THE EFFECT OF DIETHYLSTILBESTROL AND ESTRADIOL-TESTOSTERONE IMPLANTS ON RATE AND EFFICIENCY OF GAIN AND ON CARCASS QUALITY OF MARKET PIGS FED DIFFERENT FINISHING DIETS

Abstract

The interactions between hormone implant, sex and ration for finishing Yorkshire pigs are reported. Three replicates involved a total of 192 self-fed pigs. Barrows received diethylstilbestrol, gilts a combination of testosterone propionate-estradiol benzoate implanted in the ear. The four test rations were based on wheat and barley, with or without added protein and with or without 30 per cent ground alfalfa as a diluent.Implantation of the barrows had marked beneficial effects on feed efficiency, area of loin and R.O.P. score when they were fed the undiluted basal ration with added protein. On the diluted ration with no added protein, implantation of the barrows doubled the percentage of A grade carcasses. Implantation of barrows fed the diluted ration with added protein improved rate of gain, feed efficiency and carcass quality. Hormone implantation of the gilts was not beneficial.Administration of diethylstilbestrol to the barrows, especially when fed the diluted rations, increased net returns. This, coupled with the beneficial effect on carcass grades and no adverse effect on rate of gain, indicates the economic significance of the findings.