Performance of broilers fed diets containing natural growth promoters

The present study evaluated the effect of different probiotics on the performance of broiler chickens. A thousand and fifty one-day-old male Cobb chicks were distributed in a completely randomized design in a 3 x 2 + 1 factorial arrangement (3 probiotics sources in the diet, 2 probiotics concentrations in drinking water and 1 control group), with 5 repetitions of 30 birds per parcel. The results showed better feed conversion (p<0.01) (1-21, 22-35 and 1-45 days) and weight gain (p<0.05) (22-35 and 1-45 days) in the control group in relation to the groups receiving probiotics. The use of Bacillus subtilis in the diet improved (p<0.05) feed conversion during the growing phase, but this was not seen in the following period. Thus, it was concluded that probiotics supplementation had no beneficial effects on the performance

Effect of deboning time on the quality of broiler breast meat (Pectoralis major)

The present study evaluated the effect of different deboning times on the quality of broiler breast meat. Seventy-two broiler breasts were evaluated. They were distributed in a completely randomized experimental design, with six treatments, six repetitions and two birds per parcel. The treatments were denominated as follows: A - deboning immediately after chilling, B - deboning 1 h after chilling, C - deboning 2 h after chilling, D - deboning 3 h after chilling, E - deboning 4 h after chilling, and F - deboning 24 hours after chilling. Lowest pH values (p<0.05) were seen when deboning was performed 24 h after carcass chilling (pH=6.00) in comparison to deboning at 0 h (6.69) and 1 h (6.42) after chilling. R values were inversely proportional to pH values, i.e., R values were lower (p<0.05) in treatments A (1.05) and B (1.07) when compared to treatment F (1.44). No differences were seen in cooking loss during thermal treatment (broiling) of the muscle P. major. Higher shear forces (p<0.05) were seen in broiled muscles from carcasses with shorter storage times (A - 11.78 kgf and B - 10.75 kgf) before deboning, when compared to treatments E (6.11 kgf) and F (5.64 kgf). Higher L* values were observed in the treatment in which carcass deboning was performed 24 hours after chilling (49.26) in comparison to deboning immediately after chilling (44.68). Therefore, it was concluded that an interval of at least 4 hours is needed between chilling and deboning to obtain broiled breast fillets with tender texture. Furthermore, paler meat color (L* value) was produced with longer carcass storage before deboning

Effect of different probiotics on broiler carcass and meat quality

The present work evaluated the effect of different probiotics on carcass and meat quality of broilers. One thousand and fifty male Cobb chicks were distributed at one day of age in a randomized design with 3 x 2 + 1 factorial arrangement (3 probiotics, 2 levels of probiotics in drinking water and 1 negative control group), using 5 replications with 30 birds. Carcass yield was higher (p<0.05) in control birds. Nevertheless, the groups fed with probiotics showed higher (p<0.01) leg yield at 45 days of age. There was a significant decrease in color (lightness) and increase in pH of breast muscle 5 hours after slaughter in the probiotics treated birds. In the sensory analysis, meat flavor and general aspect 72 hours after slaughter were better when probiotics were added in both water and diet. There were no differences in water holding capacity, cooking loss and shearing force among different probiotics or between them and the control. Thus, meat quality was better when probiotics were fed in the water and diet instead of only in the diet. Nevertheless, carcass and meat quality showed no alteration when the control group was compared to birds fed with probiotics, except for leg yield improvement in the latter.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP