Optimising dairy cow fertility is so important, UCD
The View from Alltech: Every day that a cow remains empty after 110 days will cost dairy farmers between €2.50 and €4.15 on a daily basis. This was the sobering claim on which University College Dublin’s Dr Finbar Mulligan premised his presentation to today’s Global 500 conference, hosted by Alltech in Dublin.
“The challenge of fertility is one that is very complex, involving aspects of genetics, management, nutrition, lameness and disease control,” he added. “And the reality is that if any one piece of the jigsaw puzzle is missing, then the probability of infertility problems increasing becomes all the greater.”
Mulligan went on to point out that proper dry cow management is essential in order to maximise subsequent fertility. “We recommend that cows should be dried off at a Body Condition Score of 2.75, on a scale of 1 to 5. The optimal condition score at calving should be 3.25,” he commented.
“Staff at the UCD veterinary school have been very successful in training farmers to visually assess body score values. It is an exercise that should be carried out throughout the cow’s lactation.”
He continued: “Calcium status in the dry period will also have a significant impact on subsequent fertility. Farmers should be aware that a five per cent incidence rate of clinical milk fever will mask a 33 per cent rate of sub clinical disease.”
Turning to the nutritional requirements of the freshly calved cow, the UCD scientist stressed the absolute importance of keeping the period during which the cows is negative energy balance to an absolute minimum.
“Cows in negative energy balance will have a depressed immune system. However, there is growing evidence to show that feeding omega 3 fatty acids will help to improve progesterone levels. This, in turn, will improve fertility and conception rates,” Mulligan explained.
There is also strong evidence to show that reducing protein levels in early lactation will have a similar effect. The driver in this instance is the shortening of the period of time during which the cow is in negative energy balance.
“UCD research has also shown that a reduction in feed protein levels will not impact negatively in 305-day lactation levels,” Mulligan concluded. “By cutting the levels of protein fed, the cow produces less milk during the first 70 days of her lactation. This, in turn, allows her to come out a negative energy balance scenario more quickly. It also allows the cow to produce more milk more effectively during the later stages of her lactation.”
Pictured calves on outdoor pad. Photo O’Gorman Photography