The new COW (Cow’s Own Worth) tool is available to spring-calving herd owners who are milk recording. Margaret Kelleher from ICBF is behind the project. She says it’s not a replacement for EBI, but that it should be used alongside EBI.

“EBI is used for picking the future generation, whether that is what bulls to use or what heifer calves to keep. The COW is only available for females within the herd and is designed to be used to help make better decisions about which cows to cull, and which cows to keep,” Margaret says.

COW is available as a profile on the HerdPlus website, with the best cows in your herd at the top of the list, and the cows to be considered for culling at the bottom.

There are three elements to COW. The first is the predicted profit potential of the current lactation based on milk price, the cow’s milk yield, fat and protein yield, calving month, SCC and milking speed and temperament.

The next is the predicted profit potential of future lactations if she was to stay in the herd. This is based on a combination of information that is available, such as her expected month of calving next year and predicted information based on her genetics and how she has performed previously.

An estimate of future prices and costs is used to calculate the value of traits such as milk solids yield, cull cow weight, milking speed and temperament, mastitis, lameness, calving difficulty, calf mortality and progeny carcase value.

Future calving date was estimated based on the current month of calving and the cow’s EBI for calving interval.

At the moment, the system is designed for spring-calving herds and it is presumed that February is the optimum month to calve with cows that calve after February penalised in the system.

The probability of the cow surviving to subsequent lactations was also predicted based on the cow’s current calving date, her age and EBI for survival.

The likelihood of the cow having a high, medium or low SCC was also calculated based on her current SCC and her genetic merit for SCC and age. The value of future daughter replacements was also taken into account when working out the value for future lactations.

The third element of COW is called the net replacement cost differential.

This is the savings in replacement costs net of cull cow value, if the cow was kept and not culled. The values are calculated based on genetic merit for the carcase weight of the cow.

To be able to use COW, farmers must be recording insemination and/or pregnancy diagnosis, milk recording and recording health events such as lameness and mastitis incidences.

Speaking at the launch in Moorepark on Tuesday, Donagh Berry from Teagasc said that future modifications to COW include making COW available for herds that calve outside of spring, introducing a ranking for heifers and making better use of health data. He said that there are two ways to looking at improving herd performance and profit – breeding from the top EBI cows in the herd and culling the poor performing cows. Donagh said farmers should aim to have an 18% replacement rate, with 9% culled for involuntary reasons such as infertility and the rest culled based on their COW ranking.