【作者】 王志祥；

【导师】 计成；

【作者基本信息】 中国农业大学 ， 动物营养与饲料科学， 2005， 博士

【摘要】 选用0～8周龄健康纯种固始鸡公鸡、杂交固始鸡公鸡、艾维茵肉仔鸡公鸡、罗曼蛋雏鸡公鸡,通过饲养试验、代谢试验、屠宰试验,比较研究了固始鸡和杂交固始鸡与肉鸡和蛋雏鸡生长、营养物质沉积、养分表观代谢率、消化器官发育、消化酶活、血清生化指标、肉质性状方面的差异和相互关系,结果得出如下。 不同鸡品种间存在着显著的体重、饲料转化效率、体成分差异,初生时肉鸡体重分别是蛋鸡和固始鸡的1.12倍和1.46倍,到8周龄时变为3.17倍和4.08倍。0～8周龄肉鸡日均采食量为蛋鸡和固始鸡的2.85倍和3.48倍。快速生长的肉鸡随日龄逐渐表现出显著高于蛋鸡和固始鸡的粗脂肪含量和屠体能值。不同品种鸡代谢能沉积率和粗蛋白质沉积率都随着周龄直线下降,生长速度显著高的肉鸡高于蛋鸡和固始鸡。快速生长鸡表现出较高的蛋白质表观代谢率,慢速生长鸡表现山较高的粗脂肪表观代谢率和能量表观代谢率。与肉鸡相比,固始鸡具有较低的生长速度可能与其较低的粗蛋白质利用率和较高的能量消耗有关。 固始鸡和蛋鸡、肉鸡一样,消化器官重量具有随着体重同步变化的规律。从增长来看,肉鸡6周龄各消化器官重约为1日龄重的20倍以上,蛋鸡为15倍左右,而杂交固始鸡约为10倍左右。各段消化器官不同周龄重量体重比随日龄而下降,与体重呈负相关。固始鸡消化器官的发育规律与肉鸡更为接近。胰腺和食糜中淀粉酶活性具有品种特点,表现为肉鸡最高,蛋鸡最低,固始鸡和杂交同始鸡居中。不同鸡品种间蛋白质代谢率的差异与消化道胰蛋白酶活性高低相对应。食糜中脂肪酶活性与胰腺相一致,三种鸡4～6周龄饲料脂肪代谢率的提高与胰腺和食糜中脂肪酶活性的提高有关。 血清一些生化指标可以表达不同品种鸡的生长和代谢的差异,尿素氮、尿酸、总蛋白含量与鸡生长速度负对应,是反映不同遗传背景鸡生长和蛋白质代谢差异的敏感指标。血清AST,LDH与鸡体重呈相反趋势,ALP活性随鸡体重和生长速度提高而提高,三种酶活性是反映不同遗传背景鸡生长强弱的敏感指标。 肌肉中羟脯氨酸含量与肌肉嫩度负对应,SOD活性与肌肉品质正对应,是表达不同品种鸡肌肉品质的有意义指标。不同品种鸡随生长速度和日龄的提高,肌肉肌纤维直径增大。固始鸡由于较低的生长速度,表现出较细的肌纤维,具有较高的肌肉嫩度。同始鸡与肉鸡相比,具有较高蛋白质含量的趋势,胸肌中有相对较多、而腿肌中有相对较少的脂肪含量。同始鸡具有良好的肌肉系水性是其具有柔嫩多汁、肉质优于肉鸡的一个原因。 固始鸡在生长和代谢上与蛋鸡更为接近,固始鸡引入快大型鸡血缘后,提高了其生长速度、采食量和饲料转化效率,同时也提高了其肠道胰蛋白酶活性,提高了胸肌和腿肌肌纤维直径。更多还原

【Abstract】 The experiment compared the growth, nutrients deposition, nutrient apparent metabolic rate, digestive organs, digestive enzymes, serum biochemical values, meat quality indexes of male Gushi, Gushi hybrid, broiler and layer chicks during 0~8 weeks.The results showed that there were significance (p<0.01) for the live body weight, feed conversion efficiency and body composition among three strains. The born weight of broiler is 1.12 and 1.46 times of layer and Gushi chicks. The 8 week’s weight become 3.17 and 4.08 times. The average daily feed intake of 0~8 weeks was 2.83 and 3.48 times. The fat and energy contents of broiler were higher than that of Gushi and layers. The ME and crude protein efficiency decreased with age. The fast growth chicks showed higher apparent crude protein metabolic rate and lower crude fat and apparent energy metabolic rate. Comparing with the broilers, the reason for low growth rate of gushi chicks was possibly related with lower protein efficiency and higher energy waste.The weights of digestive organs increased with the body weight. The 6th week’s weights of broilers were above 20 times that of one day old. For layer chicks were 15 times and 10 times for Gushi hybrid chicks. The ratios of digestive organ weight to live body weight decreased as the chicks growing. The development of digestive organs for Gushi hybrid chicks was similar with broilers. The amylase activity in pancrea and duodenum chyme showed the character of the strain which the broiler was the highest and the layer was the lowest, the Gushi and Gushi hybrid were in between. The protein metabolic rate was relative to the trypsin activity in chyme. The increase from 4 to 6 week of fat metabolic rate was accordance with the change of lipase activity in pancreas and duodenum chyme.The contents of serum urea nitrogen, UA, total protein which were negative correlative with growth rate, were the sensitive indexes of difference for growth and protein metabolism between different strains of poultry. The activities of serum AST, LDH were negative correlative with live body weight. The activity of serum ALP increased with the increment of live body weight. They were also the sensitive indexes for the growth difference.The content of OH-proline was negative correlated with muscle tenderness and the activity of SOD was positive correlated with meat quality. Both of them are meaningful indexes for meat quality. The faster the growth rate was, the bigger for the muscle fiber diameter. The Gushi chicks presented the thinnest muscle fibers and it was the most tenderness muscle among three strains. The Gushi chicks showed higher muscle protein content, higher fat content in breast, lower fat content in thigh and better muscle water holding capacity than broilers.The character of growth and metabolism for Gushi chicks is similar to layer chicks. After led into new blood from fast growing strain, the Gushi chicks had a increase of growth rate, feed intake, feed conversion efficiency, trypsin activity and muscle fiber diameter.更多还原