UK dairy herds could be earning an extra 0.9p/litre by improving fertility performance, according to Somerset-based vet Paddy Gordon of Shepton Vet Group.
Only the top 25% of herds questioned during a series of workshops he ran for the MDC and Arla, had negligible losses from fertility.
The average herd, comprising 158 cows giving 7600 litres, was losing 0.6p/litre and the bottom 25% more than 0.9p/litre.
Mr Gordon calculated losses based on figures of 10 litres a cow a day less each day lactation goes over 373 days, a target 7% culls for fertility and two serves per conception.
He used individual producers’ costs for replacements and AI.
Mr Gordon also discovered that producers who use pregnancy rate – the number of serves per conception – as a measure of fertility success were kidding themselves.
His data shows it bears no relationship to overall fertility performance.
Herds with pregnancy rates of 55% and more were still losing upwards of 0.75p/litre, while one herd with a pregnancy rate over 60% was losing more than 2p/litre.
“Pregnancy rate is easy to measure.
However, it’s not about the number of services, but when and if a cow holds to service that matters.
Producers delay service to boost conception thinking this will reduce fertility problems, but they lose sight of the bigger picture and end up with extended stale lactations,” he says.
As expected, higher yields and larger herds tended to result in poorer fertility. Nonetheless, Mr Gordon also found herds achieving 10,000 litres a cow could have good results.
“Achieving it was more difficult, but these herds regarded fertility as important and had a structured approach.
They gave fertility the staff, resources and attention it needs – good heat detection, cow health at calving, feeding and the right attention to detail at AI.”
Although heat detection has been an issue on farm since the 1970s, Mr Gordon says producers should be honest about it and seek help when necessary.
“Use unskilled labour on farm to do the routine work, so that skilled labour can focus on heat detection.
“Cows show standing heat for as little as five seconds, meaning secondary signs such as sniffing or chin resting are important.”