EFFICIENT USE OF FEED

Press, Volume CIV, Issue 30739, 1 May 1965, Page 8

EFFICIENT USE OF FEED

HIGH growth rate in beef cattle was important in reducing the total feed maintenance charge in beef production. From a breeding point of view there were two fundamentally important traits about growth rate: (1) It was highly heritable with a coefficient of 50 per cent, and (2) the variation between groups of progeny of different sires was wide—o.Blb per day or more. Further growth rate

was clearly associated with efficiency of food conversion, so increased growth rate meant more live-weight per unit of food consumed.

To illustrate the progress that could be made by selection for growth rate, Mr Hollard said it might be assumed that two bulls on the same feed differed by 11b per day in gain. With a heritability of 50 per cent for growth rate the progeny of the two bulls would differ by 0.251 b under the same conditions.

Growth rate potential was expressed both in heavy weaning weight and in post-wean-ing gains.

Further there was no conflict between the traits of growth rate and conformation. It was quite feasible to select animals which had not only a growth rate much above average, but which also had superior conformation. In selecting beef breed sires, the weaning weight and growth rate of the young bulls selected were important. However, the bulls should be progeny tested for an exact measure of their genetic superiority to be obtained. Of course the progeny of different bulls should be compared under comparable conditions. To progeny test for weaning weight 25 calves per sire were required, for rate of gain 10 calves per sire, and carcase merit eight to 10 calves of each sex were required. It was assumed, always of course, that the bulls concerned were mated to comparable cows. Performance testing in beef cattle provided several clearcut advantages:—(l) Accuracy of selection was improved. Facts and records could accompany observations made by eye in the selection of both bulls and heifers. (2) In time purchasers would place added value on a bull if his performance records were available. (3) With performance records available all aspects of beef cattle management would be sharpened. (4) Performance testing was not a get-rich-quick scheme, but it did provide a sound basis on which more rapid progress could be made. (5) Performance testing was complementary to show ring assessment, but was a more sensitive measure of genetic worth.

Mr Hollard said he understood that the Economic Ser vice of the Meat and Wool Boards was prepared to analyse performance records for breeders of beef cattle. Hence all that was required of the breeders was to identify all animals at birth, record exact birth dates and weigh the young cattle at weaning, the 12 months old and 18 months old stages.

In the course of a demonstration of the various desirable conformation points of beef cattle using one of Mr Wilding’s rising five-year-old stud bulls, Mr Robin Fraser, of Pleasant Point, drew attention to what, in his opinion, was the limitation of the weight gain system in that it had to be associated with conformation points and other factors more easily recognisable to the stud breeder. However, he agreed with Mr Hollard in that he felt there was a place for the weight gain system in the stud beef system.