Limiting amino acids in meat and bone and poultry by-product meals.

Abstract

ABSTRACT:In situ, digestion, and growth studies were conducted to evaluate four meat and bone meals and six poultry by-product meals as sources of escape protein and to predict the first-limiting amino acid for growing calves. Escape protein values, determined by 12-h in situ incubation, ranged from 41.7 to 51.0% of CP for meat and bone meals; poultry by-product meals ranged from 32.0 to 39.8%. True protein digestion in the gastrointestinal tract of lambs differed among protein sources ( P < .05), ranging from 79 to 95%. In each of three growth trials, 60 steers (258 ± 24, 241 ± 23, and 230 ± 16 kg for Trials 1, 2, and 3, respectively) were supplemented with 4 of the 10 protein sources along with a urea supplement. Protein sources were fed at 30, 40, 50, and 60% of the supplemental CP, with urea supplying the remainder. Protein efficiency differed among treatments ( P < .10), ranging from .61 to 1.55. Amino acid composition was determined for each protein source, and the individual metabolizable amino acids were regressed on the protein efficiency values. Escape protein values were correlated ( R 2 = .75) with protein efficiency but had a negative slope. Metabolizable methionine was the only amino acid moderately correlated ( R 2 = .40, slope = 1.9) to protein efficiency, whereas other amino acids either correlated poorly or had negative slopes. These data indicate that the protein value of meat and bone meal and poultry by-product meal is limited by the amount of metabolizable methionine they contain.

Evaluation of feather meal as a source of sulfur amino acids for growing steers.

“…Analysis of the residue following incubation was chosen because Varvikko (1986) and Crooker et al (1981) reported that certain amino acids were more resistant to microbial degradation than others. Likewise, Klemesrud et al (1997b) reported that amino acid profiles of dietary protein were altered during in situ incubation.…”

“…Residue remaining after incubation was composited by protein source and analyzed for amino acid content (Klemesrud et al, 1997b). Samples were hydrolyzed in 6 N HCl, and amino acid content of hydrolyzates was determined with ion-exchange chromatography (AOAC, 1984).…”

“…To meet the MP requirement of the animal and increase ADG, escape protein sources generally are supplemented (Goedeken et al, 1990a;Gibb et al, 1992b;Klemesrud et al, 1997b). However, sources of escape protein vary markedly in amino acid content, influencing the supply of metabolizable amino acids available for the animal (Merchen and Titgemeyer, 1992).…”

“…Meat and bone meal (MBM) is a good source of escape protein, but it is deficient in Met (Klemesrud et al, 1997b). Supplementation of rumen-protected Met in-207 ments containing MBM.…”

Ruminal degradability of neutral detergent insoluble protein of selected protein sources

“…Ruminal undegraded protein (RUP) for the protein sources was determined following 12 h (O'Mara et al 1997;Klemesrud et al 1997). Duplicate samples of each protein source were weighed into nylon bags (9 × 12 cm; 41 µm pore size) and incubated in the rumen of a ruminally fistulated non-lactating Holstein cow for 12 h. Following removal from the rumen, the bags were rinsed in tap water and dried at 55°C for 48 h.…”