The effect of hexoestrol implantation on growth, efficiency of food utilization and carcass quality in pigs

Abstract

An experiment is described in which 64 individually-fed pigs were used to investigate the effects of dietary protein status, administration of aureomycin and hexoestrol implantation on growth, efficiency of feed utilization and carcass conformation. The results of hexoestrol implantation and interactions with the other two variables only are reported here. The pigs were implanted at 120 lb. and again at 150 lb. and killed at 200 lb. live-weight.The main features of hexoestrol treatment were:1. Body length taken from the anterior edge of the aitch bone to the junction of first rib and sternum was significantly increased by 9·75 mm.2. The percentage lean in the carcass was increased by 0·82%, representing approximately 1¼ lb. more lean meat in a 155 lb. carcass. The water content of the lean was increased but not significantly.3. Body fat was reduced but this was not reflected in a significant change in back fat measurements.4. No changes could be detected in the thyroid or adrenals, but whereas male castrates showed little effect of treatment on other organs apart from a certain amount of urethritis, the intact female manifested major changes in the genital tract. The uterus in particular was greatly enlarged and ovarian activity obviously reduced. The implications of these effects are being examined.5. There was no response to treatment in terms of growth rate or efficiency of feed utilization.

Growth, economy of feed utilization and carcass quality in pigs in relation to dietary protein level and antibiotic administration

“…EXPERIMENTAL The experiment was conducted during the summer of 1957 in a piggery equipped for the individual feeding of sixty-four pigs in eight pens. The experimental design and method of analysis have previously been reported (Morgan, Green, Costain & Williams, 1958), and it therefore suffices to indicate that this paper deals with the effects of two levels of dietary protein, with and without the addition of aureomycin (as Aurofac A) on pig performance. In this connexion data were obtained regarding growth, efficiency of feed utilization and carcass quality including records pertaining to complete dissection of half carcasses.…”