摘要
The objective of this study was to identify blood metabolites associated with variation primarily in residual feed intake (RFI) in two populations of beef steers at the University of Guelph and University of Alberta, Canada, representing the discovery and validation populations, respectively. Other productivity performance traits including average body weight (ABW), average feed intake (AFI), dry matter intake (DMI) and average daily gain (ADG) were also investigated. In the discovery population, blood plasma samples were obtained from 32 steers (16 high- and 16 low-RFI, from a population of 112 steers and maximizing the divergence between groups for RFI) at three periods 1, 2 and 3, corresponding to weeks 2, 6 and 10 respectively of the 140 d feeding and performance test. In the validation population, blood samples were obtained from 20 (10 high and 10 low RFI) steers from periods 1 and 2 corresponding to weeks 2 and 6 of a 90 d feeding test period. Metabolite concentrations in plasma were determined using nuclear magnetic resonance (NMR) and multiple regression analysis was performed in SAS 9.1. Creatine and glycine were associated (P<0.05) with RFI in period 1 accounting for 36.3% of the phenotypic variation in RFI. At period 2, threonine, carnitine, acetate, creatine, phenylalanine, lysine, citrate, betaine, glutamate and hippurate were significant (P<0.05) and accounted for 74.2% of the variation in RFI. At period 3, hydroxyisobutyrate, tyrosine and formate were significant (P<0.05) and accounted for 52.1% of the variation in RFI. In the validation population, three metabolites (creatine, carnitine and hippurate) were significant (P<0.05) in both discovery and validation populations and these three metabolites accounted for 32% of the phenotypic variation in RFI in the validation population. Some of the metabolites associated with RFI were also associated with other performance traits discussed in subsequent sections. Metabolic networks for RFI in each period were reconstructed using IPA and suggested that the biological processes associated with RFI were involved in energy and protein metabolism as well as metabolism of urea and methane. The analysis of metabolites and evaluation of biological processes create a better understanding of the metabolic processes that affect RFI. Upon further validation, these indicators may have potential to be utilized as biomarkers to enhance the selection of beef cattle.
摘要译文
F该研究的目的是确定与变化主要是在剩余的采食量（RFI）牛肉公牛的两个种群在圭尔夫大学和阿尔伯塔大学的大学相关血液代谢物，加拿大，代表发现和验证人群分别。其他生产率表现特征包括平均体重（ABW），平均采食量（AFI）干物质摄取量（DMI）和平均日增重（ADG）进行了研究。在发现人群中，血浆样本来自32公牛（16高，16得到的低RFI，从112阉人口，在三个阶段1,2和3最大化对于RFI）的组之间的差异，对应于周2，6和10分别与140ð馈送和性能测试。在验证群体，血液样本来自20（10高10低RFI）操纵获得从周期1和2对应于2周和6的90天喂养试验期。代谢物浓度在血浆用核磁共振（NMR）和在SAS 9.1进行多重回归分析来确定。肌酸和甘氨酸进行了相关（P05）与RFI期1占RFI的表型变异的36.3％。在期间2中，苏氨酸，肉碱，乙酸，肌酸，苯丙氨酸，赖氨酸，柠檬酸，甜菜碱，谷氨酸和马尿是显著（P05），并占RFI变异的52.1％。在验证群体，三种代谢物（肌酸，肉碱和马尿）是显著（P05）在这两个发现和验证的人口和这三个代谢物占的表型变异的RFI在验证人口的32％。与一些相关的射频干扰代谢物也与在后面的章节讨论的其他性能特性有关。RFI在每一个时期都用IPA重建，并建议与RFI相关的生物过程都参与能量和蛋白质代谢以及尿素和甲烷的代谢。代谢产物和生物过程的评价分析创造一个更好地了解影响RFI的代谢过程。经进一步确认，这些指标可具有潜力被用作生物标志物，以提高肉牛的选择。
B.K. Karisa[a]; J. Thomson[a][1]; Z. Wang[a]; C. Li[a][b]; Y.R. Montanholi[c]; S.P. Miller[c]; S.S. Moore[a][2]; G.S. Plastow[a]. Plasma metabolites associated with residual feed intake and other productivity performance traits in beef cattle[J]. Livestock Science, 2014,165: 200–211