Ensuring bulls stay for longer

01-05-2010 | Sandra Taylor

Bull longevity is a significant problem in the beef industry and one that is having an impact on the profitability of commercial beef herds.

At a recent beef cow efficiency field day, one hill-country farmer remarked that it was costing around a third of his calf crop to replace a new bull every two or three years .

Stud breeders at the day acknowledged it was a problem, but thought bull management was a factor in bull longevity.

Hamish McRae, from Lochiel station near Hamner, mates 860 breeding cows every year (including 160 yearling heifers) on his 5200ha hill-country property. Hamish is particular about the way he selects and manages bulls to get maximum value out of his investment in genetics. He buys between four and six bulls every year and at purchase he places more emphasis on structural soundness and type than he does on estimated breeding values.

Hamish acknowledges that bull longevity is an issue, but believes taking care to ensure bulls are structurally sound at purchase can eliminate a few problems. He particularly looks at feet placement, ease of movement, leg positioning and the correct tightness in the sheath and stresses the need to pick bulls that will suit the environment.

"You've got to think that they are going to be producing your cows."

Hamish also makes a point of only buying bulls from breeders who will guarantee their animals and be willing to replace bulls if necessary.

When the young bulls arrive at Lochiel they are kept separate from the older bulls until after their first mating. This prevents bullying and fighting. After mating Hamish finds the bulls don't seem to be interested in fighting and are quite happy to be mobbed up together

After their first mating season, Hamish makes sure the younger bulls are well fed before winter to replace condition lost. If they don't regain this condition, he finds they can struggle the following season.

Over mating yearling bulls are put to yearling heifers for two cycles at a ratio of 1:35 and the older bulls are out with the three-year-olds and mixed-age cows for 2½ cycles at a ratio of 1:45. The cows are run in seven mobs.

Hamish keeps a close eye on the bulls over mating and will spend time observing the cows and bulls to ensure there are no injuries and the bulls are working as they should.

The bulls are all swapped around after the first 1½ cycles and Hamish has two back-up bulls on hand in case of injury or breakdown.

He says some of the older bulls can get a bit clumsy and it is a matter of watching them before making a judgement call on whether they should be replaced.

Every year all of Lochiel's 30 bulls are tested to ensure they can physically serve the cows.

The bulls are used for up to six years and Hamish says he feels he has had good value out of them if they have worked well for four or five years.

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