Recent progress towards matching feed quality to the amino acid needs of ruminants

Oldham, J. D.

doi:10.1016/0377-8401(93)90069-v

Cited by 11 publications

(11 citation statements)

References 31 publications

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“…The rise of net mammary uptake of AA resulted to an increase in mammary plasma flow that was also observed by Mackle et al (1999) and Bequette et al (2001) during hyperinsulinemic-euglycemic clamps. The effect of infused glucose on mammary arterial supply of AA is in agreement with the concept of coordination of 'labile protein reserves' between body tissue and mammary use (Oldham, 1993). The considerable enhancement of partitioning of blood AA towards the mammary gland is similar to that observed during hyperinsulinemic-euglycemic clamps applied to dairy ruminants (Mackle et al, 2000;Bequette et al, 2001).…”

Section: Amino Acids and Protein Synthesissupporting

confidence: 81%

Infusion of Glucose Directs Circulating Amino Acids to the Mammary Gland in Well-Fed Dairy Cows

Rulquin

Rigout

Lemosquet

et al. 2004

Journal of Dairy Science

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The effect of intestinal glucose supply on mammary utilization of amino acids (AA) was studied in four lactating dairy cows. Glucose (0, 443, 963, and 2398 g/d) was continuously infused in the duodenum over 14-d periods using a Latin square design. A grass silage-based diet was formulated so that treatments (diet + infusions) were isoenergetic and isonitrogenous and met 100 and 110% of energy and protein requirements, respectively. Mammary AA uptake was determined by arteriovenous difference and continuous blood flow measurement. The milk protein yield tended to be quadratically increased (to +88 g/d for 963 g of glucose) by glucose infusion, but milk protein content was not significantly affected. Treatments did not change significantly arterial concentrations of urea and glucogenic AA. Mammary arterial fluxes of essential AA increased linearly with glucose infusion, whereas fluxes of nonessential and glucogenic AA were not significantly affected. Mammary arteriovenous differences and extraction rates were roughly unchanged by treatments. Mammary uptake of all essential AA, excluding Arg and Val, increased linearly with increasing supply of glucose. Ratio of blood AA uptake to milk protein output increased significantly for His, Met, and Leu. For the highest infused dose of glucose, all AA except for His were taken up in excess relative to their secretion in milk. Based on evolution of extraction rate and ratio of uptake to output, His and Leu could have limited the milk protein yield response to glucose infusions.

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Section: Amino Acids and Protein Synthesissupporting

confidence: 81%

Infusion of Glucose Directs Circulating Amino Acids to the Mammary Gland in Well-Fed Dairy Cows

Rulquin

Rigout

Lemosquet

et al. 2004

Journal of Dairy Science

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“…364 P. LEBZIEN AND J. VOIGT Beever and Cottrill (1994) concluded in their review, "that the values currently enshrined in the new systems to predict microbial protein synthesis may be an oversimplification of reality", and "that the importance of ruminally bypassed protein has been overemphasized". Other authors recognised "that the ratio of microbial protein to fermentable energy is variable, but in ways which are difficult to predict" (Oldham, 1993) and reducing degradability of protein also means lower fermentability and subsequent microbial protein production (Voigt and Piatkowski, 1987;Erdman and Komaragiri, 1991). In 1978 Jarrige et al already proposed to use a regression equation with the intake of digestible organic matter and "insoluble" nitrogen as explanatory variables to determine the non ammonia nitrogen flow at the duodenum.…”

Section: Introductionmentioning

confidence: 99%

Calculation of utilizable crude protein at the duodenum of cattle by two different approaches

Lebzien¹,

Voigt²

1999

Archiv für Tierernaehrung

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The duodenal flow of utilizable crude protein (crude protein minus endogenous protein) in cows was estimated using dietary parameters, first by multiple regression and secondly by the addition of microbial protein and undegraded feed protein. These estimates were compared with 327 results from experiments conducted with fistulated cows in Braunschweig-Völkenrode and Rostock-Dummerstorf. The regressions and the measurements for microbial protein synthesis as well as feed protein degradation and organic matter fermentation in the rumen were based on the same experimental data set. The prediction of utilizable crude protein (uCP) at the duodenum by regression with digested organic matter (kg DOM) and undegraded feed protein (g UDP) as predicting variables, was more accurate than the value given by microbial protein synthesis and rumen protein degradability. The regression model [g uCP = [188.5-(116.5 (UDP/CP))] DOM + 1.03 UDP] had the highest coefficient of determination (r2 = 0.91) and the lowest coefficient of variation (cv = 8.6); indicating the model's superiority over the other method of estimation.

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“…Em vitelos consideraram como limitantes os aminoácidos sulfurados, a lisina e, provavelmente, a treonina (WILLIAMS, 1994). Entretanto, a resposta produtiva, aos aminoácidos considerados limitantes nos ruminantes, é menos consistente do que aquela obtida para as aves (OLDHAM, 1993).…”

Section: Exigências De Aminoácidos Para Ruminantesunclassified

Importância da inter-relação carboidrato e proteína em dietas de ruminantes

et al. 2005

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ResumoEsta revisão de literatura teve como objetivo relacionar a importância da sincronização de carboidratos e proteínas em dietas de ruminantes, pois os sistemas de exigências nutricionais de ruminantes que dão suporte às formulações de rações exigem que os alimentos comumente utilizados na alimentação sejam fracionados no sentido de melhor caracterizá-los. Ao longo dos anos houve considerável avanço na nutrição dos ruminantes, mas esse progresso, na maioria das vezes, foi baseado em determinações empíricas que desconsideravam as múltiplas inter-relações microbianas e consideravam o ecossistema ruminal muito complexo e não compreendido. Palavras-chave: Energia, proteína, ruminantes, sistema cornell. AbstractThis literature review had as objective to relate the importance of the carbohydrate and protein synchronization in ruminant diets. The nutritional requirements systems to ruminant that give support to the diets formulations, require that the feeds commonly used in the feeding are fractional for best characterize them. Along the years there was considerable progress in the ruminant nutrition, but that progress, most of the time, was based on empiric determinations that not respected the multiple microbial interrelations and they considered the ruminal ecosystem are very complex and not understood.

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Recent progress towards matching feed quality to the amino acid needs of ruminants

Cited by 11 publications

References 31 publications

Infusion of Glucose Directs Circulating Amino Acids to the Mammary Gland in Well-Fed Dairy Cows

Infusion of Glucose Directs Circulating Amino Acids to the Mammary Gland in Well-Fed Dairy Cows

Calculation of utilizable crude protein at the duodenum of cattle by two different approaches

Importância da inter-relação carboidrato e proteína em dietas de ruminantes

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