Masculine—but reluctant to perpetuate

Press, Volume CXIV, Issue 33580, 8 July 1974, Page 1

Masculine—but reluctant to perpetuate

(By

LANCE EARLY)

Man. as it has been observed recently, frequently shows an unwillingness to work, but in a country which depends on its primary industries, it is bad news for the farmer when the rams don't work. Many a New Zealand farmer, after buying his rams, has found that some prefer to hang round the gate, rather than make the best of their new-found opportunities. Their ability — or lack of it — is usually dismissed as being a case of "another pampered ram,’’ and a decision is sometimes made to buy elsewhere the next season. Lack of libido (sex drive) in rams, however, is a condition which has engaged the attention of animal scientists in several countries, including New Zealand. Because conditions vary from one country to another, not all are agreed on the causes. All, however, seek a cure. Some of the most recent work published on the’ condition comes from Australia, where low libido has been investigated in Merino rams. Surprising That this should occur in the the Merino may come asi a surpris*. for this aristocrat of the sheep world, unlike some of his con-i temporaries of other} breeds, has all the attributes of animal I masculinity — vigour,j aggression, and domin-i ance. The Commonwealth Scientific and Industrial Research Organisation, in a journal published re-j cently, hastens to assure readers that lack of inter-} est in the opposite sex; is not peculiar to the Merino. •‘Reports of unmated rams remaining sexually in-} active after being introduced into flocks have! come from many other countries, so our rams have nothing to be ashamed of,” the journal says. i .Vo ability Low libido isn’t the only; problem, according to! the journal, some rams simply lack the skill. Obviously, it adds, the flockowner wants all his rams to be both willing and able. Australian animal scientists have devised a system; for picking the nonworkers. It involves a simple test in which a young ram is put in a pen with some in-season ewes. Three such tests,; they say, are a reasonable guide to subsequent 1 ability in the flock. The journal goes on to report that subsequent experi-| ments have shown that! libido doesn’t usually; improve dramatically as I rams get older — once! a non-worker, always ai poor worker seems to be; the rule. Mating dexterity sometimes im-; proves with experience, i but the least dextrous rams tend to stay at the bottom of the class. The Australians consider that libido is a hereditary factor. Sex-drive, according to the C.5.1.R.0. journal, appears to be set early i in life by hormonal in-} fluences, which would bet

at least partly under genetic control. They base their conclusion on a comparison of sires and their male progeny. New Zealand research on low libido in rams has been conducted by Dr R. Kilgour, of the Ruakura Agricultural Research Centre, but Dr Kilgour has not come to the same conclusions as the Australians. He considers that rearing has a .strong bearing on male performance in later life. Ruakura tests Three experiments have been conducted at Ruakura — in the first, two groups of rams were put out with in-season ewes. Certain rams, it was noted, exerted their dominance. Those of low social dominance were then brought together with some in-season ewes. Again, one of the rams became the dominant member, but he did not? mate at all, and he also had a low dexterity in-l dex. Rams were then obtained from Massey University — rams with a klinefelter syndrome. Dr Kilgour explained that normally there is an XY chromosome in the male; but in this case the rams had a double X factor linked with Y so that they had a stronger female than male element. They were also infertile. In spite of the extra female element in their make-up, however, these rams exhibited the same mating instincts as normal rams. A third experiment concerned rearing. Twentyfour ram lambs were raised on the bottle; 50 others were taken from an ordinary flock and reared in the normal way; while a further 50 were put in with 10 per cent of ewes (whose fallopian tubes had been tied) to see if experience would have an effect on their pre-mating tests. The libido test success rate ranged from 35 per cent in the bottle-reared lambs to 87 per cent in those reared with the ewes. The group reared in the normal way after weaning were roughly in-between, with a figure of more than 50 per cent. Libido tests, as used by Dr P. E. Mattner. of the C.5.1.R.0. and his staff, have been made at the Whata Whata hill country research station, but these are not considered to be practical at farm level. Dr Kilgour said that a 12-minute pen-test is considered to be quite adequate to show whether a ram will work or not. Further pen trials have been used at Ruakura in a pedigree sire mating system, and some of the new breeds on Mana Island have also been investigated to determine if there are differences in male reproductive performance. This research is still being analysed. Effects of travel Dr Kilgour also emphasised that travel and change of environment have a marked effect on the performance of male animals. In Scandinavia, he said, it was reckoned that if stock were moved from one place to another, they took 30 days to reach a peak. This indicated that they took time to settle down. The work of Dr Kilgour, and scientists in other countries will prove of much value to the sheep breeder. As an example, a stud breeder may pay a lot for a ram, which does

r not work. A libido test, } before the ram is offered ! j for sale, would enable a; vendor to give a guarantee. Sheep are not the only domestic animals which sometimes show a; marked lack of interest L in the opposite sex.; I Horses imported from, •overseas have also been! inhibited. * However, Mr C. H. G.: Irvine, of Lincoln College, an authority in the equine veterinary fields,, } says he does not regard} it as low libido, as such. I A stallion, he explained,} might have .the drive,}

} but- because of anatomical and psychological factors, he does not manage to complete the act. [Animats, he said, enjoyed mating, horses particularly so. Stallions often prolonged the act. Some studmasters wyuld get h annoyed with this, and I often kick the stallion in the stomach to make him complete the act. • This is one of the criticisms Mr Irvine has of New Zealand studmasters — ; they do not let their , stallions spend enough time when mating. If they did; it would assist I good conception rates.