Pérez-Clariget R, Bermúdez J, Andersson H, Burgueño J
Department of Animal Production, Faculty of Agriculture, Montevideo, Uruguay.
Reprod Nutr Dev. 1998 Sep-Oct;38(5):529-38. doi: 10.1051/rnd:19980505.
To study the effect of nutrition on spring testicular growth, four adult Corriedale rams were allowed to graze enough to maintain weight (maintenance group), while another four rams, in addition to forage, received a supplemental grain-based ration (increased gradually from 100 to 400 g during the first 5 d and kept at 400 g thereafter) daily for 63 d (supplemented group). Body weight, scrotal circumference, inguinal hyperaemia and testicular consistency were assessed. Blood concentrations of LH and testosterone were measured for 24 h on the day before supplementation began, the day after the animals were fed 200 and 400 g, and 12 and 28 d after animals began to receive the supplement. On these occasions blood contents of non-esterified free fatty acid and beta-hydroxybutyrate were measured when animals were fasting. Supplemented feeding increased body weight within 21 d and scrotal circumference within 35 d (P < 0.01). Scrotal circumference also increased in rams of the maintenance group (P < 0.01) but a lower rate than the supplemented group (P < 0.001). In both groups, testicular consistency and inguinal hyperaemia increased (P < 0.01). In the supplemented group a transient increase (P < 0.01) in LH pulsatility occurred the day after rams had received the full supplement (400 g) and 5 d later (day 12). However, no difference was found in total testosterone release between groups. In conclusion, improved nutrition accelerated the testicular growth in spring, although only a transient increase in LH pulsatility was observed. The scrotal circumference of rams kept on maintenance diet did also increase, which indicates that nutrition is not the only environmental cue responsible for the vernal testicular redevelopment in Corriedale rams.
为研究营养对春季睾丸生长的影响，选取4只成年考力代公羊，使其自由采食以维持体重（维持组），另外4只公羊除采食草料外，每天还额外给予谷物类补充日粮（前5天从100克逐渐增加至400克，之后维持在400克），持续63天（补充组）。评估了体重、阴囊周长、腹股沟充血情况和睾丸质地。在开始补充日粮前一天、动物采食200克和400克补充日粮后的第二天以及动物开始接受补充日粮后12天和28天，对促黄体生成素（LH）和睾酮的血药浓度进行了24小时监测。在这些时间点，当动物禁食时测量非酯化游离脂肪酸和β-羟基丁酸的血药含量。补充饲喂使体重在21天内增加，阴囊周长在35天内增加（P<0.01）。维持组公羊的阴囊周长也有所增加（P<0.01），但增幅低于补充组（P<0.001）。两组的睾丸质地和腹股沟充血情况均有所增加（P<0.01）。在补充组中，公羊采食完全部补充日粮（400克）后的第二天及5天后（第12天），LH脉冲频率出现短暂增加（P<0.01）。然而，两组间总睾酮释放量未发现差异。总之，营养改善加速了春季睾丸生长，尽管仅观察到LH脉冲频率有短暂增加。维持日粮饲养的公羊阴囊周长也增加了，这表明营养并非考力代公羊春季睾丸重新发育的唯一环境因素。
