GENOMICS PROVE WORTH IN COW SELECTION

It is often said that beef cows are the hardest working, least loved animal on any farm, and The Wandle is no exception. We have high expectations of them; that they wean one calf a year, eat an endless amount of rank feed and don’t melt under pressure. This is the reality of our breeding and finishing operation, where we have many priority mobs, and the cows more often than not play a supporting role. My husband Gus and I manage this 2550ha farm at Middlemarch, under the umbrella of the Lone Star Farms group. Across the three Lone Star properties that have breeding cattle, the company has been taking steps to improve the genetic merit of the Angus cow herds, with 240 head here at The Wandle.

Lone Star Farms aims to target value-add red meat programmes and supplies beef into Alliance’s Handpicked and Angus programmes. It was clear from the outset, based on the rate at which prime cattle were hitting the marble scoring specifications, that work would need to be done to improve the breeding stock’s meat- and fat-related breeding values. The first step was obvious: buy bulls that have high breeding worths for IMF, ribeye area, fat thickness and growth. However, that alone only covers 50% of the genetic merit of their offspring – if we wanted to speed up progress, we needed to invest in evaluating and improving the genetics of the cows.

We undertook a genomic testing programme on all our existing black cows and heifers using Inherit SELECT. The resulting breeding values and Leachmann analysis values led us to form A and B herds, setting the initial minimum $Profit value at $9000 for a cow to be selected for the A herd. The base of the herd is varied, with the majority of cows having been bred off farm and brought in. In total, Lone Star has DNA tested more than 1000 cows and will continue to profile more than 350 heifer calves each year.

The table shows the gains being made in $Profit, which continues to be our primary selection tool, along with some individual breeding values and phenotypical assessment. We have started utilising Rissington genetics, whose involvement with the Leachmann system and targeting of IMF and feed conversion efficiency aligns well with Lone Star’s objectives.

The first crop of calves born to this new regime hit the ground in 2022, and so it will be another year before we see what influence the improved genetics has on steers and non-replacement heifers’ marble scores. However, we expect to start consistently achieving a marble score of 2 or higher with these animals, which would achieve an $0.80/kg premium ($1/kg for score >4). Currently, rising twoyear-olds (R2) are averaging a 2 score, meaning 50% of them are not reaping any premium above the $0.30 reward for being Angus. Caberfeidh, another Lone Star property, has been targeting sires with high IMF for several seasons longer than us, and are achieving 80% of R2s’ marble scoring 2 or higher, so we can be confident that these steps will pay off here.

Our aim for the cow herd is to become self-replacing, while also lifting total numbers to about 300 EBVs. Our sire team is now all Angus bulls with high $Profit and carcase BVs and are mated to both the A and B herds. We expect the B herd will improve at a similar rate to the A herd, and while we will prioritise selecting replacements from A heifer calves, we will continue to monitor the B heifer calves’ genetic merit as we need to, to build numbers.

Currently we are focused on using the slaughter results as our primary metric of improved genetics. It is unlikely we will see heavier weaning weights than have been achieved in the past. We now wean four weeks earlier, in mid-February, and plan to pull that forward even more by a week or two in future. This allows us to make better use of those cows and lift condition sooner in the animals that we need to. Average weaning weight this year was 180kg on February 21, while in 2022, weaning on March 1, the average weight was 200kg.

In future, an important aspect for selecting cows will be that they are fit for the system we run and meet their purpose within the system. We need cows that can get in calf as one-year-olds (at a minimum weight of 360kg), and get back in calf as a two-year-old. Dry second calvers are not given a second chance. Holding condition and being fit to graze our hill country is also important.

A crucial element to the success of these efforts is quality data collection. It is very important to gather accurate and reputable data at important times of the year, be sure that what we are collecting has a purpose and that we use that information to underpin our decision making.