Yang H, Varley M A
Department of Animal Science, Huazhong Agricultural University, Peoples Republic of China.
Res Vet Sci. 1994 Jan;56(1):119-22. doi: 10.1016/0034-5288(94)90208-9.
Two experiments were carried out to investigate the effects of repeated challenges of oestradiol benzoate and progesterone on reproduction in prepubertal gilts. In experiment 1, 21 Large White cross (Meishan cross Landrace) prepubertal gilts were allocated to one of three treatments. Treatment A gilts were given oestradiol benzoate injections (15 micrograms kg-1 bodyweight) at 140 and 160 days old and daily injections of progesterone (20 mg day-1 per gilt) for four days, from day 12 after each oestradiol benzoate challenge. Treatment B gilts were given the same oestradiol benzoate and progesterone challenges but from 160 days onwards. Treatment C gilts were the controls and were given only oil injections. All the gilts were mated at their first oestrous period. In experiment 2, 45 prepubertal Hubei White gilts were allocated to the same treatments as used in experiment 1. The administration of oestradiol benzoate induced oestrus (52 of 64) and ovulation (51 of 64) in a high proportion of the gilts in both experiments. The proportions of gilts which had regular oestrous cycles (within 10 days after progesterone withdrawal) were 0.82 (18 of 22) and 0.16 (3 of 19) in treatments A and B, respectively (P < 0.001).
进行了两项实验，以研究重复注射苯甲酸雌二醇和孕酮对青春期前后备母猪繁殖性能的影响。在实验1中，将21头大白猪（梅山猪×长白猪）青春期前的后备母猪分配到三种处理方式之一。处理A组的母猪在140日龄和160日龄时注射苯甲酸雌二醇（15微克/千克体重），并在每次注射苯甲酸雌二醇后的第12天开始，每天注射孕酮（每头母猪20毫克/天），持续四天。处理B组的母猪接受相同的苯甲酸雌二醇和孕酮注射，但从160日龄开始。处理C组的母猪作为对照，只注射油剂。所有母猪在首次发情期进行配种。在实验2中，将45头青春期前的湖北白猪后备母猪分配到与实验1相同的处理方式中。在两项实验中，注射苯甲酸雌二醇均在很大比例的母猪中诱导发情（64头中有52头）和排卵（64头中有51头）。处理A组和处理B组中具有规律发情周期（孕酮撤药后10天内）的母猪比例分别为0.82（22头中有18头）和0.16（19头中有3头）（P<0.001）。
