Estimated Breeding Values go on trial

Estimated Breeding Values (EBVs) may not be a tool every beef producer has yet latched on to, but using high-indexed bulls really can bring production and financial benefits.

We have conducted research in the past at Harper Adams University that has shown progeny from Limousin bulls with different beef values have significant improvements in performance and profitability with calves sired by the higher beef value bulls.

However, to further this database, and prove yet again that EBVs work we agreed to conduct an additional study, but with Aberdeen Angus sires.

The Aberdeen Angus has traditionally been regarded as an early maturing breed type suited to extensive grass-based production systems. Those calves reared on intensive production systems from birth would typically finish at carcass weights of under 270kg at fat class 4L. These slaughter weights are considered to be relatively low, especially for the abattoirs supplying the supermarket trade.

However, recent introduction of North American genetics into the majority of  Aberdeen Angus bloodlines has significantly improved the performance of this breed.

In the study, our aim was to evaluate the performance of Aberdeen Angus x Holstein bull calves sired by bulls with either a top 10% or top 70% terminal index. We also assessed how the modern-day Angus performs on an intensive cereal beef system.

BULL COMPARISON

The two bulls we used in the trial were Lorabar Mighty Prince, which has a terminal index of +34 and is in the top 10%, and Aynho Beck, which has a terminal index of +20 and is in the top 70% of the breed.

Both bulls have good calving ease direct EBVs in the top 1% for the breed. Lorabar Mighty Prince has significantly higher EBVs for growth and eye-muscle area.

WHAT THE RESULTS SHOWED

• Performance of the bulls was satisfactory, achieving similar carcass weights to the EBLEX targets for intensive cereal-finished Holstein bulls of 285kg. This indicated the modern-day Angus could be reared on an intensive system from birth, especially Angus bred from high index sires.
  
• However, it must be noted the market premiums typically available for Angus-bred cattle would not usually be available for bulls intensively reared on these systems of production.
  
• The top 10% sired bulls recorded significantly higher daily liveweight gains, slaughter and carcass weights and conformation scores. Daily carcass gain was also higher.
  
• The top 10% sired bulls recorded higher carcass price and carcass values worth an extra £60.74 a bull.
  
• The calves sired by the top 70% bull recorded shorter gestation lengths, which agrees with the bulls’ respective EBVs.
  
• ‘Terminal index’ is an assessment of the economic genetic merit of an animal. The theoretical difference between the progeny from the sires should have been £7.  In this study, the increase in value of the carcass was £60.74 a head for the top 10% sired calves. However, the benefit of finishing the bulls sired by the top 70% sire some six days earlier, together with the reduction in gestation length of 1.8 days, was estimated to be worth £18.59. This leaves a net benefit for the top 10% sired calves worth £42.15, which exceeds the predicted value by £35.15.

More on this topic

Find out how suckler producer Simon Frost has benefited from using EBVs