Parsons C M, Castanon F, Han Y
Department of Animal Sciences, University of Illinois, Urbana 61801, USA.
Poult Sci. 1997 Feb;76(2):361-8. doi: 10.1093/ps/76.2.361.
The in vivo protein quality of 14 meat and bone meals (MBM) was evaluated in three chick growth assays and a 48-h excreta collection assay using conventional and cecectomized roosters. In addition, in vitro evaluation of protein quality was assessed using pepsin N digestibility (0.2, 0.002, or 0.0002% pepsin), KOH protein solubility, and multi-enzyme pH change. Crude protein, lysine, and SAA in the MBM varied from 48 to 56, 2.32 to 3.01, and 1.0 to 2.13%, respectively. Protein efficiency ratio (weight gain:protein intake) estimated from feeding chicks diets containing 9% protein from a MBM ranged from 0.61 to 2.89 and averaged 1.78. Lysine bioavailability determined by slope-ratio chick assay ranged from 43 to 89%. True amino acid digestibility and TMEn values determined in cecectomized roosters were generally lower (P < 0.05) than those determined in conventional roosters. True digestibility of amino acids (percentage) also varied among MBM, with the mean (and range) for lysine, methionine, and cystine in cecectomized birds being 81 (73 to 88), 85 (77 to 91), and 58% (37 to 72%), respectively. Pepsin N digestibility values determined using 0.002 or 0.0002% pepsin were positively correlated (P < 0.05) with lysine digestibility. Pepsin N digestibility determined using 0.2% pepsin, KOH protein solubility, and multi-enzyme pH change were not significantly correlated with in vivo protein quality. Ash content was negatively correlated (-0.80, P < 0.05) with protein efficiency ratio. These results indicated that there is substantial variation in protein quality among commercial MBM and that pepsin N digestibility and ash content are correlated with some in vivo protein quality measurements.
在三项雏鸡生长试验和一项使用常规公鸡和盲肠切除公鸡的48小时排泄物收集试验中，对14种肉骨粉（MBM）的体内蛋白质质量进行了评估。此外，使用胃蛋白酶N消化率（0.2%、0.002%或0.0002%胃蛋白酶）、KOH蛋白质溶解度和多酶pH变化对蛋白质质量进行了体外评估。肉骨粉中的粗蛋白、赖氨酸和总含硫氨基酸含量分别在48%至56%、2.32%至3.01%和1.0%至2.13%之间。通过给雏鸡饲喂含9%来自肉骨粉蛋白质的日粮所估算的蛋白质效率比（体重增加：蛋白质摄入量）在0.61至2.89之间，平均为1.78。通过斜率比雏鸡试验测定的赖氨酸生物利用率在43%至89%之间。在盲肠切除公鸡中测定的真氨基酸消化率和真代谢能值通常低于（P < 0.05）在常规公鸡中测定的值。氨基酸的真消化率（百分比）在不同肉骨粉之间也有所不同，在盲肠切除公鸡中，赖氨酸、蛋氨酸和胱氨酸的平均值（及范围）分别为81%（73%至88%）、85%（77%至91%）和58%（37%至72%）。使用0.002%或0.0002%胃蛋白酶测定的胃蛋白酶N消化率值与赖氨酸消化率呈正相关（P < 0.05）。使用0.2%胃蛋白酶测定的胃蛋白酶N消化率、KOH蛋白质溶解度和多酶pH变化与体内蛋白质质量无显著相关性。灰分含量与蛋白质效率比呈负相关（-0.80，P < 0.05）。这些结果表明，商业肉骨粉的蛋白质质量存在很大差异，胃蛋白酶N消化率和灰分含量与一些体内蛋白质质量测量值相关。
