THE EFFECT OF ASSISTANCE AT CALVING, INJECTIONS OF RECOMBINANT BOVINE SOMATOTROPIN AND JUGULAR CATHETERIZATION ON SERUM CORTISOL AND ITS INFLUENCE ON THE GnRH-INDUCED LH RESPONSE IN POSTPARTUM DAIRY COWS

1990 ◽  
Vol 70 (2) ◽  
pp. 723-726 ◽  
Author(s):  
D. M. LEFEBVRE ◽  
G. F. GALLO ◽  
E. BLOCK
Keyword(s):  
Dairy Cows ◽  
Dairy Cow ◽  
Jugular Vein ◽  
Serum Cortisol ◽  
Cortisol Concentration ◽  
Bovine Somatotropin ◽  
Recombinant Bovine Somatotropin ◽  
Cortisol Levels ◽  
Vein Catheterization ◽  
Key Words Cortisol

Serum cortisol levels were determined in 18 cows administered 25 mg d−1 of recombinant bovine somatotropin or a placebo following jugular vein catheterization on day 14 postpartum. Cows that received assistance at calving had lower (P < 0.01) serum cortisol concentration postpartum. Restraint and catheterization caused an elevation (P < 0.1) of cortisol levels. Treatment with rbST did not effect postpartum cortisol levels. LH response to exogenous GnRH was not affected by the postpartum Cortisol level. Key words: Cortisol, somatotropin, ganadotropin-releasing hormone, luteinizing hormone, dairy cow, stress

Recombinant bovine somatotropin: association with reproductive performance in dairy cows

1999 ◽  
Vol 52 (3) ◽  
pp. 481-496 ◽  
Author(s):  
L.J. Judge ◽  
P.C. Bartlett ◽  
J.W. Lloyd ◽  
R.J. Erskine
Keyword(s):  
Dairy Cows ◽  
Reproductive Performance ◽  
Bovine Somatotropin ◽  
Recombinant Bovine Somatotropin

scholarly journals Dose Response to Recombinant Bovine Somatotropin from Weeks 15 to 44 Postpartum in Lactating Dairy Cows

1990 ◽  
Vol 73 (10) ◽  
pp. 2907-2915 ◽  
Author(s):  
Richard A. Erdman ◽  
Bal K. Sharma ◽  
Randy D. Shaver ◽  
Ralph M. Cleale
Keyword(s):  
Dairy Cows ◽  
Dose Response ◽  
Bovine Somatotropin ◽  
Recombinant Bovine Somatotropin ◽  
Lactating Dairy Cows

scholarly journals Administration of Recombinant Bovine Somatotropin to Dairy Cows for Four Consecutive Lactations

1997 ◽  
Vol 80 (10) ◽  
pp. 2355-2360 ◽  
Author(s):  
J.T. Huber ◽  
Z. Wu ◽  
C. Fontes ◽  
J.L. Sullivan ◽  
R.G. Hoffman ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Bovine Somatotropin ◽  
Recombinant Bovine Somatotropin

Effects of recombinant bovine somatotropin on hypophyseal and ovarian functions of lactating dairy cows

1991 ◽  
Vol 71 (2) ◽  
pp. 343-353 ◽  
Author(s):  
Guillermo F. Gallo ◽  
Elliot Block
Keyword(s):  
Sustained Release ◽  
Dairy Cows ◽  
Estrous Cycle ◽  
Negative Energy ◽  
Bovine Somatotropin ◽  
Release Formulation ◽  
Sustained Release Formulation ◽  
Estrous Cycles ◽  
Plasma Progesterone ◽  
Recombinant Bovine Somatotropin

Three trials were conducted to determine the effects of recombinant bovine somatotropin (rbST) on reproductive functions of lactating Holstein dairy cows. In Trial 1, 49 cows were used to investigate the effects of 0, 320 or 640 mg of rbST in a sustained-release formulation injected every 28 d on plasma progesterone (P4) concentration during estrous cycles. Total P4 area and P4 mean were increased (P < 0.05) in rbST-treated cows during the 1st and 2nd detected estrous cycle post-rbST injection. Maximum P4 value, slope of the P4 decline and length of cycles were not affected by rbST treatment. In Trial 2, 56 cows were used to investigate the effects of 0, 320, 640 and 960 mg of rbST in a sustained-release preparation injected every 28 d on plasma P4 concentration from weeks 1 to 34 of pregnancy. Mean P4 was increased (P = 0.08) in rbST-treated cows proportionally to the rbST dose received. In Trial 3, 18 cows were used to investigate the effects of 0 or 25 mg d−1 of rbST injected from days 3 to 15 postpartum (pp) on the gonadotropin-releasing hormone (GnRH) induced luteinizing hormone (LH) response curve at 14 d pp. Total area under the LH curve and LH peak value were increased (P < 0.05) in rbST-treated cows, but LH baseline and time to LH peak were not different among groups. Cows receiving rbST were in a more negative energy balance due to higher milk production. In summary, long-term administration of rbST increased the concentration of plasma progesterone during the first two estrous cycles post-treatment and during pregnancy, and enhanced the GnRH-induced LH response at 14 d pp. Key words: Bovine somatotropin, GnRH-LH induction, progesterone, estrous cycle, pregnancy

scholarly journals Treatment of Dairy Cows with Recombinant Bovine Somatotropin: Genetic and Phenotypic Aspects

1990 ◽  
Vol 73 (1) ◽  
pp. 181-190 ◽  
Author(s):  
Helen W. Leitch ◽  
Edward B. Burnside ◽  
Brian W. McBride
Keyword(s):  
Dairy Cows ◽  
Bovine Somatotropin ◽  
Recombinant Bovine Somatotropin
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