Four new genetic indexes will be launched in 2018 which will help farmers breed dairy cows with better health, welfare and efficiency.
The four new indexes are for calf survival, carcase quality, lameness and feed efficiency, and they will be added to the existing Predicted Transmitting Abilities (PTAs).
The launch of the indexes, announced today (22 January) at the British Cattle Conference in Telford, supports AHDB Dairy’s strategic objective of improving farm productivity and optimising cow performance.
Each of the four PTAs has been developed through the use of huge datasets of information on cattle, ranging from calf survival data from the British Cattle Movement Service (BCMS) to carcase weights and grades from abattoirs across the UK.
Marco Winters, AHDB Dairy head of animal genetics says dairy cattle have “come a long way” since the advent of genetic evaluations and are now “far superior” in many ways to those of the past.
“Cows’ milk production and functional conformation have greatly improved, and many health and fitness traits have made significant strides too,” Mr Winters explained.
“These four new traits for 2018 build on that progress and address some of the pressing issues the industry faces today. Farmers want to know which dairy bulls breed calves with good survival, which daughters are less prone to lameness and which will more efficiently convert their feed into milk.
“Producers will also value the addition of carcase traits, particularly if they are rearing pure- or cross-bred dairy beef,” he says.
“By addressing health traits through breeding as well as management, farmers are improving the welfare and fitness of their dairy cattle and will enhance their ease of management in the long term.”
The new evaluations will begin to be released with the April 2018 index run and continue thereafter through the year.
The four evaluations
The Dairy Carcase Index (DCI) is primarily based on average daily carcase gain and carcase conformation. It has been developed following research showing that carcase conformation and growth rates of prime slaughter-age cattle has good heritability, estimated to be 40 to 45%.
Weight, age and carcase information is now routinely shared with AHDB’s partner EGENES-SRUC by most major abattoirs in the UK and used in this genetic evaluation.
The DCI will be of particular interest to dairy farmers producing youngstock for the beef supply chain or rearing their own beef. However, all dairy farmers will have an interest in the weight gain component of the index, which is relevant to the growth of dairy heifers as well as for dairy-origin beef.
With some 55% of UK beef originating from the dairy herd, this index has the scope to improve returns and efficiency for many dairy producers. The DCI is jointly funded by AHDB Beef & Lamb and AHDB Dairy. The data collected is also used to enhance pure beef genetic evaluations.
The Calf Survival (CS) PTA has been developed using over two million animal records from BCMS which show that calves of some sires are more likely to survive their first 300 days of life than those sired by other bulls.
The heritability of CS has been found to be around 5%, which will enable breeders who continually select bulls which improve calf survival to achieve incremental improvements with each new generation of calves. CS will be incorporated into the UK’s national breeding index, Profitable Lifetime Index (£PLI).
A new lameness index will enable UK producers to make direct genetic selection against lameness, one of the most pressing welfare issues facing the dairy farming industry which is estimated to cost around £180 for every case.
Records used in the calculation of the index will come directly from on-farm lameness incidents recorded by the milk recording organisations, NMR and CIS. This information will be combined with existing data for locomotion and feet and legs, together with bone quality scores and digital dermatitis records from the National Bovine Data Centre (NBDC) type classification system.
Research has found the heritability of lameness to be 4%, which offers the potential to make a real change to the prevalence of lameness on dairy farms. The lameness index will be incorporated into £PLI.
Feed efficiency index
A new feed efficiency index will give producers an indication of which animals most efficiently convert feed into milk.
Extensive research into dry matter intake (DMI) has been carried out on over 10,000 animals around the world, in which the UK has played a major part. From the findings, a genomic index for feed efficiency has been developed which takes account of DMI and relates it to milk production and the cow’s maintenance costs.
In helping to identify and breed for the most efficient converters, the index will play a part in reducing feed waste, providing both financial and environmental benefits. The feed efficiency index will also be incorporated into £PLI.
Source: Farming UK