Hegarty P V, Kim S H, Ahn P C
Growth. 1977 Sep;41(3):221-34.
Differences in weight of the body, six different skeletal muscles, epididymal fat pads, three different bones, spleen, heart, kidneys, testes and liver were observed in 21-day-old male Sprague-Dawley rats from two different suppliers. All rats were pair-fed a 10% casein diet ad libitum, 10%, 20%, 30% restricted for 4 or 8 weeks. Original body and tissue weight differences between the two strains of rats were maintained in all diets during the 4 and 8 week feeding periods. Trends in body and tissue weight changes due to dietary restriction were similar in both strains of rats. Diet restrictions for 4 or 8 weeks caused similar patterns of weight decrease in most tissues. Feed efficiency ratio (FER) was reduced significantly at the 20% and 30% restriction for 4 weeks only in the lighter strain of rats. FER was higher in the heavier strain than in the lighter strain of rats at all levels of diet restriction. Food conversion efficiency with reduced food intake was constant or decreased depending on the skeletal muscle studied; decreased significantly for epididymal fat pad, bone weight (one strain only), kidneys and liver (one strain only) with the 30% reduced diet for 4 weeks; and increased for bone length and testes weight. Therefore, significant deviations from ad libitum controls were found only at 30% diet restriction, and the wide differences in body and tissue weight of two strains of Sprague-Dawley rats did not affect the interpretation of results when fed the same restricted diets.
在来自两家不同供应商的21日龄雄性斯普拉格-道利大鼠中，观察了体重、六种不同骨骼肌、附睾脂肪垫、三块不同骨骼、脾脏、心脏、肾脏、睾丸和肝脏的差异。所有大鼠自由采食10%酪蛋白饮食，或分别按10%、20%、30%的比例限制采食4周或8周。在4周和8周的喂养期内，两种品系大鼠之间最初的体重和组织重量差异在所有饮食条件下均得以维持。两种品系大鼠因饮食限制导致的体重和组织重量变化趋势相似。4周或8周的饮食限制在大多数组织中导致了相似的体重下降模式。仅在体重较轻的品系大鼠中，4周20%和30%的饮食限制显著降低了饲料效率比（FER）。在所有饮食限制水平下，体重较重的品系大鼠的FER均高于体重较轻的品系大鼠。随着食物摄入量减少，食物转化效率根据所研究的骨骼肌不同而保持不变或降低；对于附睾脂肪垫、骨骼重量（仅一个品系）、肾脏和肝脏（仅一个品系），4周30%的饮食减少使其显著降低；而对于骨骼长度和睾丸重量则增加。因此，仅在30%的饮食限制时发现与自由采食对照组有显著差异，并且当两种品系的斯普拉格-道利大鼠饲喂相同的限制饮食时，它们在体重和组织重量上的巨大差异并不影响结果的解释。
