Shaping the future of animal health

The importance of genetics

Every family cares about its genetic heritage – including the fourth-generation Corrigan farming family behind Rennylea, one of the most successful Angus bull breeding operations in Australia.

With a conglomeration of properties spread within a 50 km radius of Bowna on the south-west slopes of New South Wales, Rennylea runs 2,500 cattle including 1,100 breeders and an average of 1,100 weaners a year. The stud holds a twice-annual sale of its 450 bulls, with some fetching up to $17,000 each.

Farm Manager Peter Govan says Rennylea started its genetics-focussed breeding program three decades ago with the introduction of a maternal selection program that sees superior females breeding only with proven sires.

“By combining the best genetics of both cows and sires, the likelihood of offspring having superior genetic markers is increased, making this program an important part of our business success,” Peter said.

“For some years we have been flushing a group of selected maternal genetics - cows that are proven in the 'free' traits including temperament, fertility, structure, calving ease and marbling, and balanced in the 'cost' traits including milk, muscle, fat and growth.” The extraordinary success of the program can be measured by pregnancy rates in recipients and calves born to embryos implanted. “In 2004, 84 per cent of the cows implanted with embryos calved successfully, with a total of 350 calves born. In 2005, this increased to an 85 per cent pregnancy rate with 400 calves born.

“In 2006 the pregnancy rate again increased, this time to 87 per cent with 400 calves born. In 2006 and 2007 the numbers stabilised between 350 and 380 calves out of the total number of 400.”

Peter says these exceptional results are –“as good as anywhere in the world” and can be attributed to the emphasis on herd fertility over a long period of time.

To maintain peak genetics, the careful selection of treatments is critical, he added.

“The clients who buy our bulls for their own breeding programs know that we place a high expectation on our herd and this includes carefully selecting the best treatments to ensure peak animal health at all stages of their life cycle. So whether it’s the use of Virbac’s Multimin to ensure optimal nutrition or the use of long acting worm treatments, we’re careful to use the best products and in the right combinations to ensure our herd remains in peak health.”