Effect of growth promoters for pigs on live performance, quality intestinal and the efficiency of biodigestion of wastes

This study aimed to evaluate the effects of growth promoters in growing and finishing pigs on performance and carcass characteristics, intestinal histological profile, organs weight of the digestive tract, and the consequences of these treatments on the effluent through the process of biodigestion. We used 80 pigs with an average initial weight of 40.00 ± 1.90 kg, submitted to four treatments, during 61 days, until to reach 100.00 ± 4.50 kg of livewight, corresponding to diets with the following additives: Control (diet without growth promoters); Symbiotic; Colistin (10ppm) and Tylosin (40ppm). Difference was observed to the daily feed intake during the growing phase with a greater consumption for the treatment Tylosin regarding treatment Colistin. There was no difference for carcass traits, for the weight of the organs and to the parameters evaluated in the process of digestion of manure (pH, total solids, chemical oxygen demand and biochemical oxygen demand). Regarding the intestinal morphology, animals treated with Tylosin had higher crypt depth (P ? 0.05) in the duodenum compared to animals fed with Control and Symbiotic diets, as well as larger crypt depth in the jejunum (P ? 0.05). There were differences in the rate villi / crypt with the Control treatment showing higher value compared to other treatments. For the ileum, there was a difference to crypt depth treatment of the animals compared to Control and Tylosin treatments. Despite observed differences in the characteristics of intestinal morphology, there was no advantage in the use of additives for the parameters of zootechnical interest. The effects on the fermentation process did not indicate any advantages for the additives evaluated