Marine mentality for modern diets (Feed 4 Thought issue 6)
UFAC-UK Sales Manager Mike Chown suggests feeding cows with omega 3s from marine sources will help improve efficiency by capturing some of the familiar benefits of fishmeal. Fishmeal used to be an excellent feed for dairy cows and is greatly missed by many producers. Before 2001, fishmeal provided not only an excellent and essential protein (DUP), but it also supplied omega 3’s from oil. Following the ban, protein sources have been introduced that provide an alternative source of DUP. However, these specific long chain omega 3’s have not been replaced, with a consequent impact on fertility. The principle omega 3s, EPA and DHA are not supplied in most current diets so cows have to produce them from other sources. Modern thinking is that cows have to rely on producing these long chain omega 3s from the shorter chain omega 3 (C18:3) that are found in reasonable levels in grazed grass but lower quantities in conserved forages. Research proves that this is not an effective process, leaving cows short of these essential fatty acids. Trials at the University of Florida demonstrated that feeding a balanced fatty acid profile, including Omega 3’s from by-pass marine oil, allows farmers to regain the lost fertility benefits of fish meal. These include a reduction in calving to calving index and better conception rates often regaining the 60% first and second service rates seen when fishmeal was fed. The graph shows the effect of adding omega 3 from marine to dairy diets. Most UK diets fall in the two left hand columns where diets contain predominantly saturated fats and omega 6 oils. The work also showed adding omega 3 greatly reduces early embryo loss. In addition, the trials showed a positive effect on milk yields with increases of up to 10% with no impact on milk quality. There was also an increase in feed efficiency, resulting in more production from forage. The trials also showed the optimal ratio for Omega 6: Omega 3, is 4:1. UFAC products are tailor made to provide this optimal ratio and incorporate omega 3s from marine sources which are the most efficient source for dairy diets.
Welcome from Robert Jones, MD
It takes more than a computer to feed cows profitably. It is going to take careful rationing to ensure cows milk as profitably as possible this winter. Dairy farmers must avoid the trap of relying solely on least cost formulations to develop their diets. All too often these fail to ensure cows receive all the nutrients needed as they look at cost rather than what the diet delivers in total. It takes a more measured approach to ensure cows’ requirements are met and that they will be healthy and productive. The computer is only part of the solution. Effective diets will be based on regular forage analysis, getting out amongst the cows, looking at the Cow Signals and performance data such as milk results. Armed with this information a skilled nutritionist will be able to fine tune diets to be effective. It is important to remember that cheap is not always best. To drive down cost per litre you need to meet all the cow’s requirements cost-effectively. Leaving a cow short of a nutrient because it cheapens the ration is a false economy. Remember the old adage – you only get what you pay for! Our team is here to help deliver efficient and effective diets and we will be delighted to offer a second opinion on your dairy rations.
Quality ingredients = efficient production
With every dairy farmer looking to improve efficiency to increase margins and reduce production costs, we asked Philip Vernon, UFAC-UK Business Manager in the South East for his thoughts on how to drive feed efficiency.
F4T: Surely the way to reduce cost of production is to use cheaper ingredients?
PV: The simple answer to this is no. Cows need to be managed and fed to meet their genetic potential. If we understand how the cow utilises feed, we are better placed to improve management of every aspect of the diet. To maximise milk from forage and meet her requirements, all ingredients need to be assessed for their individual contribution. This includes protein, both DUP and ERDP, as well as energy sources including starch and sugars, NDF and oils. A correct balance will help maximise dry matter intake which is key. Reducing ingredient quality can also reduce cow performance leading to an actual increased cost per litre. The diet must provide the specific nutrients to meet the cow’s genetic potential, while also maximising milk from forage. This requires careful ingredient selection based on what the ingredient provides, not what it costs.
F4T: So where should we start with diet formulation?
PV: Rumen function must be maximised before considering any other aspects of the diet. We have to supply the correct balance of rumen fermentable and bypass energy and protein, along with a balanced supply of essential fatty acids, including omega 3s. When formulating rations we must ensure the diet fully meets the cow’s requirements, and a key part of this is making sure that all limiting nutrients are met.
F4T: What does that mean?
PV: When rumen function is maximised, at some stage a specific nutrient in the diet will become limiting. Once a nutrient becomes limiting it affects the efficiency of the whole diet, reducing performance and increasing costs. The actual order in which nutrients become limiting is a factor of yield and the genetic merit of the cow (see table 1). A failure to meet the cow’s requirements will result in the loss of peak yields and a longer time spent in negative energy balance. This will have a damaging effect on overall herd health, particularly fertility, thus profitability.
Table 1: The effect of milk yield on dietary limiting factors
|Annual Yield (litres/Cow)||Nutrient Factor limiting milk production and profitability|
|8000||By-pass energy||Energy||By-pass protein|
|9000||By-pass energy||By-pass protein||Energy|
|10000||By-pass protein||By-pass energy||Energy|
|11000+||By-pass protein||By-pass energy||VFA production|
F4T: What does this mean in practice?
PV: To meet by-pass energy requirements we need to look at the types and quality of energy being fed. By-pass energy sources include rumen by-pass starch such as caustic treated wheat or rolled maize, but the most important for dairy cows is rumen inert essential fatty acids. These are vital for many processes in the cow and rumen by-pass fatty acids from marine sources have been shown to be particularly effective.
F4T: Aren’t fats expensive?
PV: We need to think value not price and consider what the energy source really provides. Fats are often the first energy source removed from the diet on the grounds of cost, yet they play a crucial role in fertility and production. In the early lactation period of negative energy balance, while a cow can generate 20% of her butterfat from VFAs produced by rumen fermentation, the remaining 80% must come from the diet. For example, a cow producing 35 litres at 3.8% butterfat, needs 1064g/day of dietary fat. Assuming a 22kg/day dry matter intake, the diet will need to contain 4.84% oils and fats. A failure to deliver this will reduce butterfat percent and potentially lower milk prices.
F4T: What about types of fat?
PV: As each fatty acid performs specific roles, cows must be fed a balanced fatty acid profile. While C16:0 fats are required for butterfat production, C18:1 fats are necessary for foot pad maintenance and for the replacement of mobilised body reserves. Shortages can result in higher levels of lameness and slower recovery of lost body condition. As cows cannot synthesise C18:2 (Omega 6) and C18:3 (Omega 3), these have to be provided in the diet. Omega 3’s in the form of EPA and DHA are required for fertility. As cows are inefficient at converting these essential fatty acids from C18:3, sufficient quantities must be fed. C16:0 fatty acids go direct to the udder and provide no energy for maintenance which is why they can be linked to excess body weight loss. Although the cow may appear to have sufficient total energy, she has to find energy for crucial body functions from elsewhere, primarily from body reserves, starting with body fat and then muscle.
F4T: Fertility will be important this winter. Any tips for diet formulation to help here?
PV: It will be critical to limit bodyweight loss. Ration to glycogenic energy requirements and the limiting factors in table 1. As outlined in the previous answer, there is only so much fat an animal can strip from body reserves, after which time they will start to lose muscle. Fertility studies have shown a correlation between increased rates of muscle loss and reduced fertility. Cows should lose no more than 0.5kg/day and return to positive energy balance by 45 days in milk. Where BCS loss exceeds this, the percentage of follicles which successfully implant and egg size will be compromised, resulting in reduced conception rates. In addition to ensuring sufficient energy supply, DUP supply must be adequate for two main reasons. The first is that when cows mobilise muscle, the amino acids in DUP are required to rebuild the muscle. If DUP is insufficient, amino acids are diverted from milk protein production, leading to lower protein content. The second is that DUP is required for effective reproductive performance.
F4T: What would be your key message to farmers this winter?
PV: Maximise milk from forage by focussing on purchasing feeds that balance their forages, to meet all their cow’s requirements. This will provide a more cost-effective diet with better performing, healthier cows.
Focus on energy sources to drive efficient milk production
Achieving and maintaining butterfat levels is a key concern for Paul Newland, who manages a herd of 185 high yielding cows at Bromham House Farm near Chippenham. The all year round calving herd averages 9,500 litres with milk sold on a liquid contract to Freshways. “To make the most of the available milk price we need to be producing 3.8% butterfat which has sometimes been a challenge,” Paul explains. “We have never bred for butterfats and so need to pay close attention to the diet.” Being on sandy soils, grazing plays a significant role on the farm with cows typically grazing from early March until late October. They are buffer fed at grazing and TMR fed in the winter with dairy compound fed in the parlour. The TMR comprises 70% maize silage, 30% grass silage with a blend and minerals. The blend currently contains soya, rape, maize distillers, maize and soya hulls. The buffer feed incorporates a higher proportion of maize, with the blend tailored to complement a grazed grass system. Paul has been working with nutritionist Rob Mintern for around a year and they appear to have got on top of the butterfat issue. Over the last winter they had fed C16 fats with minimal impact on butterfat percentage. “This spring we added 0.5kg hay and 0.5kg straw to the diet to push up fibre levels,” Rob Mintern explains. “The result was that both milk yields and butterfats improved with cows averaging 32 litres at 3.8% fat. Maize starch degradability “As fats were above the threshold, and as milk price had fallen back, the decision was taken to remove the C16 fat to try and reduce costs, and to reduce the hay and straw content. At the same time a new maize silage
pit was opened up and butterfats fell. “Clearly there were a lot of changes to the diet,” Rob Mintern continues. “With maize that had been in the clamp for a while, starch degradability might have been higher which could leave cows prone to acidosis but there were none of the typical symptoms. “To try and get the rumen functioning well and to increase butterfats again, sugar beet was added to the summer blend and we added 0.25kg/cow/day of UFAC Glyco-Buf.” Glyco-Buf is a calcium-glycerol product developed to maintain optimum rumen health and fibre digestion. It also supplies glucose direct to the liver, allowing an increase in glucogenic energy supply without compromising rumen efficiency. Effective fats pay “Within 10 days of making the changes butterfats had risen to above
3.8% again meaning we were getting the best milk price we could,” Paul Newland explains. “Cow fertility and health have been good and they are milking well. Because we have got the rumen working well, we have been able to cut the C16 fat out again with no impact on fat percent.”