- 著者
- Akira MATSUI Yoshinobu INOUE Yo ASAI Akira YAMANOBE
- 出版者
- Japanese Society of Equine Science
- 雑誌
- Journal of Equine Science (ISSN:13403516)
- 巻号頁・発行日
- vol.16, no.1, pp.19-26, 2005 (Released:2005-04-21)
- 参考文献数
- 21
- 被引用文献数
- 1 3
Different geographic regions in which thoroughbred yearling horses are bred have different climates and different types of forage in pasture and hay. These factors are likely to influence the energy metabolism and growth rate of yearling horses. However, the effects of the characteristics of geographic regions on the digestible energy (DE) intake and growth rate of thoroughbred yearlings has yet to be clarified in detail. Here, we have examined the effect of the breeding region on growth performance of young horses, by comparing the DE intakes and growth rates of thoroughbred yearlings in Hidaka (Hokkaido) and Miyazaki (Southern Kyushu) in Japan. Eighteen male thoroughbred yearlings were divided equally into two groups, and bred either at the Hidaka training and research center (HYF) or the Miyazaki yearling farm (MYF). Measurements were conducted in September (summer) and in February (winter), and the mean ages of the yearlings during these two periods were 18 months and 23-24 months old, respectively. The apparent digestible energy intake was measured by a double-indicator method using Cr2O3 and lignin. There was no significant difference in the DE intakes between the yearling horses at the HYF and MYF in either season. The warm land of Southwest Japan has been considered to be unsuitable for growing forage containing sufficient nutrients to feed thoroughbreds, but no nutritional disadvantage of this forage was detected in the yearlings bred at the MYF. On the other hand, the heart girth (HG) and cannon circumference (CC) were found to be significantly smaller in yearlings at the HYF, compared to those at the MYF, in the winter evaluation (p<0.05). Significant positive correlations between the ADG and DE intake/100 kg body weight were seen in animals at the HYF in the summer and in those at the MYF in both seasons; however, such a correlation was not found in horses at the HYF in winter. The reason for the smaller HG and CC and the absence of a significant correlation between the ADG and DE intake/100 kg body weight in the yearlings at the HYF in winter is unclear. It could be attributable to growth delay due to exposure to cold temperatures, or lack of supplementation to compensate for the increased energy requirement due to excess energy metabolism in cold weather. Closer attention must, therefore, be paid to the energy supply and nutritional composition of feedstuffs fed to thoroughbred yearlings at farms in regions with cold ambient temperatures.
- 著者
- Tomoaki ONODA Ryuta YAMAMOTO Kyohei SAWAMURA Harutaka MURASE Yasuo NAMBO Yoshinobu INOUE Akira MATSUI Takeshi MIYAKE Nobuhiro HIRAI
- 出版者
- 日本ウマ科学会
- 雑誌
- Journal of Equine Science (ISSN:13403516)
- 巻号頁・発行日
- vol.25, no.2, pp.29-35, 2014 (Released:2014-06-25)
- 参考文献数
- 17
- 被引用文献数
- 4
We propose an approach of estimating individual growth curves based on the birthday information of Japanese Thoroughbred horses, with considerations of the seasonal compensatory growth that is a typical characteristic of seasonal breeding animals. The compensatory growth patterns appear during only the winter and spring seasons in the life of growing horses, and the meeting point between winter and spring depends on the birthday of each horse. We previously developed new growth curve equations for Japanese Thoroughbreds adjusting for compensatory growth. Based on the equations, a parameter denoting the birthday information was added for the modeling of the individual growth curves for each horse by shifting the meeting points in the compensatory growth periods. A total of 5,594 and 5,680 body weight and age measurements of Thoroughbred colts and fillies, respectively, and 3,770 withers height and age measurements of both sexes were used in the analyses. The results of predicted error difference and Akaike Information Criterion showed that the individual growth curves using birthday information better fit to the body weight and withers height data than not using them. The individual growth curve for each horse would be a useful tool for the feeding managements of young Japanese Thoroughbreds in compensatory growth periods.