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Factors effecting reproduction in the pig: seasonal effects and restricted feeding of the pregnant gilt and sow
- Source :
- Animal Reproduction Science. :173-184
- Publication Year :
- 2000
- Publisher :
- Elsevier BV, 2000.
-
Abstract
- Recent advances in research on seasonal infertility are discussed with a special focus on implications of the generally recommended restricted post-mating feeding strategy of the early pregnant gilt and sow for the physiology of seasonal infertility. The endocrinological basis of seasonal breeding of the wild and domestic pig is being clarified: as in other seasonal breeders, melatonin is relaying photoperiodic information about season to the pituitary–gonadal axis. Earlier confusion on this matter appears to have been caused by a lack of specificity of the melatonin assays employed. Group housing of the pregnant sow is becoming a common practice and, as an important environmental risk factor for seasonal infertility, may lead to an increase in the incidence of seasonal infertility in the future. After an initial progesterone-mediated beneficial effect on embryonic survival, a restricted post-mating feeding strategy may have a negative effect on maintenance of early pregnancy in the gilt and sow in the summer–autumn period. The endocrinological mechanism of seasonal disruption of pregnancy is yet to be determined. However, it is proposed that LH is reduced in the summer–autumn period and this reduction is amplified by the commonly applied restricted post-mating feeding strategy. These changes in LH secretion, although not as such inducing CL regression, may exert a progesterone-mediated detrimental effect on the capability of embryos to produce adequate embryonic signaling. This may lead to a seasonal disruption of pregnancy and a return to oestrus 25–30 days after mating.
- Subjects :
- Male
Infertility
medicine.medical_specialty
Swine
040301 veterinary sciences
media_common.quotation_subject
Physiology
Biology
0403 veterinary science
Melatonin
Endocrinology
Food Animals
Pregnancy
Internal medicine
medicine
Seasonal breeder
Animals
Mating
Gonads
media_common
Estrous cycle
Reproduction
0402 animal and dairy science
Pituitary gonadal axis
Environmental Exposure
04 agricultural and veterinary sciences
General Medicine
medicine.disease
040201 dairy & animal science
Pituitary Gland
Female
Animal Science and Zoology
Seasons
Food Deprivation
medicine.drug
Subjects
Details
- ISSN :
- 03784320
- Database :
- OpenAIRE
- Journal :
- Animal Reproduction Science
- Accession number :
- edsair.doi.dedup.....a3d2843430df11942cc77eb4515d48cf