Effects of raw material source, ash content, and assay length on protein efficiency ratio and net protein ratio values for animal protein meals

Abstract

Experiments were conducted to determine the protein efficiency ratio (PER) and net protein ratio (NPR) of meat and bone meals containing 24 or 34% ash, poultry by-product meals containing 7 or 16% ash, lamb meals containing 15 or 24% ash, a lamb meal analog containing 19% ash (mixture of lamb meal and turkey meal), and two meat and bone meals processed at either a low or a high temperature. The PER values (weight gain per unit of protein intake) and NPR values (PER corrected for maintenance) were determined using a chick growth assay in which chicks were fed a N-free diet or 10% CP diets containing one of the animal meals as the only source of dietary protein for 6, 9, or 13 d. The PER of the lamb meal analog was greater (P < 0.05) than that of the other meals, and the PER values of the poultry by-product meals were generally greater than those for the lamb and meat and bone meals. The PER values for the lamb meals were higher than those for most of the meat and bone meals. The PER of the 34% ash meat and bone meal was lower (P < 0.05) than the PER of the 24% ash meat and bone meal (1.03 vs 1.63, respectively, at 9 d). Further experiments showed that the lower PER of the high ash meat and bone meal was not due to its high Ca and P content. Ash content had no significant effect on PER of the poultry by-product and lamb meals. The PER of the low-temperature meat and bone meal was higher (P < 0.05) than the PER of the high-temperature meat and bone meal. The relative differences in NPR values among the animal meals were similar to those observed for PER values. Decreasing the length of the assay from 13 to 6 d increased the PER and NPR of all meals but had little or no effect on the ranking of values among meals. The results of this study indicated that PER and NPR values of animal meals were influenced by raw material source, and that ash content and processing temperature affected the PER and NPR of meat and bone meal. The results also indicated that PER and NPR assays could be reduced to 6 d without reducing sensitivity.

The effect of dietary inclusion of meat and bone meal on the performance of laying hens at old age

“…This might have been caused by the fact that the calcium and phosphorus in MBM are in the organic forms which were utilised more efficiently during shell calcification in the hen than the inorganic forms. A contributing factor might be that the MBM in the present study contained a much higher content of calcium and phosphorus than MBM samples analysed in industrial surveys (Sell, 1996;Johnson & Parsons, 1997;Parsons et al, 1997;Wang & Parsons, 1998a,b).…”

“…It seems likely that the MBM used, which contained a high level of ash and a low level of crude protein might have contained lower amino acid concentrations than those used in other studies Wang & Parsons, 1998b;Shirley & Parsons, 2001). In fact, several industry surveys have demonstrated a wide variation in the nutrient composition of MBM (Sell, 1996;Johnson & Parsons, 1997). Furthermore, the increased egg production rate of the hens receiving the MBM supplemented diets could have had a depressive effect on egg weight.…”

Comparative biochemical profile of protein-rich products obtained from industrial rapeseed meal

“…Since no purification step was involved, the ASP contained high ash content (20.55 ± 0.66%, Table 2). By using a chick growth assay, Johnson and Parsons (1997) established that ash content in meat and bone meal (24%), poultry by-product (16%) and lamb meal (24%) did not significantly alter protein efficiency ratio and net protein ratio values for these inclusions in poultry diets. Decreases of ash content of ASP, if needed, could potentially be achieved by means of ultrafiltration and diafiltration.…”

ORIGINAL ARTICLE: Effect of rendering on protein and fat quality of animal by-products

“…Raw material (Skurray and Herbert, 1974; Johnson and Parsons, 1997; Shirley and Parsons, 2000) and processing conditions (Kondos and McClymont, 1972; Wang and Parsons, 1998; Shirley and Parsons, 2000) have been shown to affect the protein quality of animal meals. Hence, the simultaneous changes in raw material and technological process are likely to have a large influence on the protein value of current MBM.…”