Relação energia:proteína para suínos Piau de 15 a 30 kg de peso corporal criados em sistema alternativo no semiárido pernambucano

Abstract

In the swine production, the improvement of the nutritional management has been working, since the feeding is still the factor of greater impact in the total cost of the production, motivating continuous research in order to determine the best efficiency in the energy: protein ratio, joining gains biological to economic gains, with energy being the limiting factor that determines the voluntary consumption of feed by the animal, and therefore it is necessary to balance the feed according to the nutritional requirements in relation to the energy content. Given the above, the objective was to determine the best energy: protein ratio in diets for Piau male pigs from 15 to 30 kg body weight, reared in an open-air alternative system in Pernambuco Semi-arid. The experiment was carried out in the UFRPE/UAST Swine Sector, using 20 Piau male castrated piglets, with initial weight of 15 + 1.5 kg of body weight. The experimental design was completely randomized with five levels of metabolizable energy (3,230, 3,080, 2,930, 2,780 and 2,630 kcal kg-1 diet) and four replications, each animal being an experimental unit. Feed and water were freely supplied and the diets used for evaluation were formulated based on corn, wheat bran and soybean meal to meet the nutritional requirements of the animals' development (rearing phase). The animals were weighed and housed and in an experimental shed with 3.0 x 2.0 m (6 m2) stalls arranged in an east-west direction, with open sides and 0.8 m high walls, ceiling height of 2.5 m. m, fitted with a ceramic floor covering with compact floor, containing a semi-automatic feeder and pacifier drinker at a height of 40 cm from the floor in each stall. The management adopted was the one traditionally practiced in the national technified pig farming. The pigs were weighed weekly together with the rations and feed leftovers, to evaluate the performance parameters: daily weight gain, daily feed intake and feed conversion. Performance parameters were analyzed using statistical analysis of variance and F and Tukey tests with significance level at 5% probability, using R-Project version 3.5.3 for Windows software. No significant effect (P>0.05) on piglets performance was observed with the reduction of metabolizable energy levels in the diet on daily weight gain, daily feed intake and feed conversion. It was concluded that the energy reduction in the Piau castrated male swine feed at minimum levels (2,630 kcal kg -1 feed) did not affect the performance of the animals, suggesting that the energy: protein ratio of 151.59, aiming at the reduction of production costs combined with the improvement of zootechnical performance.