Amino acid availability in ruminants of cereals and cereal co‐products

Abstract

Wiley: 12 months González, J.; Arroyo, JM.; Guevara-González, JA.; Mouhbi, R.; Piquer Querol, O.; Moya, V. (2014). Amino acid availability in ruminants of cereals and cereal co-produtcs.

Ruminal Microbial Degradation of Individual Amino Acids from Heat-Treated Soyabean Meal and Corn Gluten Meal in Continuous Culture

“…The lower ruminal degradation of Asp after the in situ ruminal exposure of several supplements was also reported previously [6,45]. Gonzalez et al [12] suggested that hydrophobic non-polar AAs were less degradable in the rumen compared with hydrophilic polar AAs. Other factors, such as the solubility of the protein itself and the location of the protein within the structure of the feed or the protein, may also affect the rumen-degradability of individual AAs.…”

“…However, data from other authors [7,43] have shown the degradation of Met to be dependent on the feedstuff. The degradation of branched-chain AAs was higher than total AA degradation in CGM, although some authors found these AAs to be more resistant to degradation in the rumen, depending on the protein source [7,12,13]. Alanine, Asp, Glu, Gly, Pro and Tyr were more degradable than the average total AA in CGM, and only Asp, Pro and Tyr in HSBM.…”

“…Almost all research conducted to date investigating the rumen-degradability of individual AAs within feeds used the in situ technique [9,10,26], where most estimates were obtained after a single-point incubation, microbial colonization was not corrected in residual feed after incubation and the dynamic effects of the rumen were not considered, which may bias the estimates [12]. The slope technique is an alternative method to determine individual AA degradation.…”

“…Most available data on rumen degradability of individual AA within and between feeds were obtained using the in situ nylon bag technique [9][10][11]. However, there are some shortcomings in the methodology, as most estimates are obtained after 12 or 16 h of ruminal incubation and samples may be contaminated with amino acids from microbial origin, which may affect estimates of dietary AA supply [11,12]. The slope technique, originally proposed by Titgemeyer et al [13], is a robust method to measure the rumen degradability of individual AA, but its application in vivo is complicated, labor intensive and expensive, and few data are available [13].…”