Firth E C, van Weeren P R, Pfeiffer D U, Delahunt J, Barneveld A
Institute of Veterinary, Animal and Biological Sciences, College of Sciences, Massey University, Palmerston North, New Zealand.
Equine Vet J Suppl. 1999 Nov(31):74-8. doi: 10.1111/j.2042-3306.1999.tb05317.x.
This study aimed a the determining bone mineral density (BMD) in the 3rd carpal bone and distal radius of foals age 5 and 11 months that had been subjected to different exercise regimens from birth until age 5 months. It was hypothesised that BMD would be greater in older animals, and that differences in exercise regimens before age 5 months would be associated with differences in BMD at both age 5 and 11 months. Epiphyseal bone tissue was available from 5 and 11 month old Warmblood foals bred from sires known to have radiographic evidence of osteochondrosis (OC). The foals were in a clinical trial which assessed the effect of exercise up to age 5 months on osteochondrosis (OC). Until age 5 months, foals were either box confined, box confined and sprint trained daily, or kept at pasture. Half the horses in each group were then confined together in a large stall, with access to pasture for 2 h daily, from age 6 to 11 months. BMD was assessed by dual x-ray absorptiometry in 4 areas of interest (AOIs) of excised third carpal bone (C3) and 5 in the distal radius. Volumetric BMD was determined in C3, only surface BMD was analysed in the radius. Across age groups, exercise had an effect on BMD in the mediodorsal and mediopalmar areas of C3. In the 5-month-old animals, the training exercise had similar effect to constant pasture exercise. In all AOIs, BMD was significantly greater in 11-month than in 5-month-old animals. Between age groups there was a difference in effect of exercise regimen before 5 months, in mediodorsal C3 and medial aspect of the radius, and the difference observed between exercise groups at age 5 months was no longer present in horses age 11 months, indicating no residual effect of early exercise. BMD was lower in the group with high OC scores. In the group of horses with the most severe OC, monthly growth rate did not fall uniformly with age over the first 5 months, as it did in groups with lower OC scores. It was concluded that exercise influenced significantly BMD at 5 months, suggesting that carefully designed training programmes to increase bone mineral could be employed in young animals. There was no residual effect at 11 months.
本研究旨在测定5月龄和11月龄驹的第三腕骨和桡骨远端的骨密度（BMD），这些驹从出生到5月龄接受了不同的运动方案。研究假设是，年龄较大的动物骨密度会更高，并且5月龄前运动方案的差异会与5月龄和11月龄时的骨密度差异相关。从已知有骨软骨病（OC）影像学证据的种马所繁育的5月龄和11月龄温血驹获取了骨骺骨组织。这些驹参与了一项临床试验，该试验评估了5月龄前运动对骨软骨病（OC）的影响。在5月龄前，驹要么被关在栏舍中，要么被关在栏舍中并每天进行短跑训练，要么在牧场饲养。然后，每组中的一半马匹从6月龄到11月龄被一起关在一个大马厩中，每天有2小时可进入牧场。通过双能X线吸收法在切除的第三腕骨（C3）的4个感兴趣区域（AOI）和桡骨远端的5个区域评估骨密度。在C3中测定体积骨密度，在桡骨中仅分析表面骨密度。在不同年龄组中，运动对C3的中背侧和中掌侧区域的骨密度有影响。在5月龄的动物中，训练运动与持续的牧场运动有相似的效果。在所有AOI中，11月龄动物的骨密度显著高于5月龄动物。在年龄组之间，5月龄前运动方案在C3的中背侧和桡骨内侧方面的影响存在差异，并且在5月龄时运动组之间观察到的差异在11月龄的马匹中不再存在，表明早期运动没有残留影响。骨软骨病评分高的组骨密度较低。在骨软骨病最严重的马组中，在最初的5个月里，每月生长速率并不像骨软骨病评分较低的组那样随年龄均匀下降。研究得出结论，运动在5月龄时对骨密度有显著影响，这表明可以在幼龄动物中采用精心设计的训练计划来增加骨矿物质。在11月龄时没有残留影响。
