[Objective]The paper was to compare the slaughter performance and meat flavor of quality chicken under cage rearing and free-range farming conditions.[Method]A total of 4001-day-old cocks,S07 line cultivated by Sichua...[Objective]The paper was to compare the slaughter performance and meat flavor of quality chicken under cage rearing and free-range farming conditions.[Method]A total of 4001-day-old cocks,S07 line cultivated by Sichuan Dahen Poultry Breeding Co.,Ltd.(bred for 4 succes-sive generations),were kept in cages until the end of 5 weeks of age,which were then divided into cage rearing and free-range farming groups.All cocks were fed with the same diet,and slaughter tests and meat quality analysis were carried out at the end of 10 and 22 weeks of age,respectively.[Result]The live weight,carcass weight and abdominal fat percentage in cage rearing group were significantly higher than those in free-range farming group(P<0.01),and the percentage of half-eviscerated yield and percentage of eviscerated yield in cage rearing group were significantly higher than those in free-range farming group(P<0.05),but there were no significant differences in dressing percentage,percentage of leg muscle and per-centage of breast muscle.The intramuscular fat(IMF)content and muscle fiber density of chicken in cage rearing group were significantly higher than those in free-range farming group(P<0.01),but there was no significant difference in inosinic acid(IMP)content.The content of IMF and IMF increased with the increase of feeding age,but the deposition rate of intramuscular fat was higher than that of IMF in late feeding period.[Conclusion]The study will provide reliable guidance for production and market consumption of high quality chicken.展开更多
文摘针对室内全球导航卫星系统(Global navigation satellite system,GNSS)信号受遮挡时,农用车辆协同定位精度低、稳定性差、信号丢包等问题,本文开展面向超宽带(Ultra-wideband,UWB)调频技术的室内外农用车辆协同定位算法研究。首先,搭建三基站多边测距定位模型,实现主基站绝对位置标定以及辅助基站绝对位置坐标的变换求解;其次,提出全质心加权最小二乘的高速双边双向(Weighted least squares high double sided two-way ranging,WLS-HDS-TWR)农机协同定位算法,基于泰勒级数展开的WLS估计算法,求解主车位置。同时,提出面向室内环境的多状态基站组合的UWB定位模块布设模式,并验证其可行性;通过飞行时间法(Time of flight,TOF)获取主从车距离信息,融合GNSS标定位置信息、主车坐标信息以及测距信息,实现主从车协同定位。最后,基于Prescan/Simulink搭建联合仿真平台,验证提出算法的可靠性;通过农用履带车辆开展室内及室外协同定位实车试验,试验结果表明:全质心WLS-HDS-TWR协同定位算法可有效解决室内GNSS信号缺失问题,室内环境下,定位精度较HDS-TWR及全质心LS-HDS-TWR算法分别提高26.98%和22.03%,满足智能农机协同定位作业需求。
基金Supported by National Chicken Industry Research System of China(CARS-41-G04)Key R&D Program of Sichuan Province(2021YFN0029,2021YFYZ0031)Special Project of Financial Operation of Sichuan Province(SASA2020CZYX007)。
文摘[Objective]The paper was to compare the slaughter performance and meat flavor of quality chicken under cage rearing and free-range farming conditions.[Method]A total of 4001-day-old cocks,S07 line cultivated by Sichuan Dahen Poultry Breeding Co.,Ltd.(bred for 4 succes-sive generations),were kept in cages until the end of 5 weeks of age,which were then divided into cage rearing and free-range farming groups.All cocks were fed with the same diet,and slaughter tests and meat quality analysis were carried out at the end of 10 and 22 weeks of age,respectively.[Result]The live weight,carcass weight and abdominal fat percentage in cage rearing group were significantly higher than those in free-range farming group(P<0.01),and the percentage of half-eviscerated yield and percentage of eviscerated yield in cage rearing group were significantly higher than those in free-range farming group(P<0.05),but there were no significant differences in dressing percentage,percentage of leg muscle and per-centage of breast muscle.The intramuscular fat(IMF)content and muscle fiber density of chicken in cage rearing group were significantly higher than those in free-range farming group(P<0.01),but there was no significant difference in inosinic acid(IMP)content.The content of IMF and IMF increased with the increase of feeding age,but the deposition rate of intramuscular fat was higher than that of IMF in late feeding period.[Conclusion]The study will provide reliable guidance for production and market consumption of high quality chicken.
