Stefánsdóttir G J, Gunnarsson V, Roepstorff L, Ragnarsson S, Jansson A
1Department of Equine Science,Hólar University College,IS-551 Sauðárkrókur,Iceland.
3Department of Anatomy, Physiology and Biochemistry,Swedish University of Agricultural Sciences,750 07 Uppsala,Sweden.
Animal. 2017 Sep;11(9):1558-1566. doi: 10.1017/S1751731117000556. Epub 2017 Mar 21.
This study examined the effect of increasing BW ratio (BWR) between rider and horse, in the BWR range common for Icelandic horses (20% to 35%), on heart rate (HR), plasma lactate concentration (Lac), BWR at Lac 4 mmol/l (W4), breathing frequency (BF), rectal temperature (RT) and hematocrit (Hct) in Icelandic horses. In total, eight experienced school-horses were used in an incremental exercise test performed outdoors on an oval riding track and one rider rode all horses. The exercise test consisted of five phases (each 642 m) in tölt, a four-beat symmetrical gait, at a speed of 5.4±0.1 m/s (mean±SD), where BWR between rider (including saddle) and horse started at 20% (BWR20), was increased to 25% (BWR25), 30% (BWR30), and 35% (BWR35) and finally decreased to 20% (BWR20b). Between phases, the horses were stopped (~5.5 min) to add lead weights to specially adjusted saddle bags and a vest on the rider. Heart rate was measured during warm-up, the exercise test and after 5, 15 and 30 min of recovery and blood samples were taken and BF recorded at rest, and at end of each of these aforementioned occasions. Rectal temperature was measured at rest, at end of the exercise test and after a 30-min recovery period. Body size and body condition score (BCS) were registered and a clinical examination performed on the day before the test and for 2 days after. Heart rate and BF increased linearly (P0.05), but negative correlations (P<0.05) existed between body size measurements and Hct. While HR, Hct and BF recovered to values at rest within 30 min, Lac and RT did not. All horses had no clinical remarks on palpation and at walk 1 and 2 days after the test. In conclusion, increasing BWR from 20% to 35% resulted in increased HR, Lac, RT and BF responses in the test group of experienced adult Icelandic riding horses. The horses mainly worked aerobically until BWR reached 22.7%, but considerable individual differences (17.0% to 27.5%) existed that were not linked to horse size, but to back BCS.
本研究考察了在冰岛马常见的体重比（BWR）范围（20%至35%）内，增加骑手与马之间的BWR对冰岛马心率（HR）、血浆乳酸浓度（Lac）、乳酸浓度为4 mmol/l时的BWR（W4）、呼吸频率（BF）、直肠温度（RT）和血细胞比容（Hct）的影响。总共八匹经验丰富的教学用马用于在户外椭圆形跑道上进行的递增运动试验，由一名骑手骑乘所有马匹。运动试验包括五个阶段（每个阶段642米），以5.4±0.1米/秒（平均值±标准差）的速度进行 tölt（一种四节拍对称步态），其中骑手（包括马鞍）与马之间的BWR从20%（BWR20）开始，增加到25%（BWR25）、30%（BWR30）和35%（BWR35），最后降至20%（BWR20b）。在各阶段之间，马匹停下（约5.5分钟），以便在专门调整的马鞍袋和骑手的背心上添加铅块。在热身、运动试验期间以及恢复5、15和30分钟后测量心率，在休息时以及上述每个场合结束时采集血样并记录BF。在休息时、运动试验结束时以及30分钟恢复期后测量直肠温度。在试验前一天以及试验后两天记录马匹的体型和身体状况评分（BCS），并进行临床检查。心率和BF呈线性增加（P<0.05），但体型测量值与Hct之间存在负相关（P<0.05）。虽然HR、Hct和BF在30分钟内恢复到休息时的值，但Lac和RT没有。在试验后1天和2天行走时，所有马匹触诊均无临床异常。总之，在经验丰富的成年冰岛骑乘马试验组中，将BWR从20%增加到35%导致HR、Lac、RT和BF反应增加。在BWR达到22.7%之前，马匹主要进行有氧工作，但存在相当大的个体差异（17.0%至27.5%），这些差异与马匹体型无关，而是与背部BCS有关。
