Effects of Outdoor Access and Multi Enzyme Supplementation on Growth Performance and Meat Quality of Fast-Growing Chicken

Birds accessing outdoor are more comfortable, but the fiber in outdoor limits the digestion and absorption of nutrients and the growth of broilers. This experiment was conducted to investigate the effect outdoor access and enzyme supplementation on performance, blood indices, and carcass yield and meat quality.160 female 1day-old broiler chicks Ross 308 were divided in a completely randomized design with 4 treatments and 4 replications and 10 birds per each. Four experimental treatments include factorial arrangement (2*2) of rearing system (with or without access to outdoor) and enzyme consumption in the diet (with or without enzyme).The experimental period was lasted from 1 to 81 days of age and diets were prepared based low nutrient density. Access to the outdoor significantly decreased body weight and 1 to 81 days growth (P<0.05). In chicks with access to outdoor, enzyme consumption significantly increased body weight and 1 to 81 days growth (P<0.05).There was no significant difference in access to outdoor and enzyme consumption in carcass yield .The rearing with access to the outdoor and enzyme decreased triglyceride, cholesterol, LDL serum cholesterol, fat breast meat and increased protein of breast meat (P <0.05). The L component (bright) color of breast meat was affected by outdoor access and enzyme consumption and there was a significant difference between treatments (P<0/05).The results of this experiment showed that it is possible to reduce the growth rate and improve the meat quality of the rearing system with outdoor access resulted in poorer growth compared with a conventional system. Broilers with access to outdoor had more protein, less fat. Darker meat and lower pH which is suitable situation in organic poultry meat production.