The effect of dietary protein on reproduction in the mare. V. Endocrine changes and conception during the early post partum period
Date
1998
Authors
Van Niekerk F.E.
Van Niekerk C.H.
Journal Title
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Abstract
Pregnant Anglo-Arab and Thoroughbred mares (n = 24) were divided randomly according to age and breed into 4 groups of 6 mares each from approximately 6 weeks before their expected foaling date. Diets received by the 4 groups varied in essential amino-acid and total protein contents. Serum progestagen, FSH and LH concentrations were determined from the day of parturition until foal heat and during the 1st oestrous cycle following foal heat. Serum progestagen, FSH and LH concentrations did not differ between the treatment groups. Progestagen concentrations were high (x̄ = 7.0: 5.2-16.4 ng/ml) at parturition but decreased rapidly within 48 h. As progestagen concentrations decreased LH concentrations increased from Days 3-6 post partum to reach maximum values at, or the day after ovulation. FSH concentrations declined 3-4 d after parturition and increased 2-3 d before ovulation at foal heat. The duration of elevated progestagen concentrations during the luteal phase of the subsequent oestrous cycle affected the interovulatory period. A 12-14 d FSH cyclical releasing pattern occurred. Season/photoperiod affected the resumption of normal oestrous cyclicity during the post partum period. The duration of the 1st oestrous cycle after foal heat in mares fed a low-quality protein diet showed a greater range (13-30 d) compared to mares fed a high-quality protein diet (18-26 d).
Description
Keywords
follitropin, gestagen, luteinizing hormone, animal, article, blood, clinical trial, controlled clinical trial, controlled study, female, fertilization, horse, physiology, pregnancy, protein intake, puerperium, randomized controlled trial, reproduction, Animals, Dietary Proteins, Female, Fertilization, Follicle Stimulating Hormone, Horses, Luteinizing Hormone, Postpartum Period, Pregnancy, Progestins, Reproduction
Citation
Journal of the South African Veterinary Association
69
3
69
3