Kamalu B P
Department of Veterinary Pathology and Microbiology, University of Nigeria, Nsukka.
Br J Nutr. 1991 Sep;66(2):199-208. doi: 10.1079/bjn19910025.
Experiments were carried out to study the digestibility of a cassava (gari) diet and its effect on growth in young male dogs. Three groups of dogs were fed on diets with rice (control), cassava (gari), and rice + cyanide respectively as the carbohydrate source. Each diet contained 130 g crude protein (nitrogen x 6.25)/kg, was supplemented with vitamins and minerals, and was fed for 14 weeks. Variables measured were body-weight gain, bone growth, plasma alkaline phosphatase (EC 3.1.3.1) activity, total serum 3,5,3'-triiodothyronine (T3) and some plasma free amino acids. The apparent digestibilities of dry matter, protein and fat were not significantly different in the three groups, but the digestibility of gari fibre was significantly lower than the digestibility of rice fibre when fed to dogs (P less than 0.05). Proximate analysis of the faeces showed that the group of dogs fed on the gari diet had faeces which had a significantly higher moisture content than the faeces of the other groups (P less than 0.05), and also a significantly higher fibre content (P less than 0.05). There was no significant difference in body-weight gain and bone growth between the control and gari-fed groups of dogs, but these variables were significantly lower in the dogs fed on the rice + cyanide diet (P less than 0.05). At the end of the 14-week experimental period total serum T3 and plasma alkaline phosphatase activity were not significantly different between the control group of dogs and the gari-fed group, but were significantly lower in the rice + cyanide group. Plasma free methionine, leucine, isoleucine and valine concentrations were higher in the rice + cyanide group of dogs than in the control group and the gari group, indicating that these amino acids were accumulating and not being utilized for protein synthesis and growth to the same extent in the rice + cyanide group of dogs as in the other groups. It was concluded that the digestibilities of cassava starch and rice starch were the same in the dog but that rice fibre was more digestible in the dog than cassava fibre. It was also concluded that growth proceeded normally when a balanced gari diet or a balanced rice diet containing 130 g crude protein/kg was fed to dogs, but growth was retarded when a balanced rice + cyanide diet containing 130 g crude protein/kg was fed to dogs because total serum T3 concentration became greatly depressed.
开展了实验以研究木薯（加里）日粮的消化率及其对幼年雄性犬生长的影响。三组犬分别以大米（对照组）、木薯（加里）和大米+氰化物作为碳水化合物来源的日粮进行喂养。每种日粮含有130克粗蛋白（氮×6.25）/千克，并补充了维生素和矿物质，喂养14周。所测量的变量包括体重增加、骨骼生长、血浆碱性磷酸酶（EC 3.1.3.1）活性、血清总3,5,3'-三碘甲状腺原氨酸（T3）以及一些血浆游离氨基酸。三组日粮中干物质、蛋白质和脂肪的表观消化率无显著差异，但将加里纤维喂给犬时，其消化率显著低于大米纤维的消化率（P<0.05）。粪便的近似分析表明，以加里日粮喂养的犬组粪便的水分含量显著高于其他组（P<0.05），纤维含量也显著更高（P<0.05）。对照组和加里喂养组的犬在体重增加和骨骼生长方面无显著差异，但喂食大米+氰化物日粮的犬的这些变量显著更低（P<0.05）。在14周实验期结束时，对照组犬和加里喂养组犬的血清总T3和血浆碱性磷酸酶活性无显著差异，但大米+氰化物组显著更低。大米+氰化物组犬的血浆游离蛋氨酸、亮氨酸、异亮氨酸和缬氨酸浓度高于对照组和加里组，这表明在大米+氰化物组犬中这些氨基酸在积累，且未像其他组那样在相同程度上用于蛋白质合成和生长。得出的结论是，木薯淀粉和大米淀粉在犬体内的消化率相同，但大米纤维在犬体内比木薯纤维更易消化。还得出结论，当给犬喂食含130克粗蛋白/千克的平衡加里日粮或平衡大米日粮时，生长正常进行，但当给犬喂食含130克粗蛋白/千克的平衡大米+氰化物日粮时，生长受阻，因为血清总T3浓度大幅降低。
