GenPhySE, Université de Toulouse, INRAE, ENVT, 31326 Castanet Tolosan, France.
AVIPOLE, INRAE, 40280 Benquet, France.
Animal. 2024 Aug;18(8):101234. doi: 10.1016/j.animal.2024.101234. Epub 2024 Jul 2.
The mule duck accounts for over 90% of French foie gras production, a sector where feed represents two-thirds of production costs. This study focuses on analysing the feeding behaviours of the mule duck and its parental populations (Pekin and Muscovy) using automated feeders. To assess feed efficiency, feed conversion ratio and residual feed intake were analysed, along with six traits derived at the daily and meal levels. Genetic parameters were estimated separately in purebred populations, as well as with a joint crossbred model that estimated the parental contributions to the hybrid crossbred performances. In relation to higher feed intakes and much-reduced feeding times (P < 0.001), the feeding rate in the Pekin population was twice as high as in the Muscovy population (19 g/min vs 9 g/min), while the mule duck exhibited a large heterosis for this trait (29 g/min). Feeding traits exhibited moderate (0.38 ± 0.11) to high (0.65 ± 0.11) heritabilities. Similar correlation patterns were observed between feeding traits in the two parental populations. In the Pekin line, the feed conversion ratio did not significantly correlate with feeding traits except for daily feed intake. However, in the Muscovy population, it was negatively correlated with the number of meals (-0.51 ± 0.21) and positively with meal feed intake and meal duration (+0.79 ± 0.17 and + 0.71 ± 0.26, respectively). The contributions of the two parental species to the hybrid's performance differed, with the Pekin contributing more to feeding and meat traits compared to the Muscovy. They were similar only for liver weight. Additionally, unfavourable correlations between meat traits and liver traits were estimated in both pathways. Genetic relationships between feeding traits and slaughter traits varied by parental origin, suggesting different strategies for improving hybrid performance in the two parental species. However, in both pathways, genetic correlations between feed conversion ratio and meat traits (breast muscle and thigh weights) were favourable (<-0.42 ± 0.18), whereas they were unfavourable (>0.41 ± 0.20) for fatty liver weight. Altogether, improving liver traits and feed efficiency in the hybrid through selection in the parental populations could be enhanced by considering feeding traits recorded with electronic feeders, provided that adverse correlations are properly accounted for in a multitrait index.
骡鸭占法国鹅肝生产的 90%以上，在这个领域，饲料占生产成本的三分之二。本研究使用自动给料器重点分析了骡鸭及其亲本种群（北京鸭和麝香鸭）的采食行为。为了评估饲料效率，分析了饲料转化率和剩余饲料摄入量，以及在每日和每餐水平上得出的六个特征。分别在纯种群体中估计遗传参数，以及使用联合杂交模型估计亲本对杂种杂交性能的贡献。与较高的采食量和大大减少的采食时间（P<0.001）相关，北京鸭种群的采食率是麝香鸭种群的两倍（19 克/分钟与 9 克/分钟），而骡鸭在该性状上表现出很大的杂种优势（29 克/分钟）。采食性状表现出中度（0.38±0.11）到高度（0.65±0.11）的遗传力。在两个亲本种群中，采食性状表现出相似的相关模式。在京鸭系中，除了每日采食量外，饲料转化率与采食性状没有显著相关性。然而，在麝香鸭种群中，它与采食次数呈负相关（-0.51±0.21），与每餐采食量和采食时间呈正相关（+0.79±0.17 和+0.71±0.26）。两个亲本物种对杂种性能的贡献不同，与麝香鸭相比，北京鸭对采食和肉质性状的贡献更大。它们仅在肝重方面相似。此外，在这两种途径中，还估计了肉质性状和肝重之间的不利相关性。采食性状与屠宰性状之间的遗传关系因亲本来源而异，这表明在两个亲本物种中，通过选择提高杂种性能的策略不同。然而，在这两种途径中，饲料转化率与肉质性状（胸肌和大腿重量）之间的遗传相关性都是有利的（<-0.42±0.18），而对于脂肪肝重量则是不利的（>0.41±0.20）。总的来说，通过在亲本群体中选择来提高杂种的肝重和饲料效率，可以通过考虑使用电子给料器记录的采食性状来增强，前提是在多性状指数中正确考虑不利的相关性。
