Effects Of Stocking Density On Broiler Performance In Different Diet Energy Level And Rearing System

This paper based on the other previous researches, carried out the effects of stocking density on AAbroilers growth performance, carcass quality, meat quality, poultry behaviors and animal welfare underdifferent diets ME and rearing systems.Experiment1The Effects of Stocking Density and Dietary Energy Level on GrowthPerformance and Meat Quality of Broilers This trial was to investigate the effects of Stockingdensity and dietary energy on the growth performance and meat quality of AA broilers, andinterrelationship between stocking density and nutrition requirements.1140broilers aged2weeks wererandomly assigned to12treatments with5replicates for each one by a3×4（ME×SD）completelyrandomized factorial design. Three dietary metabolic energy levels are:12.33MJ/Kg,12.75MJ/Kgand13.17MJ/Kg, respectively. Four stocking densities in trial were:10,16,22and28birds/1.5㎡,respectively. The results showed as follows:①Stocking density and dietary energy level did affect thegrowth performance. But there was no interaction between the two factors.②Broilers in highstocking densities group had significantly decreased ADFI（P<0.01）and lower ADG（P<0.01）.③Broilers in high dietary energy level group had significantly decreased FGR（P<0.01）, increased ADG（P<0.01）and final body weight（P<0.01）.④Carcass performance and meat quality of broilers wereslightly affected by stocking density and dietary energy level. However, energy affected composition offatty acid in meat of broilers.⑤Stocking density has not caused stress of broilers. In conclusion,stocking density and dietary energy level do influent the performance of broilers, and dietary energylevel has a significant affects on the quality of the meat. However, there are not interactions between thetwo effects. It is available for broilers stocked in slightly higher density under an appropriateenvironment.Experiment2Effects of rearing system and stocking density on grow performance, carcassquality, and welfare of male broiler This trial was conducted to investigate the effects of rearingsystem and stocking density on the grow performance, carcass quality, and animal welfare of malebroiler.2×2factors,4groups experiment design was applied, each group replicating6times. Factorsinclude2rearing types: net rearing and floor rearing, and2stocking density:8birds/㎡（low density）,and18birds/㎡（high density）. The feed intake, body weight gain, feed conversion efficiency, andmortality was collected. During week5to week6, the foot feeling temperature was detected, and thebehavior of broiler was shot by digital camera, then the chicken’s behaviors, including preening,spreading, running, standing, tussle, feeding, drinking and foraging, were calculated. On d42, the groupuniformity, feather quality, foot pad dermacity and hock burn was evaluated. The results showed that:1）During weeks3-6, LSD group took less feed than HSD group significantly（P<0.01），and the F/G Ratiowas marked lower than HSD group（P=0.019）, while the average weight gain was significantly higherthan HSD group（P<0.01）; Broilers took less feed and the FGR was lower than NR significantly while reared with floor-system, also the mean weight gain was notably lower than NR Group.2）SD and RShad slightly affects on the meat production rate, but SD influenced the absolutely meat yields, LSDgroup yielded more meat than HSD group.3）SD and NR did influence the behaviors of broilers. Therunning, standing, preening and foraging rate of LSD groups were higher than HSD groups significantly（P<0.05）, however, the feeding, drinking, tussle and spreading rate were lower notably than HSDgroups（P<0.05）; FR groups feeding and foraging rate were higher than NR groups, but running,preening and tussle were lower; NR-HSD groups has highest drinking and spreading rate, whileNR-LSD groups were lowest in it.4）NR groups got higher scores in feather and foot healthy than FRgroups; and LSD performance better than HSD. What’s more, the foot felt temperature and mortality ofLSD groups were lower when compared to HSD. It was similar with NR, while comparing to FR. AndNR groups were higher in uniformity than FR groups while LSD groups were higher than EHD groups.From this trial, LSD-NR groups performance better than HSD-FR groups in growth performance andanimal welfare. It was concluded that HSD constrained the growth performance and animal welfare ofbroilers, and NR system could intensify such effects.The results explained how the stocking density imposed its effects on the broiler growth, wellguiding the practical production.