Resumo

LOPEZ-ORTEGA, Aura et al. Profile of Luteinizing Hormone, Follicle-stimulating Hormone and 17β-Estradiol during the pre-farrowing, lactation and weaning of cross-bred Landrace x Large White sows. Rev. Fac. Cienc. Vet. [online]. 2009, vol.50, n.1, pp.43-51. ISSN 0258-6576.

One of the indexes of productivity of the sow is the number of suckling pigs along the year and depends on the length of gestation, lactation and weaning-pregnancy interval. The objective of this study was to determine the profile of  LH, FSH and 17β-estradiol during the pre-farrowing, lactation and post-weaning periods,  of 15 pregnant cross-bred sows (Landrace x Large White), belonging to a farm in Yaracuy State. By punction of the jugular vein a blood sample was drawn on d 7 before the farrowing, on d 1, 7, 14 and 21 post-farrowing on d 1 and  3 post-weaning. Hormone quantification was performed using an ELISA test. The statistical analysis was made by the program SPSS version 10.0 for Windows. A descriptive test followed by multiple comparison, was applied (P<0.05). LH increased during the lactation until a maximum value on d 3 post-weaning (7.40±0.97 mU/mL). FSH levels were lower (P>0.001) during the post-farrowing period in comparison to the pre-farrowing period (6.30±1.10 mU/mL), whereas at weaning the levels increased. The maximum concentration of the E₂ was observed on the third day post-weaning (2139.67±125.2 µg/mL) and it was simultaneous with the proper estrous behavior. In the cross-bred sow the hormonal profile is a fine balance of endocrine regulation that allows the farrowing, the lactation and the recovery of the cyclic activity of the ovary, during the early post-weaning period.

Palavras-chave : Sows; hybrids; Landrace; Large White; lactation; hormones; Yaracuy.

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