The more fertility checks, the fewer cows seemed to get in calf

Jim Boyd manages the 260-cow East Kilbride-based Lettrickhills pedigree Holstein herd. For Jim, fertility is a significant driver for herd profitability.

“We are running a high input, high output all-year-round calving herd averaging 11,800 litres, milking through a robotic system and achieving 3.1 visits a day,” he explains.

“Calving Index has fallen in the last five years from 410 days to a current average 394 days, however since every open day is a big cost, we are targeting 385 to 390 days and using various measures to get there from a simple milk test to selecting sires for high fertility traits.

“We have a strict fertility policy; we start serving after 48 days; I would rather wait for up to 90 days after calving for a natural heat before the intervention, as I believe these are more fertile heats. 80% of cows we wish to breed from getting two services of sexed Holstein semen before they go to beef and if they don’t hold to either dairy or beef, then after 200 days they are classed as infertile,” he says.

Calmness across the herd

Introducing IDEXX’s Pregnancy Associated Glycoprotein (PAG test) 35 days after service has had a significant role to play in reducing CI to the current level. PAG is a simple milk test that helps to identify which cows are open and need to be served again; the sooner the better we know when a cow is in calf.

“We used to routinely PD every served animal, however, I felt the more money we spent on fertility checks, the fewer cows we seemed to get in calf; these checks were being made at a time when it’s easy to upset a pregnancy whilst it is in the early stages of gestation and still very fragile."

In contrast, the PAG test is totally non-invasive.  It’s time-saving, labour-saving, and hassle-free. The robotic milking system has introduced a calmness across the herd. Nowadays when the Vet arrives, he’s looking at just a handful of cows, usually those with silent heats. The less Vet interference and less cow handling, the better her welfare".

98% to 99% accurate

Jim says the logistics are simple. PAG is routinely carried out at Lettrickhills on a monthly basis at the time of CIS recording. Cows and heifers eligible for the milk test are cross-checked with the milk recorder and marked on the computer system to be tested when the milk recorded sample reaches the lab for analysis. He receives a text message from CIS when the results are ready for login. Turnaround time is within three days.

Lettrickhills' daily routine includes checking the heat detection collars which Jim says offer accuracy. Genus AI makes a daily visit, however, Jim complements the service and AI cows and heifers himself to optimise ideal service time. Jim is also selecting Holstein sires for high fertility - a trait which he has come to conclude is ‘quite accurate’.

"The milk test has consistently proved to be 98% to 99% accurate for both positive and negative tested cows. 3% to 4% fall into the recheck bracket and usually result in 80% to 85% being in calf; they are automatically retested at the next recording free of charge, however, I do get them checked as part of the Vet’s routine visit".

Reaching our goals

“Maintaining high herd health and welfare, including feeding to yield to maintain body condition score between 2 and 3 throughout lactation helps to minimise the challenge of metabolic disorders, as well as mastitis and feet problems, and in turn reduce stress which I believe can impact on fertility,” he says adding. “Putting to good use other modern management tools, including PAG in the routine will equally help us reach our CI goals.”