The interactive effects of dietary energy levels and genetic selection of intramuscular fat content on growth performance of Beijing-You chicken
The experiment was conducted to study the effects of different dietary metabolism energy (ME) levels on performance and carcass composition in Beijing-You chicken divergently selected for intramuscular fat. Two factors and eight treatments were designed in this experiment. Four ME levels ( 12. 122,12. 540, 12.958 and 13. 376 MJ·kg-2) ×2 strains (Up-selected and Down-selected lines,UL or DL) were included,480 male chickens with 5 replicates of 12 birds each. The birds were fed with the designed diets from 21 d to 91 d of age and with 70 days of trial period. The results showed that ADG,LW,CW,EW,BMW and TMW were elevated but FCR was re-duced significantly (P ＜ 0. 05) with dietary ME levels increased. Significant effect of IMF selection was observed on performance and carcass composition of experimental birds, ADFI and LW of UL were significantly higher than those of DL (P ＜ 0. 05). IMF selection and dietary ME levels showed significant interaction on BMW,TMW, BMR and TMR. The IMF content of breast and thigh muscle reached their peaks at ME3, but the AFW and AFR were constantly in proportion to dietary ME concentrations. The birds of DL exhibited lower IMF, AFW and AFR than those of UL, with the reverse for TC (P ＜ 0. 05). In addition, the marked interactive influence of dietary ME levels and IMF selection on AFW, AFR and TC was also observed ( P ＜ 0. 05). Increasing dietary ME levels could improve growth performance of Beijing-You chicken. However, genetic results of IMF selection couldn't be modified by changing the dietary energy level. Moreover, the availability of genetic selection on IMF contents in chickens was identified.
dietary energy levelsIMF divergent linesgrowth performanceBeijing-You chickens
国家科技期刊平台
NSTL
万方数据
维普
