Fertility visits could beat poor conception rates

Cow fertility problems are taking a big slice out of dairy herd profits as milk yields rise, herd size increases and less time is spent monitoring cows for oestrus.

At a meeting in North Yorkshire organised by Intervet/Schering-Plough Animal Health, farmers were shown how a 100-cow herd with a cull rate of 30% – driven by fertility problems – was losing more than £41,000 a year in income.

But Ruth Vernon, Intervet/Schering-Plough’s livestock vet adviser, said such huge losses could be avoided if more farmers introduced routine herd health visits by their vet.

“Latest figures show unproductive cows cost £4.90 a day,” she told the meeting at Wigglesworth, Settle. “When you combine that with current cull costs and open days in a herd with an unsatisfactory 400-day calving interval, it means it’s taking £587 off the profitability of every cow in the herd.

“If routine herd health visits can arrest that huge loss, then it’s a cost that looks good value to me.”

Conception rates were directly affected by a host of physical problems, such as timing of service, technician’s ability, cow age, nutrition, mineral status and even lameness, said Ms Vernon. But added to these were the cow’s disease status (BVD, IBR, leptospirosis, endometritis) as well as accuracy of heat detection and time of first heat after calving.

“Routine cow fertility visits are the most effective way to ensure dairy farmers don’t miss the relatively short opportunity given by cows to get them back in calf.

“Poor heat detection is an issue on many farms because management levels are stretched, but cows are changing, too, and some high-yielding Holsteins may only demonstrate oestrus for a few hours – some for only a few minutes of their cycle.”

She said routine vet visits created a planned approach to cow fertility across the whole herd and enabled dairy farmers to be “ahead of potential problems” when, 42 days after calving, cows had shown no sign of oestrus, or others had failed to hold to service.

“High yields, shorter heat periods, lower intensity of behaviour during heat and an unwillingness to exhibit heat behaviour – possibly because of slippery, concrete floors – are all adding to the problems of heat detection.

“The 365-day calving interval is the acceptable level, but only when your culling rate is low enough to achieve that. When you’re culling half the herd to get there, your 365-day calving interval is coming at a high cost.”

Neil Roberts of Settle’s Dalehead Vet Group – who has a growing number of clients undertaking routine fertility visits to improve herd fertility – said that although there was a 40% increase in the national milk yield between 1980 and 1998, there was also a 40% fall in conception rates to first service over the same period.

He told the meeting many farmers allowed too many cows to reach 50 days post-calving only to find the animals had problems that would extend their calving interval.

“But these problems would have been identified if the herd had been undertaking routine fertility visits and the loss of income would have been avoided.”

It was important that cows were fit and healthy to serve at 50 days and were actually detected on heat and served, said Mr Roberts. “And if conception rates are low, the reasons need to be investigated – nutrition and disease problems such as BVD, IBR or leptospirosis.

“The aim of routine visits is to increase the profitability of herds by reducing the calving index and reducing the number of culls being lost for fertility reasons.”