Journal ArticleDOI
A net carbohydrate and protein system for evaluating cattle diets: II. Carbohydrate and protein availability.
Charles J. Sniffen,J D O'Connor,P.J. Van Soest,Danny G. Fox,James B. Russell,James B. Russell,James B. Russell +6 more
TLDR
The Cornell Net Carbohydrate and Protein System has a submodel that predicts rates of feedstuff degradation in the rumen, the passage of undegraded feed to the lower gut, and the amount of ME and protein that is available to the animal.Abstract:
The Cornell Net Carbohydrate and Protein System (CNCPS) has a submodel that predicts rates of feedstuff degradation in the rumen, the passage of undegraded feed to the lower gut, and the amount of ME and protein that is available to the animal. In the CNCPS, structural carbohydrate (SC) and nonstructural carbohydrate (NSC) are estimated from sequential NDF analyses of the feed. Data from the literature are used to predict fractional rates of SC and NSC degradation. Crude protein is partitioned into five fractions. Fraction A is NPN, which is trichloroacetic (TCA) acid-soluble N. Unavailable or protein bound to cell wall (Fraction C) is derived from acid detergent insoluble nitrogen (ADIP), and slowly degraded true protein (Fraction B3) is neutral detergent insoluble nitrogen (NDIP) minus Fraction C. Rapidly degraded true protein (Fraction B1) is TCA-precipitable protein from the buffer-soluble protein minus NPN. True protein with an intermediate degradation rate (Fraction B2) is the remaining N. Protein degradation rates are estimated by an in vitro procedure that uses Streptomyces griseus protease, and a curve-peeling technique is used to identify rates for each fraction. The amount of carbohydrate or N that is digested in the rumen is determined by the relative rates of degradation and passage. Ruminal passage rates are a function of DMI, particle size, bulk density, and the type of feed that is consumed (e.g., forage vs cereal grain).read more
Citations
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Journal ArticleDOI
The nutritive value and forage productivity of Leucaena leucocephala
TL;DR: Leucaena forage productivity indicated that the optimum harvesting interval or age at harvest should be about 8 weeks or just before the onset of flowering, and a model developed in one source suggested 42% rumen degradable protein (RDP), with 48% of the undegradableprotein (UDP) being digested post ruminally, giving a TADCP value of 70%.
Journal ArticleDOI
The effect of ruminal bypass lysine and methionine on milk yield and composition of lactating cows
S. Xu,Joe Harrison,William Chalupa,Charles J. Sniffen,W.E. Julien,Hiroyuki Sato,T. Fujieda,Kazumasa Watanabe,T. Ueda,H. Suzuki +9 more
TL;DR: The mammary arteriovenous difference of whole blood AA indicated that Met along with His and Arg may be the most limiting AA for milk yield.
Journal ArticleDOI
Invited review: Nitrogen in ruminant nutrition: A review of measurement techniques.
Alexander N. Hristov,André Bannink,Les A. Crompton,Pekka Huhtanen,Michael Kreuzer,Mark McGee,Pierre Noziere,Christopher K. Reynolds,Ali R. Bayat,David R. Yáñez-Ruiz,Jan Dijkstra,Ermias Kebreab,Angela Schwarm,K. J. Shingfield,Zhongtang Yu +14 more
TL;DR: Methods to study ruminant N metabolism have been developed over 150 yr of animal nutrition research, but many of them are laborious and impractical for application on a large number of animals and results can be variable, especially the methods based on measurements of digesta or blood flow.
Journal ArticleDOI
Endogenous fraction and urinary recovery of purine derivatives obtained by different methods in Nellore cattle.
Analívia Martins Barbosa,Rilene Ferreira Diniz Valadares,S.C. Valadares Filho,Douglas dos Santos Pina,Douglas dos Santos Pina,Edenio Detmann,Maria Ignez Leão +6 more
TL;DR: The data suggest that in Nellore heifers the respective values of endogenous PD excretion, urinary recovery, and true digestibility of RNA in the small intestine were 0.30, 0.80, and 0.93, respectively.
Journal ArticleDOI
Feed intake relative to stage of lactation for dairy cows consuming total mixed diets with a high or low ratio of concentrate to forage
TL;DR: The effect of feed quality on the relationship between intake and stage of lactation in dairy cows was examined and significant interactions between total mixed diet and period were observed for DMI and milk yield, however, no significant residual effects of changing from one total mixed diets to the other were observed.
References
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Journal ArticleDOI
Methods for dietary fiber, neutral detergent fiber, and nonstarch polysaccharides in relation to animal nutrition.
TL;DR: In addition to NDF, new improved methods for total dietary fiber and nonstarch polysaccharides including pectin and beta-glucans now are available and are also of interest in rumen fermentation.
Forage fiber analyses (apparatus, reagents, prcedures, and some applications)
H.K. Goering,P.J. Van Soest +1 more
Journal ArticleDOI
A net carbohydrate and protein system for evaluating cattle diets: I. Ruminal fermentation.
TL;DR: The Cornell Net Carbohydrate and Protein System (CNCPS) has a kinetic submodel that predicts ruminal fermentation and the protein-sparing effect of ionophores is accommodated by decreasing the rate of peptide uptake by 34%.