Getting 90% of cows to calve in the first six weeks of the calving season is worth €258/ cow/year in the average herd.
The six-week calving rate stands at 58% nationally, but the top 5% of milk producers are achieving over 85%.
Even a 10% increase in the calving rate is worth €80.70/ cow/year, said Dr Laurence Shalloo of Teagasc, Moorepark, at the recent cattle reproduction conference for vets hosted by Interchem Ireland Ltd and Ceva Animal Health, at Horse And Jockey, Co Tipperary.
He said minimising infertility is one of two key drivers of dairy farm productivity and efficiency — along with increased grass utilisation.
Six-week calving rate is the one single trait that reflects the costs of infertility. Key areas for increasing the six-week calving rate are genetic selection, EBI, the fertility sub-index, cross-breeding, submission rates, heat detection aids, pre-breeding management, heat recording, scanning non-cycling cows and treatment and synchronisation, body condition scores, once-daily-milking, transition cow management, supplementation, heifer management, and targeting calving at the start of the calving season.
Success in these areas also makes the dairy farmer’s life easier; Dr Shalloo estimated the potential for one person to manage 100 cows is reduced to 80 cows by infertility. This is due to the longer breeding and calving seasons, more heifers, more calves, the greater likelihood of disease due to buying in extra replacements, increased AI usage and other interventions.
Herds with poorer fertility have higher costs, for more services per conception, more synchronisation and infertility treatments, and scanning requirements. There is also reduced potential for expansion, reduced genetic gain, inability to maintain a closed herd or to sell heifers.
Dr Shalloo said bringing calving dates back from March to February would increase milk yield by 366 litres per cow. March 14 is the average Irish calving date, February 14 is achieved on research farms; March 5 is the target.
Co-ops could have scope to increase milk prices about 0.35 cent per litre if the mean herd calving date comes back to February 14 from March 15, according to Moorepark re-search (assuming 2008-2010 dairy product prices).
Reducing the replacement rate from 28% to 18% would increase yield 163 litres. It averages 28% on farms, 18% on research farms, and 22% is the recommended target.
The optimum replacement rate is thought to be 18% for balance between new genetics, the reduced performance of first calvers, cull cow values, and heifer rearing costs. Compared to fourth lactation cows, first lactation animals produce only 75%; second lactation animals produce 92%.
Calving interval averages 397 days, it’s 365 on research farms, and 373 is the target.
© Irish Examiner Ltd. All rights reserved