At 3 experimental farms, gilts aged 6-7 months were treated for induction of puberty with 500 IU PMSG + 250 IU HCG. Ten days later, the females were treated for 12 days with 5 g daily of Suisynchron-premix, and were given timed inseminations. At the 3 farms, experimental females averaged 235, 231...

Eighty gilts were slaughtered at various times after puberty induction, using 500 IU of PMS and 250 IU of HCG, and stimulation of ovulation (using 500 IU of HCG 72 hours after puberty had been induced). Most gilts ovulated between 96 and 120 hours after puberty induction. Only 3.2% of the follicles ...

In 86 gilts in which puberty had been induced by administration of 500 IU of PMS and 250 IU of HCG, only 26.9% of the group without HCG had completed ovulation 120 hours from puberty induction, but 93.5% had done so in the group which had received an additional 500 IU of HCG 78 hours after the...

Gilts were each fed 5 g Suisynchron premix daily for 20 days and were then given 1000 IU PMS, plus 0, 100, 200 or 300 IU HCG 24 h after the end of treatment. All groups received 500 IU HCG 72 h after the 1st HCG injection, and were inseminated 24 and 42 h later. Five wk later, the gilts were...

In a series of experiments, puberty was induced in gilts by injection of 500 IU PMS + 250 IU HCG, and insemination with pooled semen was carried out once, twice or 3 times. Gilts were slaughtered 4-8 wk after insemination. For 41, 38 and 41 females averaging 220 days of age and inseminated once,...

Groups of 79, 77 and 80 gilts were inseminated once, either 26 or 36 h after HCG injection, or were inseminated twice (at 26 and 36 h). In the 3 groups resp., the CRs were 52.6, 61.0 and 77.2%, the farrowing rate 51.9, 61.0 and 76.3%, and litter size of liveborn piglets 6.5, 7.1 and 7.7 resp. In a...

A review of work published in the German Democratic Republic during 1973-76.

Data were analysed on 1159 sows which were allowed to suckle their litters for 42 days, and were then given hormones to synchronise oestrus. Firstly, a comparison was made between set times for AI after cessation of hormone treatment. When sows were given a double insemination 12 and 24 h after HCG ...

In 2338 gilts on 6 commercial farms, oestrus was synchronised by 5 mg methallibure daily for 20 days, followed by a PMS injection on day 1 (the day after withdrawal of methallibure), an HCG injection on day 4, and insemination in the morning and again in the evening of day 5. Pregnancy rate to 1st...

Of 221 sows injected once with 2000 or 2500 IU PMS 21-28 days after farrowing, 58.8% exhibited oestrus and 72.3% of mated sows farrowed v 63.3 and 61.1% resp. of 30 sows injected 29-49 days after farrowing; litter size averaged 10.9 and 10.3 in the 2 treatment groups resp. Sows given 2500 IU PMS...