The primary reason for shortening the breeding season is to tighten up the following calving season. This is to increase profitability and simplify workload during the coming year.

Many farms will choose to operate a 12-week breeding season, which then reduces the length of the calving season. Herds with a very spread out calving pattern generally can’t afford not to milk over the coming winter, according to Teagasc.

Nationally an average of 389,000 cows or just over one quarter of ‘spring-calving’ dairy cows calved between April and June in 2019 and 2020. Teagasc’s target is that only 10% of spring-calving cows should calve in the period – and those should calve in the month of April not in May and June.

The reason for this is to maximise the proportion of grazed grass in the cow’s diet. For this to happen, February calving is the best month.

Correcting the calving pattern involves taking the following steps:

  • Establish a date on which to end the breeding season this year. July 20 will confine calving to April next year. If you continue to breed until later in the year, you will have later calving cows and the cycle will start all over again;
  • Where calving pattern is spread out, it may be difficult to stop milking altogether for this winter so accept that this winter you will continue to milk the late calvers through the season;
  • Introduce extra home reared heifers or purchase suitable early spring-calving replacements for next year. They will produce as much milk in the coming year as a late calver and are certainly more likely to remain in the herd calving in early spring in future years;
  • Next spring either cull this year’s late calvers from the parlour or, if accommodation and forage is available, finish them next spring.