• Proceedings of the KSAR Conference
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• 2004.06a
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• pp.248-248
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• 2004

농장의 효율적 경영을 위해서는 농장경영비의 절감과 농장 소득의 증대가 매우 필수적이며 소득증대를 위해 가축번식은 그 무엇보다도 중요하다 하겠다. 특히, 젖소에서는 번식효율이 낮을 경우 산자의 생산효율이 낮으며 우유생산량도 낮아져 농가경영을 위태롭게 할 수 있는 중요인자이다. 따라서 번식효율 증진에 관한 연구는 세계의 많은 연구자들에 의해 오랜 시간 동안 연구되어지고 있다. 또한 번식효율 증진을 위해 사양관리개선, 번식능력이 양호한 종모우의 선발, 배란촉진제 사용, hCG 주사, bST 투여 등의 연구가 활발하게 진행되어지고 있다. (중략)

• 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).

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.224-225
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• 1989

• Journal of Veterinary Clinics
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• v.9 no.1
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• pp.333-366
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• 1992

Safety of recombinant porcine somatotropin administration on pig was studied using 32 Landrace x Yorkshire crossbred pigs. The starting body weight ranged from 55.5kg to 65.3kg. Eight pigs were allotted to each low dose group of sustained releasing rPST(SL), high dose group of sustained releasing rPST(SH), daily injection group of rPST(DI), and control group(C). Pigs in SL group and SH group were injected subcutaneously twice in 3 week-interval with 1000$\mu\textrm{g}$ and 2000$\mu\textrm{g}$ of sustained releasing rPST per kg body weight, respectively. Pigs in DI group were injected intramuscularly with 100$\mu\textrm{g}$ of rPST everyday for 6 weeks. Blood was collected from anterior vena cava just before the first treatment, and at four weeks and six weeks of experiment. Hematological parameters and blood chemical parameters indicating liver function, kidney function, electrolyte metabolism, mineral metabolism and lipid metabolism were determined. Necropsy and urinalysis were performed after final blood collection. The results were summarized as follows, and it is concluded that rPST administration does not affect pig health negatively. 1. rPST administration did not affect kidney function as manisfested by BUN, creatinine and urinalysis. 2. rPST administration did not affect liver function as manisfested by total protein, albumin, serum AST activity serum ALT activity serum ALP activity, serum LDH activity, serum GGT activity and serum SDH activity. 3. rPST administration did not affect skeletal muscle, cardiac muscle and brain as manifasted by serum AST activity and serum LDH activity. 4. rPST administration increased blood glucose level within normal range. 5. rPST administration did not affect lipid metabolism as manisfested by triglyceride, cholesterol, and phospholipid concentrati on. 6. rPst administration dia not affect mineral metabolism as manisfested by calcium, phosphorus, magnesium and iron concentration. 7. rPST administration did not affect electrolyte metabolism as manisfested by Na, K, chloride concentration. 8. rPST administration did not affect erythrocyte count, leukocyte count, thrombocyte count, and plasma fibrinogen level.

• Journal of Pharmaceutical Investigation
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• v.32 no.3
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• pp.199-207
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• 2002

In order to develop a sustained release formulation of bovine somatotropin (BST), which has been used to increase the body weight of oxen or the milk production of dairy cows, poly(D,L-lactide-co-glyceride)(PLGA) microspheres were made by W/O/W multiple emulsification method and solvent extraction method. Physical properties including particle size, drug entrapment, drug release, protein denaturation, and in vivo body weight increase in rats were characterized. The size of the microspheres was increased as the molecular weight of PLGA increased. When Span 65 and stearic acid during preparation were added, the size was decreased but the amount of surface protein was increased, resulting in a high loading efficiency, with fast release of BST from the microspheres. Aggregation or fragmentation of BST by SDS-PAGE during microsphere preparation and drug release study was not observed. Body weight of Sprague-Dawley's male rats was significantly increased after subcutaneous administrations of BST-loaded PLGA microspheres. There was a good correlation between in vivo weight gain and in vitro release rate of microspheres. PLGA microspheres with a high surface protein ratio could be a good candidate for the sustained delivery of BST.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.2
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• pp.230-238
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• 2011

Effects of cooling and supplemental recombinant bovine somatotropin (rbST) on hemato-biochemical characteristics were studied at different stages of lactation of crossbred Holstein Friesian cows in a tropical environment. Ten primiparous cows were divided into two groups of five animals each. The first group was housed as the non-cooled animals in an open-sided barn with a tiled roof in a normal shaded house (NS), while the second group was housed as cooled cows in an open-sided barn with a tiled roof under misty fan cooling (MFC). Three injections with rbST (500 mg per dose) at each stage of lactation (early, mid and late lactation) significantly increased total milk yield as compared with pretreatment in both cooled and non-cooled cows. Milk fat was significantly increased, while total solids, solid not fat, milk protein and lactose were not affected by the rbST treatment. Hematological parameters, plasma proteins, albumin, glucose, triglyceride, cholesterol, creatinine, alkaline phosphatase (ALP), plasma inorganic phosphate and the activities of plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were not affected by supplemental rbST in cooled and non-cooled cows. Supplementation of rbST caused a significant decrease in plasma urea concentration, while plasma FFA concentrations significantly increased in both cooled and non-cooled cows. The results of the present study suggest that exogenous rbST is efficacious in increasing milk yield without adverse effects on lactating crossbred Holstein cows in a tropical environment.

• 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.

• Journal of Animal Science and Technology
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• v.48 no.5
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• pp.663-670
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• 2006

The present study was performed to investigate the effect of plant type recombinant porcine somatotropin (pST) adminstration on growth performance and blood profile of finishing pigs. Forty-eight Landrace barrows weighing 78 kg were employed for six week growth trial. Twelve barrows were allocated into various rpST types ; the control (CONT), the 4:1 type rpST (TRT 1), the 1:1 type rpST (TRT 2); and the 4:1 type rpST group(TRT 3) respectively. CONT group were not planted rpST. TRT 1 group was treated with rpST once a week for 6 weeks. Each dose contained the rpST equivalent to 100mg from initial to two weeks and 125mg from three weeks to finial week. TRT 2 and TRT 3 groups were planted rpST four times contained the rpST equivalent to 100mg during trial period from initial to two weeks, and 125 mg from three weeks, to four weeks, respectively. All pigs were fed a commercial feed containing 0.9% lysine ad lib. Daily gain increased by 19.4% in TRT 1(p<0.05) compared to the CONT. rpST improved feed/gain by 13.4～28.9% in all treatment groups(p<0.05). Back fat thickness of the all rpST treated groups were 23.3～29.2% thinner than that of the CONT. These results indicated that the rpST stimulated growth performance in finishing pigs and plant type rpST could be used as a growth stimulant for finishing pigs.

• 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.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1232-1235
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• 2004

In order to investigate the effect of recombinant bovine somatotropin (rbST) on blood metabolites and milk yield of lactating buffaloes, 30 lactating buffaloes after acclimatization for 30 days were divided into 2 groups as control (n=10) and experimental (n=20). Animals were injected 250mg of rbST (Boostin-250) on 0, $14^{th}$ and $28^{th}$ day subcutaneously at ischiorectal fosse, where as control animals were given placebo of 2 ml normal saline. Fortnightly blood samples were collected from 15 days prior to 60 days post injection to estimate different blood metabolites. Daily milk yield was recorded and weekly average yield of each animal was calculated. From this study, it was found that blood metabolites such as glucose, triglycerides, total proteins, albumin, globulin and electrolytes like sodium and potassium were not altered by rbST injection. However, there was a significant (p<0.05) decrease in blood urea nitrogen (BUN) concentration in experimental group as compared to that of control group. The weekly average milk yield was significantly (p<0.001) higher (25%) in rbST injected group over the control group.