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Registro Completo |
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Biblioteca(s): |
Embrapa Caprinos e Ovinos. |
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Data corrente: |
23/06/2017 |
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Data da última atualização: |
23/06/2017 |
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Autoria: |
KNIGHT, C. H.; FOWLER, P. A.; WILDE, C. J. |
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Título: |
Galactopoietic and mammogenic effects of long-term treatment with bovine growth hormone and thrice daily milking in goats. |
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Ano de publicação: |
1990 |
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Fonte/Imprenta: |
Journal of Endocrinology, v. 127, n. 1, p. 129-138, Oct. 1990. |
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Idioma: |
Inglês |
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Conteúdo: |
Abstract: Starting in mid-lactation, goats were treated daily for 22 weeks with 0.15 mg recombinant bovine GH (bGH)/kg, or an equivalent volume of vehicle. One gland of each goat was milked thrice daily throughout treatment, the other twice daily. Mammary differentiation was studied in biopsy samples obtained before treatment and after 3 and 22 weeks of treatment, by determination of in-vitro synthesis rates of milk constituents and measurement of enzyme activities. Mammary growth was measured using a whole-body imaging technique (magnetic resonance imaging; MRI). bGH caused an immediate and sustained increase in milk yield of approximately 23% overall, whilst the glands milked thrice daily produced approximately 14% more than the control glands milked twice daily. The effects of the combined treatment were additive, but not synergistic. A synergistic effect of the combined treatment resulted in a significant improvement in lactation persistency. A stimulatory effect of milking frequency on mammary enzyme activities was evident only in bGH-treated goats at 3 weeks, but in both groups at 22 weeks. Synthesis rates of casein and lactose were increased at 3 weeks only by the combined treatment. Thus bGH accelerated or augmented the differentiative response to thrice daily milking. Mammary parenchyma volume, estimated by MRI, increased significantly during the first 12 weeks of bGH treatment and remained higher throughout the rest of the treatment period. Cell number was estimated from parenchyma volume and DNA concentration; this decreased significantly in the controls between weeks 1 and 22, but remained constant in the bGH group. In nine of the ten goats, parenchyma volume and cell number increased in the gland milked thrice daily relative to the control gland milked twice daily during the course of the experiment. Thus bGH stimulated growth of the mammary gland over and above that induced by the frequent milking. The absence of any detectable increase in thymidine incorporation suggests that this growth consisted of cellular hypertrophy rather than hyperplasia. MenosAbstract: Starting in mid-lactation, goats were treated daily for 22 weeks with 0.15 mg recombinant bovine GH (bGH)/kg, or an equivalent volume of vehicle. One gland of each goat was milked thrice daily throughout treatment, the other twice daily. Mammary differentiation was studied in biopsy samples obtained before treatment and after 3 and 22 weeks of treatment, by determination of in-vitro synthesis rates of milk constituents and measurement of enzyme activities. Mammary growth was measured using a whole-body imaging technique (magnetic resonance imaging; MRI). bGH caused an immediate and sustained increase in milk yield of approximately 23% overall, whilst the glands milked thrice daily produced approximately 14% more than the control glands milked twice daily. The effects of the combined treatment were additive, but not synergistic. A synergistic effect of the combined treatment resulted in a significant improvement in lactation persistency. A stimulatory effect of milking frequency on mammary enzyme activities was evident only in bGH-treated goats at 3 weeks, but in both groups at 22 weeks. Synthesis rates of casein and lactose were increased at 3 weeks only by the combined treatment. Thus bGH accelerated or augmented the differentiative response to thrice daily milking. Mammary parenchyma volume, estimated by MRI, increased significantly during the first 12 weeks of bGH treatment and remained higher throughout the rest of the treatment period. Cell number was estimate... Mostrar Tudo |
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Palavras-Chave: |
Drug effects; Galactosy; Glucosephosphate Dehydrogenase; Growth Hormone; Time Factors. |
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Thesaurus Nal: |
Fatty Acids; Goats; Lactation; Mammary Glands; Milk; Physiology; Recombinant Proteins. |
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Categoria do assunto: |
L Ciência Animal e Produtos de Origem Animal |
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Marc: |
LEADER 02917naa a2200289 a 4500
001 2071411
005 2017-06-23
008 1990 bl uuuu u00u1 u #d
100 1 $aKNIGHT, C. H.
245 $aGalactopoietic and mammogenic effects of long-term treatment with bovine growth hormone and thrice daily milking in goats.
260 $c1990
520 $aAbstract: Starting in mid-lactation, goats were treated daily for 22 weeks with 0.15 mg recombinant bovine GH (bGH)/kg, or an equivalent volume of vehicle. One gland of each goat was milked thrice daily throughout treatment, the other twice daily. Mammary differentiation was studied in biopsy samples obtained before treatment and after 3 and 22 weeks of treatment, by determination of in-vitro synthesis rates of milk constituents and measurement of enzyme activities. Mammary growth was measured using a whole-body imaging technique (magnetic resonance imaging; MRI). bGH caused an immediate and sustained increase in milk yield of approximately 23% overall, whilst the glands milked thrice daily produced approximately 14% more than the control glands milked twice daily. The effects of the combined treatment were additive, but not synergistic. A synergistic effect of the combined treatment resulted in a significant improvement in lactation persistency. A stimulatory effect of milking frequency on mammary enzyme activities was evident only in bGH-treated goats at 3 weeks, but in both groups at 22 weeks. Synthesis rates of casein and lactose were increased at 3 weeks only by the combined treatment. Thus bGH accelerated or augmented the differentiative response to thrice daily milking. Mammary parenchyma volume, estimated by MRI, increased significantly during the first 12 weeks of bGH treatment and remained higher throughout the rest of the treatment period. Cell number was estimated from parenchyma volume and DNA concentration; this decreased significantly in the controls between weeks 1 and 22, but remained constant in the bGH group. In nine of the ten goats, parenchyma volume and cell number increased in the gland milked thrice daily relative to the control gland milked twice daily during the course of the experiment. Thus bGH stimulated growth of the mammary gland over and above that induced by the frequent milking. The absence of any detectable increase in thymidine incorporation suggests that this growth consisted of cellular hypertrophy rather than hyperplasia.
650 $aFatty Acids
650 $aGoats
650 $aLactation
650 $aMammary Glands
650 $aMilk
650 $aPhysiology
650 $aRecombinant Proteins
653 $aDrug effects
653 $aGalactosy
653 $aGlucosephosphate Dehydrogenase
653 $aGrowth Hormone
653 $aTime Factors
700 1 $aFOWLER, P. A.
700 1 $aWILDE, C. J.
773 $tJournal of Endocrinology$gv. 127, n. 1, p. 129-138, Oct. 1990.
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Registro original: |
Embrapa Caprinos e Ovinos (CNPC) |
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