Effects of species raw material source, ash content, and processing temperature on amino acid digestibility of animal by-product meals by cecectomized roosters and ileally cannulated dogs.

Abstract

We conducted experiments to determine amino acid (AA) digestibility of nine animal by-product meals using precision-fed cecectomized roosters and ileally cannulated dogs. The products initially evaluated in roosters were meat and bone meals (MBM) containing 24 or 34% ash, poultry by-product meals (PBP) containing 7 or 16% ash, lamb meals (LM) containing 15 or 24% ash, a LM analog containing a mixture of LM and turkey meal, and two MBM processed at either a low or high temperature. The MBM and PBP differing in ash, low-ash LM, and low-temperature MBM then were incorporated into extruded dry dog foods and evaluated in cecectomized roosters and ileally cannulated dogs. True digestibility of total AA in roosters averaged 76% for the nine meals fed alone, with the low-temperature MBM being highest at 84% and the low-ash LM being lowest at 66% (P < .05). No consistent differences in rooster AA digestibility were observed between pairs of meals differing in ash content. Digestibilities of AA were higher in the low-temperature MBM than in the high-temperature MBM. Differences in rooster AA digestibility values among the six extruded dog foods containing selected animal meals were similar to those observed when the animal meals were fed alone. The ileally cannulated dog assay yielded results for AA digestibilities that were highly correlated (r = .87 to .92) with those of the rooster assay, whereby the high-ash MBM and low-temperature MBM foods had the highest mean AA digestibility at 82% and the low-ash LM food had the lowest mean AA digestibility at 62% (P < .05). Again, no consistent differences in AA digestibilities for dogs were observed between pairs of dog foods containing MBM or PBP differing in ash content. Results of this study indicated that processing temperature influenced AA digestibility of MBM, but species raw material source and ash content had no consistent effect on AA digestibility. Results also indicated that the precision-fed cecectomized rooster assay could be used to predict differences in AA digestibility among animal by-product meals for dogs.

Determination of true digestible amino acids of feedstuffs utilizing cecectomized roosters

“…The differences in the composition of the feedstuffs can also interfere in the digestibility coefficients of the nutrients, e.g., in the case of the meat and bone meal, in which there is no standardization during the processing to its obtainment, thus leading to variations mainly in the content of mineral matter and protein; Johnson et al (1998) elevated contents of ash cause decrease in the amount of protein, decreasing the levels of essential amino acids per unit of protein, without affecting its quality. The pearl millet presented different true digestibility coefficients of essential amino acids from the two varieties assessed by Rodrigues et al (2001a), like Rostagno et al (2005), who showed different values, except for arginine, which presented value similar to that of the present study.…”

The energetic significance of cooking

“…However, it is instructive that these studies generally report that ileal digestibility of MBM is reduced by cooking. Among dogs, for example, Johnson et al (1998) found the ileal digestibility of MBM to be inversely correlated with processing temperature. Among roosters, Johns et al (1987) found negative effects of cooking time on ileal digestibility of MBM heated at 150°C for 1, 1.5, 3, 4, and 5 hours.…”

Avaliação de dietas com diferentes fontes protéicas para cães adultos

“…O processamento da farinhas animais na graxaria, especificamente a temperatura, a pressão e o tempo empregados, também pode comprometer a qualidade do produto, seja carbonizando matéria orgânica, diminuindo a digestibilidade total, seja tornando aminoácidos específi-cos indisponíveis. Essas variações têm reflexo direto na qualidade protéica destes ingredientes, podendo ocasionar grandes diferenças entre batidas e principalmente entre fornecedores destes subprodutos (Parsons et al,1997;Shirley & Parsons, 2000;Johnson et al, 1998). Johnson et al (1998) estudaram a digestibilidade de aminoácidos da farinha de carne e ossos processada em alta (145 o C) ou baixa temperatura (110 o C) e encontraram, respectivamente, coeficientes de digestibilidade aparente médios de 79,2 e 86,4% para os aminoácidos essenciais e de 75,2 e 84% para aminoácidos totais, demonstrando a grande influência do processamento sobre a digestibilidade.…”

“…Como a origem e o processamento dos ingredientes são fatores determinantes para sua qualidade e digestibilidade (Johnson et al, 1998), a escassez de informações sobre o aproveitamento destas matérias-primas, especialmente as de origem animal, dificulta a formulação de dietas para cães no Brasil, pois os nutricionistas têm acesso apenas a dados de estudos internacionais.…”