Knowledge gap on dairy cattle energy gap hits fertility satisfaction

Just four per cent of dairy farmers are happy with their herd's fertility levels, according to a survey conducted by Merial Animal Health at April's National Holstein Show - and the results also highlighted a worrying lack of knowledge about tackling poor fertility levels.

Although the concept of the post-calving energy gap was widely understood, it appears that many dairy producers overlooked one of the major factors affecting the impact of the energy gap - and were therefore needlessly putting up with less-than-perfect fertility levels.

"We found that the majority of producers interviewed at the show were only 'satisfied' or even 'under satisfied' with their herd's fertility performance," reports Helen White, technical manager with Merial Animal Health. "Looking at the average calving interval of 410 days reported by respondents, that news came as no surprise.

"Producers should be aiming at the Milk Development Council's target calving interval of 365-375 days," she advises, "but in order to do this they need to fully understand what factors can affect cow fertility and, more importantly, how careful choice of cost-effective management options can promote good fertility."

Farmers correctly identified oestrus detection, nutrition and lameness as having significant effects on herd fertility, but the one factor that was consistently under-rated was parasite burdens.

"Yet when discussing the energy gap, the survey showed that most producers understood the relevance of nutrition and appetite in helping to reduce the duration and extent of the energy gap," Ms White points out.

"Producers appear to understand that appetite during early lactation is important, yet they're failing to appreciate that parasite burdens often suppress appetite and dry matter intake."

Research shows that decreased dry matter intake can prolong the energy gap, causing undesirable knock-on effects on fertility and suppressing the display of oestrus and lengthening calving to conception intervals.

"If producers are to take action to improve herd fertility, they need a clear understanding of the direct and indirect causes of infertility," she stresses. "The undesirable and costly impact of parasites must not be overlooked, nor should appropriate parasitic treatment be missed.

"With an accurate system in place for recording fertility levels, regular contact with their vets to advise on correct treatment , and prompt action to limit fertility problems, the MDC target rates are well within grasp. Ultimately, that means higher profits are within sight," she concludes.