Effect of association of yeast (S. cerevisiae) with threonine in broilers feeding.

R.D. MIAZZO; M.F. PERALTA; A.J. NILSON; A.P. MAGNOLI,

Congreso; IV MEDITERRANEAN POULTRY; 2014

Yeast (Saccharomyces cerevisiae) alone, replacing part of premix or associated with E vitamin is known like their positive effects on productive performance and carcass quality. Threonine, increase the intestinal mucosae health, improving absorption capacities. The objective was to determinate the effect of Saccharomyces cerevisiae associated with threonine in diets, on productive, carcass quality and gut histomorphometric variables in broilers. Hundred Ross male broilers were used, from birth to 43 days old, distributed in 20 pens, 5 replicated/treatment with 5 chicks/replicated. The diets were: D1: commercial type covering the minimum requirements for threonine, D2: D1 plus 0.5% yeast, D3: D1 plus 30% more than minimum threonine requirement; D4: D3 plus 0.5% yeast. The production variables (Average Daily Weight Gain (ADWG) (g/bird/day), Average Daily Consumption (ADC) (g/bird/day), and Feed Conversion Ratio (FCR)), carcass quality (Carcass Performance (CP)(%), Breast Weight (BW)(g), Thigh Weight (TW)(g) and Abdominal Fat Weight (AFW)(g)) and gut histomorphometry (High Villi (HV,µ), Crypt Depth (CD, µ) and Villi Area (VA, µ2)) were evaluated. The production and carcass quality data were analyzed by ANOVA, while gut histomorphometric data were analyzed by nested design with two factors and LSD test. In all case p ≤ .05 were consider significant. Results: D4 group showed significantly better ADWG (70.97 ± 2.2 g) than D3 (67.74 ± 2.2 g); D4 broiler demonstrated significantly (p ≤ .05) better FCR (1.79 ± .04) than D2 and D3 chickens (1.92 ± .07, 1.88 ± .03), respectively. Also, D4 broilers deposited significantly (p ≤ .05) more BW (850.5 ± 64.6 g) that D3 chickens (750.5 ± 69.8 g) and significantly (p ≤ .05) less AFW (36.8 ± 10.7 g) that D1 broilers (48.3 ± 7.4 g). About gut histomorphometry, D4 group have significantly (p ≤ .05) high CD and VA (CD: 212.8 ± 33.09 µ; VA: 160300 ± 36399.66 µ2) than D1 chickens (CD: 139.22 ± 57.70 µ; VA: 118007.1 ± 40686.11 µ2). Also, the chickens receiving threonine (D3 and D4) had higher cell sparing and high number goblet cells producing mucus in the villus. It be concluded that the combination of Yeast and threonine improved in part, the productivity in broilers received them