Norsvin, Department of Research, Storhamargata, NO-2317Hamar, Norway.
Department of Animal and Aquacultural Sciences, Norwegian University of Life Sciences, NO-1432 Ås, Norway.
J Anim Sci. 2023 Jan 3;101. doi: 10.1093/jas/skad227.
Improved nutrient digestibility is an important trait in genetic improvement in pigs due to global resource scarcity, increased human population and greenhouse gas emissions from pork production. Further, poor nutrient digestibility represents a direct nutrient loss, which affects the profit of the farmer. The aim of this study was to estimate genetic parameters for apparent total tract digestibility of nitrogen (ATTDn), crude fat (ATTDCfat), dry matter (ATTDdm), and organic matter (ATTDom) and to investigate their genetic relationship to other relevant production traits in pigs. Near-infrared spectroscopy was used for prediction of total nitrogen content and crude fat content in feces. The predicted content was used to estimate apparent total tract digestibility of the different nutrients by using an indicator method, where acid insoluble ash was used as an indigestible marker. Average ATTDdm, ATTDom, ATTDn, and ATTDCfat ranged from 61% to 75.3%. Moderate heritabilities was found for all digestibility traits and ranged from 0.15 to 0.22. The genetic correlations among the digestibility traits were high (>0.8), except for ATTDCfat, which had no significant genetic correlation to the other digestibility traits. Significant genetic correlations were found between ATTDn and feed consumption between 40 and 120 kg live weight (F40120) (-0.54 ± 0.11) and ATTDdm and F40120 (-0.35 ± 0.12) and ATTDom and F40120 (-0.28 ± 0.13). No significant genetic correlations were found between digestibility traits and loin depth at 100 kg, nor backfat thickness at 100 kg (BF), except between BF and ATTDn (-0.31 ± 0.14). These results suggested that selection for improved feed efficiency through reduced feed intake within a weight interval, also has led to improved ATTDdm, ATTDom, and ATTDn. Further, the digestibility traits are heritable, but mainly related to feed intake and general function of the intestines, as opposed to allocation of feed resources to different tissues in the body.
养分消化率的提高是猪遗传改良的一个重要特征，这是由于全球资源短缺、人口增加以及猪肉生产的温室气体排放。此外，较差的养分消化率代表了直接的养分损失，这会影响农民的利润。本研究旨在估计猪的氮表观全肠道消化率（ATTDn）、粗脂肪表观全肠道消化率（ATTDCfat）、干物质表观全肠道消化率（ATTDdm）和有机物表观全肠道消化率（ATTDom）的遗传参数，并研究它们与猪其他相关生产性状的遗传关系。近红外光谱法用于预测粪便中的总氮含量和粗脂肪含量。使用指示剂法，用酸不溶灰分作为不可消化的标记物，预测的含量用于估计不同养分的表观全肠道消化率。ATTDdm、ATTDom、ATTDn 和 ATTDCfat 的平均值范围为 61%至 75.3%。所有消化率性状均具有中度遗传力，范围为 0.15 至 0.22。消化率性状之间的遗传相关性很高（>0.8），除了 ATTDCfat 与其他消化率性状没有显著的遗传相关性。ATTDn 与 40 至 120 公斤活重之间的饲料采食量（F40120）（-0.54±0.11）和 ATTDdm 与 F40120（-0.35±0.12）和 ATTDom 与 F40120（-0.28±0.13）之间存在显著的遗传相关性。消化率性状与 100 公斤背膘厚（BF）之间没有显著的遗传相关性，但 BF 与 ATTDn 之间存在显著的遗传相关性（-0.31±0.14）。这些结果表明，通过在体重区间内减少饲料摄入量来选择提高饲料效率，也导致了 ATTDdm、ATTDom 和 ATTDn 的提高。此外，消化率性状是可遗传的，但主要与饲料摄入量和肠道的一般功能有关，而不是与饲料资源在体内不同组织中的分配有关。
