Keep on top of your cows' heat cycling
Published 21/12/2011 | 06:00
This is the first year that many dairy farmers have stopped milk production over the Christmas period. Normally, these farmers will milk late calvers and empty cows from the spring breeding programme during the winter period. Some of these cows would normally be bred to calve down next autumn, while others would be bred next spring.
Once again the risk of superlevy penalties has meant that these cows have been sold for fattening. Cull cow prices have been exceptional this year, which has encouraged many to dispose of empty cows.
Liquid milk producers and a hard core in manufacturing milk have begun their breeding programmes for calving from September. There is a radical difference in the genetic potential for milk production between autumn and spring calving cows. Many farmers in liquid milk production have pedigree Holstein herds with a genetic potential for more than 8,000 litres in 305 day yields.
The breeding management of the autumn cow is made more difficult by the requirement to house cows. The nutritional and housing needs dictate that they are optimised to achieve the desired reproductive management targets.
Heat detection is more difficult indoors. The signs of heat and duration of it are the primary concerns. The target of a 90pc heat detection rate among cows eligible for breeding is the exception rather than the norm. Genetics, housing environment and nutritional requirements have to be in sync to optimise heat detection rates.
Visual heat detection without any aids is generally used with dairy cows indoors. Based on a survey of dairy herds housed indoors for the winter, we have recorded heat detection rates using visual observations of 25-80pc. This was based on cows scanned and identified as cycling normally.
Research data show that missed heats cost around €200. There is a need for greater uptake of technology for heat detection. Tail paint is not used successfully by farmers indoors. Tail chalk is used to achieve heat detection rates in excess of 70pc on farms in the north of Ireland. This system is used by Genus, where they provide a heat detection and AI service for farmers.