Estudo sobre fontes de proteína de origem animal e vegetal em dietas para leitões em período de creche

Abstract

The research was developed in the Sector of Swine of the Department of Zootechnia of the Center of Agrarian Sciences of the Federal University of Ceará. The experiment had the duration of 42 days and it was accomplished with the objective of evaluating the zootechnic performance, the intestinal histomorfometry, the fecal microbiological profile, the diarrhea occurrence, the serical indicators of the nitrogen metabolism and the production cost of piglets submitted to diets containing different sources of animal and vegetable protein origin during the phases 1 (21-42 days of age)and 2 (42-63 days of age) in the nursery period. They participated in the assay, initially, 80 male piglets of commercial lineage weaned at 21 days of age and with medium weight of 5,49kg. The experiment followed randomized blocks, with 5 treatments, 4 repetitions and 4 animals per repetition in the 1st week, 3 animals per repetition in the 2nd week and 2 animals per repetition in the 3rd week (end of phase 1) and for the whole phase 2, being made the unfolding in a factorial 2 x 2 + 1, composed by two sources of animal protein (meat meal - MM and powdered sanguine plasma - PSP), two sources of vegetal protein (cotton meal - CM and cashew nut meal - CNM) and an additional one (diet control - T1). When the variance analysis detected significance among the treatments, contrasts were applied to test the effects of the factors. Besides, the comparison of averages for protein of animal origin (PAO) and protein of vegetal origin (PVO) with the diet control which was done through the Dunnet tests. The diets were isonutritives with crude protein (CP) of 22% and level of energy of 3.500 kcal DE/kg in the phase 1, being T1 - Diet control (DC) + 10% of skimmed powdered milk (SPM); T2 - DC + 5% PSP+ 15% CM; T3 - DC + 5% MM + 15% CM; T4 - DC + 5% PSP + 15% CNM and T5 - DC + 5% MM + 15% CNM. For the phase 2 the treatments contained 21% CP and 3.400 kcal DE/kg, being T1 - Diet control (DC) + 5% SPM; T2 - DC + 4% PSP+ 12% CM; T3 - DC + 4% MM + 12% CM; T4 - DC + 4% PSP + 12% CNM and T5 - DC + 4% MM + 12% CNM. It was concluded that the substitution of SPM for PSP or for MM, as sources of protein of animal origin, is viable with regard to the histomorfometric parameters in the first and second week of phase 1; counting of the fecal colonies (CFC) and plasmatic concentration of total proteins (PCTP), at the end of phases 1 and 2; and plasmatic concentration of urea (PCU), at the end of phase 2. Nevertheless, for the parameters of zootechnic performance, in both phases; and diarrhea occurrence, in the first week of phase 1, just PSP was shown viable. The inclusion of 15% of CM or 15% of CNM, in partial substitution by the soybean meal, as source of vegetal origin protein, is satisfactory in relation to the histomorfometric parameters in the first and second week of phase 1; CFC, PCTP and PCU, at the end of phases 1 and 2; besides the diarrhea occurrence, in the first week of phase 1. However for the zootechnic parameters only the CM was revealed viable in both phases. Significant interactions were not registered (P>0,05) among the factors (protein of animal origin - PAO x protein of vegetal origin - PVO) for the zootechnic performance parameters, in phases 1 and 2, to the CFC and PCTP, at the end of phases 1 e 2; besides PCU, at the end of the phase 2. Among the factors (week x experimental diet) significant interactions were not verified (P>0,05) for the histomorfometric parameters. Though for PCU, at the end of the phase 1, significant interactions were verified (P <0,05). In the phase 1, the diet control, and the diets containing MM, like PAO, and CNM, like PVO provided the largest number of microbial stumps in the feces of the piglets. In phase 2, the diets containing PSP, as PAO, and CM, like PVO the largest number of microbial stumps in the feces of the piglets was provided. The best economical answer for production of piglets in the nursery period was obtained with the diet containing PSP and CM (T2).