Genomic predictions applied to a trial of dairy beef cattle have shown how to enhance carcase performance while sidelining those animals of lower finishing worth.
The trial was conducted by GENEZ, a genetics company specialising in beef genetics for beef on dairy, and PBB NZ, the administrator for cattle breed societies.
The main aim was to validate the use of beef sire estimated breeding values (EBVs) for beef on dairy sire selection and better predict carcase performance at slaughter using genomics.
Genomic testing is a simple and effective way to allow more predictability for future performance for commercial beef and it was exciting to see the correlation was pretty strong also for the dairy beef.
Genomic testing allows a producer to easily eliminate uncertainty and reduce risk by identifying the genetic potential for the most valuable traits, from growth to hot carcase weight and marbling, according to PBB South Island area manager Trudy Benstead.
“This test should create more market value for buyers wanting to source quality calves.
“We commonly see a fairly standard 100kg price but the question always for the finisher is ‘What makes that animal more superior, compared to the rest?’
“Studs have put in the hard work in breeding and generating EBVs and now we have tools like genomics and Igenity to help us make more selective decisions.
“We will be able to understand what strengths are within the calves that are being purchased for a more confident return.”
GENEZ general manager Ben Watson said the trial was conducted at Kakahu Farms, Geraldine, with selected Kakahu Angus sires over crossbred dairy cows, mated in November 2020.
Targeting the Alliance Pure South Handpicked premium programme, 65 steers and heifers were taken through their second winter and slaughtered in November and December 2023.
Ear tissue samples were taken using the Allflex Tissue Sample Unit and sent to PBB genomic partners Neogen Australia, where they were tested on the commercial beef genetic test Igenity Beef.
The Igenity Beef test is supported by genetic and performance data from over 18 million animals across the globe.
The International Genetic Solutions (IGS) database is included in the Igenity reference population and holds several million genotypes and data points across multiple beef breeds.
This database was chosen in the hope that dairy beef animals would be predicted accurately due to the multi-breed make-up of IGS.
The steers and heifers killed in two lines weighed between 270kg-370kg carcase weight, within the Handpicked range, where premiums are gained for the degree of marbling.
The results showed significant correlations between genomic predictions, sire breeding values and carcase quality at slaughter.
For the slaughter cattle from sires with intramuscular fat (IMF) at or above the breed average of 2.2, some 68% marbled at carcase assessment and gained premiums.
When genomic predictions by Neogen/PBB were overlayed, the percentage gaining premiums improved to 71%.
Neogen genomics accurately predicted the highest marbling animal, which was the only one predicted at an eight for marbling.
This carcase also scored a seven on the AUS-MEAT scale at chiller assessment.
Conversely, the Kakahu sire bull with the second-lowest IMF breeding value of +0.7 sired the animal with the lowest Neogen prediction for marbling, which scored zero on the AUS-MEAT chiller assessment for marbling.
“We saw that a combination of good sire selection and genomic screening showed around 70% accuracy in predicting marbling at slaughter,” Watson said.
“This is an excellent result considering marbling can be influenced by environmental and management factors.
“My message to farmers is to target meat company premiums and avoid targeting lower-quality livestock, use genomics alongside good sire selection using EBVs.
“Beef on dairy already provides over half of our finishing cattle and GENEZ aims to scale up the quality outcomes for all participants.”
