Effects Of Welfare Rearing Techniques On The Performance And Welfare Of Broilers

Animal welfare appeals to people more and more in recent years. Natural behavior and activities of chicken are seriously restrictred in the current model of intensive rearing condition, followed by increasing incidence of foot pad dermatitis and hock burns. Ammonia is the most harmful gas in broiler house, which causes respiratory diseases and ascites of broiler. Two kind welfare rearing technologies are designed to solve these problems:1. perch is placed in broiler house to enrich the monotonous environment and increase the movement of broiler. 2. Urease inhibitor is added to the feed to reduce ammonia concentration.The first experiment:birds were grouped in styles of 3 (stocking density)×2 (perch) absolutely random. Three different stocking densities are 12, 16, and 20 birds/m~2. Perch group is adding perch and wood barrier in Environment. 1152 of 0-day healthy birds were selected and distributed to 6 treatments with 3 replicates. The results are as follows: density and perch had no significant effect on feed intake, body weight gain, feed conversion ratio and mortality. Rate of Roosting behavior was significantly high when birds were raised at stocking densities of 12, 16 birds/m~2. There were more birds roosting on the wood barrier than those on the perch in from to 4 weeks of age, but in 5 to 6 weeks the number of birds on the perch is more than that on the wood barrier. In higher density, rate of walking behavior lowered and rate of lying behavior heightened. Evironmental enrichment materials brought about that rate of feeding behavior increased in first , scend, forth, fifth weeks, and rate of drinking behavior reduced in 1 to 5 weeks, but walking behaviorand lying behavior reduced ( P<0.05). Foot pad dermatitis,hock burns and feather damage were more serious in higher density, but evironmental enrichment materials could significantly reduce the three injuries. Density and perch had no significant effect on broiler slaughter performance, meat quality and blood parameters. The second experiment: 432 healthy 14-day birds were allocated into three groups with different treatments, which were cold-water perche group (perches access within the cycle of cold-water around 20℃, normal perch group (water), control group with no perch, with 4 replicates per treatment. The results showed that: feed intake and feed conversion ratio didn't change significantly in three treatments, but body weight gain of cold-water perch group was higher than other two groups(P<0.0001). Rate of Roosting behavior of birds in cold-water perch group was much higher than those in normal perch group (P <0.0001), and rate of heavy breath of birds in cold-water perch group was much lower than those in normal perch group(P<0.0001). Compared with the control group and the normal perch,cold-water perch could improve foot pad dermatitis, hock burns and feather damage significantly(P<0.05), increase the rate of thigh meat and breast(P<0.05), and reduce the cooked loss of breast and thigh meat(P<0.05).The third experiment: birds were grouped in styles of 3 (stocking density)×2 (cold-water perch) absolutely random. Three different stocking densities are 12, 16, and 20 birds/m2, 1152 of 0-days old healthy birds were selected and distributed to 6 groups with different treatments with 3 replicates. The results are as follows: density had no significant effect on broiler performance (P> 0.05). Compared with control group, feed intake and but body weight gain increased significantly, with feed conversion ratio and mortality decreasing significantly. Rate of feeding behavior, drinking behavior and roosting and touching cold-water perch were higher in lower density. Cold-water perch reduced rate of feeding behavior and drinking behavior. The higher density could increase rate of behavior of heavy breath, but cold-water perch could significantly reduce the rate of behavior of breathing heavily and broiler body temperature (P <0.05). Foot pad dermatitis,hock burns and feather damage were more serious in higher density, cold-water perch could significantly reduce the three diseases. Density and cold-water perch had no significant effect on broiler slaughter performance, meat quality and blood parameters.The fourth experiment: Add urease inhibitor AHA and NBPT in chicken droppings with ratio of 300mg/kg. The result showed that: compared with control group, the amount of ammonia release of droppings in AHA-treatment group reduced by 45.03%, with NBPT treatment by 57.81%.The fifth experiment: broilers were fed a diet supplemented with urease inhibitor AHA and NBPT, which was coated with polyacrylic resinⅢ. The result showed that: urease inhibitor AHA and NBPT supplementation could inhibit urease activity in droppings (P<0.05). The total protein of AHA-treatment group didn't change significantly. But NBPT-treatment increased total protein (P=0.0996). Compared with control group, there was no significant difference in UA and BUN under AHA-treatment and NBPT-treatment. Moreover, AHA and NBPT could reduce amount of ammonia emission by 56.70% and 52.90%.