摘要
Wood, K. M., Montanholi, Y. R., Fitzsimmons, C. F., Miller, S. P., McBride, B. W. and Swanson, K. C. 2014. Characterization and evaluation of residual feed intake measured in mid- to late-gestation mature beef cows and relationships with circulating serum metabolites and linear body measurements. Can. J. Anim. Sci. 94: 499–508. To evaluate the use of residual feed intake (RFI) models measured in mid-to-late gestating beef cows, a dataset was used combining data from five experiments containing nine treatment and/or replicate groups for a total of 321 animal records. Investigations of RFI models included the effects of age, ultrasound measures of body composition, pregnancy corrected gain, and dietary treatment group. A subset of animals had serum analyzed for circulating metabolites (glucose, non-esterified fatty acids, urea, beta-hydroxybutyrate; n=227) and/or linear body measures (hip height and width, body length, body circumference at the heart, mid-body and at flank; n=114) for correlation analysis with efficiency traits. Goodness-of-fit for all RFI models was assessed using R 2, CV, and Bayesian information criteria. Across treatment/replicate groups, the largest improvements in model fit were made by accounting for management group and dietary treatment. Circulating urea concentrations were positively correlated (P ≤0.05) with average daily gain, dry matter intake, gain:feed, and group RFI model. Linear body measures and circulating metabolites measured (with the exception of urea) were not correlated (P>0.05) with economically relevant traits. Measures of RFI as an indication of feed efficiency may be challenging for use in gestating beef cows. Large variation in efficiency between cows remain, and may be related to mechanisms influencing maintenance and energy expenditures.
摘要译文
Wood,KM,Montanholi,YR,Fitzsimmons,CF,Miller,SP,McBride,BW和Swanson,KC 2014.在妊娠中后期成熟牛肉中测量残留采食量的特征和评估以及与循环血清代谢物和线性体测量。能够。 J. Anim。科学。 94:499-508。为了评估在中晚期妊娠奶牛中测量的残余采食量(RFI)模型的使用,使用数据集结合来自包含9个处理和/或重复组的5个实验的数据,总共321个动物记录。 RFI模型的调查包括年龄,超声测量身体成分,妊娠纠正增益和饮食治疗组的影响。动物的一个子集用血清分析循环代谢物(葡萄糖,非酯化脂肪酸,尿素,β-羟基丁酸; n = 227)和/或线性身体测量(臀部高度和宽度,体长,心脏,身体中部和侧腹的体周; n = 114)用于与效率特征的相关性分析。使用R 2 sup>,CV和贝叶斯信息标准评估所有RFI模型的拟合优度。在治疗/复制组中,通过考虑管理组和饮食治疗,模型拟合的最大改进。循环尿素浓度与平均日增重,干物质摄入,增益:饲料和组RFI模型呈正相关(P≤0.05)。测量的线性体测量和循环代谢物(尿素除外)与经济相关性状无相关性(P> 0.05)。作为饲料效率指标的RFI测量对于在怀孕的牛奶中使用可能是具有挑战性的。奶牛之间的效率差异很大,可能与影响维护和能源支出的机制有关。
K. M. Wood;[1] Y. R. Montanholi;[2] C. F. Fitzsimmons;[3][4] S. P. Miller;[1] B. W. McBride;[1] K. C. Swanson[5]. Characterization and evaluation of residual feed intake measured in mid- to late-gestation mature beef cows and relationships with circulating serum metabolites and linear body measurements[J]. Canadian Journal of Animal Science, 2014,94(3): 499-508