Miller David W, Bennett Ellen J, Harrison Joanne L, Anderson Fiona, Adam Clare L
1School of Veterinary and Life Sciences, Murdoch University, 90 South St, Murdoch, WA 6150 Australia.
2Scotland's Rural College (SRUC), Peter Wilson Building, Kings Buildings, West Mains Road, Edinburgh, EH9 3JG UK.
J Anim Sci Biotechnol. 2018 Nov 12;9:80. doi: 10.1186/s40104-018-0295-4. eCollection 2018.
There is considerable interest in implementing mobile scanning technology for on-farm body composition analysis on live animals. These experiments evaluated the use of dual energy X-ray absorptiometry (DXA) as an accurate method of total body fat measurement in live sheep.
In Exp. 1, visceral and whole body fat analysis was undertaken in sheep with body condition scores (BCS) in the range 2 to 3.25 (scale 1: thin to 5: fat). The relationship of BCS was moderately correlated with visceral fat depot mass ( = 0.59, < 0.01, = 24) and whole body fat ( = 0.70, < 0.001, = 24). In Exp. 2, sheep with BCS in the range 2.25 to 3.75 were blood sampled to analyse circulating leptin concentrations, and were DXA scanned immediately post mortem for total body fat. Plasma leptin concentrations had low correlations with BCS ( = 0.50, < 0.05, = 17) and DXA body fat ( = 0.42, < 0.05, = 17), and no correlation with chemical body fat ( = 0.17, > 0.05, = 9). There was a moderate correlation between DXA body fat and BCS ( = 0.70, < 0.01, = 17), and DXA body fat was highly correlated with chemical body fat ( = 0.81, < 0.001, = 9). In Exp. 3, a series of five DXA scans, at 8-week intervals, was performed on growing sheep over a 32-week period. The average BCS ranged from 2.39 ± 0.07 (S.E.M.) to 3.05 ± 0.11 and the DXA body fat (%) ranged from 16.8 ± 0.8 to 24.2 ± 1.2. There was a moderate correlation between DXA body fat and BCS over the 32 weeks ( = 0.61, < 0.001, = 24).
Overall, these experiments indicated that there was good agreement between BCS, DXA and chemical analysis for measuring total body fat in sheep, and that DXA scanning is a valid method for longitudinal measurement of total body fat in live sheep.
人们对在农场中使用移动扫描技术对活体动物进行身体成分分析有着浓厚兴趣。这些实验评估了双能X射线吸收法（DXA）作为一种准确测量活体绵羊全身脂肪的方法的应用情况。
在实验1中，对身体状况评分（BCS）在2至3.25（范围1：瘦至5：胖）的绵羊进行了内脏和全身脂肪分析。BCS与内脏脂肪储存量呈中度相关（r = 0.59，P < 0.01，n = 24），与全身脂肪呈中度相关（r = 0.70，P < 0.001，n = 24）。在实验2中，对BCS在2.25至3.75范围内的绵羊进行采血以分析循环瘦素浓度，并在死后立即进行DXA扫描以测量全身脂肪。血浆瘦素浓度与BCS的相关性较低（r = 0.50，P < 0.05，n = 17），与DXA测量的身体脂肪的相关性较低（r = 0.42，P < 0.05，n = 17），与化学分析得出的身体脂肪无相关性（r = 0.17，P > 0.05，n = 9）。DXA测量的身体脂肪与BCS之间存在中度相关性（r = 0.70，P < 0.01，n = 17），DXA测量的身体脂肪与化学分析得出的身体脂肪高度相关（r = 0.81，P < 0.001，n = 9）。在实验3中，在32周的时间内，对生长中的绵羊每隔8周进行一系列五次DXA扫描。平均BCS范围为2.39±0.07（标准误）至3.05±0.11，DXA测量的身体脂肪百分比范围为16.8±0.8至24.2±1.2。在这32周内，DXA测量的身体脂肪与BCS之间存在中度相关性（r = 0.61，P < 0.001，n = 24）。
总体而言，这些实验表明，在测量绵羊全身脂肪方面，BCS、DXA和化学分析之间具有良好的一致性，并且DXA扫描是纵向测量活体绵羊全身脂肪的有效方法。
