|
|
||||||||
Journal of Animal Science, Vol 77, Issue 7 1851-1859, Copyright © 1999 by American Society of Animal Science
JOURNAL ARTICLE |
C. Farmer, M. T. Sorensen, S. Robert and D. Petitclerc
Agriculture and Agri-Food Canada, Dairy and Swine Research and Development Centre, Lennoxville, Quebec.
Third-parity sows received s.c. injections of sterile water (CTL, n = 12) or 15 mg of recombinant porcine prolactin (pPRL, n = 12) at 0730, 1530, and 2330 from d 2 to 23 of lactation. Litters were standardized to 11 or 12 pigs and were weighed weekly until weaning (d 24). On d 22 of lactation, milk production was estimated, and a milk sample was obtained the next day. Jugular blood samples were collected from sows on d 2, 7, 14, and 21 of lactation. Sows were slaughtered and mammary glands collected at d 24. Injections of pPRL doubled the serum concentrations of prolactin (P < .001) on d 7, 14, and 21 of lactation and decreased IGF-I concentrations on d 14 (P = .07) and 21 (P < .01). Weight, backfat, and milk yield of sows and mean pig weights were not affected by pPRL (P > . 1), yet the mean duration of intervals between nursings was reduced by 4.2 min (P = .06) in pPRL litters (45.9 vs 41.7 min). Dry matter and fat percentages in milk were lower in pPRL sows (P < .01). Weights of parenchymal and extraparenchymal tissues were not altered by pPRL treatment (P > .1). Number of prolactin receptors in parenchymal tissue as well as receptor affinity were similar in both groups (P > .1). Results indicate that virtually all prolactin receptors were saturated in CTL sows. This is probably the reason why additional exogenous prolactin had negligible effects.
This article has been cited by other articles:
![]() |
F. Simard, F. Guay, C. L. Girard, A. Giguere, J.-P. Laforest, and J. J. Matte Effects of concentrations of cyanocobalamin in the gestation diet on some criteria of vitamin B12 metabolism in first-parity sows J Anim Sci, December 1, 2007; 85(12): 3294 - 3302. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. K. Theil, K. Sejrsen, W. L. Hurley, R. Labouriau, B. Thomsen, and M. T. Sorensen Role of suckling in regulating cell turnover and onset and maintenance of lactation in individual mammary glands of sows J Anim Sci, July 1, 2006; 84(7): 1691 - 1698. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. Farmer and D. Petitclerc Specific window of prolactin inhibition in late gestation decreases mammary parenchymal tissue development in gilts J Anim Sci, July 1, 2003; 81(7): 1823 - 1829. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |