Efficacy of a yeast derivative on broiler performance, intestinal morphology and blood profile.

摘要

The trial objective was to investigate the efficacy of a yeast derivative (YD) on performance, health status, distal jejunal structure, and blood profile of broiler chickens. In a 35 day feeding trial, 1 day-old broilers were allocated to 3 experimental groups with 8 replicates (26/pen): control, treatment 1 (1 kg YD/t feed) and treatment 2 (2 kg YD/t feed). Feed and water were provided ad libitum. On day 35 the distal jejunum was collected from 8 chickens per group (1/pen) for morphometric measurements. Blood samples were collected (1/pen) on day 35 and analyzed by flow cytometry for leukocyte, heterophil, lymphocyte and monocyte enumeration. In the course of the trial a positive influence was observed by supplementation of YD. On day 35 body weight (BW) (1520 g) and daily weight gain (42.37 g/day) were greater in birds receiving 1 kg/t of YD compared to the control (1374 g BW, 38.18 g/day, respectively; P=0.05). Supplementation with 2 kg/t of YD did not improve 35 day BW but did improve cumulative feed-to-gain ratio by 13% (P<0.05) versus birds fed the control diet. Histological evaluation demonstrated greater goblet cell density in birds fed either concentration of YD (P<0.05). Villus height and crypt depth, however, were unaffected. Apoptotic enterocytes were decreased by both concentrations of YD (P=0.02). Supplementation of YD had no effect on blood cell counts (P>0.05). The inclusion of YD in diets of broilers was able to improve broiler performance, intestinal goblet cell numbers and to reduce numbers of enterocytes undergoing apoptosis.