粪便收集时间和饲料中肉骨粉含量对异育银鲫(Carassius auratus gibelio) 消化率的影响

本研究探讨了通过收集器不同粪便收集时间和饲料中肉骨粉(MBM)含量对异育银鲫干物质、蛋白、能量、磷的表观消化率 (ADC) 影响.不同梯度(0, 20, 40, 60, 80 ,100%)的肉骨粉替代鱼粉(FM) 蛋白配制成六种等氮 (粗蛋白: 410 g/kg) 等能 (总能: 18 kJ/g) 的饲料,通过11周的饲养实验,实验开始后2周开始收集粪便,收集时间分别是:排粪后 1 min, 投喂后4h和16h. 结果表明,干物质、蛋白、能量、磷的消化率明显随粪便收集时间增加而升高(p<0.05),但在高肉骨粉替代饲料中差异不显著(p>0.05). 干物质、蛋白、能量、磷的消化率随饲料中肉骨粉含量的增加呈线性或近线性下降.因此,在消化率测定中应该尽快收集排出的粪便以保证消化率的真实性.消化率是影响肉骨粉利用一个因素.

Effect of faecal collection interval and dietary meat and bone meal levels on digestibility of nutrients in gibel carp (Carassius auratus gibelio)

The present study was undertaken to evaluate the effects of faecal collection interval (using a settling column) and the levels of dietary meat and bone meals (MBM) on the apparent digestibility coefficient (ADC) for dry matter, protein, energy and phosphorus in gibel carp. Six iso-nitrogenous (crude protein: 410 g/kg) and iso-energetic (gross energy: 18 kJ/g) diets were used in which fish meal (FM) protein was gradually replaced by MBM at 0%, 20%, 40%, 60%, 80% and 100%. These diet combinations were fed to juvenile gibel carp for 11 weeks. The faecal samples were collected two weeks after the beginning of the experiment using a settlement column starting 1 min after excretion started, or 4h and 16h after feeding. The results showed that the ADCs of dry matter, protein, energy and phosphorus increased significantly as the time from excretion to faecal collections increased while not being significant for the high MBM inclusion diets. ADCs of dry matter, crude protein, energy and phosphorus decreased linearly or almost linearly with the increase in dietary MBM levels. These findings suggest that faeces should be collected soon after they had settled under the conditions of this study for digestibility determination while rapid leaching is apparently responsible for this false reading of digestibility with increasing sampling interval. It is also apparent that the digestibility is one of the problems affecting the use of MBM in juvenile gibel carp.