Nitrogen Metabolism in the Rumen

Leng, R. A.; Nolan, John

doi:10.3168/jds.s0022-0302(84)81409-5

Cited by 288 publications

(173 citation statements)

References 89 publications

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“…d -1 ), alone or with Met, increased plasma Lys concentration by 117 and 135% respectively compared to treatment 'Met'. Since AA absorption by the rumen wall is negligible [10], these results confirmed that a substantial proportion of the administered AA escaped the rumen and was absorbed from the small intestine. The changes in plasma AA profile 3 h after AA administration confirmed that this mechanism was rapid.…”

Section: Resultssupporting

confidence: 71%

Rumen escape of methionine and lysine administered intraruminally to growing double-muscled Belgian Blue bulls

et al. 2002

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tected AA from rumen fermentation are sometimes incorporated into the diets in order to improve protein efficiency. These AA are less used for growing cattle because of a lower economical interest related to less intensive breeding systems. INTRODUCTIONMethionine (Met) and Lysine (Lys) are often the first and second limiting amino acids (AA) for milk [13,15] Abstract -In many dietary conditions, methionine (Met) and lysine (Lys) are the most limiting amino acids (AA) for ruminants. The AA protected from ruminal fermentation are not commercially available, with the exception of Met which is not always economical, especially for meat production. This study measured ruminal escape of free Met and Lys supplemented intraruminally to fast growing bulls. Six double-muscled Belgian Blue bulls, fed a high concentrate diet and fitted with a rumen cannula, received free Met (40 g . d -1 ) and free Lys (60 g . d -1 ), individually or simultaneously, in a duplicated Latin square design. The mean ruminal escape of Met and Lys reached 37 and 45% respectively, and did not differ if administered separately or together. Plasma Lys and Met concentrations were increased by 504 and 126%, respectively. Substantial proportions of free AA escaped ruminal fermentation and were available for absorption from the small intestine when they were administered at physiologically high levels.ruminant / methionine / lysine / rumen escape / plasma Reprod. Nutr. Dev. 42 (2002) 537-544 537

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Section: Resultssupporting

confidence: 71%

Rumen escape of methionine and lysine administered intraruminally to growing double-muscled Belgian Blue bulls

et al. 2002

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“…Unlike current recommendations for feeding dairy cattle (NRC 2001), previous protein recommendation (NRC 1989) was not specific to rumen undegradable protein (RUP) and rumen degradable protein (RDP). This is very important because proper protein nutrition in ruminants depends on consumption of RUP and RDP to support optimum rumen fermentation and microbial protein yield, provide metabolizable protein for utilization by maternal and fetal tissues (Leng and Nolan 1984) and desirable reproductive performance (Curtis et al 1985).…”

Section: Nutrient Densitymentioning

confidence: 99%

Factors affecting dry matter intake prepartum in relationship to etiology of peripartum lipid-related metabolic disorders: A review

Hayırlı¹,

Grummer

2004

Can. J. Anim. Sci.

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Hayirli, A. and Grummer, R. R. 2004. Factors affecting dry matter intake prepartum in relationship to etiology of peripartum lipid-related metabolic disorders: A review. Can. J. Anim. Sci. 84: 337-347. Transition from gestation to lactation is a tremendous challenge for dairy cattle and requires metabolic and hormonal adjustments. The periparturient period, particularly the last week of gestation, is characterized by a dramatic decline (20 to 40%) in dry matter intake (DMI) prior to parturition and a slow rate of increase in DMI after parturition. As a result of negative energy balance during the periparturient period, excessive fat mobilization in adipose tissue and inability of disposing fatty acids (FA) via β-oxidation and exporting triglyceride (TG) as very low density lipoproteins (VLDL) in the liver cause hepatic lipidosis. Controlling hepatic lipidosis, therefore, depends on either limiting non-esterified fatty acids (NEFA) uptake by the liver or increasing oxidation of FA and export of TG by the liver, or both. Results of studies regarding lipid metabolism in the liver to minimize lipidosis are controversial. Thus, until factor(s) limiting hepatic VLDL-TG export are identified, limiting fat mobilization from adipose tissue will play a key role in prevention of hepatic lipidosis and ketosis. Depression in DMI prior to parturition shifts metabolism from anabolism to catabolism. Animal factors such as parity and body condition score and dietary factors such as density of organic nutrients influence DMI. Particularly, increasing energy density of the transition cow diet, without causing acidosis, by supplemental nonstructural carbohydrate (NFC) increases DMI and serum insulin concentration, which suppress lipolysis in adipose tissue and favors anabolic status. In summary, level of DMI and magnitude of DMI depression prior to parturition are linked to the etiology of postpartum lipid-related metabolic disorders. Thus, easing transition from gestation to lactation by offering high dietary NFC in consideration with other factors allows cows to produce more milk, become healthier, and be rebred sooner during postpartum.Key words: Periparturient dairy cattle, dry matter intake, hepatic lipidosis, ketosis Hayirli, A. et Grummer, R. R. 2004. Paramètres affectant l'ingestion de matière sèche avant le vêlage et leurs liens avec l'é-tiologie des troubles peripartum du métabolisme des lipides. Can. J. Anim. Sci. 84: 337-347. Le passage de la gestation à la lactation est une dure épreuve pour les vaches laitières et exige certains ajustements métaboliques et hormonaux. La période entourant la mise bas, en particulier la dernière semaine de gestation, se caractérise par une chute draconienne (de 20 à 40 %) de l'ingestion de matière sèche (IMS) suivie par la lente remontée de cette dernière après le vêlage. À cause du bilan énergétique négatif survenant peu avant la mise bas, une mobilisation excessive des graisses dans les tissus adipeux et l'incapacité d'éliminer les acides gras par β-oxydation et d'exporter les trigly...

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“…One of the main goals of the ruminant nutritionist is to decrease excessive protein breakdown and ammonia production by the rumen microbial population and, as a result, to increase nitrogen efficiency in the ruminant animal (Leng & Nolan, 1984). Gram-negative bacteria from the genus Prevotella (formerly classified as Bacteroides) play a significant role in the breakdown of peptides in the rumen (Bladen et al, 1961;Russell, 1983;Depardon et al, 1996).…”

Section: Introductionmentioning

confidence: 99%

Cloning and functional expression of dipeptidyl peptidase IV from the ruminal bacterium Prevotella albensis M384T

Walker¹,

McEwan²,

Wallace³

2003

Microbiology

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Ruminal bacteria of the genus Prevotella play a crucial role in peptide breakdown in the rumen, a component of protein catabolism that leads to the inefficient use of dietary protein by ruminant animals. This is the first report of the cloning of a peptidase gene from a ruminal bacterium. Part of the dipeptidyl peptidase type IV (DPP-IV) gene from Prevotella albensis M384 T was cloned using degenerate primers designed from conserved regions found within other known DPP-IV sequences. Flanking regions were determined by genomic walking. The DPP-IV gene was expressed in Escherichia coli. The cloned enzyme required a free N terminus and catalysed the removal of X-Pro dipeptide from proline-containing oligopeptides, where proline was the second residue from the N terminus. It was inhibited by serine protease inhibitors and the substrate analogue for mammalian DPP-IV, diprotin A. The properties of the cloned enzyme were similar to those of the native form in P. albensis and, in general, DPP-IVs from other organisms. The enzyme contained a conserved motif which is associated with the S9 class of prolyl oligopeptidases. The DPP-IV gene appeared not to be part of a contiguous operon. Regions with similarity to other putative promoters of Prevotella spp. were also identified. Construction of a phylogenetic tree demonstrated that the DPP-IV of P. albensis clusters with other DPP-IVs found in bacteria of the Cytophaga-Flexibacter-Bacteroidaceae (CFB) phylum, which are more closely related to eukaryotic DPP-IVs than the DPP-IV-like enzyme (PepX) of the lactic acid bacteria.

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Nitrogen Metabolism in the Rumen

Cited by 288 publications

References 89 publications

Rumen escape of methionine and lysine administered intraruminally to growing double-muscled Belgian Blue bulls

Rumen escape of methionine and lysine administered intraruminally to growing double-muscled Belgian Blue bulls

Factors affecting dry matter intake prepartum in relationship to etiology of peripartum lipid-related metabolic disorders: A review

Cloning and functional expression of dipeptidyl peptidase IV from the ruminal bacterium Prevotella albensis M384T

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