• Journal of Food Hygiene and Safety
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• v.10 no.2
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• pp.61-64
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• 1995

The present study was conducted to examine the effect of recombinant bovine somatotrpin(${\gamma}$BST), which was administered to cow to promote milk production, on bST levels in milk. Fourteen cows were divided cows were divided into two groups: 1) control cows received neither ${\gamma}$bST nor vehicle, 2) treated cows were administered twice at two-week interval with 500 mg ${\gamma}$bST each cow byj after lst injection. Milk samples were taken on day 0 (prior to injection), day 7 (7 days after lst injection), day 21 (7 days after 2nd injection) and day 35 (21 days after 2nd injection). Milk bST concentration was measured by the radioimmunoassay method. There was no statistical difference(p<0.05) in milk bST levels between two groups showing bST levels in the range of 1.8 ng/m/ to 3.1 ng/m/. That is, ${\gamma}$bST administration did not increase bST levels in milk.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.2
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• pp.194-199
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• 2007

Effects of recombinant bovine somatotropin (bST) on plasma hormonal concentration, embryo quality, and pregnancy rate were examined during the superovulation and synchronization treatment in donor and recipient cows. Hanwoos (Korean native beef cattle) were treated with controlled internal drug release (CIDR) combined with bST (CIDR+bST) or without bST (CIDR) as donor cows. The embryos recovered from donors were transferred into Holstein recipient heifers treated with bST (CIDR+bST) or without bST (CIDR) for synchronization. The correlation between IGF-I and P4 showed a positive pattern in the CIDR+bST group (r=0.44, p<0.01), but a negative pattern was shown in the CIDR group (r = -0.59, p<0.02) at day 7 of estrous cycles. Although the number of recovered, transferable, and degenerated embryos was not different, quantities of grade 1 (excellent) embryos in CIDR+bST group were significantly higher than those of the CIDR group (p<0.01). The pregnancy rate was higher in the CIDR+bST recipient group compared to CIDR group (p<0.05), when the embryos were recovered from the donors treated with CIDR. However, the pregnancy was maintained highly in both recipient groups, when the embryos were produced by CIDR+bST treated donors. It can be concluded that bST administration combined with CIDR is an effective method for superovulation and synchronization treatment to stabilize plasma hormonal levels, to obtain excellent quality of embryos, and to get higher pregnancy rate.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.1
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• pp.88-95
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• 2003

The objective of the present study was to determine the effect of exogenous bovine somatotropin on the mammary function in late lactating crossbred Holstein cows. Twelve 87.5% late lactating Holstein cows, approximately 30 weeks postpartum, were divided into two groups of 6 animals each. Animals in the control group were given sodium bicarbonate buffer by subcutaneous injection, while animals in the treated group were given recombinant bovine somatotropin (bST) by subcutaneous injection with 500 mg of bST (14 day prolonged-release bST). After bST injection, milk yield significantly increased from the control level on day 8 to day 20 (p<0.05) with a concomitant increase in mammary blood flow (p<0.01). An increase in mammary blood flow in response to bST treatment was greater than an increase in milk production. An increased plasma concentration of IGF-I coincided with an increase in mammary blood flow in animals treated with bST. There were no significant changes in the concentration of arterial plasma glucose concentration, the arteriovenous concentration difference (A-V difference) and mammary extraction ratio while the mammary glucose uptake increased when compared to the control group. The concentration of arterial plasma triglyceride decreased throughout the experimental period in animals give bST. The plasma concentration of acetate, and the mammary uptake for acetate significantly increased (p<0.05) after bST treatment. The action of bST did not affect the plasma concentration, A-V difference and extraction ratio across the mammary gland for $\beta$-hydroxybutyrate. The concentrations of milk fat and lactose tended to increase during bST treatment. Milk protein concentration initially increased in the first few days and decreased after bST injection when compared to the pretreated period. The present results indicated that bST could affect the mammary function in late lactating cows by increase in milk yield involving changes in both extra-mammary and intra-mammary mechanisms. The exogenous bST exerted its galactopoietic action through an increase in circulating IGF-I of the late lactating Crossbred Holstein cattle.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 1994.12a
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• pp.15-26
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• 1994

Bovine somatotropin(bST) or bovine growth hormone (bGH) is a protein of 191 amino acids produced by the anterior pituitary gland of cattle. Recombinant bovine somatotropin(rbST) is biosynthetic versions of the naturally occurring pituitary hormone in cows. The use of rbST in dairy cows promises to improve the efficiency of milk production around the world. Using recombinant DNA technology, bST can now be produced in commercial quantities. The recombinant bST(rbST) is biologically identical to the found in the bovine pituitary. Milk from rbST-treated cows has been found to have the same nutritional value and composition as milk from untreated cows. In November of 1993, rbST finally was approved by the FDA, nearly 10 years after filing a licence applica-tion. rbST has been one of the most extensively studied animal drug products to be reviewed by the agency. Three scientific facts will help to reassure the public about the safety of the milk suppy.: 1. rbST has no biological activity in humans when indigested orally or when given by intramuscular injection. 2. Insulin-like growth factor 1(IGF-1) is not orally active. Any changes in IGF-1 levels in milk are well within normal variation and are lower than those reported in human milk. 3. All cow's milk contains bST, and no significant change in bST levels in milk occurs as a result of giving cows supplemental bST. Based on the scientific evidence, the public can be confident that milk and meat from rbST-treated cows is safe to consumers.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.127-127
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• 1995

The present study was conducted to examine the effect of recombinant bovine somatotropin(${\gamma}$ bST), which was administered to cow to promote milk production, on bST levels in milk. Fourteen cows were divided into two groups: 1) control cows received neither y bST nor vehicle, 2) treated cows were administered twice at two-week interval with 500mg ${\gamma}$ bST each cow by subcutaneous injection. Milk samples were taken on day 0 (prior to injection), day 7 (7 days after 1st injection), day 21 (7 days after 2nd injection) and day 35 (21 days after 2nd injection).

• Korean Journal of Veterinary Research
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• v.51 no.1
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• pp.1-6
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• 2011

Sixteen steers were used to investigate the efficacy of the sustained-release implant of bovine somatotropin (bST) in improving growth and feed:gain ratio during 12 weeks. Administration of the 400 mg bST implant resulted in a 16.1% increase in growth rate, and this increase was significant (p<.05). The use of the sustained-release implant did not alter (p>.05) feed intake and feed:gain ratio. Thirty-four cows were used to investigate the efficacy of the sustained-release implant of bST in milk production during 4 weeks. Administration of the 200 mg bST implant resulted in an 8.7% increase in milk production, and this increase was significant (p<.05). Twenty-four barrows were used to investigate the efficacy of the sustained-release implant of porcine somatotropin (pST) in improving growth, feed:gain ratio and backfat thickness during 6 weeks. Administration of the 120 mg pST implant resulted in a 11.4% increase in feed:gain ratio and a 60% decrease in backfat thickness, and these results were significant (p<.05). But the use of the sustained-release implant did not alter (p>.05) growth rate and feed intake.

• Korean Journal of Agricultural Science
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• v.38 no.4
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• pp.667-672
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• 2011

This study was carried out to increase the breeding rate using sustained recombinant bovine somatotropin (bST) and examine the reproductive disorder and disease prevalencies of cow and calf, respectively. Sixty cows were allotted randomly to three groups in randomized complete block design; (1) No treatment, (2) 500 mg bST two times + 250 mg bST SC injection five times from 3 weeks before to 9 weeks after parturition every two weeks, (3) 500 mg bST two times before 3 weeks parturition + 250 mg bST SC injection three times from five to 9 weeks after parturition every two weeks. Developmental data of birth weight, weaning weight, total gain and average daily gain in control was $22.9{\mu}0.45$ kg, $88.0{\mu}1.13$ kg, $65.1{\mu}0.74$ kg and $0.54{\mu}0.08$ kg, respectively. There is no significant difference between Group 1 and 3 in the examined factors. However, there is significant difference between Group 1 and 2 in the birth weight ($24.4{\mu}0.88$ kg), weaning weight ($101.0{\mu}1.77$ kg), total gain ($76.7{\mu}0.9$ kg) and average daily gain ($76.7{\mu}0.9$ kg). Total gain was showed higher in Group 2 and 3 than Group 1 in the >2nd parity, and in Group 2 than Group 1 and 3 in the 1st parity. There is no significant difference in the BCS, no return days and disease occurrence of cow and calf by bST treatment. Number of service per conception was slightly increased in the Group 3 compared to Group 1 and 2. To increase the breeding ability of Hanwoo, it is recommended that 500 mg bST two times + 250 mg bST injection five times from 3 weeks before to 9 weeks after parturition every two weeks.

• Proceedings of the KSAR Conference
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• 2002.06a
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• pp.14-14
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• 2002

The purpose of this study was to determine the effect of bST treatment on progesteron concentration, embryo recovery and pregnancy rate following embryo transfer. Donor cows were superovulated with Folltropin-V and PGF₂ α combination method and then inseminated with frozen semen 3 times 12 hrs interval. Donor and recipient cows were assigned to control and bST group, of which was given a single injection of bST (500 ㎎, sc) at insemination or estrus detection. Embryo collection of superovulated cows were flushed nonsurgical method at 7 to 8 days after artificial insemination. (omitted)

• Korean Journal of Veterinary Research
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• v.37 no.4
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• pp.917-924
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• 1997

Estrus cycle of cow, season and follicldar stimulating treatment, having an effect on the number of follicle, are investigated for the oocyte recovery rate in ovum pick-up(OPU). The number of follicle aspirated and oocyte collected on the different days of estrus cycle(D 4~5, D 9~10 and D 14~15) were not significantly different among the groups. The higher number of viable oocytes were produced on Jan-May(79.0%) than Jun-Aug(33.3%) by OPU in cow. The number of follicle and aspirated oocyte in cows treated FSH or PMSG combined with bovine somatotropin(bST) were 1.2~1.5 times higher than in cows treated alone follicular stimulating hormone(FSH) or pregnant mare serum gonadotropin(PMSG). In conclusion, OPU can be repeatedly practiced 2 or 3 times in an estrus cycle. In addition, the high environmental temperature is not good for ovarian function of cow and the bST co-treatment with FSH or PMSG is increasing the number of aspiratable follicle.

• Asian-Australasian Journal of Animal Sciences
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• v.9 no.1
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• pp.101-106
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• 1996

This experiment was conducted to investigate the effect of bST administration on growth performance and carcass characteristics of finishing Korean native bulls. Fifty four Korean native bulls of about 14 months of age weighting an average 420 kg were assigned to receive no injection of bST, 250 mg of bST s.c. injection every week, or 500 mg bST s.c. injection every 2 weeks (Control, 250ST, 500ST) in a $3{\times}3$ randomized block design for a period of 20 weeks Animals administered with bST responded with decreased feed DMI by 8%(p < 0.01), increased ADG by 12%(p < 0.05), and increased gain/feed ratio by 20%(p < 0.01). But there was no significant difference in the growth performance between 250ST and 500ST. Administration of bST increased dressing percentage by 1.8%(p < 0.05), and tended to increase longissimus muscle area and decrease backfat thickness and marbling score.