdown of dung on pasture would take much longer and grassland productivity would be much reduced. In fact, dung beetles can save the UK livestock industry, and individual farmers, serious money.

The UK has more than 40 native species of dung beetle, according to Pembrokeshire-based Dr Sarah Beynon, senior research associate of the University of Oxford [6[3]]. “By tunnelling and breeding within dung, feeding on it and burying it below ground, dung beetles play an essential role in its breakdown and decomposition,” she explains.

A healthy dung beetle population can create a long list of benefits to soil health and pasture productivity including:

• Increased soil fertility and grassland productivity

• Improved soil aeration and reduced compaction

• Reduced pasture fouling and rejection, and therefore better grass utilisation

• Less need to harrow and so time saved, with diesel use and tractor hours reduced

“Without dung beetles, faeces from just 12 cows would cover a hectare completely in one year,” Dr Beynon adds. She warns how dung beetle populations “appear to have decreased dramatically” in the UK, and that some wormers and other parasiticides can be toxic to them. “To ensure dung beetles continue working for our benefit, we must look after them,” she urges. “To protect dung beetle populations, only medicate animals with a level of parasite burden that justifies treatment.”

Still at the mucky end of livestock farming, there is also the spreading of stored manure and slurry. At face value, these can make a worthwhile contribution to soil nutrient and organic matter levels. But many samples of slurry in particular are far from benign, explains Liz Russell, a specialist in biological conditioning applications for agriculture at Envirosystems UK.

“Typically over the winter storage period, fibrous material will float to the surface and create a crust through with light and oxygen cannot penetrate,” she explains. “Below this, small particle solids form a sludge at the bottom, with a liquid portion above it. Anaerobic microbial activity creates acidic, septic and foul smelling conditions in both the liquid and sludge layers.

“Clearly, spreading this on farmland makes a beneficial contribution of plant nutrients and organic matter, but also innoculates soil with a high loading of anaerobic microbes washed into the ground in an acidic soup.”

To assess the impact of this, Envirosystems has been involved in a research project with Lancaster University. One aspect was a respirometry test to measure carbon dioxide production from soil samples as an indicator of its biome’s metabolic activity. Two different cattle manure slurries were added to soil samples and assessed. One was innoculated with a commercially available microbial and enzyme cocktail to stimulate aerobic respiration and oxygenation (label SB on the graphic), and the other untreated (label S).

The project report confirms a consistent increase was found in cumulative carbon dioxide concentration from soils across the experiment, consistent with respiration of carbon during the soil incubation, and that the highest respiratory activity was observed from inoculated slurry [7 ].

The research also conducted phospholipid fatty acid analysis (PLFA) as an indicator of microbe proliferation in the soil samples, also finding a higher level in soil treated with the inoculated slurry.

EnviroSystems UK’s involvement in this research was prompted by anecdotal reports from farmers about plentiful fresh pasture grass being ignored by hungry high yielding cows. Herd manager and ruminant specialist Dave Lievesley [8[1]] says, “it’s deeply frustrating to watch cows turned out onto fresh grass and not see them put their heads down to graze – and it’s not as unusual as you may think.

“What’s even more disconcerting is that it’s happening more on farms that take great pride in their grassland management and are used to growing bumper crops of grass. Yet successful farming is totally dependent upon the soil.

“It’s every farm’s biggest asset but for at least 40 years the importance of a farm’s soil profile has been ignored by the management practices that have been promoted to farmers.”

Lievesley believes a lot of metabolic issues that dairy cows now suffer are directly linked to shortcomings in soil biology that supports the grass and conserved forages they eat. On a number of farms, he credits biological aerobic slurry conditioning and a corresponding reduction in bagged nitrogen fertiliser with transforming pastures from “plenty but unpalatable” into “lush and irresistible” over a five year period.

Moreover, EnviroSystems UK managing director Liz Russell reports that biological conditioning prevents crust formation in slurry stores and helps create uniform consistency from surface to the bottom. “This means minimal stirring is required before spreading, reducing markedly the workload and fuel consumption involved,” she explains.

“Clearly, this reduces costs and helps improve the farm’s carbon footprint. However, over the long term, I’m convinced that the value of improving the soil microbiome will dwarf these more immediate gains.”

Of course, it could take at least a decade to prove this and publish the peer-reviewed evidence. Meanwhile, encouraged by Dave Lievesley’s evangelism, a steady trickle of farmers are conducting their own farm-scale trials in pursuit of one of Sir Dave Brailsford’s marginal gains.

They are also employing Second World War US Army General George S Patton’s strategy that a good plan executed now is better than waiting for a perfect plan to be ready [9[2]].

Green bedding questions and other options for dairy cow cubicles

From time to time, interest in the use of recycled manure solids (RMS) – ‘green bedding’ according to some – reappears in the dairy sector, not without controversy. For a balanced view, guidelines dated 18 December 2015 have been published by AHDB Dairy (website address at bottom of article).

In summary:

1) Wales – not allowed.

2) Scotland & England – allowed subject to defined procedures, including 14 legal requirements. Must comply with Red Tractor assurance, which includes a self-assessment of risk, an annual vet’s review (both using RT template), copies of both kept on farm for showing to RT assessor, and informing RT that RMS is being used3) RMS as bedding material continues to be under review and its conditions of use may change.

The stimulus, of course, is recurring interest in reducing costs while matching the strengths and overcoming weaknesses of other materials. Sand is popular for cow comfort and being inert and therefore inhospitable to mastitis pathogens, but not all slurry systems can cope with it.

Clearly, straw is readily available for anyone willing to pay the going rate, which flucuates markedly with supply and demand, but chopping consumes fuel and staff time. Even when chopped, straw is low absorbency. Wood shavings offer better absorbency, but are expensive. As long as sawdust has been screened to remove large splinters and even nails, it offers good comfort and moderate absorbency. Shredded paper has been tried in the past but suffers from high cost and low absorbency. Dried paper pulp blended for additional bulk with sawdust is gaining users for ‘blotting paper’ absorbency and good cow comfort.

Of course, all options demand a standard set of conditions: Store in a dry place, use plenty, keep clean and top up daily, and periodically clean out completely and start again with 100% fresh material.

RMS information source:

https://dairy.ahdb.org.uk/technical-information/buildings/housing/recycled-manure-solids/#.V5r5pqLYDbQ.

Written by.. Phil Christopher BSc Agric

Knowledge transfer assistant at EnviroSystems UK Ltd, developer of innovative biological conditioning applications for livestock farming.

Previously dairy herd manager, farm management consultant, press & publicity officer, PR contractor to vet-pharma and Agritrade companies.

Member of the Guild of Agricultural Journalists, Royal Association of British Dairy Farmers (RABDF), Linking Environment and Food (LEAF), National Sheep Association, British Grassland Society.

Owner and sole employee at Red Rock Publicity Ltd. Co-Owner and Marketing director at www.yourperfectnightin.co.uk

As genetic selection within the dairy herd establishes milking machines with higher yields and apparently greater efficiency, their ability to consume additional feed has not kept pace with their ability to produce milk. This poses an increasing challenge to farmers and their advisors.

Spring and the introduction of grazing further complicates the above problem since it is difficult to control and accurately predict the quantity of grass consumed. Variations in feed intake, particularly if inadequate concentrates or buffer feeds are available, could present a serious challenge resulting in depressed milk yield and quality, increased mobilisation of body reserves and impaired fertility.

Grass Consumption – How much will cows eat?

Although recent research suggest that cows can consume up to 20.7 kg of grass dry matter per day during early lactation, such intakes may not be “common” on most farms since:

They were recorded during June/July when grass dry matters are normally significantly higher than April or May.

They were also recorded with mature cows in their 2nd, 3rd and 4th lactations. A typical UK herd will include around 25% first lactation heifers that possess a lower intake capacity.

Grass consumption is more typically between 12 – 17 kg DM per day. In addition, the cow herself is influenced by a number of factors associated with sward characteristics, grazing time and buffer feeding.

Zero grazed, fresh weight grass, fed to cows each day at a trial carried out by the Kingshay Trust established that in wet weather, cows had to consume 100 kgs each to achieve a grass dry matter intake of 15 kgs. On drier days this was reduced to only 75 ks per head.

Sward / Pasture Characteristics

The grass leaf has a higher digestibility than the stem thus the greater the proportion of leaf the higher the digestibility

Generally a 5% increase in leaf content would be equivalent to a 1% improvement in digestibility. Good sward management is essential in order to maximise digestibility since grass above 6 cm will be predominantly leaf whereas below 6 cm there are higher levels of dead and low digestibility material. At turnout target grass cover should be around 10 – 12 cm in order to provide satisfactory supplies of readily available material.

A recent series of trials looked at the impact of different sward digestibility’s (Organic Matter Digestibility OMD) on dairy cow performance using spring calved cows in late summer and autumn.

Daily milk yields and grass dry matter intakes were directly related to grass digestibility. Cows allocated the 76% OMD sward were able to consume 0.6 kg more grass and this produced an extra 1 kg more milk than those offered the 73% sward.

Comparison between the 73% and 71% OMD groups shows a similar pattern of intake and milk production.

The milk yield improvements were however, less dramatic (+1.3 kg milk from 1.8 kg dry matter) than that with the highest OMD sward due to the poorer quality.

Other studies have extended these results to show that when pasture OMD exceeds 74% each extra kg of DM intake can result in a 1 kg increase in milk yield.

Grass Allocation/Allowance

Most farmers are keen to commence grazing in the spring as early as conditions allow. This date is influenced by a number of factors including grass supply, stocking rate, spring nitrogen application and calving pattern.

Some key points for consideration are:

• Target grass cover at turnout should be around 3500 kg DM/ha or a grass height of 10 – 12 cm.

• A post grazing height of 6 cm and a grazing cycle of 21 days has been recommended. This combination will allow acceptable herbage re-growth combined with grass intake without any loss of herbage quality.

• Grazing to a grass height below 4.5 cm during this period will slow down future regrowth.

• If ground conditions are not suitable, farmers if possible should not be forced into turning cows out early otherwise grass growth will suffer in the long term.

This NebGuide stresses the importance to the dairy cow of water, an essential but often overlooked nutrient.

Providing insufficient water or water of poor quality to dairy cattle can limit milk production and growth, and can cause health problems. An adequate supply of clean water promotes normal rumen function, high feed intake, digestion and nutrient absorption. Water also maintains blood volume, supplies tissue needs, and makes up about 87 percent of the milk secreted by the cow. The following sections discuss water intake and requirements, water quality and guidelines for proper use of cattle waterers.

Water Intake and Requirements

The expected daily water intake for different classes of dairy cattle is shown in Table I. Even a small limitation in water intake will decrease dry matter intake by 1-2 pounds daily which could limit peak milk production by 2-5 pounds. Lactating dairy cows require 4.5-5 pounds of water per pound of milk produced. This equates to roughly one-half gallon of water for every pound of milk secreted. As an example, a cow producing 100 pounds of milk daily could consume as much as 50 gallons of water. Remember that daily water intake comes from both drinking and moisture (water) in the consumed ration. For example, if a ration contains 40 percent moisture, that means that it contains 40 percent water and that a cow eating 80 pounds of this ration daily would be consuming 32 pounds of water (80 pounds × 40 percent moisture = 32 pounds of moisture, or water).

Some of the factors that affect drinking behaviour include: the cow’s eating patterns and ease of access to the watering area, the temperature of the water, whether the water is given in a trough (tank) or a water bowl, cow dominance if water bowls are shared, and stray voltage.

Eating pattern.

Cows have peak water intake during the hours when feed intake is greatest. When given the opportunity, cows tend to alternately consume feed and drink water. Ideally, fresh, clean water should be available to the cow whenever she consumes feed.

Water temperature.

In a cold environment, most cows will prefer liquid water to snow or crushed ice. Therefore, to promote adequate water intake it is important to keep waterers and water tanks or troughs open and relatively free of ice during winter months. Research on drinking chilled water (about 50°F) has given mixed results in lactating dairy cattle. In some studies, cows consumed more chilled water with no effect on feed intake or milk yield. However, other studies have shown that cows drink less chilled water, but that milk yield is higher. Practically, it may not be economical for most Nebraska dairy producers to consider chilling water, given the expense and variable responses.

Type of waterer.

Cattle generally have fewer drinking bouts with water troughs (tanks) compared with water bowls. In a British study, time spent drinking ranged from 2-8 minutes daily, with higher drinking times usually associated with use of water bowls. However, drinking rate can vary from 10-30 pounds per minute, with lower rates generally found for cows using water bowls.

Cow dominance.

Research has shown that submissive cows use a water bowl less frequently than their more aggressive partner using the same water bowl. These cows consume less water and feed, and produce milk with less milk fat. Social interactions such as this may be important for producers who house their cattle in stanchion or tie stall barns where pairs of cattle share a common water bowl. Sometimes, simply moving cattle from one stall to another can eliminate the problem.

Stray voltage.

Research at Cornell University indicates that cows subjected to three or less volts of alternating current between the water bowl and hind feet adapted within two days with no change in water consumption. Beyond 3-4 volts, however, many cows refused to drink. However, field observations indicate that voltage above one-half volt can cause a decrease in water consumption in some animals. Thus, from a practical standpoint, stray voltage in excess of one-half volt could lead to water consumption problems.

Calf requirements.

Calves fed milk replacers with high levels of magnesium have a higher incidence of kidney and bladder stones. Higher than necessary magnesium levels can either come from the replacer or from higher than normal levels in the water. The National Research Council (1989) recommends .07 to .08 percent magnesium on a dry basis for milk replacers. Also, recent evidence suggests that calf performance can be improved by giving calves free access to water early in their lives.

If water intake varies by more than 15-20 percent from the amounts listed in Table I, you may have a water quality or intake problem which is limiting herd milk production. Water intakes may be higher when air temperatures are over 80°F, and lower than expected when air temperatures fall below 50°F, and much less at very cold temperatures. Table II lists some of the major causes of poor water intake by dairy cattle.

Table I. Drinking Water Requirements of Dairy Cattle(1)

Livestock class

Age or production Gallons/day(2)

Holstein calves 1 month 1.3 to 2.0

2 months 1.5 to 2.4

3 months 2.1 to 2.8

4 months 3.0 to 3.5

Holstein heifers 5 months 3.8 to 4.6

15 to 18 months 5.9 to 7.1

18 to 24 months 7.3 to 9.6

Jersey cows 30 pounds milk/day 13.0 to 15.5

Guernsey cows 30 pounds milk/day 13.8 to 16.0

Ayrshire, Brown Swiss,

and Holstein cows 30 pounds milk/day 14.5 to 17.0

50 pounds milk/day 24.0 to 27.0

80 pounds milk/day 38.0 to 42.0

100 pounds milk/day 48.0 to 52.0

Dry cows Pregnant, 6 to 9 months 9 to 13

(1) Adapted from: Adams, R.S. 1986. Water Quality for Dairy Cattle. Pennsylvania State University.

(2) Higher levels of water intake apply for an all-hay ration (greater than or equal to 80% dry matter).

Table II. Possible Causes of Inadequate Water Intake

Lack of supply to drinking devices Corroded valves

Inadequate system pressure Need 20 pounds minimum pressure

Poor chemical quality Very acidic or alkaline

Hydrogen sulphide (rotten egg odour)

Metallic taste from iron

High dissolved solids content

Pollution(1) Coliform bacteria from manureAlgae growth

Chemicals

Stray voltage Drinking devices

Surface that cow stands on

Poor cow access to waterers Poor waterer placement; slippery, muddy surfaces; cow overcrowding

(1) Sites in the water supply that can become polluted include: the source (e.g., well, spring), pressure tank or reservoir, and the drinking device with feed or manure.

Signs of Inadequate or Excessive Water Intake.

Low water intake results in low urine output and constipated, firm manure. This may also be a symptom of dehydration from disease or fever. Restricted water intake leads to reduced milk yield and may promote intestinal disease if cattle drink from puddles of water containing urine. Note that lack of salt, potassium, and crude protein in the ration may also cause this behaviour. Excessive water intake leads to excessive urine production, abnormally loose manure and a relatively bloated condition. This bloated appearance is especially apparent in young calves. Diarrhoea caused by excessive water intake will still be normal in colour and odour.

How to Measure Water Intake.

Water intake should be measured only at the drinking device itself to accurately determine the water supply available to the animal. Water meters are available from many water system equipment dealers which can be used to measure water flow in lines leading to waterers. Data should be collected for 5-10 days to minimise effects of weather on water intake. Compute water intake from the ration (as moisture percent) and then calculate total daily water intake from drinking and from the ration. Finally, compute average daily water intake per pound of milk produced and compare with the typical 4.5-5 pounds of water needed per pound of milk produced. Useful conversion factors to remember include:

one gallon of water weighs 8.34 pounds,

one cubic foot of water weighs 62.4 pounds.

Problems with Water Quality.

Water quality problems can occur with wells and springs, especially when associated with poor environmental management. Often, septic tanks, milkhouse wastes and industrial drainage may be involved. Cows are particularly sensitive to poor water quality because high-producing cows may consume 200-300 pounds of water or more daily. Cows allowed to drink from surface water sources such as ponds and creeks are potentially at risk from bacteria and cropland runoff containing pesticides. Often, it is best to fence off these areas for better cattle health.

Chemical Quality.

Hard water or antibacterial water treatment usually have no adverse effect on cows. High water levels of sulphate and magnesium may cause diarrhoea and increase dietary requirements for selenium, vitamin E and copper. Water with high iron levels may also increase the need for dietary copper, especially in lactating dairy cattle. Water with pH less than 5.5 (acidic) may increase problems related to mild acidosis such as:

reduced milk yield,

depressed milk fat percentage,

low daily gains,

off-feed problems,

more infectious and metabolic disease,

increased infertility,

increased cow culling.

Alkaline water (pH greater than 8.5) may result in problems related to mild alkalosis such as amino acid and B-vitamin deficiencies, and symptoms similar to mild acidosis. When cows are drinking alkaline water, rations high in alfalfa, buffers and minerals are more likely to contribute to mild alkalosis. Nitrate (NO3) levels over 100-150 parts per million (ppm) may cause reproductive problems in adult cattle. Replacement heifers will experience reduced growth rates. Generally, there is no significant effect of mildly elevated water nitrate levels on milk production. Nitrite levels in water which are over 4 PPM may be toxic to cattle. Symptoms include infertility, reduced gains, abortions, respiratory distress and eventually death. Other minerals which may cause problems include:

lead — over .10 PPM may be toxic

magnesium and sulphate — over 125 PPM magnesium and 250 PPM sulphate may be laxative.

Bacterial Quality.

Water for animal consumption must contain no coliform bacteria for calves, and coliform count should be under 10 per 100 millilitres for adult cattle. Bacterial polluted water may increase susceptibility or contribute to a variety of calf and cow disease problems. Drinking bowls, cups and troughs (tanks) should be kept relatively clean. A raised base around tanks helps to keep manure contamination problems to a minimum. Cleaning tanks and water bowls to prevent build-up of old feed and other debris is important.

Checking Water Quality

The water supply for cattle should be checked yearly for coliforms, pH, nitrate and nitrites, and total bacteria — especially if a water quality problem is suspected. Many commercial laboratories offer water testing services. To obtain information about where water can be tested, contact your local Extension Office. Expected levels for common water quality tests are given in Table III.

Table III. Analysis of Water Supplies (1)

Item

Average Expected (2) Possible Cattle

Problems

pH 7.0 6.8 – 7.5 Under 5.5; Over 8.5

(PPM) (PPM)

Dissolved solids 368 500 or less Over 3,000

Total alkalinity 141 0 – 400 Over 5,000

Sulphate 35.5 0 – 250 Over 2,000

Fluoride 0.23 0 – 1.2 Over 2.4

(Mottling of teeth)

Calcium 60.4 0 – 43 Over 500

Magnesium 13.9 0 – 29 Over 125

Iron 0.8 0 – 0.3 Over .3 (taste

Manganese 0.3 0 – 0.05 Over .05 (taste)

Copper 0.1 0 – .6 Over .6 to 1.0

Arsenic __ 0.05 Over .20

Cadmium __ 0 – .01 Over .05

Mercury __ 0 – .005 Over .01

Lead __ 0 – .05 Over .10

Nitrate as NO3 33.8 0 – 10 Over 100

Nitrite as NO2 .28 0 – 0.1 Over 4.0 – 10.0

Hydrogen sulphide __ 0 – 2 Over .1 (taste)

Barium __ 0 – 1 Over 10 (health)

Zinc __ 0 – 5 Over 25

Total bacteria/100 ml 336,300 under 200 Over 1 million

Total coliform/100 ml 933 less than 1 Over 1 for calves

Over 15 to 50 for cows

Faecal coliform/100 ml __ less than 1 Over 1 for calves

Over 10 for cows

Faecal strep/100 ml __ less than 1 Over 3 for calves

Over 30 for cows

(1) From: Adams, R.S. 1986. Water Quality for Dairy Cattle. Pennsylvania State University.

(2) Based primarily on criteria for good water for human use.

Adequate Watering Facilities

There should be no more than 20 cows for each waterer, in freestall or holding areas. Waterers, like feed bunks, should be convenient and readily accessible for the cattle. Lactating cows should be close to a water supply, especially during periods of heat stress or bitter cold and frozen surfaces. If possible, under these conditions try to place a clean supply of water near shaded or otherwise cooled loafing areas, and safe slopes if frozen. Take care to avoid excessive water accumulation in lots or other loafing areas, which may increase the incidence of mastitis and other diseases in the herd.

In summary, although we are often most concerned with ration protein, energy levels and dry matter intake, providing an adequate supply of fresh, clean water is one of the most essential feeding practices. You cannot expect maximum cow and calf performance unless the needs for water quality and intake are satisfied fully. If water quality problems are suspected, your veterinarian can recommend and interpret any tests that might be necessary.

Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. Kenneth R. Bolen, Director of Cooperative Extension, University of Nebraska, Institute of Agriculture and Natural Resources.

University of Nebraska Cooperative Extension educational programs abide with the non-discrimination policies of the University of Nebraska-Lincoln and the United States Department of Agriculture.

By Rick Grant, Extension Dairy Specialist 

Mastitis is a very significant disease of dairy cattle and occurs in all dairy herds. It is an inflammation of the udder usually caused by a bacterial infection, although stress can predispose to this disease. Mastitis may occur in clinical form, where changes in milk are obvious, or subclinical form, where there are no visible changes. It can also be acute, where the cow is seriously ill, or chronic, where the cow may show no outward sign of ill health.

In general, mastitis pathogens belong to one of two categories: contagious or environmental. Bacteria causing contagious mastitis are spread from infected quarters to other healthy quarters of the same or other cows. The spread of this type may be caused by the milker, the milking machine or dirty bedding. Mastitis caused by environmental bacteria is generally associated with dirty, wet bedding and frequently occurs in poorly ventilated housing areas. The bacteria can also be transmitted during the process of milking. Environmental mastitis often affects cows around the time of calving when protection provided by antibiotic dry cow therapy has waned and immunity may be reduced.

The cost of mastitis to the UK Dairy Industry is currently estimated at £93 million per year (British Mastitis Conference, 1997). These costs arise from antibiotic treatment, discarded milk, financial penalties, reduced lactation yield following an infection and increased milking times. The disease results in discomfort, pain and premature culling.

The incidence of both clinical and sub-clinical mastitis has fallen over recent decades. Somatic cell counts (SCC) provide a broad indication of the general level of udder health within the herd and have fallen from almost 600,000 cells/ml in 1971 to about 170,000 in 1997. Papers presented at the British Mastitis Conference in 1997 indicate that clinical cases per 100 cows have fallen from 135 in the early 1960s and are considered to be between 35-40 at the present time.

The decrease in both clinical and sub-clinical mastitis is largely attributed to the introduction of the National Institute for Research in Dairying (NIRD)/Central Veterinary Laboratory Five Point Plan. A reduction in cell counts has been hastened by relating milk payments to cell counts and EC Directive 92/46, which effectively prohibits milk with a high count from being sold off-farm for liquid milk consumption. Latterly, milk buyers have imposed more stringent financial penalties on milk with high SCC and some pay bonuses for very low counts. Experience has shown that where there is a problem with mastitis in herds, part or all of the Five Point Plan is usually improperly implemented. However, where environmental mastitis is a problem, additional attention needs to be paid to the hygiene of the lying area, particularly in calving areas.

The visual identification of clinical cases is primarily subjective and tends to underestimate the number of quarters with a bacterial infection. Although clinical cure rates following antibiotic administration may be high, the elimination of bacteria may not have occurred following such treatment. Experimental evidence has identified that early detection of mastitis and early treatment allow for a greater bacteriological cure. The presence of bacteria in the udder leads to a reduction in the conductivity of infected milk and may prove a useful marker in identifying early cases of mastitis.

A third type of mastitis, referred to as summer mastitis, is an acute illness of dry cows and heifers which causes extensive and painful damage to the udder. The infected quarter is permanently damaged and results in early culling of the cow. Infections are more likely to occur when cows are in an environment where teats can be damaged and fly populations are high. In the UK, summer mastitis affects around 20,000 cattle each year. The disease is transmitted by flies and peak incidence occurs when these are most frequently around cattle. Clinical signs of summer mastitis are a hot, hard and swollen quarter in association with a thick secretion, characterised by a foul smell. In severe cases, cows may develop swollen hocks and become lame. Summer mastitis can also lead to abortion and death in extreme cases.

All dairy producers should follow the Five Point Plan:-

• Hygienic teat management – combined with sound housing management

• Prompt treatment of clinical mastitis

• Dry cow therapy

• Culling chronically affected cows

• Correct maintenance of the milking machine

In addition, it is a requirement of the Dairy Products (Hygiene) Regulations 1995 that the foremilk is examined and discarded. Foremilking is considered the best means of detecting the early signs of mastitis and allows for the stimulus for milk let down.

Environmental mastitis is more likely to occur when cows are housed when there is greater exposure to faecal contamination. Pre-milking dipping with an approved disinfectant may be beneficial.

Poor environmental conditions predispose to mastitis and there is evidence that loose housing in straw yards results in a higher incidence of mastitis than housing in cubicle yards. However, there are good and bad examples of both types of housing: much depends on stockmanship and management. Whatever system is used, cleanliness is a most important factor and plays a significant part in controlling mastitis.

Since de-regulation of the milk market in November 1994, SCC data are no longer collected centrally. This is regrettable and needs addressing to allow proper measurement of trends and to allow the data to be used in breeding programmes. On-farm records of clinical mastitis need to be collated to provide a national picture of clinical mastitis and to aid breeding and research programmes.

More funding of mastitis research is required to identify further the causes and therefore aid prevention and treatment of this costly disease. With antibiotic resistance becoming a concern, research is urgently needed to look for effective alternatives.

Recommendations

• All dairy producers should adhere to the NIRD/CVL Five Point Plan which, together with good stockmanship, will help control mastitis infection.

• Mastitis control should be part of herd health monitoring with targets set for incidence.

• Monitoring and recording of antibiotic tube usage should be an integral part of herd monitoring and should include tubes used per herd and per individual cow.

• Mastitis monitoring and control should be a part of routine veterinary visits. Milk samples should be taken in order to identify the causal agent and antibiotic sensitivity testing carried out to allow better targeting with antibiotics or other efficacious treatments.

• The development of systems to aid the early detection of mastitis should be encouraged by the Government and the industry.

• Controls for summer mastitis should include control of flies (particularly from July to September), use of eartags impregnated with insecticide, sprays or pour-on preparations and avoidance of high risk pastures.

• If summer mastitis occurs as a significant herd problem, veterinary advice should be sought and a suitable control programme implemented.

• Further research should be undertaken to develop vaccines, and other treatments, for the prevention and control of mastitis and to avoid routine usage of antibiotics.

• Consideration should be given by the industry to the central collection of SCC data, and records of cases of clinical mastitis, to aid monitoring of mastitis health in the national herd.

To keep track of calf starter consumption, Clark clips colored clothespins on top of the hutches. When a calf eats 2 lb. of grain a day, he attaches a green clothespin.

After she has eaten 2 lb. of grain per day in two consecutive days, he clips a yellow clothespin on top of the hutch. After she has eaten 2 lb. a day for three days, Clark attaches a blue clothespin to the hutch and he weans the calf.

“We used to house our calves in 40 wooden hutches that were rarely cleaned out in the winter, and we used to wean at four months old,” Clark says. “Our calves are healthier and doing much better in the plastic hutches we purchased in February 1998. Now we wean at five to six weeks of age and have no problem with it. Our calves are much bigger.” Adds Corbett: “Now, they are weaning calves based on dry matter intake, and age has nothing to do with it.”

After weaning, calves stay in the hutches for a couple of weeks to ease sucking problems and to ensure adequate dry matter intake. Usually, they’re eating a bucketful of grain, or about 6 lb. of starter, when they’re moved to the “calf colony” – a simple three sided, half-shaded structure with waterers, a hard-pack floor and 4′ cement feedbunk apron.

Here the heifers get a 17% protein total mixed ration (TMR) with 10% hay. As the heifers get older, the precentage of forage goes up. At wix months, they’re also getting a half-pound per day of a rumen microbial growth enhancer. The Bowns feed the TMR every two to three days and encourage intakes by pushing it up twice a day.

Free-choice water helps the calves eat more dry matter. The Bowns weren’t giving calves water during the winter months because it froze. Corbett convinced them that feed intake would go up with free-choice water and it did. “It’s like eating a peanut butter sandwich without milk” Corbett says. “You need something to wash it down.” The Bowns have found calves in hutches will drink up to 4 gal. of water a day. Sometimes, the calves drink even more in winter. They place water buckets inside the hutches and let the calfs body heat help keep the water from freezing. Heifers lagging behind herdmates are culled at 300 lb. to 400 lb. The Bowns don’t mess around with small, unthrifty animals. They sell them and pocket a little profit. Culling also helps make a group of heifers more uniform.

Overall, the Bowns are quite happy with how their heifers look and perform today.

“We used to think we were saving money by not pushing grain and hay.” Clark says. “But, it was costing us by not getting cows sooner into the milking string. Now we understand the importance of dry-matter intake in calves and we can monitor it.”

In general, pigs in outdoor units have high health status due to low stocking density and reduced infectious challenge. Whilst treatment may be more difficult outdoors, one advantage of this method of pig-keeping is that infection dilution occurs in the open air and lower stocking densities and stress levels tend to keep the animals in better condition: so outdoor pigs are generally healthier than those kept indoors.

However, where disease occurs the implications for outdoor units are serious due to the difficulty in isolating the pig and administering treatment. Prevention is always better than cure and the advice given by the Pig Welfare Advisory Group is that a preventive health programme should be drawn up in conjunction with a veterinary surgeon and incorporating a vaccination, an anthelmintic programme and effective control of external parasites which cause disease.

Any disease can cause welfare problems and stockmen should be aware of this and take preventive action where possible. This may be achieved using routine vaccination programmes. Whilst many diseases may be controlled by vaccination, routine protection against E. coli, swine erysipelas, clostridial diseases and porcine parvovirus should be seriously considered. Outdoor pigs are still susceptible to the usual range of pig diseases and therefore constant vigilance and prompt action is essential. Veterinary assistance should be sought if the stockman’s immediate action is not effective.

In order to maintain herd health it is important to start with high health status stock and to isolate them, as far as practicable, from other herds. Stockmen must be on the lookout for injury, disease and contamination of the site by birds and wild animals and treat the pigs as soon as symptoms occur.

Separate inspection/isolation facilities should be available and can be achieved by the use of electric fencing to isolate a small area which includes a well-bedded, draught-free hut. It is accepted that problems due to re-mixing after a period of separation may preclude this option. Nonetheless, it may be necessary to isolate a sick animal particularly if it is being bullied by its companions.

It is important to monitor the health of boars and to deal quickly with any deterioration whilst the animals are still within their social group. This is particularly the case if a boar is lame, because activity in the service paddock could exacerbate the problem. Should a boar not respond to treatment whilst in the group it should be removed although there are likely to be difficulties in re-introducing the animal. This emphasises the need for early treatment whilst still in the group.

Systems that use groups of boars in service paddocks increase the risk of injury through continuous contact with sows, especially those on heat. This is reflected in higher ratios of boars to sows and higher culling rates. For these systems boars selected for their robustness should be used.

Systems that allow individual housing of boars and supervised services reduce the risk of injury and allow boars to be used of a higher genetic potential, more suitable for the market requirements.

The Window of Opportunity

The transition phase of the adult dairy cow is usually defined as the last three weeks of the dry period and the first seven to ten days of lactation. Proper care and nutrition of the dairy cow during this period will improve the health and increase the production potential during the entire lactation. At no other time in the life of the dairy cow, can nutritional intervention have such a dramatic effect on production potential, in such a short period of time.

As the pregnant cow approaches the end of the dry period, or pregnant heifers approach the end of their first pregnancy, their nutritional requirements increase considerably. The foetus is growing more rapidly during this time period than at any other point in gestation. The mammary gland is preparing for the ensuing lactation by increasing in size and starting production of mammary gland secretions. However, at the same time, the dry matter intake of the close-up dry cow gradually decreases as she approaches parturition. Since the nutritional requirements increase and dry matter intake decreases, ration changes must be made to increase the energy and protein density of the ration in order to fulfil these requirements. Failure to do so will result in negative energy balance and subsequent weight loss in the close-up dry pen. The Net Energy for lactation (NEI) should be between 0.68 and 0.72 Mcal/Ib. of dry matter and the crude protein should be a minimum of 16% on a dry matter basis.

Every effort must be made to maximise the dry matter intake of the close-up dry cow. High quality, palatable forages should be utilised along with smaller proportions of the same commodities utilised in the lactating ration. Exposing the rumen micro-organisms to the same feeds used in the lactating ration promotes the development of the populations needed for maximum utilisation of these feeds once the cow is introduced to the lactating ration. This allows the fresh cow to go on feed faster, increase dry matter intake, have fewer digestive upsets and increase production earlier in lactation. Cleaning the feed bunks on a regular basis will prevent the build-up of spoiled feed in the bottom, also resulting in improved dry matter intake. Keeping the feed pushed up to the cows is important if flat cement slabs are used for feed bunks. Overcrowding the close-up pen and/or insufficient bunk space for the number of cows in the pen should be avoided. Older, more dominant cows may push first calf heifers away from the feed bunk. These animals may need to be separated if this problem exists.

The dry matter intakes of the close-up dry cows and heifers should be closely monitored to ensure that the needed nutrients are being consumed. Even though the energy and protein density of the ration has been increased, the close-ups must consume so many pounds of the ration in order to fulfil their nutritional requirements. This information is essential to the nutritionist in his efforts to decrease metabolic disease around the time of freshening.

When the lactating cow is dried up, she is usually taken off of a ration that contains a substantial amount of concentrate and put on a ration of mostly lower quality forages. The rumen papillae (the finger like projections that protrude inwardly from the lining of the rumen thai are involved in absorption of nutrients from the rumen) shrink in size when this ration change takes place. This process is considered necessary to provide the lining of the rumen a chance to rest and regenerate. However, if the rumen papillae are not stimulated to lengthen out before the cow is placed back on the lactating ration consisting of more concentrates, severe digestive upsets and acidosis may occur. The rumen papillae are stimulated to lengthen out by the presence of volatile fatty acids in the rumen. Volatile fatty acids are produced as a result of the fermentation of grains in the rumen. Therefore, the close-up ration must contain enough starch from grains to produce the volatile fatty acids necessary to stimulate the development of the rumen papillae. This process takes approximately 5 weeks to complete, so it is important to utilise the last 3 weeks of the dry period to get this process well on its way.

Development of the rumen papillae is just as if not more important to the springer heifer since she has been on a high forage ration for close to a year before she freshens. A large percentage of dairies do not keep track of breeding dates on heifers or do not utilise the computer to generate a list of heifers ready to be moved to the close-up pen. It is fairly common practice to visually observe heifers on a weekly basis to determine which ones should be moved to the close-up pen. Heifers are much more difficult to determine the approximate calving date by visual observation than are cows. As a result, some heifers are not moved to the close-up pen soon enough, and do not receive the benefits of the close-up ration for the necessary amount of time. Both the heifers and cows should have the date written down or entered into the computer when they are moved into the close-up pen. The days in the close-up pen should be recorded for each animal when it calves. Close-up rations are often blamed for metabolic disease at freshening, when the reason is insufficient time in the close-up pen.

Probably the most common metabolic disease observed by the dairyman around the time of calving is periparturient hypocalcemia or milk fever. This problem also needs to be addressed in the formulation of the close-up dry cow ration. Research has shown that by altering the ratio of the positively charged ions (cations) such as Sodium (Na+) and Potassium (K+) to the negatively charged ions (anions) such as Chloride (CI ) and Sulphur (S ), the metabolism of the dairy cow can be altered so that more calcium is absorbed from the diet and also from the bones. This is commonly referred to as the DCAD (dietary cation anion difference) ratio. A negative DCAD, which would indicate more anions than cations, greatly improves the ability of the dairy cow to increase calcium absorption from the diet and its bones.

Probably the most common way to change this DCAD ratio is to add “anionic salts” to the ration of the close-up dry cow. These anionic salts such as ammonium chloride, calcium chloride, calcium sulphate and magnesium sulphate contribute chloride and sulphur anions to decrease the DCAD ratio. If the cow ingests a sufficient quantity of these anionic salts, calcium absorption is greatly improved and the signs associated with low blood calcium levels at calving are significantly decreased. However, the major drawback of anionic salts is the fact they are not very palatable. If anionic salts are added to the ration, the dry matter intake of the close-up cows is usually decreased. It is very common for the forages being fed to the close-up dry cows to be high in potassium. If this problem exists, more anionic salts have to be added to receive a negative DCAD ratio. Therefore, it becomes very difficult to add the appropriate amount of anionic salts to counteract the high potassium forages, and still maintain the desired level of dry matter intake. If dry matter intake decreases, the animal enters into a state of negative energy balance and also will most likely not be able to consume enough of the anionic salts to improve calcium absorption. If forage inventories permit, utilising low potassium forages in the close-up ration greatly enhances the success rate of feeding anionic salts.

Potassium is usually higher in forages that are harvested from fields that are heavily fertilised with manure. Reserving some fields for forages utilised in close-up rations that are not fertilised with manure is extremely helpful. Also, the first cutting of alfalfa is usually much higher in potassium than are subsequent cuttings, especially if the fields were fertilised with manure during the winter months. Molasses and whey are also quite high in potassium and their use should be kept to a minimum.

In the past, high calcium levels have received the blame for causing milk fever. As a result, rations have been formulated that are extremely low in calcium to try and prevent milk fever. The theory was that low calcium levels would stimulate the animal to initiate the process of reabsorbing calcium from its bones so it would already have this process in place at the time of calving. The animal could then draw from its own calcium reserves in its bones to compensate for the high level of calcium secreted into the colostrum. This approach was often successful at reducing the incidence of clinical milk fever, but many other problems associated with low blood calcium levels still persisted.

Calcium is necessary for all muscle contraction. Animals that have low blood calcium levels but not low enough to exhibit signs of milk fever, have a multitude of problems related to a decreased muscle contraction in the body. This syndrome referred to as subclinical hypocalcemia results in problems such as retained placenta, increased incidence of uterine infections, digestive upsets and decreased dry matter intake due to poor contraction of the rumen musculature and displaced abomasum. Even though the theory of feeding low levels of calcium to the close-up dry cows seemed effective in decreasing the incidence of milk fever, these other problems previously mentioned still had severe effects on the overall health and productivity of the lactating cows.

The ideal approach would be to increase the ability of the cow to absorb more calcium from its digestive tract and bones and at the same time supply extra calcium in the diet. When anionic salts are fed, additional calcium is usually added to the ration in an effort to accomplish this. However, because of the prevalence of high potassium forages and the poor palatability of anionic salts, problems with milk fever and subclinical hypocalcemia often occur sporadically in herds feeding anionic salts. If anionic salts could be fed and at the same time increase the dry matter intake of the close-up dry cow, the incidence of metabolic disease around the time of freshening would be greatly decreased. One product is available that contributes a high level of the chloride anion and at the same time is very palatable’. University studies have also shown that rumen microbial yield and dry matter intake are increased in close-up dry cows that consume this product.

In review, the following things must be accomplished in the close-up dry cow ration in order to maximise the health and productivity of the fresh cow:

1. Increase the energy and protein density

2. Improve palatability and dry matter intake

3. Stimulate the development of the rumen papillae

4. Increase the absorption of calcium from the diet and increase calcium resorption from the bones

5. Adapt the rumen microflora to the feeds found in the lactating ration.

The fresh cow ration also needs to be formulated to increase the potential profitability and decrease the incidence of nutritionally related disease so often seen around the time of freshening. It was mentioned that it takes approximately 5 weeks for the rumen papillae to lengthen out once exposed to the volatile fatty acids produced from starch fermentation. If this process is initiated in the close-up ration, it still takes approximately two more weeks after freshening for the process to be completed. The fresh cow ration should contain a level of non structural carbohydrates (starch, sugar, pectin, etc.) that is intermediate between the close-up ration and the high production ration. This permits the continued maturation of the rumen papillae without the danger of rumen acidosis developing.

Exposing the rumen of the fresh cow to high levels of NSC results in the production of large amounts of volatile fatty acids. Shorter rumen papillae have less surface area available for the absorption of these volatile fatty acids. This results in a build-up of acid in the rumen and an ensuing rumen acidosis. Severe rumen acidosis results in inflammation of the rumen lining and permits bacteria to penetrate the rumen wall and enter the bloodstream. These bacteria often end up in the liver and cause the development of liver abscesses. Some of the rumen wall may be sloughed which compromises the ability of the rumen to absorb volatile fatty acids even more. If they survive, these animals usually have to be culled because of poor productivity.

Milder cases of rumen acidosis result in laminitis and other foot problems associated with laminitis such as sole abscesses, sole ulcers, uneven growth of the hoof wall and white line disease. Diarrhoea and butterfat suppression are other signs of rumen acidosis. Decreased dry matter intake and poor utilisation of the ration are also signs of rumen acidosis.

Displaced abomasum is another common problem seen in fresh cows. Lower levels of NSC and higher fibre levels have been shown to decrease the incidence of displaced abomasum. Length of the fibre in the fresh cow ration is especially important in maintaining rumen health and preventing displaced abomasum. However, if a total mixed ration contains a large amount of long course fibre, it is easy for the cow to sort through the longer fibre and eat more of the concentrate fraction of the ration, thus increasing the chances of rumen acidosis and displaced abomasum.

Higher levels of protein in the fresh cow ration have been shown to increase dry matter intake and increase peak milk yield. Crude protein levels should be in the 18 to 20% range on a dry matter basis. Therefore, forages that contain high levels of protein such as alfalfa, are ideal for inclusion in the fresh cow ration.

Fresh cow rations that contain an intermediate level of NSC and high levels of protein and fibre will naturally be lower in energy. For this reason, the fresh cow should only be on this ration for 7 10 days. This allows ample opportunity for the rumen papillae to mature and decreases the chances for rumen acidosis and displaced abomasum. It also provides the necessary time for further adjustment to the lactating ration and increases in dry matter intake without affecting rumen health. However, since the ration will be lower in energy, cows should not be fed this ration for much more than ten days.

The following parameters should be used when formulating the fresh cow ration:

1. Higher levels of longer length fibre

2. High quality forages that are high in protein

3. Intermediate level of NSC between the close-up ration and the lactating ration

4. Consist of the same ingredients as the lactating ration

5. Only fed for the first 7 10 days of lactation.

The benefits from a well managed transition cow program far outweigh the costs and labour to implement and manage it. Studies have shown that 8 to 10% of all lactations begin with milk fever. Cows that experience milk fever will produce approximately 14% less milk during their lactation. A 100 cow dairy with a rolling herd average of 20,000 lbs. and a rate of 10% milk fever would lose approximately 280,000 lbs. Of milk per year. At $12.00 per hundred weight, that amounts to $33,600 loss. This loss is strictly due to the milk fever episode and does not take into consideration all the other problems that may accompany milk fever. If these other losses are taken into consideration, a conservative estimate would $40,000 per 100 cows in the example just mentioned.

Cows with milk fever have been shown to be up to 8 times more likely to develop a case of mastitis, especially coliform mastitis. One study showed that milk fever cows are 24 times more likely to develop ketosis than non milk fever cows. Milk fever also increases the incidence of retained placenta, uterine infections, uterine prolapse, calving problems, displaced abomasum and digestive upsets. Another study indicated that a case of milk fever may reduce the cow’s productive life by 3.4 years.

Ketosis is a metabolic disease that exists to some extent in all dairy herds. The major underlying cause of both ketosis and fatty liver syndrome is decreased dry matter intake both in the close-up pen and in the fresh cows, resulting in a negative energy balance. Cows with ketosis often have a decreased appetite and are sluggish in appearance. A very high percentage of cows with ketosis go undiagnosed and untreated. This greatly limits their production potential during lactation. Fat cows are more prone to ketosis and fatty liver because they have lower dry matter intakes than cows that are not overconditioned. However, a good transition program that consists of a well balanced highly palatable ration decreases the incidence of ketosis and fatty liver by improving dry matter intake.

Cows that have twins have gained a well deserved reputation of falling apart after calving. Recent work has shown that the dry matter intake of cows with twins drops off approximately 2 weeks before cows with single pregnancies toward the end of the dry period. If a cow is diagnosed with twins at the time of pregnancy check, she should be moved into the close-up pen 5 weeks prior to calving. With a good transition program, and more time in the close-up pen, cows with twins can calve with relatively few problems, experience less weight loss and have a more productive lactation.

The exact cause or causes of udder edema in first calf heifers has not been completely determined. However, high potassium forages and close-up rations with positive DCAD ratios seem to predispose heifers to more severe udder edema. The majority of heifers on a close-up ration with a correctly calculated DCAD ratio will experience much less udder edema. Excessive udder edema is costly by increasing the number of heifers with broken down udders, increased incidence of mastitis and decreased milk production.

Regular reproductive programs have been in place on dairies for many years. Yet even with the same veterinarian and the same type of program, the reproductive efficiency varies greatly among dairies. When poor conception rates are a problem, it is most likely blamed on infertile bulls, poor quality frozen semen, improper techniques by the AI technician, breeding cows that are not in heat and poor heat detection. First service conception rates are a good way to evaluate the success of the transition cow program. In every case I’ve observed, where there was a major improvement in the management and nutrition of the transition cows, there was a dramatic improvement in the first service conception rate, especially in first calf heifers.

Research from North Carolina indicated that it takes approximately 60 days for an egg to ovulate from the ovary once it has been stimulated to mature. The voluntary wait period to first breeding for the average dairy is usually around 60 days. If the cow is in a negative energy balance at the time the egg is stimulated to mature, the fertility of this egg is extremely low 60 days later when it ovulates. The greatest time of negative energy balance is usually around the time of parturition. Therefore, probably the worst time to breed a cow would be 60days after calving. Herds that have a good transition cow program in place have extended their voluntary wait period to 80 90 days without an increase in average days open. At the same time, they have increased their first service conception rates and reduced their semen costs.

The most dramatic change observed in herds that improve their transition cow program is their dry matter intakes around the time of freshening and how fast the fresh cows come to their milk. It is not uncommon to see cows with over 100 lbs. Of milk within 14 days of calving. Monitoring the milk weights of the early fresh cows is an excellent way to evaluate the success of the transition cow program. Also, the number of cows in the herd that are over 100 lbs. and less than 60 days fresh along with the total number of cows in the herd over 100 lbs. Of milk are valuable figures. Herds with a good genetic base that are milking 3 times a day should be able to reach a goal of 15 to 20% of the herd over 100 lbs. Of milk. Likewise, herds milking 2 times a day should be able to have 10 to 15% of their herd over 100 lbs. Of milk. With a good lactating cow nutrition program, these cows will peak much higher than before and remain more persistent during their lactation, resulting in a much more profitable dairy operation.

Good transition cow programs are essential in maximising the response to BST. Cows that are in a more positive energy balance, have higher dry matter intakes and are not suffering from metabolic disease around the time of freshening have a much greater response to BST. Increased milk production must be compensated for by increased dry matter intakes. Excellent response to BST can be seen without a resulting weight loss when dry matter intakes are improved through good transition cow nutrition, a comfortable environment and a well balanced lactating cow ration.

If the cows in transition are managed intensively with proper nutrition and cow comfort, the dairyman will receive dividends throughout the entire lactation.

These dividends will be received in the following ways:

1. Higher milk yields earlier in lactation

2. Higher peak milk yields

3. Greater persistency throughout lactation

4. Less metabolic disease around the time of freshening (milk fever, ketosis, etc.)

5. Decreased retained placenta and uterine infections

6. Improved reproductive efficiency

7. Decreased udder edema

8. Improved dry matter intakes before and after freshening

9. Improved colostrum quality

10. Decreased incidence of displaced abomasum

11. Increased response to BST

12. Decreased death loss and cull rates, especially in fresh cows.

This narrow window of time, called the transition period, has more effect on the profitability of the dairy operation than any other time in the lactation cycle. Focusing management efforts on this period will yield results rapidly and easily monitored.

Top Tips for Success

11 tips to win the “Bacterial War”, which are the key to successful silage making.

Whether you are looking for high yields per cow, or to maximise silage intakes and get high yields from forage, your cows need grass silage to be palatable with high levels of quality nutrients – and that depends upon your skill and management of the crop?

1. Concentrate on good ryegrass based swards: Secondary grasses and old pastures have lower yields and sugars, so modify the fertiliser applied if you have to ensile these.

2. Do not use excess nitrogen: That dark green colour is excess nitrogen that reduces sugar levels. It increases the time and difficulty to get the silage pH to drop and eventually produces toxic and unpalatable by-products. The maximum N is 75-1 05 units per acre depending on the sward and soil fertility for most dairy farms, unless following cereals.

3. Make full allowance for the nutrient N.P.K value of all slurry applied: and it must be included in the maximum Nitrogen recommended. Avoid contaminating the grass with slurry i.e late applications to bare pasture or leafy swards.

4. Cut dry: Eight inches of wet grass, cut at 9 am, and bundled into a swath, does not wilt effectively. It is essential to mow when the crop is dry, with no dew or rain on it, i.e. after 12 pm. Make the swath as wide as possible or ted as soon as possible.

5. Cut high: Leave at least three inches of aftermath, and leave the base rubbish in the sward bottom.

6. If raking or tedding, set well to avoid ground contact, especially if you have applied slurry and F.Y.M: Soil and slurry are perfect inoculants of the wrong spoilage bacteria. Slurry/soil on wheels in the clamp achieves the same. Do not rake large swaths too far in front of the forager.

7. Wilt quickly to concentrate sugar: The faster the better, do not wilt for more than 24 hours. 27% dry matter is a good target – essential to reach at least this, if there is a problem such as high N, contamination or low sugars.

8. Fill fast, but evenly, no air pockets, roll as you fill but minimise length of time exposed to air: i.e. “Dorset Wedge” if possible. Short chopped, thin layers well rolled if dry.

9. Roll for /2 hour maximum in the evening, sheet down every night: It takes just 20 minutes to use up oxygen in a silo, then a lactic fermentation starts if no more air is getting in.

10. Don’t roll next morning: It squeezes out carbon dioxide, sucks in fresh air, and restarts the butyric fermentation instead.

11. Completely seal the silo, and weight down shoulder and top sheets as soon as possible: Lactic acid fermentations do not start until all air has gone – and no more is getting in. Side walls should be sealed before starting.

What is the pay-off for attention to silage detail?

• Palatable, very low ammonia, high intake, high performance silage.

• More silage