Maternal Effects in Swine Reproduction

Pharmacological intervention in swine reproduction

If gilts are known to be cyclic, the options to control estrus are breed-and-abort or feeding allyl trenbolone (Regumate®). For breed and abort, terminate pregnancy 25–30 days postbreeding with two injections of prostaglandin F2a (PGF2a), 6–8 hours apart. Gilts should return to estrus within 4–6 days with normal fertility. When feeding allyl trenbolone, you must ensure individual feeding so tha...

Troubleshooting Swine Reproduction Failure

Some reproductive failure occurs in all swine breeding operations, but for practical purposes reproductive failure is regarded significant only when production levels fall below the expected norm. These norms may vary from operation to operation and are based on such things as percentage of animals cycling, conception and farrowing rates, average litter size and number of pigs produced per sow ...

P-65: Maternal Effect Genes in Mammalian Reproduction

Background: Regulation of gene expression in mammalian embryos is not completely known. Pre-implantation embryos need maternal RNA and proteins synthesized during oogenesis, to regulate development before mater-embryo transition, as the grown oocyte and the 1-cell zygote are transcriptionally silent. There are some oocyte-specific genes called maternal effect genes which may account for this ea...

Preweaning Survival in Swine: Heritability of Direct and Maternal Effects

Tryptophan requirement for reproduction in swine.

Twenty-five crossbred gilts were used in an experiment to determine the tryptophan (Trp) requirement for reproduction. L-tryptophan was added to a fortified corn-gelatin diet to attain the five Trp levels of .64, 1.04, 1.44, 1.84 and 2.24 g per day. These diets were fed at 2 kg daily during pregnancy I and 1.82 kg daily during pregnancies II and III. During each 3-week lactation, all animals we...