Boukhliq R, Martin G B, White C L, Blackberry M A, Murray P J
Faculty of Agriculture (Animal Science), The University of Western Australia, Nedlands.
Reprod Fertil Dev. 1997;9(5):515-24. doi: 10.1071/r96113.
This study tested whether the effects of nutrition on gonadotrophin secretion and testicular growth in mature rams are due to increases in the supply of glucose, fatty acids (FA) or amino acids. Responses to protein (casein) and glucose, alone or in combination, were compared with responses to lupin grain and responses to a combination of protein, glucose and FA (acetate, propionate and vegetable oil). Glucose and casein were infused intra-abomasally whereas lupins and FA were added to the diet. Lupin feeding decreased blood growth hormone (GH) concentrations, but increased pulsatile luteinizing hormone (LH) secretion and increased the concentrations of follicle-stimulating hormone (FSH), prolactin, glucose and insulin. These effects were associated with testicular growth. Glucose or casein increased insulin concentrations and decreased GH concentrations, but did not affect gonadotrophins or testicular growth. There was no synergism between casein and glucose. Responses elicited by adding FA to the glucose+casein treatment were similar to those observed with lupins. In conclusion, the reproductive axis does not seem to be closely linked with dietary intakes of amino acids or with circulating concentrations of glucose, insulin or GH. However, the energetic components of the diet, particularly the fatty acids, appear to play a key role in the reproductive responses to changes in nutrition.
本研究旨在测试营养对成年公羊促性腺激素分泌和睾丸生长的影响是否归因于葡萄糖、脂肪酸（FA）或氨基酸供应的增加。将单独或联合给予蛋白质（酪蛋白）和葡萄糖后的反应，与给予羽扇豆谷物后的反应以及给予蛋白质、葡萄糖和FA（乙酸盐、丙酸盐和植物油）组合后的反应进行比较。葡萄糖和酪蛋白通过皱胃内输注给予，而羽扇豆和FA添加到日粮中。饲喂羽扇豆会降低血液生长激素（GH）浓度，但会增加促黄体生成素（LH）的脉冲式分泌，并增加促卵泡激素（FSH）、催乳素、葡萄糖和胰岛素的浓度。这些效应与睾丸生长有关。葡萄糖或酪蛋白会增加胰岛素浓度并降低GH浓度，但不影响促性腺激素或睾丸生长。酪蛋白和葡萄糖之间没有协同作用。在葡萄糖+酪蛋白处理中添加FA引发的反应与羽扇豆观察到的反应相似。总之，生殖轴似乎与氨基酸的日粮摄入量或葡萄糖、胰岛素或GH的循环浓度没有密切联系。然而，日粮的能量成分，特别是脂肪酸，似乎在对营养变化的生殖反应中起关键作用。
