The effect of temperature during processing of rape seed meal on amino acid degradation in the rumen and digestion in the intestine

Rumen and total intestinal tract digestibility of protein and amino acids from different roughages, determined <i>in situ</i>

“…The above results indicate that intestinal crude protein digestibility could be a good predictor of intestinal AA digestibility. However, in other studies with intact and rumen undegraded protein, the higher digestibility of AA than of crude protein has been found for roughages (Skórko-Sajko et al, 1994) and for rapeseed meal (Dakowski et al, 1996).…”

“…This was also observed for many other AA, such as lysine, isoleucine, leucine, phenylalanine and valine, all of which had low degradabilities. This was probably due to the heat treatment during the production process which may modify the degradation of protein and individual AA (Kerry et al, 1993;Dakowski et al, 1996). found that the effective degradability of crude protein was a good predictor of effective degradability of total AA and lysine and methionine originating from concentrates, although in some feeds (cottonseed cake, palm kernel cake, maize gluten feed) the effective degradability of methionine could be overestimated.…”

“…Arginine has been assumed to be the most quickly degraded amino acid in the rumen (Chalupa, 1976;Tamminga, 1979;Mir et al, 1984;Cozzi et al, 1995;Dakowski et al, 1996), and according to Puchala et al (1991), the degradability of arginine in plant proteins (particularly in lucerne hay, grass hay, maize and grass silage) is faster than in proteins of animal origin feeds. A substantial part of feed arginine is degraded during the ensiling process (Makoni et al, 1990cf.…”

“…Since the amount of microbial protein synthesized in the rumen is inadequate to fulfill the AA requirement for high producing cattle, the quantity of feed protein escaping rumen degradation and its amino acid composition, particularly the amount of the most limiting amino acids, play an important role in covering an animal's AA requirements. The degradability of crude protein has been used to predict the degradation of individual AA and their supply to the duodenum (Rulquin and Verite, 1993), although results from some experiments suggest that the degradability of total AA can deviate from that of crude protein, and that variations in degradation can occur among individual amino acids (Susmel et al, 1989;Boila and Ingalls, 1994;Skorko-Sajko et al, 1994;Cozzi et al, 1995;Dakowski et al, 1996). Therefore, prediction of the amount of feed AA supplied at the duodenum based on the original AA composition of the feed and degradation of crude protein can be inaccurate.…”

Effects of temperature, heating time and particle size on values of rumen undegradable protein of roasted soybean

“…One of the first noticeable changes of proteins on heating (even at temperatures around 100 ºC) was the loss of labile amino acids such as cysteine and lysine. Lysine is one of the most temperature-sensitive amino acids and destruction of lysine is often 5 to 15 times greater than that occurring with other amino acids (Dakowski et al, 1996).…”