Animal Welfare Science Centre, School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, SA, Australia.
Animal Welfare Science Centre, South Australian Research and Development Institute, Primary Industry and Regions SA, The University of Adelaide Campus, Roseworthy, SA, Australia.
J Anim Sci. 2018 Sep 7;96(9):3856-3862. doi: 10.1093/jas/sky248.
Anogenital distance (AGD) has been used to reflect masculinization in litter-bearing species. As masculinization affects behavior and reproduction, AGD could be measured to assist in selecting gilts with a temperament more suited to commercial production and greater reproductive potential. We hypothesized that gilts from a male-biased litter would have a longer AGD and poorer reproductive performance. In Exp. 1, AGD and weight were measured at day 1, day 21, and week 16 of age for gilts from male-biased litters (≥60% males; n = 51) and female-biased litters (≥60% females; n = 51). Sow AGD was measured 3 d after farrowing. In Exp. 2, AGD was measured at gilt selection at approximately 24 wk of age and gilts followed to second parity. Litter sex ratio affected AGD at 16 wk of age, with gilts from female-biased litters having longer AGD (mean ± SEM, 9.1 ± 0.7 mm vs. 11.0 ± 0.6 mm, P = 0.013). Anogenital distance was not different on day 1 or day 21. There was no effect of sex ratio on weight at any time, and sow AGD was not associated with the sex ratio of her litter. Gilts with an AGD longer than the mean of 11.55 mm were heavier (mean ± SEM, 118.8 ± 0.4 kg vs. 117.7 ± 0.4 kg, P = 0.023), were achieved puberty earlier (179.6 ± 0.6d vs. 182.2 ± 0.6 d, P = 0.001), were mated younger (200.6 ± 0.6 d vs. 203.2 ± 0.6 d, P = 0.001), and were more likely to be mated (91% vs. 83%, P = 0.005) than gilts with an AGD shorter than the mean. Gilts with an AGD greater than 11.55 mm had a greater born alive litter size (11.79 ± 0.20 vs. 11.20 ± 0.19, P = 0.018) compared with gilts with an AGD shorter than 11.55 mm. At 16 wk, AGD was associated with sex bias and could be used as a selection tool to predict reproductive success of the first parity, with a longer AGD being associated with gilts that had been born into a female-biased litter and that had better reproductive performance.
肛门生殖器距离（AGD）已被用于反映产仔物种的雄性化。由于雄性化会影响行为和繁殖，因此可以测量 AGD，以帮助选择更适合商业生产和更大繁殖潜力的性情温顺的小母猪。我们假设来自雄性偏多的窝的小母猪的 AGD 更长，繁殖性能更差。在实验 1 中，我们在雄性偏多的窝（≥60%雄性；n=51）和雌性偏多的窝（≥60%雌性；n=51）中测量了小母猪在 1 日龄、21 日龄和 16 周龄时的 AGD 和体重。母猪的 AGD 在产后 3 天测量。在实验 2 中，我们在大约 24 周龄时的小母猪选择时测量了 AGD，并对其进行了第二次产仔跟踪。窝的性别比例影响 16 周龄时的 AGD，来自雌性偏多窝的小母猪的 AGD 更长（平均值±SEM，9.1±0.7mm 与 11.0±0.6mm，P=0.013）。1 日龄或 21 日龄时 AGD 没有差异。性别比例在任何时候都不会影响体重，母猪的 AGD 与窝的性别比例无关。AGD 长于 11.55mm 的小母猪更重（平均值±SEM，118.8±0.4kg 与 117.7±0.4kg，P=0.023），更早达到初情期（179.6±0.6d 与 182.2±0.6d，P=0.001），更早配种（200.6±0.6d 与 203.2±0.6d，P=0.001），并且更有可能配种（91%与 83%，P=0.005），而 AGD 短于平均值的小母猪则不然。AGD 大于 11.55mm 的小母猪的活产仔数更大（11.79±0.20 与 11.20±0.19，P=0.018），与 AGD 短于 11.55mm 的小母猪相比。在 16 周龄时，AGD 与性别偏差有关，可以用作预测第一胎繁殖成功的选择工具，较长的 AGD 与来自雌性偏多窝的小母猪有关，并且繁殖性能更好。
