The high producing dairy cow faces many challenges in regards to their health and performance. The most important of these is reproductive performance, which can drastically impact cattle performance, productivity and dairy farm profitability.

David Wilde, Ruminant Technical Manager with Anpario, discusses the challenges facing the modern dairy cow and how omega-3 fatty acids can impact on reproductive success:

Reproductive failure has been identified as the most prevalent reason for involuntary culling globally. The financial impact is significant, due to milk losses as a result of low fertility rates and culling, as well as the cost of replacing the animals”. 

The cost associated with replacing a mature cow with a new heifer, taking into account the loss of milk production and calf profits is estimated to be nearly £1800. Therefore, increasing the productive lifespan of the high producing dairy cow is fundamental. “At the recent American Dairy Science meeting, Dr Albert de Vries, from the University of Florida highlighted that a productive lifespan of 5-6 lactations was a minimum target.”

cows being milked

Difficulties to Overcome: Conception Rates and Establishing Pregnancy

“Conception rates of under 30% are all too common in modern farming systems, whereas a target of over 40% should be achievable”, suggests Mr Wilde. A recent study by Wiltbank (2016) demonstrated that whilst 80% of inseminations were successful and resulted in a fertilised egg, by day 28 post-insemination, only 50% of cows were actually pregnant. By day 42, this was reduced to 38% as a result of early embryonic mortality. 

After ovulation, the hormone progesterone is produced to maintain the uterus ready for implantation of the fertilised egg. “There is a window of just 14-16 days for the fertilised egg to successfully implant”, explains Mr Wilde. 

The hormone interferon tau (IFNτ) is produced by the embryo and is the signal for the maternal recognition of pregnancy in ruminants. IFNτ acts to inhibit the release of prostaglandin (PGF2α), a hormone that would otherwise cause the pregnancy to terminate. However, Mr Wilde explains that it takes around 12-13 days for the embryo to develop and grow large enough to produce the hormone IFNτ. “If too much PGF2α or insufficient IFNτ is produced, then pregnancy is not recognised, leading to the termination of the cycle and a return to oestrus”. 


Positively Impact Conception Rates with Omega-3 Supplementation

Whilst there are numerous factors that impact dairy cow conception rates, including: genetics; management; housing; stress, one of the most important influencers is nutrition. Mr Wilde stresses that:

 “nutrition can have a direct impact on the fine hormonal balance within the dairy cow, which in turn can determine the success of insemination”. 

Changes to the diet achieved by feeding long chain polyunsaturated fatty acids (PUFAs), such as omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), can positively impact conception rates due to their effect of suppressing PGF2α production.

Many forages and feed ingredients are naturally low in omega-3 fatty acids, therefore addition of a supplement high in these essential fatty acids can be beneficial”, Mr Wilde explains. 

EPA and DHA are two of the most effective omega-3 fatty acids at suppressing the production of PGF2α, more so than other omega-3 fatty acids, such as α-linolenic acid (ALA) from linseed oil (Figure 1).

omega-3 fatty acids comparison graph

Figure 1. Omega-3 fatty acids EPA and DHA suppressed prostaglandin (PGF2α) secretion by 60% compared with the control (no omega-3 fatty acids), nearly 40% more than omega-3 fatty acid ALA. 

Trial Background

A trial conducted by the University of California Davis in conjunction with Anpario was undertaken to determine the effect of omega-3 fatty acids EPA and DHA on high-yielding dairy cow fertility and milk quality. 

300 multiparous, lactating dairy cows, producing more than 50kg milk/cow/day, were assigned to one of two dietary treatments. This was either a control diet, consisting of a basal TMR, or the same base diet supplemented with Optomega® Plus at 160g/head/day. 

The cows were artificially inseminated following a double-OvSynch programme for 1st service and, if unsuccessful, a single-OvSync programme for 2nd service. 

Trial Results

“The cows were from a high performing dairy herd with conception rates above 50% to 1st service, therefore we did not expect to see a substantial improvement here”, states Mr Wilde. 

“However, the supplementation of TMR with omega-3 fatty acids EPA and DHA increased conception to 2nd service by almost 10% which is a fantastic result” (Figure 2). 

The trial also demonstrated an 18% increase in the ‘relative risk’ of a cow becoming pregnant.

the effect of EPA and DHA on conception rates of a high-yielding dairy cow graph

Figure 2. The effect of EPA and DHA on conception rates of a high-yielding dairy cow (Robinson et al., 2018).

The fatty acid composition of the milk from these high yielding cows was also assessed, to determine the benefits that dietary supplementation with omega-3 fatty acids EPA and DHA offered. 

“An increased beneficial fatty acid composition in the milk was achieved, whilst the proportion of saturated fats in comparison to unsaturated fats was reduced” conveys Mr Wilde. 

The overall “Health Promoting Index” of the milk was also improved when considering human consumption (Table 1.)

Table 1. The effect of EPA and DHA on key components of the milk fatty acid profile. 

the effect of EPA and DHA on key components of the milk fatty acid profile

Nutrition specialist Jerry Trowbridge from Lakeland Scottish Feeds & Services has been working with the product for over a year with many of his dairy clients. 

“The feedback from the farms has been very positive indeed, with all the farms who started still including the supplement in the cowsdiets” he states. “In fact, on one farm, we added just 120g per cow per day and, against recommendation, 500g of a calcium soap product was removed, with no loss in milk production and fertility improved in line with the California study.” 

This may, in part, be due to better palatability of the ration as well as the known effects of EPA and DHA on the mammary gland’s ability to secrete milk. 

Mr Trowbridge is now recommending all his clients to incorporate these essential fats in to the rations to ensure fertility is not compromised, especially at a time where palm oils are being removed from diets.

“Simply supplementing your herd with sustainably sourced omega-3 fatty acids, such as EPA and DHA has been shown to improve conception rates and overall herd pregnancy rates. In turn, this will help to cost-effectively reduce the involuntary culls due to poor fertility. At the same time, the milk will be naturally higher in beneficial fats, good for the calves and for us”, concludes Mr Wilde.

Optomega Plus | Sustainable Source of Omega-3 Rich in EPA DHA

Optomega Plus, Anpario's leading Omega-3 fatty acid supplement. Made from 100% natural high quality fish oil. Specifically formulated to ensure consistent high levels of EPA and DHA.

  • An excellent source of readily digestible energy.
  • Supports lactation performance and milk yield.
  • Feeding EPA and DHA can assist in elevating Omega-3 levels in milk.
  • EPA and DHA are well documented to support fertility in all ruminant species.

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