Effect of Bovine Somatotropin on Metabolism of Lactating Dairy Cows: Influence on Rates of Irreversible Loss and Oxidation of Glucose and Nonesterified Fatty Acids

Bauman, Dale E.; Peel, C. J.; Steinhour, Wayne D.; Reynolds, Paul J.; Tyrrell, H.F.; Brown, A. C. G.; Haaland, G. L.

doi:10.1093/jn/118.8.1031

Cited by 157 publications

(93 citation statements)

References 40 publications

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“…β-hydroxybutyrate arises mainly from rumen butyrate in the fed animal (Leng and West 1969). The high values of concentrations of arterial plasma β-hydroxybutyrate of non-cooled animals would be consistent with an increase in oxidation of free fatty acids (Bauman et al 1988). A greater energy requirement due to panting of non-cooled animals during heat stress (McDowell 1972), resulting in increased hepatic ketogenesis due to greater mobilization of fat reserves (Schultz 1974), might be apparent under high temperatures (Oshiro et al 1981).…”

Section: Discussionmentioning

confidence: 95%

Effects of evaporative cooling on the regulation of body water and milk production in crossbred Holstein cattle in a tropical environment

2008

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The aim of this study was to determine how evaporative cooling modifies body function with respect to water metabolism and other variables relevant to milk synthesis in crossbred cattle. The study was conducted on two groups of 0.875HF:0.125RS crossbred Holstein cattle (87.5%) housed in an open-sided barn with a tiled roof (non-cooled animals) and in a close-sided barn under an evaporative cooling system (cooled animals). The maximum ambient temperature and relative humidity for the non-cooled group were 33 degrees C and 61%, with the corresponding values for the evaporatively cooled barn being 28 degrees C and 84%, respectively. The temperature humidity index (THI) of under non-cooled conditions was higher (P < 0.05) than that in the cooled barn. Rectal temperatures and respiration rates of non-cooled animals were higher (P < 0.05) than those of cooled animals. Daily dry matter intake (DMI) of cooled animals was higher while water intakes were lower (P < 0.05) than those of non-cooled animals. The mean absolute values of plasma volume, blood volume, and extracellular fluid (ECF) of cooled animals were significantly higher (P < 0.05) than those of non-cooled animals throughout all stages of lactation. Milk yields of cooled animals were higher by 42%, 36% and 79% on average than those of non-cooled animals during early-, mid- and late-lactation, respectively. The decline in milk yields as lactation advances was markedly apparent in late-lactating non-cooled animals, while no significant changes in milk composition at different stages of lactation were observed in either group. Mean arterial plasma concentrations, arteriovenous concentration differences (A-V differences) and the extraction ratio across the mammary gland for acetate, glucose and triglyceride of cooled animals were not significantly different compared with values for non-cooled animals. No differences were seen in plasma hormonal levels for triiodotyronine (T(3)) and insulin-like growth factor-1 (IGF-1), but plasma cortisol and thyroxine (T(4)) levels tended to be lower in non-cooled animals. This study suggests that low cooling temperature accompanied by high humidity influences a galactopoietic effect, in part through increases in ECF, blood volume and plasma volume in association with an increase in DMI, which partitions the distribution of nutrients to the mammary gland for milk synthesis. Cooled animals were unable to maintain high milk yield as lactation advances even though a high level of body fluids was maintained during long-term cooled exposure. The decline in milk yield, coinciding with a decrease in net energy for lactation as lactation advances, could be attributed to a local change within the mammary gland.

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Section: Discussionmentioning

confidence: 95%

Effects of evaporative cooling on the regulation of body water and milk production in crossbred Holstein cattle in a tropical environment

2008

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“…Segundo Bauman et al (1988) e Tyrrel et al (1988, a suplementação com somatotropina recombinante bovina, para vacas em lactação, acarreta um aumento da demanda por nutrientes, consequentemente aumenta a ingestão de matéria seca, por parte do animal, mas a velocidade desse aumento é de tal magnitude, que se faz necessária a mobilização de reservas corporais para sustentação dos níveis de produção. As principais reservas mobilizadas nestes casos são os ácidos graxos não-esterificados presentes no tecido adiposo EISEMANN et al, 1986).…”

Section: Discussionunclassified

“…Para que isso realmente aconteça são necessárias alterações metabólicas como o aumento da taxa de gliconeogênese hepática e a musculatura esquelética deve reduzir o consumo desse substrato e diversos tecidos devem reduzir a oxidação de glicose (PEEL; BAUMAN et al, 1988;BURTON et al, 1994;).…”

Section: Discussionunclassified

“…Para se estabelecer a extensão da mobilização dos ácidos graxos, que são conseqüência da utilização da rBST, temos os valores plasmáticos de NEFA e o balanço energético como ferramentas muito úteis, uma vez que a correlação entre eles é muito alta (EISEMANN et al, 1986;BAUMAN et al, 1988). Ao avaliar os efeitos metabólicos da aplicação de rBST sobre o metabolismo de lipídios em vacas leiteiras observa-se que as alterações na partição de nutrientes, provocada pelo maior direcionamento de nutrientes para a glândula mamária, sustentando os aumentos de produção, associadas com um aumento mais lento no consumo de matéria seca em relação a estes aumentos de produção de leite, resultam em mobilização de reservas corporais e na maior concentração plasmática de NEFA, mesmo quando vacas são tratadas com rBST em diferentes fases da lactação.…”

Section: Considerações Sobre a Somatotropinaunclassified

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Influência da aplicação da somatotropina recombinante bovina (rBST) no lipidograma e composição do leite de bubalinos da raça Murrah em lactação

Feckinghaus¹

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“…For example, exogenous administration of GH to dairy cows increases the oxidative use of lipids at the expense of glucose (Bauman et al 1988). A major portion of this organismal effect represents the ability of GH to attenuate glucose uptake by skeletal muscle (Sechen et al 1990, Boisclair et al 1994.…”

Section: Introductionmentioning

confidence: 99%

Dairy cows experience selective reduction of the hepatic growth hormone receptor during the periparturient period

Kim¹,

Rhoads²,

Block³

et al. 2004

Journal of Endocrinology

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At parturition, dairy cows experience a 70% reduction in plasma IGF-I. This reduction coincides with decreased abundance of GHR1A, the liver-specific transcript of the growth hormone receptor (GHR) gene, suggesting impaired growth hormone-dependent synthesis of IGF-I. It is not immediately obvious that the periparturient reduction in GHR1A is sufficient to reduce hepatic GHR abundance. This is because 50% of total GHR mRNA abundance in prepartum liver is accounted for by ubiquitously expressed transcripts which remain collectively unchanged at parturition. In addition, the possibility that parturition alters GHR expression in other growth hormone target tissue has not been examined. To address these questions, we measured GHR gene expression and GHR protein in liver and skeletal muscle of four dairy cows on days -35,+3 and+56 (relative to parturition on day 0). Hepatic GHR abundance and GHR1A transcripts were lower on day+3 than on day -35 and returned to late pregnancy value by day+56. Additional studies in two other groups of cows indicated that the hepatic levels of the GHR protein recovered substantially within 10 days after parturition. These changes occurred without variation in the abundance of HNF4, a liver-enriched transcription factor activating the promoter responsible for GHR1A synthesis. In contrast to liver, levels of GHR gene expression and GHR protein were identical on days -35,+3 and+56 in skeletal muscle. These data suggest a role for the GHR in regulating tissue-specific changes in growth hormone responsiveness in periparturient dairy cows.

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Effect of Bovine Somatotropin on Metabolism of Lactating Dairy Cows: Influence on Rates of Irreversible Loss and Oxidation of Glucose and Nonesterified Fatty Acids

Cited by 157 publications

References 40 publications

Effects of evaporative cooling on the regulation of body water and milk production in crossbred Holstein cattle in a tropical environment

Effects of evaporative cooling on the regulation of body water and milk production in crossbred Holstein cattle in a tropical environment

Influência da aplicação da somatotropina recombinante bovina (rBST) no lipidograma e composição do leite de bubalinos da raça Murrah em lactação

Dairy cows experience selective reduction of the hepatic growth hormone receptor during the periparturient period

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