An on-farm evaluation of three growth promotants for pigs

Abstract

The performance of 160 crossbred pigs on a commercial piggery was studied from weaning, at an average age of 20 days, to slaughter at 27 weeks. They were fed control diets (treatment 1) or similar diets containing the growth promotants tylosin + sulphadimidine, virginiamycin + sulphadimidine + furazolidone, and carbadox + oleandomycin, (treatments 2, 3 and 4), according to regimes recommended by the 3 manufacturers. During the starter phase (3 to 11 weeks) pigs in treatments 2 and 3 (P < 0.01) and treatment 4 (P < 0.05) grew faster than the controls. Growth on treatment 3 was faster than that on treatment 4 (P < 0.05). Food conversion ratios did not differ. Growth rate and food conversion ratio on all treatments were similar during the grower phase (11 to 27 weeks). Overall, the growth rate, food conversion ratio, cold dressed weight, carcase dressing percentage and depth of fat over the eye muscle did not differ significantly between treatments. It is concluded that the growth promotants tested failed to improve overall growth rate and food conversion.