The Effect of Recombinant Bovine Somatotropin on Ovarian Function in Heifers: Follicular Populations and Peripheral Hormones

Gong, J.G.; Bramley, T. A.; Webb, Robert I.

doi:10.1095/biolreprod45.6.941

Cited by 178 publications

(110 citation statements)

References 40 publications

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“…However, somatotropin injection starting at 10 days post partum had no effect on the interval from calving to first ovulation (Carriquiry et al, 2009a). Nevertheless, the number of recruited follicles is increased in dry cows or heifers injected with somatotropin (Gong et al, 1991 andKirby et al, 1997). This effect persisted for at least 21 days after termination of treatment (Kirby et al, 1997).…”

Section: Introductionmentioning

confidence: 98%

Effect of prepartum somatotropin injection in late-pregnant Holstein heifers on metabolism, milk production and postpartum resumption of ovulation

Schneider

Schwegler

Montagner

et al. 2012

Animal

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The aim of this study was to determine the effect of prepartum somatotropin injection in late-pregnant Holstein heifers on metabolism, milk production and resumption of postpartum ovulation. For this study, 31 late-pregnant Holstein heifers were used. The heifers were assigned randomly into two treatments: (1) 500 mg sc injections of somatotropin (somatotropin treatment, n 5 15) at 235 and 221 days, and, if pertinent, at 27 days from expected calving date and (2) no treatment (control group, n 5 16). Blood samples were collected weekly from 25 to 7 weeks after calving. Heifers with progesterone concentrations in plasma above 1 ng/ml in two consecutive postpartum samples were considered as having resumed ovarian activity. A higher proportion (P 5 0.04) of heifers treated with somatotropin resumed ovarian activity in the first 7 weeks post partum (73.3%; 11/15) compared with the control group (37.5%; 6/16). A higher number (P 5 0.02) of heifers in the somatotropin treatment group also ovulated during the first postpartum follicular wave (53.3%; 8/15) compared with the control group (12.5%; 2/16), as indicated by the number of heifers ovulating in the first 3 weeks post partum. Pregnancy rate was not affected by treatments (P . 0.10) and averaged 40.0% (6/15) in somatotropin-treated and 25.0% (4/16) in control heifers when evaluated up to 150 days in milk. Somatotropin treatment increased the average daily milk production by 2.8 kg/cow per day (P , 0.0001) and reduced the somatic cell count (P 5 0.009). Plasma IGF-I was higher (P , 0.05) for somatotropin-treated heifers in the prepartum period. Insulin and body condition score were higher (P , 0.05) and non-esterified fatty acids were lower (P , 0.05) for somatotropin-treated cows in the early postpartum period. In conclusion, somatotropin injection during the prepartum period in late-pregnant Holstein heifers was able to increase the proportion of heifers resuming ovarian activity early post partum, inspite of higher milk production.Keywords: bST, dairy heifers, IGF-I, ovarian activity, primiparous ImplicationsPhysiological changes during the transition period can have a great impact on health and performance. In our study, prepartum injection of somatotropin reduced negative energy balance (NEB) intensity as indicated by several metabolic markers evaluated in the postpartum period. A more intense NEB is usually associated with a delay in resumption of normal ovarian function. In this way, we observed a higher proportion of somatotropin-treated heifers ovulating earlier.Moreover, cows treated with somatotropin prepartum increased milk production. Along with earlier resumption of estrous cycles, this strategy can have an important impact on farm profitability. IntroductionDuring the early postpartum period, high-producing cows experience a period of negative energy balance (NEB) that occurs as the requirements for milk production exceed the -E-mail: augusto.schneider@live.com 935 energy obtained through feeding (Butler, 2003). In early postpartum dairy cows, the du...

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Section: Introductionmentioning

confidence: 98%

Effect of prepartum somatotropin injection in late-pregnant Holstein heifers on metabolism, milk production and postpartum resumption of ovulation

Schneider

Schwegler

Montagner

et al. 2012

Animal

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“…Diversos autores têm reportado que o tratamento com rbST aumenta o número de folículos ovarianos (Gong et al, 1991;De La Sota et al, 1993;Lucy et al, 1993;Webb et al, 1994;Kirby et al, 1997ab) e o número de folículos classificados como pequenos (Gong et al, 1991;Crystal et al, 1997;Bols et al, 1998;Buratini Jr. et al, 1999;Pivato et al, 1999;Buratini et al, 2000;Roth et al, 2002). Entretanto, neste estudo, o crescimento folicular aumentado não foi observado após o uso de rbST.…”

Section: Resultsunclassified

“…Essa maior disponibilização de oócitos pode ser obtida pelo uso de somatotropina bovina recombinante (rbST), que tem apresentado efeito no crescimento folicular em vacas (Gong et al, 1991(Gong et al, , 1993De La Sota et al, 1993;Lucy et al, 1993).…”

Section: Introductionunclassified

“…A rbST aumenta a população de folículos em animais de origem européia (Gong et al, 1991(Gong et al, , 1993(Gong et al, , 1996(Gong et al, , 1997De La Sota et al, 1993;Webb et al, 1994;Kirby et al, 1997a,b;Bols et al, 1998) e em vacas Nelore (Carter et al, 1998;Buratini Jr. et al, 1999). Crystal et al (1997) demonstraram que o número de folículos com diâmetro de 3 a 5 mm e de 6 a 9 mm é maior em vacas tratadas com BST em relação àquelas não tratadas e relataram que o efeito deste hormônio seria primeiramente na fase de recrutamento do crescimento folicular, não sendo afetadas a seleção de folículos grandes e a taxa de ovulação.…”

Section: Introductionunclassified

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Efeito da somatotropina na população folicular, recuperação de oócitos e produção in vitro de embriões em vacas Gir

et al. 2007

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RESUMO -Avaliou-se o efeito da pré-estimulação ovariana com somatotropina bovina recombinante (rbST), associada ou não ao FSH, sobre a população folicular, a recuperação de oócitos e a produção in vitro de embriões em vacas Gir. Utilizaram-se vacas não-lactantes, em boas condições reprodutiva e corporal, cujo ciclo estral foi sincronizado pela administração de 0,5 mg de cloprostenol. Durante o experimento, as vacas receberam continuamente implantes auriculares de norgestomet, renovados a cada 14 dias, e, posteriormente, foram submetidas aos tratamentos: T1 ou controle -punção sem tratamento pré-estimulatório; T2 -aplicação única de 160 mg de rbST antes de cada punção; e T3 -punção após o tratamento com 160 mg de rbST em aplicação única, seguida de administração de 250 UI de FSH em doses decrescentes. Os oócitos foram maturados e fertilizados in vitro e os presumíveis zigotos foram cultivados por 192 horas pós-fertilização. Os tratamentos não foram diferentes quanto à população folicular presente no ovário. Entretanto, com a administração de 250 UI de FSH (T3), verificou-se aumento no diâmetro do maior folículo e no número de folículos grandes e médios e diminuição no número de folículos pequenos. A taxa de recuperação não diferiu entre o tratamento controle e T3 (com administração de FSH), mas foi menor no T2 (aplicação, em dose única, de 150 mg de rbST antes de cada punção). O número de oócitos de grau 1 foi maior e o de degenerados, menor no T3 em relação ao T1 e ao T2. O rbST (T2) aumentou a taxa de clivagem e a produção de blastocistos e, quando associado ao FSH, melhorou a qualidade dos oócitos nos animais Gir.Palavras-chave: bovinos, Gir, punção folicular, rbST Effect of somatotropin on follicular population, oocyte retrieval and in vitro embryo production in Gir cowsABSTRACT -The aim of this study was to evaluate ovarian pre-stimulation using recombinant bovine somatotropin (rbST) or rbST associated to FSH on follicular population, oocyte retrieval and in vitro embryo production in Gir cows (Bos indicus). Estrous cycle of non-lactating cycling cows with similar body and reproductive conditions were synchronized with cloprostenol followed by norgestomet ear implants, replaced every fourteen days. The animals were randomly distributed in three treatments: TI or control (punctured without pre-stimulation), TII (injection of 160 mg of rbST, before each aspiration) and TIII (injection of 160 mg of rbST followed by administration of 250 U.I. of FSH, before each aspiration). Oocytes were maturated and fertilized in vitro and presumptive zygotes were cultured in vitro for 192 hours post-fertilization. Treatments did not differ for ovarian follicular population. However, an increase in the diameter of the largest follicle and in the number of large and medium follicles with reduction in the number of small follicles was observed for TIII. Oocyte recovery did not differ between TI and TIII, but recovery rate was lower for TII. The number of grade I oocytes was higher and the number of degenerated oocytes was lower ...

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“…In contrast, treatment of normal heifers with bovine GH during the prepubertal period delayed the onset of puberty (Murphy et al 1991). GH treatment during several oestrous cycles was without effect on ovulation, but increased the number of developing oocytes per ovary in heifers (Gong et al 1991); GH also increased the concentration of progesterone in the plasma and altered the pattern of LH secretion in lactating cows (Schemm et al 1990).…”

Section: Growth Hormone Influences Puberty and Gonad Developmentmentioning

confidence: 99%

Growth hormone (GH) and reproduction: a review

Gac

Blaise

Fostier

et al. 1993

Fish Physiol Biochem

172

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ResumeLes interactions entre les fonctions de croissance et de reproduction mises en evidence chez de nombreux vert6br6s, sont particulierement aigiies A certaines tapes du cycle vital des poissons. Nous d6crivons les interactions endocrines existant entre les axes somatrope et gonadotrope en insistant sur le role jou6 par l'hormone de croissance (GH). L'analyse compare de ces phenomenes chez les mammiferes, les poissons et les amphibiens permet de sugg6rer que la GH joue un rle sp6cifique dans la physiologie de la puberty, la gametog6nese et la fertility. Nous mettons en evidence l'apport original des tudes effectu6es sur le module poisson dans ce champ d'investigation. AbstractInteraction between growth and reproduction occurs in many vertebrates and is particularly obvious at certain stages of the life cycle in fish. Endocrine interactions between the gonadotropic axis and the somatotropic axis are described, the potential role of GH being emphasised. A comparative analysis of these phenomena in mammals, amphibians and fish, suggests a specific role of GH in the physiology of puberty, gametogenesis and fertility. It also shows the original contribution made by studies on the fish model in this field of investigations.

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The Effect of Recombinant Bovine Somatotropin on Ovarian Function in Heifers: Follicular Populations and Peripheral Hormones

Cited by 178 publications

References 40 publications

Effect of prepartum somatotropin injection in late-pregnant Holstein heifers on metabolism, milk production and postpartum resumption of ovulation

Effect of prepartum somatotropin injection in late-pregnant Holstein heifers on metabolism, milk production and postpartum resumption of ovulation

Efeito da somatotropina na população folicular, recuperação de oócitos e produção in vitro de embriões em vacas Gir

Growth hormone (GH) and reproduction: a review

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