The amino‐acid composition of processed bones and meat

Abstract

Quantitative amino‐acid analyses were made by ion‐exchange chromatography on two samples of commercial feeding meals containing high contents of meat and bone, respectively, after processing in an Iwel cooker and acid hydrolysis. The processed bones had an amino‐acid composition close to that of collagen with slightly larger amounts of most essential amino‐acids. The meat material contained significantly higher amounts of essential amino‐acids than the processed bones and had an overall composition intermediate between whole muscle protein and collagen. The hydroxyproline contents, supported by values for other amino‐acids, indicated that the protein from processed bones contained about 83%, and the meat protein some 58%, of collagen, and that in commercial meat and meat‐and‐bone meals 50 to 65% of the total protein was collagen. Since collagen is deficient in several essential amino‐acids, its presence in large amounts may be expected significantly to reduce the nutritional value of the total protein of feeding meal. It is suggested that the determination of hydroxyproline could form the basis of a simple method for the assessment of protein quality in meat and bone meals.

Effects of inulin or yeast cell-wall extract on nutrient digestibility, fecal fermentative end-product concentrations, and blood metabolite concentrations in adult dogs fed raw meat–based diets

“…3 Because the fiber sources and amounts used in the present study were tightly controlled, differences in total tract apparent macronutrient digestibility were likely not due to fiber but to the higher concentration of animal fiber (ie, collagen) in the chicken-based versus beef-based diets, which was also considered in another study. 36 Fecal fermentative end-product concentrations can be used to infer the degree of protein and carbohydrate fermentation in the large bowel. Carbohydrate fermentation by colonic microbes primarily produces SCFAs in the large intestine, providing an important energy source for colonocytes.…”

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

“…Like blood meal, MBM is a good source of lysine. However, MBM may contain between 50 and 65% collagen (Eastoe and Long, 1960), which is devoid of tryptophan and low in methionine (Atkinson and Carpenter, 1970).…”

“…Meat and bone meal varies in ruminal escape protein, amino acid composition, and amino acid availability (Knabe et al, 1989;Gibb et al, 1991). This may be the result of heat damage during rendering (Leibholz, 1979;Batterham and Darnell, 1986;Knabe et al, 1989) and(or) the type of tissues rendered (Eastoe and Long, 1960;Atkinson and Carpenter, 1970). Gibb et al (1991) reported higher escape protein values for MBM made from bones than MBM made from viscera or deadstock.…”

Determination of Ileal Amino Acid Digestibilities of Some By-products for Chickens

“…Collagen is the major protein in bone, connective tissue, cartilage and tendon. Eastoe and Long [21] found that collagen is severely deficient in most indispensable amino acids and poorly digested because of the low level of collagenase in digestive tract.…”