Ruminants are fascinating creatures. What sets them apart from monogastric organisms with one simple stomach, is that they possess a huge fermentation chamber – the rumen. The rumen is full of a microbial population made up of bacteria, protozoa and fungi. This microbial population is able to break down forage and raw materials, that aren’t edible for humans into essential nutrients that can be used for body function and performance.
When we think about feeding the cow, we are actually feeding the rumen bugs, the rumen bugs will then feed the cows. As dairy producers we must make full use of this, manipulating the rumen population and its end produce to meet the cow’s requirement for production.
Protein
The cow doesn’t have a crude protein requirement, instead, like monogastric, they metabolise amino acids (AA). Metabolisable Protein (MP) is the protein available for absorption by the animal in the small intestine, coming from a combination of microbial protein (60-65%) and protein that has not been broken down in the rumen, but is available for absorption in the small intestine -known as bypass protein, contributing up to 35% of MP supply.
Rumen degradable protein (RDP), can be supplied as nonprotein nitrogen (NPN) or true protein (Amino N as shown below in Figure 1). This is then broken down in the rumen to ammonia, which is used to create microbial protein as the rumen bugs multiply. The rumen bugs also need sufficient fermentable carbohydrates such as starch and sugar to feed the bug’s energy. If there is much ammonia and insufficient energy, ammonia will build up and passes through to the bloodstream. Ammonia is toxic to ruminants so is converted to urea in the liver. There is an energy and metabolic cost to doing this which can affect performance.
UK diets are often based on grazed grass or grass silage as the main forage source. Although a great feed source and the cheapest available dry matter on the farm, these diets are unbalanced for generating MP. Grazed grass and grass silages are high in crude protein, from amino nitrogen and NPN, meaning there is an excess of ammonia within the rumen. The limiting factor for MP generation in these types of diets are often fermentable carbohydrates (starch and sugar).
Protein is one of the most expensive ingredients on the farm, so efforts should be made to capture as much quality protein as possible form grass to limit the need to purchase as much to supplement the diet. Due to the deficit in fermentable carbohydrates in the diet, we are losing metabolisable protein production, and wasting a lot of the protein which has been fed into the rumen, which was expensive to do so.
There is a huge opportunity to address the imbalance through supplementary feeding, whether it is 0.5t/year or 3t/year of purchased feed, make sure it’s making full use out of your homegrown forage and is complementing the performance.
Increasing starch within diets is usually associated with increasing the risk of SARA (Sub Acute Rumen Acidosis), especially fibre sources are often replaced with starch to increase overall starch supply. Understanding Neutral Detergent Fibre (NDF) and how we can balance rumen fibre allows for higher rates of starch within our diets, without exposing the rumen to SARA and achieving higher MP production from less supplemental protein.
NDF analytics from Cornell University allows us to break NDF down into 3 pools allowing us the opportunity to balance accordingly with supplementation. Through understanding the degradability of the fibre sources, it is possible to increase starch within our diets safely capturing more of the nitrogen within the rumen, therefore being more efficient.
If we are unable to generate sufficient microbial protein from the rumen, the ration will be short of the MP requirement of the cow. At this time the use of rumen-protected proteins, through rumen-protected rape meal and soya, play a vital part in the diet. However microbial protein synthesis is the cheapest source of MP and we should realise this potential first.
The AminoMatch concept is based on this theory to deliver what the cow needs in the most cost-effective and efficient way. Here are a few tips from the AminoMatch concept to
ensure greater efficiency in the performance of the animals, financial performance and environmental efficiency;
Capture as much protein form homegrown forage as possible
Reduce the need to supplement purchased protein
Increase fermentable carbohydrates within the diet
Balance fibre pools
Supplement bypass protein when necessary
Iwan Vaughan
Head of Dairy Technical Services
m: 07990 578548
e: iwan.vaughan@wynnstay.co.uk
@maesmochnant
We are coming out of one of the toughest winters in terms of forage stocks in recent memory and although the grass is not blowing in the wind quite yet, there is light at the end of the tunnel. It is time to be planning forage stocks.
There are many options when it comes to bolstering your feed stocks for the future, but some are far more costly than others when all is considered. We are entering a time where it is going to be harder and harder to run dairy farms with high stocking rates, due to ammonia legislations and proposed phosphorus regulations. This, combined with ever more competition for land form AD plants, other dairy businesses and non-agricultural land use, means that dairies and other livestock enterprises have to be as efficient with cropping, land use and feed supplies than ever. There is an obvious hang over from the current period of unprecedented levels of forage, that will lead to some very inflated prices for forage crops or substitutes. Below are some key points to consider
if you are in the market for more food.
Know what you need
235 acre (95Ha) farm with only dairy cows, milking 200 cows selling 8500L per cow per year, looking at what currently happens
A dairy cow will use around 12kgDM of feed for every 1kg of milk solids per year. Below is an example how to calculate how much feed you need
For 200 cows, you will need 1028 tonnes of dry matter
Assume the farm grazes 35Ha and grows 9TDM/Ha This supplies 325tDM
10Ha of maize yielding 13T/ha as fed (16t/acre fresh weight after losses at 33% DM) Supplies 130tDM
The remaining 50ha (124 acres) produces on average 11TDM/ha (13.4t/fresh/acre) Supplies 550T
The farm is in deficit by 23T
Usually, this would not be much of an issue, as rollover stocks or forage/forage replacers can fill the gap. But with poor yields last year and brewers grains costing £200/tDM and forages bought out of clamps costing £150/tDM, these sums come under a lot of scrutiny. Increasing forage production where possible would be the first step.
It is always hard to cost in the value of protein or energy accurately when comparing feeds, but an educated attempt is better than nothing.
Make more from your land
The range in crop yields are phenomenal when actually measured. The biggest variation is often in grassland, where there can be a spread of 6t/DM to 13t/DMHa grown and utilised on the best farms. There are many ways to improve on farm yield, of which we have covered in other articles (see our website) but here are some key points to maximise farm utilisation.
Use rotational grazing of the right type of cow
Grow the right crops for your farm and herd
Test and properly manage your soil using trained agronomists
Reseed, reduce compaction and manage grass as a crop
Double crop/use catch crops to ensure fields are always productive
Embrace technology to help measure yield and accurately apply nutrients
Buy Wisely
DAfter getting the most from your farmed area, you may still be better off buying in extra feed, whether that is clamp silage, moist feeds, more concentrates or standing crops. Whichever you do, be sure to do your maths before any purchases, to avoid being caught out. It is always hard to cost in the value of protein or energy accurately when comparing feeds, but an educated attempt is better than nothing. Below is an example of comparing two options, where there is deficit of 150 tonnes of Dry Matter.
As you can see from this comparison, there is little difference in the cost of these two options when fully calculated, with the maize option being cheaper for ME and starch, but would mean more expense needed to balance the protein, which works out substantially cheaper in the Wheatfeed option. There are other factors, such as slurry management and the effect on the rest of the ration – especially NDF pools, slurry management and storage logistics, but it certainly highlights the need to do through calculations when deciding what extra feed to buy.
With uncertainty around feed prices, due to the volatility of currency, along with a falling milk price, feeding decisions will be put under ever increasing scrutiny over the coming months. Making the most from your farmed area and being thorough with any feed purchasing calculations will stand your dairy business in good stead for the future.
Making the most from your farmed area and being thorough with any feed purchasing calculations will stand your dairy business in good stead for the future.
When we think of feeding calves, the first thing that comes to mind is often milk. As Calf Specialists, we have often focused on the pre-weaned calf. The milk feeding stage is of great importance, and sets the calf up for life. However, the weaning and post weaning phase also requires attention.
The first 60-70 days of life are a golden opportunity to exploit the genetic potential of your calves. The weaning period and the days following are also an opportunity that we need to make the most of.
Weaning
Calves begin life as a simple stomached animal – essentially a monogastric. They will however spend the majority of their lives as a ruminant. A successful weaning period is heavily
dependant on your calves being functioning ruminants.
Water is directly linked to starter intake so provide fresh clean water from birth to encourage starter intake. Also provide good quality (ideally chopped) straw.
The question is often asked when should I wean my calves. The most important factor to consider here is not the age or weight of the animal, but rather the volume of starter being consumed. By weaning (and essentially removing the nutrient dense liquid that has been providing nutrients for maintenance and growth) we need to be sure that enough starter is being consumed,
and the rumen developed to such an extent to allow the calf to continue to grow. If the calf has not been consuming starter for a long enough period to allow adequate rumen development,
the calf will not grow, and may lose body weight after weaning, until such time as the rumen is well enough developed. This is often referred to as a weaning check.
Considerations for weaning:
Has the calf doubled birth weight?
Has milk feeding been gradually reduced (Over a 2-3-week period)?
Is the calf eating enough starter (2kgs) for 3-4 consecutive days?
Is the calf healthy?
Post Weaning
Calves like consistency and routine. Do not change too many things at once. For the few days before and after weaning, do not: rehouse, regroup, change feed, vaccinate, dehorn or castrate.
Intake of starter pre -weaning helps promote growth and development of the rumen in calves. However, we would be mistaken to assume, that once weaned the calf is now a fully functioning ruminant. Rather it will be 4-6 months of age before the calf is a full ruminant. By paying close attention to the diet of the post weaned heifer, the rumen will continue to develop – maximising the growth potential of the heifers.
Although we want to take advantage of high feed-conversion rates, this freshly weaned calf is not the ideal time to be introducing a high forage diet. Heifers need to be continuously
growing at a minimum of 0.8kgs/day to reach bulling weight goal. Forages should be gradually introduced between 4-6 months for the calf to be able to utilise efficiently.
An annual pattern of milk composition has been well recognized on dairy farms across the world for years, with the highest milk fat and protein concentration in milk observed during the winter and lowest occurring in the summer. This trend is manipulated solely by season, and impacts housed and grazing cows similarly. So, when we get to spring, and then turnout for some, and milk butterfats start to decline- how do we know if this is real milk fat depression or not?
Is it simply a seasonal response which we have little manipulation over, or are we seeing changes which can be regulated by the feed, avoiding loss of milk and associated impacts throughout lactation? We can have a better idea by analysing multiple bulk milk parameters, individual cow milk recordings, along with the diet and identifying what is really going on.
Butterfat and Protein
Firstly, look out for sudden or ‘out of season’ changes to butterfat or protein % on bulk tank recordings. As we head into spring we would expect butterfat to drop slightly, but mostly as a result of ‘dilution’ as yields go up (see Figure 1), and total milk solids should be consistent. We want to minimise any further drops that could be caused by SARA (Sub Acute Ruminal Acidosis) which is fairly common on lush early grass, reducing the rumens ability to synthesis milk fat pre-cursors. Reductions of >0.3% butterfat could indicate SARA, which could lose you -2.5L/cow, on top of the reduced value per litre. It is important to provide enough palatable buffer feed, containing high digestible fi bre feeds such as sugar beet which contains ‘acid-regulating’ pectins, and ensure minerals are balanced.
On the contrary, if butterfat is abnormally >1.35 times the protein, the cows are in early lactation, and losing condition, they are likely mobilising body fat for energy and may be in ketosis. The energy level of the ration should be reviewed, is there enough fermentable carbohydrates for the rumen and importantly is there enough rapidly available glucogenic energy for the higher yielding cows. Sometimes a top up energy source such as propylene glycol may be needed for particularly high yielding fresh cows. Protected fats, ensuring they are the right fatty acid profile, can also supply much needed energy boosts. Protected fats like Dynalac is formulated for earlier lactation and will provide the correct fatty acid profile, on top of a balanced diet, needed for milk production and spare body condition; which in turn will help fertility. Looking after the early lactation or transition cow is critical for the remaining lactation performance, so make sure milk quality parameters are monitored and acted on if needed.
MUN
Another important indicator on the daily milk results which is often overlooked, is MUN (Milk Urea Nitrogen). This tells us how much Nitrogen from protein is excreted in the milk and positively correlated to blood urea levels. MUN can tell us a lot about the diets balance of rumen available energy to protein, indicate if there may be sorting of the ration, whether the protein supplied in the diet is optimum for this production level, and if we are maximising rumen efficiency. MUN is often a precursor to drops in milk yield and protein percent and can indicate metabolic problems. If milk urea’s are consistently >300 mg/L or 0.030% (NML reports) then the protein in the diet is not being utilised effectively. Excess protein in the rumen is turned into Ammonia through Proteolysis, this is absorbed into the blood but will be ‘detoxified’ by the liver to Urea and this uses up valuable energy, which could otherwise be used for milk production. This is then excreted in urine and milk which is a waste of nutrients from the cow and lost to the environment. Consistently high circulating Urea can also be detrimental to fertility, reducing heat expression, pregnancy rates and ability to hold service (Butler et al, 1996).
However, during grazing, milk ureas are often above 0.03% and hard to manage, as the high rumen available protein is not being fully captured due to lack of digestible fibre in grass. We
can help prevent them getting excessively high and therefore utilise more of the protein available by feeding a buffer feed or concentrate low in oil and RDP (rumen degradable protein), high in quality digestible fibre (Sugar beet) and slowly fermentable starch (Maize). Another benefit of supplementing additional digestible fibre at grass is that it will encourage cudding, where the cow will produce saliva containing urea which recirculates it back to the rumen for another chance to incorporate it into microbial protein.
On the other hand, low levels of MUN may indicate a shortage of RDP however this must be taken with caution, as there are many other factors influencing the rumens function and ability to utilise protein and generate microbial protein. However, both scenarios are economically and metabolically adverse to any commercial dairy herd.
Figure 1: Shows the seasonal effect on milk constituents throughout the year, no matter what system, but when either fall outside these ratios we need to take appropriate action with the feeding
Bethany May
Dairy Technical Specialist – North Wales
m: 07771 740857
e: bethany.may@wynnstay.co.uk
For the last few years, the industry has been advising grass silage producers to cut little and often to maximise the energy and protein yield form their silage ground.
Cutting every 4 weeks from the last week of April has seen to be the holy grail of silage making, creating many small cuts of ‘rocket fuel’ silage, high in metabolisable energy (ME) and crude protein (CP), low in NDF and as much or even more yield than the traditional three cut method across the season. With more opportunities to apply slurry, a shorter harvesting operation and more consistency in the final product, it seems a win-win for the farmer, nutritionist and certainly for the contractor. Often this is not the case. Of course, there is no denying a higher ME and CP from pretty much all cuts and there is no yield penalty across the whole season, but this is where the gains can end. First off , there is a larger contractors bill to pay, which is not always offset by increased milk from forage. The extra ME can often come with higher oil levels that nutritionally, do not bring much to the table and can often create a butterfat slump. The increase in CP can be mainly ammonia, so having little nutritional value. This increase in ammonia can be a result of the crop having less time to use the slurry or nitrogen applied post cutting which in turn, is detrimental to fermentation. Another thorn in the side of multi-cut fermentation can be that fact that these light cuts can go from too wet to very dry in a matter of hours, so dry matter (DM) can vary a lot. If it is on the damp side, we see a lot of clamp slipping cause excessive heating and waste, along with some very high lactic silages, due to the high sugar
levels in the grass.
Consistency
Consistency is key to high performing herds, whatever the system. Cows love consistency, rumens love consistency and consistency is important for farm businesses. In principal, multi-cut should help consistency, but it can impede it. Cows eat more ‘multi cut’ silage, due to lower NDF reducing the full effect of silage which means you burn through each cut very fast, resulting in more diet changes. As much as we try, each cut does vary and often needs a diet change, whether its due to DM, fermentation characteristics or the unavoidable seasonal variation in grass silage. Moreover, in some cases, due to higher intakes, bought in or poorer quality silage is needed to fill the gap, negating many of the benefits of feeding high quality forage.
NDF
Finally, it is important to consider that the role of forage is not just to provide as much ME and CP as possible, in fact forage is just that – a forage, a fibre source. Fibre or NDF is often the biggest variable in a dairy ration, so let’s try and make silage with consistent NDF levels, as we can easily balance other nutritional parameters. Why do we so often make so such high quality ‘multi-cut’ grass silage and balance it nicely with 1kg of chopped hay? Often because there is not enough NDF supplied. In most cases by extending the cutting interval by a week for first and second cut and then reverting to shorter cutting intervals, we would get more consistent NDF levels across cuts. Multi cut techniques have a place and a lot can be gained by reducing cutting intervals, as mentioned earlier, but only if well managed. There are a few points that first need to be considered to reap the rewards-
Ensure that you have enough forage to account for higher grass silage intakes
Consider using forage wagons to reduce the cost of production, especially in late season
Consider delaying first cut by a week and lengthening second cut a 5-week interval, then reverting to a 4-week interval to get more consistent NDF levels and maximise yield of first and second cut
Layer each cut in the clamp, so all are fed evenly at the same time, reducing ration changes at feed out
Ensure crops are wilted enough. Better to be too dry than too wet on lush silages
Use an additive on all cuts to reduce the risk of poor fermentation
Be sure of your nitrate levels before cutting -test where necessary
Minimise slurry applications after June because of the risk of contamination and elevated nitrogen levels in the summer and autumn. Make sure low volumes are applied using a shoe or dribble bar
We are often dictated so much by the weather and have to cut silage when we can, throwing all good plans out of the window, but having a plan at least, to maximise your grass silage production will stand you in good stead to increase milk from forage and overall farm utilisation.
Our advice on how you get your spring born heifers to grow, and keep growing!
With the spring calving season upon us it is important to think ahead to the imminent grazing season and how to get the calves born this spring (Feb-April) to grow well and efficiently.
Rearing spring-calved heifers to calve at around two years of age from grazed grass is a specific challenge.
In order to achieve a calving at the desired 22-24 months a calf must average 0.8kg-1kg per day DLWG. To achieve this, they must consume at least 3% of their body weight in dry matter a day. Spring calves born to grazing type crossbreds or small, hardy breeds can be turned out when they are between 6-8 weeks old depending on the weather whilst the calves are still on milk. This is important because it avoids excess stress around the time of weaning and give the calves chance to adapt to grazing whilst on milk. Calves should still be receiving concentrates around this time as they aren’t fully eating enough grass and are not able to effectively utilise it yet. They should have access to water and shelter and additional feed should be provided if weather is poor.
Managing the grass-quality and quantity
For calves that are turned out in late March-early April, it is important that they aren’t limited when it comes to access to quality grass and should be priorities when considering the rest of the cows on the grazing platform. Grazing cover should be between 2500-2800 kg/DM/Ha when the calves go onto the paddock in a rotational grazing system. It is also recommended that the calves are not limited behind a wire or pushed too hard to meet residual in the first few months and should be moved at least every other day, therefore set stocking is not recommended. Measure grass covers as they enter and exit paddocks to accurately monitor intakes, alongside starter feed fed. It is also important to know and regularly review the dry matter (DM) content. DM can vary depending on weather and time of year so make sure you know the value of the grass.
The weaning process should be done very slowly and carefully to minimise stress and any sort of check. The rate of weaning will largely depend on the weather and amount of grass they are eating. To determine how well the calves are transitioning they should be weighed and monitored regularly- changing group and rationing to support poorer calves. Once the calves are weaned, they can then be put into more of a block grazing system and given three days break at a time. By August/ September the calves can then work the residual to 1800kg/ DM/Ha then follow up with in calf heifers.
In order to achieve a calving at the desired 22-24 months a calf must average 0.8kg-1kg per day DLWG
The importance of concentrates
Concentrates should be provided until the calves can eat enough high-quality grass to sustain growth. The calves should be changed from their starter feed (Start N wean) to a rearer feed when the calves are around 12-14 weeks old. Grazed grass generally has a high crude protein content so there is no need to supplement with high protein concentrates. Low protein, high-fibre concentrates are available and have been specifically designed to help compliment a heifer’s diet whilst at grass, such as Heifer Grazer. Calves can be fed on a purely grass diet only if quality of grass and conditions can be guaranteed.
The energy that a heifer requires to achieve target growth rates will depend on liveweight. It is therefore important to determine whether dry matter intakes from grass will be sufficient to
supply heifers with the required levels of energy to sustain daily liveweight growth rate. Concentrate feed should be used to balance any predicted shortfall in energy requirements and to maintain optimum growth rates.
Field and health management
In young calves a decent field shelter (good tall hedges) should be provided for them to escape very extreme conditions and continue to monitor growth and adjust feeding as necessary. Short term losses in growth will take a long time to recover from. Fresh clean water is also of upmost importance to encourage DM intake and balance the body systems. To maintain good pasture management, good electric fencing and access routes are vital to stop calves breaking out and disrupting the grazing plan. Do not forget to discuss with your vet or health advisor a suitable vaccination and health programme, also not forgetting to supplement with vitamins and minerals as required.
To conclude
Heifers in their first grazing season should be the priority and fed high quality grass in front of the cows
The western side of the UK has the potential to be one of the best grass growing regions of the world. However, are we fully utilising this quality feed source to our advantage?
It has been well documented that grass when grazed is the cheapest feed available on farm. The Grass Value Project run by Coleg Sir Gar at Gelli Aur between 2011 and 2013 found
that grazed grass costs around £97/tonne of dry matter (DM). We can look to increase utilisation through the way we supplement.
The case for supplementation at grass depends on the specific farm situation;
Purchasing DM onto the farm to maintain a higher stocking rate
Increase DM intake on higher yielding cows
Supplying nutrients to match performance
Whatever the reason and/or yield aspiration and cow type, it is critical to only bring in feed or nutrients which will have a positive influence on performance and not just to fill the DM gap because of a higher stocking rate.
As can be seen in Figure 1, crude protein (CP) is very high in grazed grass all your round, always being above 20% CP, meaning there is always a sufficient supply of rumen degradable protein available. As a result, there is no need to supplement with more CP, because as we do we are just adding cost, increasing the rate of nitrogen excreted and running a higher risk of pollution though ammonia emissions and nitrate runoff.
Grazing cows are very inefficient at converting the rumen degradable protein into metabolisable protein the cow can absorb in the small intestine. To become more efficient and environmentally proactive we can look to reduce CP intakes whilst increasing carbohydrates through starch when supplementing, this will increase rumen nitrogen efficiency and boost production.
Work done at Cornell University and Teagasc in Ireland by Professor Mike Van Amburgh and Mike Dineen (Figure 2) shows how the degradability of NDF changes through the season, with early season spring grass being very degradable, with grass disappearing rapidly within the rumen and broken down and absorbed. As the season goes on, as can be seen by autumn grass this is degraded slower in rumen, although this is far quicker than most other forages we would feed. The degradability of NDF follows the growth rate curve through the season, with very digestible grass being seen through April and May (2nd and 3rd round grass) and also as we get a second peak of growth in late August/September. As growth rates drop in mid-summer, the degradability of the grass NDF will also drop and break down slower within the rumen.
To maximise the output of grazed grass and reduce nutrient loss out of the rumen, rumen outflow rates will be increased on more degradable NDF grass, this is when we see the cows having loose faeces, nutrients have passed through the rumen too quickly and the potential for better performance has been lost.
Figure 2 is a feeding programme best suited to maximise output and capture of the nutrients of grazed grass.
Amino Match Grazing Programme
The programme is designed to match the nutrient requirements to optimize the performance of grazed grass as the quality of the pasture changes through the grazing season.
Figure 3 shows where the compounds fi t and when best to utilise. During the shoulders of the grazing season, when also feeding silage, Extra Balanced 16 would be the preferred feeding option.
Grass Booster MP
Designed to optimise the use of the most digestible spring and autumn grass to maximise intakes, increase nitrogen efficiency and nutrient capture within the rumen.
Ideally suited to complement high quality pasture – second and third round grass rotations – can be fed throughout grazing season
Inclusion of NIS (Nutritionally Improved Straw), to increase the amount of slow pool NDF, and complement very digestible grass
Inclusion of Protected Soya to increase metabolisable protein and complementing high protein grass
High starch to utilise and capture more of the protein within grass to increase production
Mineralised to prevent grass staggers and deficiencies along with elevated levels of chelated zinc and copper to fully support milk production at low feed rates
Grass Booster 12 or 14
Designed to balance the use of grazed grass throughout the grazing season, that is high in rumen degradable protein and low in fi bre. Designed to increase rumen nitrogen efficiency, improve rumen health and increase production. Available in 12% and 14% Crude Protein.
High starch, low protein feed, formulated to be fed at a lower feed rate (2-4kg) to cows at pasture.
Ideally suited to complement mid-summer and autumn pasture – after second and third round grass rotations – can be fed throughout grazing season
High starch to utilise and capture more of the protein within grass to increase production
Greater utilisation and increased rumen nitrogen efficiency
Mineralised to prevent grass staggers and deficiencies along with elevated levels of chelated zinc and copper to fully support milk production at low feed rates
In the dairy industry where margins are often tight, making the most out of home-grown forages is key. Grazed grass is the cheapest feed on the farm yet often it is not utilized to its full potential. Providing good grassland management is carried out it can have a positive impact on profitability, more milk from forage = improved margins.
Careful planning of your grazing platform early in the season before cows are even out is crucial for a successful grazing season. Set up a rotation and grass wedge from the beginning, but the length of rotation will all depend on grass growth rate. As the season goes on there can be a large variation in growth rates as seen in Table 1. Therefore, regularly monitor grass growth and adjusting the rotation length accordingly is important. Having a flexible approach is key to a successful rotation, with the heaviest covers grazed first.
To start with cows will need to be trained to graze. Turn cows out for around 2-3 hours a day for around 2 weeks before full turn out this allows for the rumen adaption and will help to set up a grass wedge as they will be eating a small amount around 5kg dry matter (DM) a day. As cows have their two largest meals at sunset and sunrise turn cows into new area post afternoon milking, the grass will be higher in sugars and have a higher dry matter therefore intakes will be greater.
Even though the optimum cover for grazing is 2800-3000kg DM, at the beginning of the season turn cows out when the cover is around 2,300kg dry matter. Grazing lower covers here compared to the rest of year allows cows to be off the pastures quicker which will reduce poaching. Poaching will lead to a reduced DM yield throughout the season, graze the dryer pastures first which are less susceptible. Aim to finish the first rotation by the third week of April. Grazing intervals will vary during the season. In April/May due to the rate of grass growth the interval will be the shortest and a higher stocking rate (Table 2) can be used to keep up with grass growth.
Make sure residuals are grazed down to the right height from the onset on season, residuals influence sward density, grass nutrient quality, DM yields and regrowth in the subsequent rotations. Target residuals at 5-6cm (1600- 1700kg/DM/ha). Grazing below 4cm will diminish the plant reserves so regrowth will be slower. To rectify pastures which haven’t been grazed low enough consider premowing in the next rotation or following with far off dry cow/ heifers, providing a high stocking rate for a short period of time before leaving the paddock to re grow for the milking herd.
During May- August when grass growth is at its maximum fields above 3300kg DM consider cutting for silage then putting them back into the grazing rotation. If the pastures are left too long/ grazed too late the tillers will continue to produce new leaves, however there will be no increase in grass mass due to the bottom tillers produced first will die off . If this occurs the dead material will build up in the base of sward which has very little feed value, decreasing grass utilisation.
By measuring pastures and assessing the grass supply for the next few weeks will allow any shortfall/excess to be addressed quickly. If there is a surplus of grass, the supply must be reduced. This can be done by either decreasing the total grazing area or rotation length by cutting a paddock for big bale silage, increasing the stock numbers on a grazing area e.g. introduce the dry stock onto pasture following milking cows. If a shortage has been identified, then increase the grass supply by either increasing the rotation length by buff er feeding or introducing silage ground into the rotation or decreasing the number of stock by housing dry cows etc.
In conclusion to have a successful grazing season grass monitoring is vital, by doing this it will enables several management decisions to be made. It allows excesses/ shortages to be planned for and better grass utilisation by grazing at correct covers and residuals.
Rachel Gardner
Dairy Technical Specialist
South Wales
m: 07810 444834
e: rachel.gardner@wynnstay.co.uk
Far too often calf rearers get caught up blaming “uncontrollable factors”, mainly the weather, for poor growth rates or poor health in their calves. But arguably, doing a better job of things that are within our control would produce a stronger calf able to deal with additional challenges.
Calf rearing will always be a balancing act because of the varying factors involved and facilities we are working with. However, if simplified into four key categories; colostrum, nutrition, housing and hygiene, you can evaluate your own system to determine how much control you have and to what extent you exploit it.
Colostrum
Colostrum is arguably the most important step to allowing any calf to get the start it needs for a good future. Measuring and monitoring the quality of colostrum from each cow allows for an informed decision to be made as to whether it is good enough for a newborn calf. Every bucket and piece of equipment the colostrum is put through before getting to the calf should be thoroughly cleaned. This is an area we have full control to get right every time, if we have the correct tools and protocols in place. For successful colostrum management timing and attention to detail is imperative.
Nutrition
Feeding the calf appropriately contributes to both external and internal development; it allows the organs and immune system to develop; it also gives the calf energy and warmth to help deal with environmental conditions.
This is a unique area where there is full control; control in terms of the product chosen to feed, quantity fed, number of feeds, time of feeds, method of feeding, temperature fed at, etc. It is an area that should be taken full advantage of with best practice protocols in place to give the calf more strength and vigour to deal with the uncontrollable factors. Spending time designing specific feeding regimes and protocols for different age groups can extremely valuable to getting the nutrition right.
Housing
This area is where the “control” aspect is limited due to most calf sheds not being built for purpose along with our great British weather challenge. There is a fine line between fresh air reaching calves for air exchange and causing a draught. The temperature in calf sheds is generally the same as the outdoor temperature, as baby calves are not generating heat so keeping them warm through the winter can require additional management steps.
Hygiene
Although many farms do muck out pens between calves, are we really doing enough? Hygiene is often focussed on the area where calves are housed, but within this category calving pens and feeding equipment must also be considered. Back to the idea of the balancing act – calves’ susceptibility to disease is the direct relationship between the health of the animal and the disease pressure they are put under.
Some materials are simply not possible to clean, e.g. wooden hurdles, stone walls and cracked concrete flooring. Other materials can be cleaned, but unless the correct detergents and disinfectants are used, some bacteria and protozoa can survive in the biofilm (greasy layer on equipment).
In an ideal world we would have full control over these four factors, but in reality, a practical compromise must be met. Investing time into improvements in colostrum management, nutrition and hygiene may allow you to overcome the more difficult environmental challenges such as poor housing or cold temperatures. Although time and labour are precious on many farms, attention to detail can quickly pay back in reducing the time spent treating sick animals – not to mention the frustration and upset on staff moral that a run of sick calves can cause.
Having farm specific protocols for each job can instil consistency which calves thrive on; for help and advice putting together such protocols, please speak to your local Wynnstay Calf & Youngstock Specialist.
Rethink feeding calves on a restricted diet and concentrate on the benefits of feeding a high plane of nutrition.
It has become evident that in recent years nutrition and management in the first weeks of life can have long term effect on production. Restricted feeding is considered to be short term cost effective, encourages earlier weaning and produces a reasonably productive cow. However, even if we forget about the underlying long term effects that comes with it, in the short term, restricted feeding faces us with higher mortality and morbidity rates.
An elevated milk feeding programme reduces, mortality, morbidity, increased average daily gain (ADG), improves rumen development and increased milk yield in the first lactation. Feeding an elevated plane of nutrition and weaning later, promotes long term growth and productivity (Soberon F 2018). An elevated milk programme is beneficial to the calf’s health in terms of organ development. (Drackley 2015)
(Trouw Nutrition, N.D)
Calves fed a higher plane of nutrition had better ADG, were healthier and reached their genetic potential, whilst having decreased disease status, than those fed on a restricted diet.
“Feed conversion efficiency is much higher during the first weeks of life than at any other point in the growth cycle. So, every kilo you feed in the first two months of life will cost you less than doing so later in the cow’s life.” (Batch A 2018) I would say it’s important to set high targets of ADG in the first eight weeks to ensure early growth for longer lifetime performance.
“The calf has a requirement for maintenance and once maintenance requirements are met, growth can be achieved if enough nutrients and the proper balance of nutrients are provided to the calf.” (Soberon. F 2018) This indicates that underfeeding will not benefit your ADG, it costs you more in the long run with heifers calving down later, and lower yields. feeding your calves on a restricted feed plan could mean you’re only covering the calf’s maintenance requirements, resulting poor growth rates and organ development.
Worrying about feeding too much because of scouring?
A common belief for farmers is that feeding higher amounts of milk can cause scouring. It is true that calves’ faeces may be looser but that is evident due to the amount of liquid being consumed, loose faeces do not count as scours! Data has shown that calves fed a higher plane of nutrition did have higher faecal score than those on a restricted diet, but the faecal dry matter was the same (Trouw Nutrition, 2017). Faecal consistency doesn’t contain as much liquid when dry feed is consumed, due to the fibre content in the feed. Calves fed more of a high-quality milk replacer will not cause scour, although calves fed a poor-quality milk replacer, are more likely to experience scours (Bagley, 1997).
Unlocking genetic potential
How can a pre-weaning diet influence life time performance? Metabolic programming involves training the animals genes to respond in a specific way to maximise traits such as growth, milk yield and composition. Spending time and money choosing a bull to suit your system is exciting, but for that calf to have high production levels and continue to do so we can’t forget to feed it correctly. Farmers think nothing of spending £££’s on AI straws, but what are the benefits if you’re not feeding your calves enough?
For the future milk production of our cows it’s important to know that you must unlock the genetic potential as early on as possible. A higher plane of nutrition will unlock genetic potential and prepare the calf for metabolic programming. Young growth it crucial if you want to achieve full performance. During those first weeks this is when metabolic programming happens. The first weeks of the calf’s life can interpret whether that cow will be productive or not (Kaske 2018). The intensity of feeding in the first eight weeks of life can reassure you to having a healthier and more productive cow.
How to feed your calves on an elevated feeding plan:
Increase calf milk replacer (CMR) from 500g – 900g a day
and more..
