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1.
Staniar WB Kronfeld DS Akers RM Harris PA 《Journal of animal physiology and animal nutrition》2007,91(9-10):390-399
The objective of this longitudinal study was to characterize growth and plasma insulin-like growth factor I (IGF-I) concentrations in pasture-raised thoroughbreds fed two sources of dietary energy. Mares and foals were randomly assigned to either a sugar and starch (SS) or fat and fibre (FF)-rich feed, and plasma IGF-I and growth were measured once a month from 1 to 16 months of age. These dependent variables were also compared with day length and ambient temperature. There was an association between plasma IGF-I concentration and average daily gain (ADG) (r = 0.32, p < 0.001). There were also clear seasonal patterns in both ADG and plasma IGF-I, with high values in June and May, and a low value in March. Plasma IGF-I and ADG were positively associated with day length and temperature. Plasma IGF-I was never higher (p > 0.10) in the FF group when compared with the SS group, and was higher in the SS group during a rapid growth phase in the spring of year 2 (p < 0.10). The results establish an association between ADG and IGF-I in the horse and indicate that environment and age may influence this relationship. In addition, plasma IGF-I is influenced by dietary energy source at particular times of year. This link has important implications in designing feeding management strategies that are aimed at addressing skeletal development. 相似文献
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The associations between velocity during a standardized, submaximal 800-m exercise test and blood lactate concentration after exercise were investigated in Thoroughbred racehorses on sand and grass racetracks. Predicted lactate concentrations for each horse's exercise test velocity were calculated from the line of best fit derived from results at each racetrack. The repeatability of the differences between the measured and predicted blood lactate response to exercise was also investigated. Exercise tests were conducted at speeds ranging from 12.8 to 16.6 m/s. The variability of velocity within the exercise test was expressed as the coefficient of variation (CV) of the times for the four 200-m sections.On the sand track, the coefficient of determination for the lactate-speed relationship was highest for an exponential regression equation [lactate (mmol/L) = 0.08e(0.33x)(m/s);r(2)= 0.58, P< 0.05;n = 21]. Similar coefficients of determination were calculated for linear (r(2)= 0.56) and second order polynomial equations (r(2)= 0. 57). On the grass racetrack, the relationship was best described by a second order polynomial equation [lactate (mmol/L) = -0.87x(2)+ 28. 17x - 211.41;r(2)= 0.57, P< 0.05;n = 25]. The mean differences between the measured and predicted blood lactate concentrations in repeated tests were 1.9 +/- 1.8 (SD) and 1.8 +/- 1.7 ( SD) on the sand and grass racetracks. There were no significant associations between the velocity of the exercise and the CV on either racetrack. Differences between measured and predicted blood lactate concentrations, based on track-specific lines of best fit, have potential application in field studies of fitness in Thoroughbred horses. 相似文献
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To assess the effect of human interferon-alpha (IFNα) on shipping fever of Thoroughbred
racehorses subjected to long-distance transportation, an IFNα preparation was orally
administered to 48 horses three times (once daily, 3 successive days) before
transportation (IFNα group). In the control group (25 horses), maltose was administered in
the same way. These treatments induced no abnormal findings in Thoroughbred racehorses
before transportation. Immediately after transportation, significant increases in rectal
temperature were observed in both treatment groups, whereas the rectal temperature of the
IFNα group tended to be lower than that of the control group. Although WBC, Fbg, and SAA
immediately after transportation were significantly increased due to transportation in
both groups, the extent of the increases in the IFNα group was significantly smaller than
in the control group. Long-distance transportation had a relatively profound impact on
Thoroughbred racehorses, which was mitigated by IFNα treatment. 相似文献
4.
Kanichi KUSANO Yuhiro ISHIKAWA Kazuhiro SEKI Ryo KUSUNOSE 《Journal of Equine Science》2008,19(2):25-29
Inflammatory airway disease (IAD) is a common cause of poor performance, interruption of
training and premature retirement in racehorses. It is also reported that up to 80% of
horses are affected at some point in the first years of training in UK and Australia.
However, no studies with regard to the information on occurrence of IAD in Japanese
Thoroughbred racehorses have been reported. To investigate the occurrence and the
characteristics of IAD, epidemic research including endoscopic examination of the airway
tract and trachea wash was conducted for Thoroughbred racehorses presenting coughs or poor
performance which airway tract disease was suspected stalled in training facility managed
by Japan Racing Association. Fifty-six out of 76 Thoroughbred racehorses (73.7%)
presenting coughing or poor performance were diagnosed as IAD. Mean incidence rate of IAD
was 0.3% and it has been confirmed that constant number of IAD exists in Japan. Up to
35.7% of IAD horses showed upper airway abnormalities in some extent. There was a trend
for IAD horses to use wood shavings for bedding and fed hay from the ground compared with
the control group. Therefore, improvement of stabling environment may aid in preventing
IAD. This study demonstrated that Japanese Thoroughbred racehorses are affected by IAD
likewise other countries as well as demonstrated the characteristics of IAD which may
contribute to the clarification of the pathogenesis of IAD. 相似文献
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Objective To describe the number of cases, etiologies, healing times, and results of microbial culture and susceptibility testing of corneal ulcers in thoroughbred racehorses in Japan. Procedure Retrospective study of the medical records of racehorses belonging to the Japan Racing Association (JRA) from 1997 to 2008. Results A total of 2846 horses suffered ulcerative keratitis. These horses accounted for 90.5% of all the corneal problems and 54.9% of the entire number of horses with ocular diseases. Running in races was the cause in 64.3% of the cases. The mean healing time of the ulcers developed in races was 5.5 ± 9.6 days, which was shorter than that of the ulcers unrelated to racing (8.6 ± 11.7 days). In horses presented for examination by the next day after the race, healing was even more rapid (4.1 ± 7.5 days) than in horses presented later (12.4 ± 14.7 days). Microbial culture was performed on 74 samples of 58 horses. Forty‐four bacterial and four fungal organisms were isolated from 35 samples of 29 horses. Pseudomonas aeruginosa (10) and Streptococcus equi subspecies zooepidemicus (5) were the bacteria most frequently isolated. There was no tendency of increasing antibiotic resistance of these organisms. Conclusions Ulcerative keratitis is the most frequent corneal and ocular disease of the racehorse in Japan. Careful observation of the eyes after racing is necessary as early diagnosis and treatment of corneal ulcers speeds healing. Many antibiotic have efficacy against the bacterial isolates, however, potent antibiotics should be reserved for the most severe corneal ulcers. 相似文献
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M.A. Bower M. Whitten R.E.R. Nisbet M. Spencer K.M. Dominy A.M. Murphy R. Cassidy E. Barrett E.W. Hill M. Binns 《Zeitschrift für Tierzüchtung und Züchtungsbiologie》2013,130(3):227-235
The potential future earnings and therefore value of Thoroughbred foals untested in the racing arena are calculated based on the performance of their forebears. Thus, lineage is of key importance. However, previous research indicates that maternally inherited mitochondrial DNA (mtDNA) does not correspond to maternal lineage according to recorded pedigree, casting doubt on the voracity of historic pedigrees. We analysed mtDNA of 296 Thoroughbred horses from 33 maternal lineages and identified an interesting trend. Subsequent to the founding of the Thoroughbred breed in the 16th century, well‐populated maternal lineages were divided into sub‐lineages. Only six in 10 of the Thoroughbreds sampled shared mitochondrial haplotype with other members of their maternal lineage, despite having a common maternal ancestor according to pedigree records. However, nine in 10 Thoroughbreds from the 103 sub‐lineages sampled shared mtDNA with horses of their maternal pedigree sub‐lineage. Thus, Thoroughbred maternal sub‐lineage pedigree represents a more accurate breeding record than previously thought. Errors in pedigrees must have occurred largely, though, not exclusively, at sub‐lineage foundation events, probably due to incomplete understanding of modes of inheritance in the past, where maternal sub‐lineages were founded from individuals, related, but not by female descent. 相似文献
10.
Estimation of dietary threonine requirement using plasma amino acid concentrations in mature thoroughbreds 下载免费PDF全文
The experiment was conducted to estimate dietary threonine (Thr) requirement using plasma amino acid concentrations as a criterion in mature thoroughbreds. Four adult thoroughbreds were used, and a 4 × 4 Latin square design was used for four dietary Thr levels. Plasma Thr concentration was constant until 0.41%, and then increased rapidly with increasing dietary Thr levels. The Thr requirement was estimated to be 67% of lysine with plasma Thr concentration at four Thr levels. 相似文献