Abstract
The contribution deals with two aspects of lactational anestrus in the sow: (1) the depth of anestrus weakens with length of lactation, (2) the suckling stimulus and oxytocin release during lactational anestrus.
There is firm evidence that prolongation of lactation makes the anestrous sow increasingly susceptible to manipulations that aim at termination of lactational anestrus. These include removing of the suckling stimulus by weaning or treatment with PMSG/HCG. Circulating LH and prolactin levels reflect the changing status.
As to the suckling stimulus, a number of components have now been defined which suggests that one or more may be responsible for lactational anestrus. The relatively high initial suckling interval becomes prolonged as lactation advances, so does the secretory frequency of oxytocin and the total amount of oxytocin released. It needs to be determined whether escape from inhibition of the sows reproductive activity occurs at the level of the CNS or is due to some direct action of oxytocin at the ovarian level.
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© 1985 ECSC, EEC, EAEC, Brussels-Luxembourg
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Ellendorff, F., Elsaesser, F., Parvizi, N., Smidt, D. (1985). Endocrine Interactions During Lactational Anestrus in Sows. In: Ellendorff, F., Elsaesser, F. (eds) Endocrine Causes of Seasonal and Lactational Anestrus in Farm Animals. Current Topics in Veterinary Medicine and Animal Science, vol 31. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-5026-9_17
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DOI: https://doi.org/10.1007/978-94-009-5026-9_17
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