Caton J S, Jesse G W, Day B N, Ellersieck M R
J Anim Sci. 1986 May;62(5):1203-9. doi: 10.2527/jas1986.6251203x.
In the late fall and winter of 1982 to 1983, 112 crossbred gilts were used in a factorially arranged experiment to determine the effect of confinement on the age at which a gilt reaches first estrus (puberty). Two environments (confinement and non-confinement) and three ages at movement to non-confinement (100, 140, and 180 d) were studied. No differences were detected (P greater than .05) between confinement and non-confinement in the proportions of gilts reaching puberty by 210 d of age. Gilts were older at puberty (P less than .05) in confinement than in non-confinement (192.0 vs 187.7 d) and had a longer interval (P less than .05) from first boar contact to first estrus (12.1 vs 7.8 d). Age at puberty (192.1 vs 187.0 vs 190.5 d) and the proportion reaching puberty (56.4 vs 45.7 vs 65.8%) were not different (P greater than .05) between age-of-movement groups. However, a higher (P less than .05) proportion of the non-confinement gilts reached puberty within 10 d after the beginning of boar exposure than confinement (44.6 vs 26.8%). Moving gilts from confinement to non-confinement (pasture) at 180 d appeared to be the most effective method tested for inducing puberty in gilts.
在1982年至1983年的秋冬季节，112头杂交后备母猪被用于一项析因试验，以确定圈养对后备母猪达到初情期（青春期）年龄的影响。研究了两种环境（圈养和非圈养）以及转移至非圈养环境时的三个年龄（100、140和180日龄）。在210日龄时达到青春期的后备母猪比例方面，圈养和非圈养之间未检测到差异（P大于0.05）。圈养环境中的后备母猪初情期年龄更大（P小于0.05）（192.0日龄对187.7日龄），从首次接触公猪到首次发情的间隔更长（P小于0.05）（12.1天对7.8天）。转移年龄组之间的初情期年龄（192.1日龄对187.0日龄对190.5日龄）和达到青春期的比例（56.4%对45.7%对65.8%）没有差异（P大于0.05）。然而，非圈养的后备母猪在开始接触公猪后10天内达到青春期的比例高于圈养（44.6%对26.8%）（P小于0.05）。在180日龄时将后备母猪从圈养转移到非圈养（牧场）似乎是诱导后备母猪青春期最有效的测试方法。
