Hormone Trials With Sheep

Press, Volume CIV, Issue 30827, 12 August 1965, Page 6

Hormone Trials With Sheep

(New Zealand Press Association)

HAMILTON, August 11.

The sex hormone which can result in multiple human births, is being used in lamb twinning experiments at Ruakura Agricultural Research Centre.

The hormone gonadotrophin has been used experimentally at the research unit for some time as scientists try to establish its practical potential for animal breeding. However, economic factors and the present stage of scientific knowledge limited the practical use of hormones to increase anima! productivity, Dr. D. J. Edgar, Assistant Director (Animal Research), said yesterday. The practical problem frus-

trating attempts to use hormones to increase the number of lambs born to a ewe or the number of calves born to a cow was that the number of off-spring could not be controlled. The ideal effect researchers hope might be achieved, Dr. Edgar said, is the production of a maximum number of twins from ewes. They want to reduce the number of single births to a minimum; maximise the number of twins born; and ensure that not too many ewes give birth to more than twins. As the number of lambs born to a ewe increase, hodever the statistical chances of their survival decrease. The death rate among twins is higher than the death rate among single lambs, Dr. Edgar said. Several thousand sheep have been used for scientific experiments with hormone on local farms and at Ruakura. The sex trials have dealt with multiple births, synchronisation of breeding, and control of the timing of the breeding season. At present there are some lambs at Ruakura which are about ready for killing. These were born earlier this year—well ahead of the normal lambing season. Through the management of the breeding season of sheep it could be possible to maintain a continuity of supply of lambs at the killing works. “This of course embodies other problems in finishing the lambs because of the seasonal nature of pasture growth,” Dr. Edgar said.

Arbor Day. Lyttelton school children yesterday celebrated Arbor Day by planting trees at Corsair Bay.