N.Z. beef herds long way from potential

Press, Volume CXI, Issue 32612, 21 May 1971, Page 13

N.Z. beef herds long way from potential

Under selection methods that have bqen used in the past in New Zealand beef herds, cattle have fallen far short of the growth rate that it is possible to reach, according to Mr J. G. Failoon, a member of the council of the New Zealand Angus Cattle Breeders’ Association, who is also president of the Wairarapa Angus improvement group and runs the nucleus stud for the group.

In the course of die Angus Association’s tour of Canterbury and Westland herds this week, Mr Failoon spoke to breeders about the importance of the sire in the herd. “Present methods of by guess and by God have proved to be of little value in raising production,” he said. “It has been estimated that the present average daily gain for beef herds in New Zealand is about 1.51 b per day and in America this is being produced at 81b of dry matter to 11b of liveweight gain. “Estimated biological limits (again American), however, are 41b per day gain for a dry matter intake of 51b per lb of liveweight gain. “Assuming that fanners and stud breeders have been trying to make more money from their herds by buying bulls that they considered would improve them, then if the criteria used had been correct, we would be a lot nearer our projected improvement than we are today. "What then should be the criteria for bull selection to

prevent deterioration and begin improvement? To determine this, a decision has to be made as to what characters are necessary to raise production and make more money for the farmer,” Mr Failoon said. There were only two factors in beef production and they were fertility or getting a live calf on the ground, and growth rate, or how fast a calf would grow through to a saleable weight, he said. These were luckily two factors that were easily measured and no bull should be purchased without these two most relevant details being made available. This was most important, as not only should the sires be selected from a plane of nutrition similar to that upon which they were going to be expected to perform, but also from studs with something constructive to offer in breeding for more efficient production. Such practices as foster mothering, rearing on hard feed and changing the environments of inferior bulls in an effort to sell them, were not only detrimental to improvement, but disastrous

for the breed as a whole, he added. The amount of progress in a herd was governed by two factors—the selection differential or how far above the population average in growth rate the bull was, and the generation interval or how quickly a bull could be used and replaced. For every year that a bull was used his progeny remained genetically static and the more extensively be was used the greater effect he had upon the total lifetime production of the herd. Illustrating how important accurate measures were in selection, Mr Falloon said, in a single sire herd of 30 to 40 cows one bull sired the complete calf drop and, if the bull was used for three years, he would sire a complete generation, or 8 per c mt of the lifetime production of the herd. “Can you then afford not to use constructive measured standards of performance for sires that you use, rather than, as at present, base your selection upon the rather airy-fairy eye appraisal, which although probably not particularly harmful, is most certainly useless.” The sire of the future would be expected to raise the production of the herd from the present New Zealand average of 1.51 b per day on 81b of dry matter per 11b of live-weight gain, to 41b per day on 51b of dry matter per 11b of live-

weight gain. Or, looked at in another way, instead of having to wait 24 months for the 10001 b live-weight finished animal (5401 b deadweight), it could ultimately be obtained in eight months. No-one knew what this 41b-per-day animal would look like because to the best of his knowledge noone had seen one. Some had seen animals that had been achieving this sort of result for a short period. So, if breeders ' did not know what this ultimate beef sire would look like, how could they possibly select visually

for it? "Ail tie do know for certain is that present methods of visual selection do not produce it," said Mr Falloon. He said that in a breeding herd, either stud or commercial, the cow had a very small part to play in improvement but a big part to play in efficient production. She should have two main uses—to produce a live calf regularly and to wean it to a high weight. She was in point of fact—if the farmer had a constructive breeding plan—just a gestation medium for the superior sires purchased.