Soppela P, Nieminen M, Saarela S
Finnish Game and Fisheries Research Institute, Rovaniemi.
Acta Physiol Scand. 1992 May;145(1):65-73. doi: 10.1111/j.1748-1716.1992.tb09337.x.
Captive reindeer were fed four different rations which supplied equal energy but varying amount of crude protein: lichens (3%), mixed hay plus lichens (10%) and two feed concentrates with medium (12%) or high (18%) protein content. Kinetics of total body water were measured with tritiated water from February to March 1985, and thermal energy cost of daily water intake was estimated. Biological half-time of water was shorter, and daily water intake significantly higher on the hay plus lichens diet and on the medium- or high-protein concentrates diet than on the lichens diet during March 1985. Similar differences were found between reindeer on medium-protein concentrate and on lichens at the end of the corresponding feeding period during April 1986. Daily water inflow was positively correlated with a dietary supply of digestible crude protein (r = 0.916). Thermal energy costs of daily water intake were highest 1.9 MJ (3.7 l-1) in reindeer on high-protein concentrate during March 1985, and 2.0 MJ (3.9 l-1) in reindeer on medium-protein concentrate during April 1986. The reindeer fed on lichens had minimal and nearly twice as small thermal energy cost of daily water intake (mean 1.1 MJ 2.1 l-1) as on either of the concentrates. Our results show that even a moderate feed protein ration can significantly increase free water intake and its thermal energy cost in reindeer as compared to dominant natural feed (lichens) during winter. Careful protein supplementation is recommended to support body condition with a concomitant addition of easily soluble carbohydrates to compensate for increased thermal costs of water intake.
圈养的驯鹿被喂食了四种不同的日粮，这些日粮提供等量的能量，但粗蛋白含量不同：地衣（3%）、混合干草加地衣（10%）以及两种蛋白质含量中等（12%）或高（18%）的精饲料。1985年2月至3月期间，用氚水测量了全身水的动力学，并估算了每日水摄入的热能成本。1985年3月，食用干草加地衣日粮以及中蛋白或高蛋白精饲料日粮的驯鹿，其水的生物半衰期较短，每日水摄入量显著高于食用地衣日粮的驯鹿。1986年4月相应饲养期结束时，食用中蛋白精饲料的驯鹿和食用地衣的驯鹿之间也发现了类似差异。每日水流入量与可消化粗蛋白的日粮供应量呈正相关（r = 0.916）。1985年3月，食用高蛋白精饲料的驯鹿每日水摄入的热能成本最高，为1.9兆焦（每升3.7兆焦）；1986年4月，食用中蛋白精饲料的驯鹿每日水摄入的热能成本为2.0兆焦（每升3.9兆焦）。以地衣为食的驯鹿每日水摄入的热能成本最低，比食用任何一种精饲料的驯鹿低近两倍（平均1.1兆焦，每升2.1兆焦）。我们的研究结果表明，与冬季占主导地位的天然饲料（地衣）相比，即使是适度的饲料蛋白日粮也能显著增加驯鹿的自由水摄入量及其热能成本。建议谨慎补充蛋白质以维持身体状况，同时添加易溶性碳水化合物以补偿水摄入增加的热能成本。
