Lee J H, Oh S-H, Lee Y M, Kim Y S, Son H J, Jeong D J, Whitley N C, Kim J J
Department of Animal Sciences, North Carolina A&T State University, Greensboro, NC 27411, USA .
School of Biotechnology, Yeungnam University, Gyeongsan 712-749, Korea .
Asian-Australas J Anim Sci. 2014 Sep;27(9):1250-3. doi: 10.5713/ajas.2013.13797.
The objective of this study was to estimate the parameters of Gompertz growth curves with the measurements of body conformation, real-time ultrasound longissimus dorsi muscle area (LMA) and backfat thickness (BFT) in Hanwoo cows. The Hanwoo cows (n = 3,373) were born in 97 Hanwoo commercial farms in the 17 cities or counties of Gyeongbuk province, Korea, between 2000 and 2007. A total of 5,504 ultrasound measurements were collected for the cows at the age of 13 to 165 months in 2007 and 2008. Wither height (HW), rump height (HR), the horizontal distance between the top of the hips (WH), and girth of chest (GC) were also measured. Analysis of variance was conducted to investigate variables affecting LMA and BFT. The effect of farm nested in location was included in the statistical model, as well as the effects of HW, HR, WH, and GC as covariates. All of the effects were significant in the analysis of variance for LMA and BFT (p<0.01), except for the HR effect for LMA. The two ultrasound measures and the four body conformation traits were fitted to a Gompertz growth curve function to estimate parameters. Upper asymptotic weights were estimated as 54.0 cm(2), 7.67 mm, 125.6 cm, 126.4 cm, 29.3 cm, and 184.1 cm, for LMA, BFT, HW, HR, WH, and GC, respectively. Results of ultrasound measurements showed that Hanwoo cows had smaller LMA and greater BFT than other western cattle breeds, suggesting that care must be taken to select for thick BFT rather than an increase of only beef yield. More ultrasound records per cow are needed to get accurate estimates of growth curve, which, thus, helps producers select animals with high accuracy.
本研究的目的是利用韩牛母牛的体况测量值、实时超声背最长肌面积（LMA）和背膘厚度（BFT）来估计冈珀茨生长曲线的参数。这些韩牛母牛（n = 3373头）于2000年至2007年出生在韩国庆尚北道17个市或县的97个韩牛商业农场。2007年和2008年，共收集了这些母牛在13至165月龄时的5504次超声测量数据。同时还测量了鬐甲高度（HW）、臀高（HR）、髋部顶端之间的水平距离（WH）和胸围（GC）。进行方差分析以研究影响LMA和BFT的变量。统计模型中纳入了嵌套在地理位置中的农场效应，以及HW、HR、WH和GC作为协变量的效应。在LMA和BFT的方差分析中，除LMA的HR效应外，所有效应均显著（p<0.01）。将两项超声测量值和四项体况性状拟合到冈珀茨生长曲线函数中以估计参数。LMA、BFT、HW、HR、WH和GC的上渐近权重分别估计为54.0平方厘米、7.67毫米、125.6厘米、126.4厘米、29.3厘米和184.1厘米。超声测量结果表明，韩牛母牛的LMA比其他西方牛品种小，BFT比其他西方牛品种大，这表明在选择时必须注意选择背膘厚的牛，而不仅仅是提高牛肉产量。每头母牛需要更多的超声记录才能准确估计生长曲线，从而帮助生产者更准确地选择动物。
