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

EFFECTS OF A 28-DAY SUSTAINED-RELEASE FORMULATION OF RECOMBINANT BOVINE SOMATOTROPIN (rbST) ADMINISTERED TO COWS OVER TWO CONSECUTIVE LACTATIONS

1990 ◽  
Vol 70 (3) ◽  
pp. 795-809 ◽  
Author(s):  
M. LÉONARD ◽  
M. GALLO ◽  
G. GALLO ◽  
E. BLOCK
Keyword(s):  
Sustained Release ◽  
Body Condition ◽  
Body Condition Score ◽  
Bovine Somatotropin ◽  
Numerical Magnitude ◽  
Release Formulation ◽  
Sustained Release Formulation ◽  
Recombinant Bovine Somatotropin ◽  
Total Treatment ◽  
Effect Of Treatment

Efficacy of a sustained-release formulation of recombinant bovine somatotropin (rbST) was evaluated for two consecutive lactations. In trial 1, 48 multiparous and 12 primiparous Holstein cows were allocated randomly by parity to four treatment groups receiving 0, 320, 640, or 960 mg rbST in a sustained-release formulation at 28-d intervals starting in early, mid-, or late lactation with the total treatment period being 252, 168, or 84 d for the three different starting periods, respectively. Fifteen cows receiving 640 or 960 mg rbST 28 d−1 in trial I received 640 mg rbST 28 d−1 in trial II for a full second lactation and were paired with cows receiving a placebo and which were never administered rbST. Cows were fed total mixed rations ad libitum and milked twice daily. Response in milk and milk component yield was positive and very consistent for multiparous cows between trials. Primiparous cows responded in both lactations with the same numerical magnitude as multiparous cows but with higher variability. No adverse effect of treatment on final body condition score and achievement of proper condition for a subsequent lactation was found because treated cows had lower condition scores for a longer period of time but regained body condition at a faster rate in late lactation. No effect of treatment was observed on health parameters in either lactation. Trends towards longer days open and more breedings per conception were apparent for both lactations. Key words: Somatotropin, milk production, health, dairy cows, primiparous cows

The use of bovine somatotropin (bst) to increase summer milk production

1990 ◽  
Vol 1990 ◽  
pp. 44-44
Author(s):  
D J Roberts ◽  
R J Wells ◽  
D N Logue ◽  
A G Buchanan
Keyword(s):  
Sustained Release ◽  
Dairy Cows ◽  
Milk Production ◽  
Research Work ◽  
Bovine Somatotropin ◽  
Late Winter ◽  
Release Formulation ◽  
Sustained Release Formulation ◽  
Grazing Cattle ◽  
Feeding Systems

Farmers are receiving a price incentive to produce more milk during the summer months. Bovine somatotropin (BST) could be used as a means of increasing milk yield from late winter/spring calving cows during the summer months. However, most of the research work with BST has been with housed cattle on winter feeding systems. The objective of this experiment was to evaluate the use of BST with grazing cattle supplemented with silage as a buffer feed.Thirty-six January to March calving multiparous Friesian dairy cows were allocated to 4 treatments: CG - Control/Grazing, TG - Treated/Grazing, CB - Control/Buffer fed, TB - Treated/Buffer fed. The treated cattle were given 640 mg of recombinantly derived bovine somatotropin (Somidobove Elanco Products Limited) in a sustained release formulation at 28 day intervals. The treatment period at grass lasted for 8 weeks from 18 August 1988. The cattle were then housed for a further 8 weeks in 2 groups of sixteen cows (with one block of cows omitted from the experiment).

scholarly journals Dose Titration of Sustained-Release Recombinant Bovine Somatotropin in Lactating Dairy Cows

1993 ◽  
Vol 76 (4) ◽  
pp. 1125-1136 ◽  
Author(s):  
J.V. Downer ◽  
D.L. Patterson ◽  
D.W. Rock ◽  
W.V. Chalupa ◽  
R.M. Cleale ◽  
...  
Keyword(s):  
Sustained Release ◽  
Dairy Cows ◽  
Bovine Somatotropin ◽  
Dose Titration ◽  
Recombinant Bovine Somatotropin ◽  
Lactating Dairy Cows

Effect of bovine somatotropin injected as a sustained-release formulation at three injection intervals on the production and composition of milk from dairy cattle grazing pasture and supplemented with a grain concentrate

1990 ◽  
Vol 30 (4) ◽  
pp. 457 ◽  
Author(s):  
SC Valentine ◽  
GJ Ball ◽  
BD Bartsch ◽  
LB Lowe
Keyword(s):  
Dairy Cattle ◽  
Sustained Release ◽  
Milk Fat ◽  
Cattle Grazing ◽  
Bovine Somatotropin ◽  
Release Formulation ◽  
Sustained Release Formulation ◽  
Grazed Pasture ◽  
Milk Protein Content ◽  
Yield Responses

Milk production and composition were measured, during spring, in 63 autumn-calving Holstein-Friesian dairy cattle either not injected or injected subcutaneously with a sustained-release bovine somatotropin formulation. Injections were given at 28-, 21- or 14-day intervals over a period of 84 days commencing in the sixth month of lactation. The cattle grazed pasture and were supplemented with a grain concentrate. Mean daily yields of milk (L), fat (kg) and protein (kg) were significantly higher in cattle injected at 28-day (17.6, 0.73, 0.56), 21-day (18.1, 0.76, 0.59), and 14-day (18.8, 0.80, 0.61) intervals, compared with yields of cows not injected (15.9, 0.68, 0.51). Yields of fat and protein were significantly different between all the injection interval treatments. Yield responses to injection were greater in cows than in heifers. There were no significant differences between treatments in milk fat content. The milk protein content (g/kg) of cows injected at 21-day intervals (33.2) was significantly greater than that of cows not injected (32.7) and those injected at the 28-day (32.6) and 14-day (32.6) intervals. It was concluded that bovine somatotropin injected subcutaneously as a sustained-release formulation was effective at all injection intervals in increasing the production of milk and milk components in mid to late lactation in dairy cattle grazing pasture and supplemented with a grain concentrate.

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