Your Committee invited me to talk to you and confirm that the era of animal breeding was over. Ten years ago that subject might have been mildly interesting, but meanwhile nutrition, pathology and even physiology have also lost their independent existence in the field of animal production. This, I assume, you will take for granted. On a superficial view, therefore, one might say that the era during which all these subjects made their separate approaches to animal production problems was over. But there is a wider sense in which our traditional thinking has become obsolete.

The degree of penetration of advances in nutritional research to the benefit of the pig producer is of considerable concern to both scientists and advisers. In formulating the nutritional policy for his pig enterprise, the farmer relies heavily on the advice which he receives from either national or commercial advisory services, and on his own first-hand experience. There may be other influences affecting his decisions, such as the reputation of a particular product or company, but apart from these it is rare to find farmers who have made a really serious objective attempt to evaluate their whole feeding programme. Recent developments in the economic climate have produced a situation in which profit margins for compounders and producers have reached critical levels; this, combined with world shortages of ‘safe’ protein concentrates such as fish meal, has provided a stimulus for the reassessment of established practices and loyalties. The purpose of this paper is to examine some of the ways which are open to the farmer or his adviser for evaluating in an objective way the possible consequences of changing from one diet or feeding practice to another.

At a recent conference on marginal land (Jenkins, Oxley and Gething, 1974) a conclusion was reached that hill land must ultimately contribute more to the growing requirements of food production. Setting aside the economic and sociological constraints, which at present are large, it is clear that increased animal production from the hills is basically a problem of providing sufficient feed. Improved pasture production is therefore a primary prerequisite for this aim.

Hill farms vary greatly in size, soil and climate and each has its particular problems. The task of the scientist is to investigate each facet of production from the hill and to provide information which will improve the overall understanding of the potentials and limitations to output. From that understanding, the solutions to the problems of the individual farms may be derived.

In countries with developed agricultural systems the proportion of dairy cattle inseminated artificially increased substantially following the Second World War, but a similar expansion in the use of artificial insemination (AI) has not been experienced for beef herds. The availability of deep frozen semen provided a further incentive to increase the percentage of dairy cattle artificially inseminated, for the more progressive herd owners soon realized that the technique offered the advantage of a long-term breeding programme with semen from progeny-tested sires available at a relatively modest cost. More recently, however, various developments in herd management have tended to militate against the use of AI in dairy herds, and during the past year there has been a substantial decrease in the total number of dairy cows inseminated which can only be partially explained by the smaller decrease in the size of the national herd. Amongst reasons advanced is the increase in average size of individual herds, resulting in more cows per man and therefore less time available for the observations of oestrus. Since accurate detection of the onset of oestrus is so important in obtaining high fertility following AI, some herd owners have returned to using natural mating. Evidence supporting this view can be derived from the fact that during 1973/74 there was an increase of over one thousand in the number of bull licences issued in England and Wales above the seventeen thousand issued in 1972/73. Of the 18.2 thousand bulls licensed, there were 3.2 thousand crossbred bulls, some obviously for use in dairy herds. The availability of synchronized and controlled ovulation would largely remove the difficulties which have been encountered, and would permit planned management techniques to be more widely applied within such herds.

In summer 1973, the sheep farmer in most parts of the Irish Republic could telephone his local cattle Artificial Insemination (AI) station and ask for a technician to treat his ewes for ‘early-lamb’ (December/January) production with intravaginal sponges and pregnant mare's serum gonadotrophin (PMSG). The 60 p per ewe service, which first became available at that time, covered two visits by the technician: the first to insert sponges; the second, 14 days later, to withdraw them and administer the gonadotrophin. On the basis of considerable experimental evidence, the farmer could expect about 60 to 70% of ewes treated to conceive to first services and lamb within a short period of each other, and some 80% to produce offspring to the combined first and second services. The scheme, based on natural service, was used by several hundred farmers in that first year of operation, and was made available on a similar basis again in 1974. The introduction of this cheap, effective and simple technique for the hormonal control of reproduction in sheep was the result of considerable activity over the years by Dr Sean Crowley and his staff in An Foras Taluntais and various workers in University College, Dublin (UCD). Due credit must be given, however, to the Irish Department of Agriculture, which sponsored extensive field testing of controlled breeding techniques in 197/172, and subsequently arranged with cattle AI stations to provide countrywide coverage on a fee per ewe basis from 1973.