National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China 100193.
Beijing Jinxing Golden Star Duck Center, Beijing, China 100076.
Poult Sci. 2018 Jul 1;97(7):2365-2371. doi: 10.3382/ps/pey079.
The purpose of this study was to evaluate the correlation between live body measurements and several fat traits in Pekin ducks, and ultimately to formulate multiple regression equations for the in vivo estimation of the carcass fatness of Pekin ducks. Several traits were measured in a total of 208 Pekin ducks aged 6 wk (107 males and 101 females). All ducks were weighed and measured for a set of body measurements including live body weight, body slope length, breast muscle thickness, skin fat thickness, chest width, keel length, and neck length. The breast muscle thickness and skin fat thickness was measured using B-scan sonography. Carcass information, including eviscerated weight, subcutaneous fat with skin weight, and abdominal fat weight, was collected after slaughter. Our results revealed that sex effects on most traits were significant (P < 0.05), and that the weight of subcutaneous fat with skin was significantly correlated with live body weight (r = 0.57 to 0.71, P < 0.01). Four additional traits of males were closely correlated with the weight of subcutaneous fat with skin, namely breast muscle thickness (r = 0.20, P < 0.01), skin fat thickness (r = 0.43, P < 0.01), chest width (r = 0.24, P < 0.01), and neck length (r = 0.20, P < 0.05). The abdominal fat weight, percentage of fat, and percentage of subcutaneous fat with skin of ducks were significantly correlated with live body weight (r = 0.38 to 0.43, P < 0.01), and skin fat thickness (r = 0.38 to 0.49, P < 0.01). These traits provided the basis for constructing regression equations to predict weight (or percentage) of subcutaneous fat and abdominal fat with high values of coefficients of multiple correlation (R) between the dependent variable and the independent variables. Two equations were verified to be applicable in other duck groups, with high accuracy, as more than 80% of estimated values were within the margin of error (<10%), compared with the actual values.
本研究旨在评估活体测量与北京鸭几种脂肪性状之间的相关性，最终为北京鸭胴体脂肪活体估计制定多元回归方程。共测量了 208 只 6 周龄（雄性 107 只，雌性 101 只）北京鸭的多个性状。所有鸭子称重并测量了一组体尺，包括活体体重、体斜长、胸肌厚、皮脂厚、胸宽、龙骨长和颈长。胸肌厚和皮脂厚采用 B 型超声进行测量。屠宰后收集屠体信息，包括去内脏重、带皮皮下脂肪重和腹脂重。结果表明，多数性状的性别效应显著（P < 0.05），带皮皮下脂肪重与活体体重显著相关（r = 0.57 至 0.71，P < 0.01）。雄性的另外 4 个性状与带皮皮下脂肪重密切相关，分别是胸肌厚（r = 0.20，P < 0.01）、皮脂厚（r = 0.43，P < 0.01）、胸宽（r = 0.24，P < 0.01）和颈长（r = 0.20，P < 0.05）。鸭的腹脂重、脂肪率和皮脂率与活体体重（r = 0.38 至 0.43，P < 0.01）和皮脂厚（r = 0.38 至 0.49，P < 0.01）显著相关。这些性状为构建回归方程预测皮下脂肪和腹脂重（或百分比）提供了基础，因因变量与自变量之间的复相关系数（R）值较高，具有较高的预测价值。验证了两个方程在其他鸭群中的适用性，估计值的准确率超过 80%，在误差范围（<10%）内，与实际值相差不到 10%。
