Pregnancy rates best indicator of fertility - farmers weekly

PRODUCERS NEED TO STOP FOCUSING ON CALVING INTERVAL AS AN INDICATOR OF FERTILITY PERFORMANCE AND INSTEAD LOOK AT PREGNANCY RATES. Speaking to Farmers Weekly at the Dairy Event and Livestock

Show, vet Jon Mouncey, Westpoint Vets said although looking at calving interval was important, it was an historic figure that only included the animals that had become pregnant. “Calving

interval does not give an accurate indication of where fertility is at that current time. The 21-day pregnancy rate – the proportion of animals eligible to become pregnant in that 21 days

that became pregnant – is the most accurate figure we can use. “Regardless of yield, all dairy farms should be able to achieve pregnancy rates of 20%. At the moment the UK average sits at

about 14-16%.” However, Mr Mouncey stressed it was crucial to recognise that pregnancy rate was an outcome of conception rate and submission rate, and as such it was important to keep an eye

on all three factors. “Increasing submission rates is a small change that can make a big difference to fertility. This can be achieved by using an automated heat detection system or putting

an oestrus synchronisation programme in place or just looking at the cows more.” Mr Mouncey also described milk progesterone analysis as an under-used tool. And ensuring good conception

rates comes down to making sure the basics of cow management are correct, including air quality, feed bunk design and cow comfort. Vet John Cook, Genus ABS said pregnancy rate showed how

effectively the management system was set up for the cow and was by far the most important fertility figure to look at. He also stressed that at a time when input costs were high, it may be

attractive to cut costs. However, it was important to recognise the potential long-term negative impact this could have on fertility. “If you make management decisions today that will affect

fertility, they won’t show on the bottom line for 11 months,” he said. “When producers are trying to cut costs, it is common to focus on reducing variable costs, and more particularly

feeding, vet med and breeding costs. The trouble is that all these factors directly affect pregnancy rates, so reducing costs here could be dangerous.” Mr Cook said cutting feed costs now

may improve the balance sheet in the short term, but it could result in reduced fertility in 11 months time. Feed choices were also strongly influenced by their effect on pregnancy rates –

even if it was not immediately obvious. “Why do producers feed cereals and soya?” asked Mr Cook. “Farmers don’t realise it, but it all comes down to pregnancy rate. They may be high priced,

but they are low-risk feeds – they are all relatively consistent in terms of composition and as such cows react to them in a consistent way. As a result there is low risk of them upsetting

pregnancy rates.” Bread waste or palm kernels may be cheaper, but because of variable quality, they presented a higher risk to fertility. “You are playing with fire in terms of pregnancy

rates if you feed these products. It demonstrates with higher feed price, it is still beneficial to feed more consistent feeds.”