Troy Setter’s presentation on fertility at World Congress last month was professionally delivered and very informative. I was delighted to find that Rockley Brahmans and industry leader CPC are so closely aligned in terms of our thinking and practice around this trait. At Rockley, fertility is currently the priority among our 7 elite breeding attributes. And now that our developing herd has the visual appeal that we’re looking for, our breeding focus is to add additional reproduction pressure.
While one of our breeding goals is for all Rockley cattle to retain and improve their visual appeal, a second goal is fertility. Having moved our stud cattle from coastal Rockley to the highly productive country at Ungarra, we are interested to see how our females respond to reproduction pressure in this improved environment. We want Rockley females to mate as yearlings, rebreed early while lactating as three-year-olds and continue to wean a calf for their entire breeding life. And we want Rockley males to show optimal scrotal size and semen motility at a young age to help us identify those that express early sexual maturity.
For all breeders, the earlier an animal can become productive, the higher the potential financial rewards. Early puberty helps us manage our costs and is a desirable trait that we can pass on to our customers. At Rockley, we are currently trialing yearling mating in our new herd. We look for low birth weight bulls to join with these yearling heifers with a view to seeing unassisted births of low birth weight calves.
Growth rate & weight
EBVs and visual appraisal are helping us to identify animals with fast young growth but moderate mature weight that are easy fleshing (not lean). An animal with fast young growth can become productive sooner than one that grows more slowly. To take this a step further we are searching for cattle that express fast early growth then level out to produce a moderate mature weight. We know how some heavy mature weight or large-framed females can struggle to hold body condition. This can affect their ability to get back in calf and can mean they don’t produce a heavy weaner because they are busy looking after themselves. Animals with a moderate mature weight are less costly to maintain and generally hold condition better, giving them a better chance of rebreeding and producing high quality weaners.
We are identifying females that breed first as yearlings, rebreed while lactating as three-year-olds and then yearly for the rest of their breeding life (longevity). We particularly like those that rebreed early and stay early. In our experience, earlier calves do better in general. Also, early rebreeding tends to become a habit for these females – and it’s one that we encourage. Our long-term plan is to use IVF to multiply older females that got in calf as yearlings, have had visually appealing progeny, rebred early and never missed a calf.
All our new-look registered females’ progeny are calf-recorded and can be found on the ABBA website. This easy-to-access fertility data gives our clients a simple and effective way of finding out a dam’s worth. Bulls from a female who has calved every year for a decade or also more are likely to be highly fertile. And we use fertility data ourselves when selecting bulls.
In selecting sires to join with our highly fertile females, we target animals with superior visual appeal out of dams with a full calving record. We value scrotal size and semen motility as indicators of fertility and for all our herd sires, we measure scrotal circumference annually and semen quality must be over 70% motile for us to turn them out with females.
Some may say that in aiming to increase cattle fertility while retaining strong visual appeal, we’ve set ourselves quite a challenge. But we’re confident that this is achievable in time, and the early signs are very encouraging.
To find out more, please contact Ashley on 0408 780 810 or Chris on (07) 4934 6317.