Evaluation of Genotype, Therapeutic Antibiotic, and Health-Management Effects and Interactions on Lean Growth Rate

Purdue University 1999 Swine Research Report. It has often been shown in research trials that pigs from genetic populations selected for high percent lean (54+% Fat-Free Lean Index; NPPC, 1994) carcasses perform best in ideal conditions. It has also been demonstrated that these same pigs grow substantially slower in less than ideal, commercial situations. With typically lower feed intakes, these animals are more susceptible to environmental stressors. Pigs from average percent lean (50% Fat-Free Lean Index; NPPC, 1994) genetic populations tend to be less sensitive to typical commercial environments. Also, pigs with average percent lean tend to become fatter and relatively less efficient when reared under more ideal conditions. In order to reduce the loss in performance of pigs in growth-limiting environments, different types of antibiotic and vaccination treatments have been prescribed. Tilmicosin (Pulmotil) is a medication designed for use in pigs at risk for bacterial pneumonia. Previous research has shown this to be an effective tool to increase performance and decrease death loss. Little research has been done on the joint effects of genetic potential for lean growth and health management system and effects of antibiotic/vaccination treatment on the performance of pigs. There is also little information about the effects of these criteria on pork quality. The effects of these treatments and differences in performance and quality of the pigs are crucial to a better understanding of the underlying biology of the pig in response to environmental and disease challenges.