The relationship among live weight, chemical body composition and energy content (at artificial insemination (AI) and three days before parturition), estimated by bioelectrical impedance with fertility rates and the percentage of kits born alive, was studied during the first three AI. The first AI was conducted at 16 weeks of age in 137 rabbit does that weighted 3.91 ± 0.46 kg. Their body chemical composition was 17.4 ± 0.50%, 16.1 ± 2.6%, 1067 ± 219 kJ/100 g body weight, for protein, fat and energy, respectively. An increase in body protein, fat and energy content at the first AI did not affect fertility at the first AI but improved it at the second AI (p ≤ 0.030). Moreover, an increase in body fat and energy content at the second AI improved fertility at the second AI (p ≤ 0.001). Fertility at the third AI was positively influenced by body protein at the third AI and the increase in body protein and fat between the second parturition and the third AI (p ≤ 0.030). The percentage of kits born alive at the first and at the second AI improved with the increase in body protein at the first AI (p ≤ 0.040). In conclusion, a minimal body protein and fat content is required at the first AI to optimize the reproductive performance in young does.

中文翻译：

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兔体内化学成分与生殖性状的关系

在前三个人工授精期间，研究了活重、身体化学成分和能量含量（人工授精 (AI) 和分娩前三天）之间的关系，通过生物电阻抗与生育率和活产成活婴儿的百分比进行估计。第一次 AI 是在 16 周龄时在 137 只体重为 3.91 ± 0.46 kg 的兔子中进行的。他们的身体化学成分分别为蛋白质、脂肪和能量的 17.4 ± 0.50%、16.1 ± 2.6%、1067 ± 219 kJ/100 g 体重。第一次 AI 时身体蛋白质、脂肪和能量含量的增加不会影响第一次 AI 的生育能力，但会提高第二次 AI 的生育能力 ( p ≤ 0.030)。此外，第二次 AI 时体脂和能量含量的增加提高了第二次 AI 的生育能力（p≤ 0.001)。第三次人工授精时的生育力受第三次人工授精时的体蛋白以及第二次分娩和第三次人工授精之间体蛋白和脂肪增加的积极影响（p ≤ 0.030）。第一次和第二次 AI 时存活的成活率随着第一次 AI 时身体蛋白质的增加而提高 ( p ≤ 0.040)。总之，在第一次人工授精时需要最少的身体蛋白质和脂肪含量，以优化幼崽的繁殖性能。