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
1994 ◽  
Vol 77 (11) ◽  
pp. 3371-3381 ◽  
Author(s):  
Emilio Esteban ◽  
Philip H. Kass ◽  
Leon D. Weaver ◽  
Joan D. Rowe ◽  
Charles A. Holmberg ◽  
...  

2019 ◽  
Vol 17 (1) ◽  
pp. e0403 ◽  
Author(s):  
Jessica Flores ◽  
José E. García ◽  
Jesús Mellado ◽  
Leticia Gaytán ◽  
Ángeles De Santiago ◽  
...  

The objective of this study was to determine the effects of the administration of recombinant bovine somatotropin (rbST) throughout lactation to high-yielding subfertile (conception > 270 days postpartum) Holstein cows undergoing extended lactations (≥480 d) on milk production and reproductive performance. The study used two large adjacent commercial herds with similar management in a hot area of northern Mexico (25° N). Cows in one herd (n=2341) received a 500-mg dose of rbST every 14 d until dried off, starting 60 days postpartum. The other herd served as control (n=984). Across parity, rbST-treated cows produced 20% greater milk yield than control cows in 305-d lactations. Across parities, milk yield from 305 d postpartum to the end of lactation was 2734 kg higher in rbST-treated cows than control cows. Across parities rbST-treated cows produced 4777 more kg of milk during the entire lactation (mean 605 d) than the control group (mean 572 d). Conception rates (CR) at first service were only 3.2% and 5.9% (p<0.05) for control and rbST-treated cows, respectively. Overall CR was 43.5% and 61.6% (p<0.05) for control and treated cows, respectively. Control cows required 2.4 more (p<0.01) services per conception than rbST-treated cows. It was concluded that in this hot environment, the use of rbST suits dairy producers because it substantially improves both milk yield and reproductive performance in subfertile high-yielding Holstein cows. By markedly increasing lactation length and lactation persistency farm efficiency is greatly improved due to extended herd life.


1990 ◽  
Vol 73 (10) ◽  
pp. 2907-2915 ◽  
Author(s):  
Richard A. Erdman ◽  
Bal K. Sharma ◽  
Randy D. Shaver ◽  
Ralph M. Cleale

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

1991 ◽  
Vol 71 (2) ◽  
pp. 343-353 ◽  
Author(s):  
Guillermo F. Gallo ◽  
Elliot Block

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


1990 ◽  
Vol 70 (2) ◽  
pp. 723-726 ◽  
Author(s):  
D. M. LEFEBVRE ◽  
G. F. GALLO ◽  
E. BLOCK

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


Sign in / Sign up

Export Citation Format

Share Document