|
|
||||||||
Journal of Animal Science, Vol 73, Issue 7 2086-2093, Copyright © 1995 by American Society of Animal Science
JOURNAL ARTICLE |
D. P. Ryan, B. Bao, M. K. Griffith and G. L. Williams
Animal Reproduction Laboratory, Texas A&M University Agricultural Research Station, Beeville 78102, USA.
Two experiments were conducted to evaluate the effects of dietary fat supplementation and a synthetic progestogen on metabolic hormone patterns and(or) in vitro and in vivo characteristics of induced corpora lutea (CL) in undernourished, post-partum beef cows. Metabolizable energy intake was restricted in all cows in both experiments before calving to achieve a body condition (BC) score of 4 (thin), with cows fed to maintain BW and condition after calving. In Exp. 1, 16 cows were fed isocaloric and isonitrogenous diets after calving with either no added fat (NL, n = 8) or added fat (HL, n = 8; .374 kg of fat/500 kg BW). In Exp. 2, 32 pluriparous cows that had reached targeted body condition were divided randomly at calving into a 2 x 2 factorial treatment arrangement: 1) HL-no implant; HL-CON, 2) HL-norgestomet implant d 14 to 21; HL-NORG, 3) NL-CON and, 4) NL-NORG. Forty-eight-hour calf removal on d 21 and GnRH on d 23 were used to induce CL. The HL diet increased (P < .03) serum growth hormone (GH) concentrations, changed the puerperal pattern of serum insulin from cubic (P < .05) to linear (P < .05), and increased (P < .01) the in vitro production of IGF-I by luteal tissue (Exp. 1). In Exp. 2, both HL diets and NORG treatments (HL-NORG, HL-CON, NL NORG) tended to promote an increased (P < .09) frequency of luteal activity after GnRH, but only HL-CON and NL-NORG enhanced (P < .04) luteal lifespan.(ABSTRACT TRUNCATED AT 250 WORDS)
This article has been cited by other articles:
![]() |
C. L. Engel, H. H. Patterson, and G. A. Perry Effect of dried corn distillers grains plus solubles compared with soybean hulls, in late gestation heifer diets, on animal and reproductive performance J Anim Sci, July 1, 2008; 86(7): 1697 - 1708. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. W. Hess, S. L. Lake, E. J. Scholljegerdes, T. R. Weston, V. Nayigihugu, J. D. C. Molle, and G. E. Moss Nutritional controls of beef cow reproduction J Anim Sci, June 1, 2005; 83(13_suppl): E90 - 106. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. N. Maciel, D. A. Zieba, M. Amstalden, D. H. Keisler, J. P. Neves, and G. L. Williams Chronic administration of recombinant ovine leptin in growing beef heifers: Effects on secretion of LH, metabolic hormones, and timing of puberty J Anim Sci, October 1, 2004; 82(10): 2930 - 2936. [Abstract] [Full Text] [PDF] |
||||
![]() |
M.N. Maciel, D.A. Zieba, M. Amstalden, D.H. Keisler, J.P. Neves, and G.L. Williams Leptin Prevents Fasting-Mediated Reductions in Pulsatile Secretion of Luteinizing Hormone and Enhances Its Gonadotropin-Releasing Hormone-Mediated Release in Heifers Biol Reprod, January 1, 2004; 70(1): 229 - 235. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. A. Zieba, M. Amstalden, M. N. Maciel, D. H. Keisler, N. Raver, A. Gertler, and G. L. Williams Divergent Effects of Leptin on Luteinizing Hormone and Insulin Secretion Are Dose Dependent Experimental Biology and Medicine, March 1, 2003; 228(3): 325 - 330. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. R. Garcia, M. Amstalden, C. D. Morrison, D. H. Keisler, and G. L. Williams Age at puberty, total fat and conjugated linoleic acid content of carcass, and circulating metabolic hormones in beef heifers fed a diet high in linoleic acid beginning at four months of age J Anim Sci, January 1, 2003; 81(1): 261 - 268. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. R. Garcia, M. Amstalden, S. W. Williams, R. L. Stanko, C. D. Morrison, D. H. Keisler, S. E. Nizielski, and G. L. Williams Serum leptin and its adipose gene expression during pubertal development, the estrous cycle, and different seasons in cattle J Anim Sci, August 1, 2002; 80(8): 2158 - 2167. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Amstalden, M.R. Garcia, R.L. Stanko, S.E. Nizielski, C.D. Morrison, D.H. Keisler, and G.L. Williams Central Infusion of Recombinant Ovine Leptin Normalizes Plasma Insulin and Stimulates a Novel Hypersecretion of Luteinizing Hormone after Short-Term Fasting in Mature Beef Cows Biol Reprod, May 1, 2002; 66(5): 1555 - 1561. [Abstract] [Full Text] |
||||
![]() |
M. Amstalden, M.R. Garcia, S.W. Williams, R.L. Stanko, S.E. Nizielski, C.D. Morrison, D.H. Keisler, and G.L. Williams Leptin Gene Expression, Circulating Leptin, and Luteinizing Hormone Pulsatility Are Acutely Responsive to Short-Term Fasting in Prepubertal Heifers: Relationships to Circulating Insulin and Insulin-Like Growth Factor I1 Biol Reprod, July 1, 2000; 63(1): 127 - 133. [Abstract] [Full Text] |
||||
![]() |
K. Stagg,, L.J. Spicer,, J.M. Sreenan,, J.F. Roche,, and M.G. Diskin Effect of Calf Isolation on Follicular Wave Dynamics, Gonadotropin and Metabolic Hormone Changes, and Interval to First Ovulation in Beef Cows Fed Either of Two Energy Levels Postpartum Biol Reprod, October 1, 1998; 59(4): 777 - 783. [Abstract] [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |