摘要
Correlated responses on carcass and meat quality characteristics after 3 generations of divergent selection for intramuscular fat (IMF) content were assessed by comparing the high and low lines. Selection was based on the phenotypic value of IMF content of LM, measured in 2 full sibs of the first parity. Traits measured were: BW, HCW, commercial carcass weight (CCW), reference carcass weight (RCW), scapular (SF) and perirenal fat (PF) content, meat-to-bone ratio (M:B) of the hind leg, pH of LM, color (lightness, L*; redness, a*; and yellowness, b*) of the carcass and of a LM section, protein content, and fatty acid (FA) composition of LM. A total of 174 records was used to estimate the correlated selection response. Data were analyzed using Bayesian methodology. We considered one-third of the phenotypic SD of a trait as a relevant value for the difference between lines. Then, the probability of the difference being greater than a relevant value (PR) was calculated. A low PR implies that the lines compared are similar. Carcass weights (PR between 0.24 and 0.31) and M:B of the hind leg (PR = 0.15) were not modified by selection for IMF content. There was a slight negative correlated response for BW, although evidence of its relevance was low (PR = 0.48). Scapular fat content was similar between lines (PR = 0.03). There were differences for PF content, although there was low evidence for showing its relevance (PR = 0.47). Color traits of the carcass were not affected by selection (PR between 0.04 and 0.30). In muscle, L* was also similar between lines (PR = 0.26). There were differences for a* and b*, although there was little evidence of their relevance (PR = 0.35 and 0.40, respectively). There was a positive correlated response on muscle pH and differences could be relevant (PR = 0.77). Protein content of LM was similar between lines (PR = 0.13), whereas FA composition was affected by selection. There were relevant differences between lines for MUFA (PR = 0.99), n-3 (PR = 0.95), and n-6 (PR = 0.98) percentages. For individual FA, differences were relevant for C18:1n-9 (PR = 0.97) and C20:5 n-3 (PR = 0.98). In conclusion, selection for IMF content may modify carcass quality by increasing PF content. Moreover, it led to some modifications in pH and FA composition of LM.
摘要译文
通过比较高线和低线，评估了经过3代不同选择的肌内脂肪（IMF）含量后对胴体和肉质量特征的相关反应。选择基于LM的IMF含量的表型值，以第一胎次的2个完整同胞进行测量。测量的性状为：BW，HCW，商业胴体重量（CCW），（RCW），肩胛骨（SF）和肾周脂肪（PF）含量，后肢肉骨比（M：B），LM的pH值，颜色（亮度，L *;发红，a * ;和黄色，b *）的胎体和LM部分，蛋白质含量和LM的脂肪酸（FA）组成。共有174个记录被用来估计相关的选择响应。使用贝叶斯方法分析数据。我们认为性状的表型SD的三分之一作为线之间差异的相关值。然后，计算差值大于相关值（P R）的概率。低P R意味着比较的线是相似的。胴体重量（P R在0.24和0之间。31）和后腿的M：B（P R \x3d 0.15）没有通过选择IMF含量来修改。体重指数有轻微的负相关，但其相关性的证据很低（P \x3d 0。48）。线条之间的肩胛脂肪含量相似（P R \x3d 0.03）。 PF含量有差异，尽管证据不足表明其相关性（P R \x3d 0.47）。胴体的颜色特征不受选择的影响（P R在0.04和0.30之间）。在肌肉中，线之间的L *也相似（P R \x3d 0.26）。 a *和b *有差异，尽管几乎没有证据显示它们的相关性（P R分别为0.35和0.40）。肌肉pH值呈正相关，且差异可能相关（P R \x3d 0.77）。LM之间的蛋白质含量在品系间相似（P R \x3d 0.13），而FA组合物受选择影响。 MUFA（P R \x3d 0.99），n-3（P R \x3d 0。95）和n-6（P R \x3d 0.98）百分比。对于单个FA，差异与C18：1n-9（P R \x3d 0.97）和C20：5 n-3（P R \x3d 0.98）相关。结论是，IMF内容的选择可能会通过增加PF含量来改变屠体质量。此外，它导致LM的pH和FA组成的一些改变。
C. Zomeño;A. Blasco;P. Hernández. Divergent selection for intramuscular fat content in rabbits. II. Correlated responses on carcass and meat quality traits[J]. Journal of Animal Science, 2013,91(9): 4532–4539