Progeny from the first crop will be either processed or within the breeding cow herd (and have produced the first calves of their own). The second crop will have weaning and yearling weights analysed and the third crop will be on their mothers.
Brief recap of test
The B+LNZ Genetics Beef Progeny Test involves mating a mix of New Zealand and international bulls (using AI) over about 2200 commercially-farmed cows and heifers each season. All progeny are tracked, with steers and terminally-sired heifers assessed on their carcase traits and replacement heifers tracked for their maternal characteristics. The trial is being carried out on five large-scale, commercial New Zealand sheep and beef farms.
Key message to date
B+LNZ Genetics General Manager Graham Alder says the key message so far is very clear: “Estimated breeding values (EBVs) work. They deliver what they predict.
“The latest analysis of progeny performance shows how closely the sire bulls’ EBVs match their calves’ performance.”
The line graph shows that, for every 1kg more in 400 Day Weight EBV, 0.45kg was gained in average yearling weight. Given the bull contributes half of a calf’s genes, this translates to 90% of the expected yearling weight advantage – as predicted by the EBV figure – being realised.
Mr Alders says results reinforce the story that the weaning weights vs EBVs showed, where the correlation was also strong, at more than 80%.
Not all bulls are equal
The yearling weight analysis also highlighted the range of sire means (see the bar graph). The results show that not all bulls are equal – the impact of different bulls’ genetics comes through under the commercial conditions.
Mr Alder says that, based on current store cattle prices, the difference in yearling progeny weight between the highest and lowest maternal breed sires (i.e. excluding Simmental and Charolais) would be worth approximately $90 per head.
“If the terminal breeds are included, this difference in calf value jumps to $170. Of course, growth rates are only part of the picture for these bulls, and the challenge in breeding is to balance all of the attributes that are important to a particular operation. Carcase quality and maternal performance of daughters are the other important attributes being monitored over time.”
Over the next 12 months, reproductive data from the replacement heifers and processing data from the finishing progeny will begin to come through, with the first progeny due for processing from May onwards.
Scientists are currently processing recently-collected data on the heifers’ first mating, based on outcomes from scanning to determine foetal age. They will look at correlations with the sires’ EBVs for Days to Calving, Mature Cow Weight and other attributes.
Test’s wider benefits
Mr Alder says the beef progeny test is setting New Zealand up for quality beef research into the future. “We are building up a population of animals that is well recorded and analysed, but is also managed completely commercially. This group of animals and their progeny will be particularly valuable as the Trans-Tasman Beef Cow Profitability Program builds momentum.”
Field days for 2017
Two B+LNZ Genetics BPT field days will be run over coming months: Caberfeidh Station in the south and Tautane Station in the north.
The B+LNZ Genetics Beef Progeny Test is supported by Angus New Zealand, Focus Genetics, New Zealand Hereford Association and Simmental New Zealand.