Phytate-phosphorus and phytase on performance, bone characteristics, tissue and serum mineral concentration on broilers.

Male broiler chickens (384), Cobb 500, were housed in metabolic cages to assess the efficacy of phytase in diets with low and high phytate-phosphorus on the performance, bone physical characteristics, tissue and serum mineral deposits. Birds were distributed in four treatments with a 2 x 2 factorial arrangement in a completely randomized block design. Experimental diets based on maize-soybean meal were T1 - diet low phytate-phosphorus; T2 - diet low phytate-phosphorus and phytase (500 FTU/kg); T3 - diet high phytate-phosphorus; T4 - diet high phytate-phosphorus and phytase (500 FTU/kg). Feed intake, body weight, weight gain and feed conversion ratio were assessed. Two left tibias per experimental unit were analyzed for physical characteristics and mineral concentration; a section of skinless breast muscle and blood were collected to measure the concentration of calcium, phosphorus and sodium. Results showed interaction between bone stiffness and serum calcium. The inclusion of phytase in diets with low and high phytate-phosphorus did not alter performance, bone resistance and flexibility, mineral deposits in the tibia and breast muscle, but increased bone stiffness after 22 days of age. It also provided a higher serum calcium rate in broilers fed diets with low phytate-phosphorus up to 32 days of age.

Cut yield and meat quality of brown eggshell laying hens housed in an alternative system and submitted to different feeding volumes.

The aim was to evaluate the effect of different feeding volumes on the cut yield and meat quality of brown eggshell laying hens strain Embrapa 051 (E051) during the laying cycle, reared in an alternative system and slaughtered at 73 weeks, with reference to the lineage Lohmann Brown (LB). 600 hens E051 and 200 hens LB were used in an entirely randomized experimental design totalizing 5 replicates with 40 birds each. The treatments were: Control (LB fed with 100% of their dietary requirements), E051 fed with 93% of the control diet, E051 fed with 100% of the control diet, and E051 fed with 107% of the control diet. Birds were supplemented daily with 30g of ground grasses. Different feeding volumes did not alter the physicochemical quality of the meat and the cut yield. Body and cold carcass weight were greater in the E051 fed with 107% of the reference feed compared to the LB or the E051 fed with 7% less than the control diet. Yellow color intensity was greater in the E051 than in LB. The results demonstrated that, at the end of their productive cycle, the E051 without a restricted diet presents good carcass characteristics and potential for industrialized development.