Review: divergent selection for residual feed intake in the growing pig.
Review: divergent selection for residual feed intake in the growing pig.
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DOI：
10.1017/s175173111600286x
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发表时间：
2017-09
期刊：
影响因子：
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通讯作者：
Noblet J
中科院分区：
文献类型：
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作者：
Gilbert H;Billon Y;Brossard L;Faure J;Gatellier P;Gondret F;Labussière E;Lebret B;Lefaucheur L;Le Floch N;Louveau I;Merlot E;Meunier-Salaün MC;Montagne L;Mormede P;Renaudeau D;Riquet J;Rogel-Gaillard C;van Milgen J;Vincent A;Noblet J
本综述总结了 INRA（国家农业研究所）在九代选择过程中对生长大白猪的剩余采食量 (RFI) 进行发散选择实验的结果。它讨论了提高生长猪饲料效率的剩余挑战和前景。已经研究了在标准条件下和在热应激、炎症挑战或哺乳等替代条件下饲养的生长猪的影响。经过九代选择后，RFI 的不同选择导致 RFI 品系差异非常显着（P<0.001）（低 RFI (LRFI) 品系与高 RFI 品系相比为 -165 克/天）和日采食量（-270 克/天）。生长率（-12.8 克/天，P<0.05）和身体成分（+0.9 毫米背膘厚度，P=0.57；-2.64% 瘦肉含量，P<0.001）反应较低，而饲料转化率（-0.32 千克饲料/千克增重，P<0.001）反应显着。在 LRFI 猪中观察到最终 pH 值降低和肉亮度增加 (P<0.001)，对肉的感官质量影响较小。肉质的这些变化与肌肉能量代谢的变化有关。 LRFI猪的维持能量需求（五代选择后-10%）和活动（六代选择后站立时间-21%）的减少极大地促进了能源效率的提高。然而，RFI 选择对猪蛋白质代谢的影响仍不清楚。无论是饲喂传统日粮的猪还是饲喂高纤维日粮的猪，能量和营养素的消化率均不受选择的影响。通过选择吃纤维日粮的猪，可能会显着提高消化效率。目前还没有找到令人信服的遗传或血液生物标志物来解释 RFI 的差异，这表明猪有多种方法来实现饲料的有效利用。没有观察到选择对母猪繁殖性能的有害影响。资源分配理论指出，低 RFI 可能会减少专门用于应对压力的缓冲室，从而降低应对压力源的能力。所有关注猪对压力或挑战反应的实验都无法证实这一理论。了解 RFI 与对压力和能量需求过程（例如免疫和哺乳）的反应之间的关系，仍然是更好地理解该性状的潜在生物学机制并将实验结果与资源分配理论相一致的主要挑战。
This review summarizes the results from the INRA (Institut National de la Recherche Agronomique) divergent selection experiment on residual feed intake (RFI) in growing Large White pigs during nine generations of selection. It discusses the remaining challenges and perspectives for the improvement of feed efficiency in growing pigs. The impacts on growing pigs raised under standard conditions and in alternative situations such as heat stress, inflammatory challenges or lactation have been studied. After nine generations of selection, the divergent selection for RFI led to highly significant (P<0.001) line differences for RFI (−165 g/day in the low RFI (LRFI) line compared with high RFI line) and daily feed intake (−270 g/day). Low responses were observed on growth rate (−12.8 g/day, P<0.05) and body composition (+0.9 mm backfat thickness, P=0.57; −2.64% lean meat content, P<0.001) with a marked response on feed conversion ratio (−0.32 kg feed/kg gain, P<0.001). Reduced ultimate pH and increased lightness of the meat (P<0.001) were observed in LRFI pigs with minor impact on the sensory quality of the meat. These changes in meat quality were associated with changes of the muscular energy metabolism. Reduced maintenance energy requirements (−10% after five generations of selection) and activity (−21% of time standing after six generations of selection) of LRFI pigs greatly contributed to the gain in energy efficiency. However, the impact of selection for RFI on the protein metabolism of the pig remains unclear. Digestibility of energy and nutrients was not affected by selection, neither for pigs fed conventional diets nor for pigs fed high-fibre diets. A significant improvement of digestive efficiency could likely be achieved by selecting pigs on fibre diets. No convincing genetic or blood biomarker has been identified for explaining the differences in RFI, suggesting that pigs have various ways to achieve an efficient use of feed. No deleterious impact of the selection on the sow reproduction performance was observed. The resource allocation theory states that low RFI may reduce the ability to cope with stressors, via the reduction of a buffer compartment dedicated to responses to stress. None of the experiments focussed on the response of pigs to stress or challenges could confirm this theory. Understanding the relationships between RFI and responses to stress and energy demanding processes, as such immunity and lactation, remains a major challenge for a better understanding of the underlying biological mechanisms of the trait and to reconcile the experimental results with the resource allocation theory.