摘要
A divergent selection experiment on intramuscular fat (IMF) was performed in rabbits. The aim of this study is to estimate the response to selection, the correlated responses in carcass and meat quality traits, and their genetic parameters. Selection criterion was the averaged phenotypic value of IMF measured at 9 wk of age in 2 full-sibs of the candidate. Traits considered were IMF, BW, chilled carcass weight, reference carcass weight, scapular and perirenal fat weights, carcass and meat color, pH, protein and fatty acid composition of meat. Total direct response to selection for IMF was 2.6 phenotypic SD of the trait, around 5% of the mean (1.09 g/100 g) per generation, with both lines following a symmetrical trend. Heritability of IMF was high (0.54), and in general, all traits related to carcass fat depots and IMF fatty acid composition showed high heritabilities (dissectible fat of the carcass, 0.70; MUFA percentage, 0.61; PUFA percentage, 0.45; and PUFA:SFA ratio, 0.42), except SFA percentage (0.09). The other carcass and meat quality traits showed moderate to low heritabilities. Intramuscular fat and dissectible fat percentage showed a low genetic correlation (0.34). Intramuscular fat was positively correlated with MUFA percentage (0.95) and negatively correlated with PUFA percentage (−0.89) and PUFA:SFA ratio (−0.98), corroborated with high correlated responses to selection. The rest of the traits did not show any substantial correlated response except protein content, which was greater in the high-IMF line than in the low-IMF line.
摘要译文
在兔子中进行肌肉内脂肪（IMF）的选择性实验。这项研究的目的是估计对选择的反应，胴体和肉质性状的相关反应及其遗传参数。选择标准是在9周龄时在候选者的2个全同胞中测量的IMF的平均表型值。考虑的特性是IMF，体重，冷冻胴体重量，参考胴体重量，肩胛骨和肾周脂肪重量，胴体和肉色，肉，蛋白质和脂肪酸组成。对IMF的选择的总直接响应是该性状的2.6表型SD，约为每代平均值（1.09 g / 100 g）的5％，两条线均呈对称趋势。 IMF的遗传率很高（0.54），总的来说，与胴体脂肪库和IMF脂肪酸组成相关的所有性状均表现出较高的遗传率（胴体的可分解脂肪，0.70; MUFA百分比，0.61; PUFA百分比，0.45;和PUFA：SFA比率为0.42），但SFA百分比（0.09）除外。其他胴体和肉质特征显示中度至低度遗传力。肌内脂肪和可溶性脂肪百分比显示低的遗传相关性（0.34）。肌内脂肪与MUFA百分比呈正相关（0。95）与PUFA百分比（-0.89）和PUFA：SFA比率（-0.98）呈负相关，证实了对选择的高相关反应。除蛋白质含量外，其余特征没有显示出任何实质相关的响应，高蛋白质含量的蛋白质含量高于低蛋白质含量的蛋白质含量。
M. Martínez-álvaro;P. Hernández;A. Blasco. Divergent selection on intramuscular fat in rabbits: Responses to selection and genetic parameters[J]. Journal of Animal Science, 2016,94(12): 4993–5003