Kellems R O, Aseltine M S, Church D C
J Anim Sci. 1981 Dec;53(6):1601-8. doi: 10.2527/jas1982.5361601x.
Single cell protein (SCP) derived from secondary clarifiers of pulp mills is a potential commercial protein supplement in many areas. Samples of SCP were collected from several pulp mills in the Pacific Northwest and evaluated by laboratory procedures. Six in vivo digestion trials were conducted to determine the relative nutritive value of SCP that was dewatered by centrifugation or by the addition of a polyacrylamide polymer before being put through a belt press and dried with a sonic dehydrator. Amino acid analyses showed that SCP was higher in methionine than was cottonseed meal (CSM) and had a similar level of lysine. True protein, based upon amino acids recovered in SCP samples, ranged from 51.6 to 65.9% of the crude protein (CP). Pepsin digestibility of the CP ranged from 16.2 to 36.8%. Pepsin digestibility increased by 6.3 to 11.3 percentage units when SCP were incubated in a buffered rumen fluid for 24 hours. Solubility of the nitrogenous components in 10% Burroughs' buffer solution ranged from 12.4 to 36.5%. The range in mineral composition was : P, .62 to 1.55%; Ca, .14 to .99%; K, .21 to 5.52%; Mg, .07 to .59%. The concentration of trace minerals and heavy metals varied considerably from sample to sample. Digestion trials were conducted with sheep to compare SCP with CSM; 20 to 50% of the total CP was provided by the SCP sources. The CP digestibilities of the centrifuged and the polymer-dewatered SCP were 70.5 to 70.8% and 66.3 to 69.9%, respectively, of that observed for CSM. In all digestion trials, sheep consumed the SCP diets readily, and no digestive disturbances were observed. On the basis of laboratory and in vivo results, pulp mill SCP has the potential to be a viable protein supplement for livestock.
源自纸浆厂二次澄清池的单细胞蛋白（SCP）在许多领域都是一种潜在的商业蛋白质补充剂。从太平洋西北部的几家纸浆厂采集了SCP样本，并通过实验室程序进行了评估。进行了六项体内消化试验，以确定经离心脱水或在通过带式压榨机并使用声波脱水器干燥之前添加聚丙烯酰胺聚合物脱水的SCP的相对营养价值。氨基酸分析表明，SCP的蛋氨酸含量高于棉籽粕（CSM），赖氨酸含量与之相似。基于SCP样本中回收的氨基酸，真蛋白含量占粗蛋白（CP）的51.6%至65.9%。CP的胃蛋白酶消化率在16.2%至36.8%之间。当SCP在缓冲瘤胃液中孵育24小时时，胃蛋白酶消化率提高了6.3至11.3个百分点。含氮成分在10%巴勒斯缓冲溶液中的溶解度在12.4%至36.5%之间。矿物质组成范围为：磷，0.62%至1.55%；钙，0.14%至0.99%；钾，0.21%至5.52%；镁，0.07%至0.59%。微量元素和重金属的浓度因样本而异。用绵羊进行消化试验以比较SCP和CSM；SCP来源提供了总CP的20%至50%。离心脱水和聚合物脱水的SCP的CP消化率分别为CSM的70.5%至70.8%和66.3%至69.9%。在所有消化试验中，绵羊都很乐意食用SCP日粮，未观察到消化紊乱。基于实验室和体内试验结果，纸浆厂SCP有潜力成为家畜可行的蛋白质补充剂。
