南方鲇的排粪量及消化率同日粮水平、体重和温度的关系

THE FAECAL PRODUCTION AND DIGESTIBILITY OF THE SOUTHERN CATFISH (SILURUS MERID1O-NALIS CHEN), IN RELATION TO RATION LEVEL, BODY WEIGHT AND TEMPERATURE

于1988年2月—1989年2月测定了南方鲇幼鱼的排粪量,从而估算其消化率。结果表明,当水温为25℃时,在日粮水平分别是体重的1％,2％,4％和达饱食的条件下,平均消化率分别为摄入食物能量的80.32％,84.94％,88.40％和87.27％;在平均初始体重分别为8.72,25.43,45.16,78.18和127.5g的实验组中,平均消化率分别为86.59％,81.15％,90.38％,86.91％和81.14％。当初始体重相近时(43.84—47.19g),在温度分别为15,20,25和30℃的条件下,平均消化率分别为78.07％,81.98％,85.23％和90.03％。采用回归分析,建立了由摄食量(C:J/d)、体重(W:g)、和温度(T:℃)预测该种鱼的排粪量(F:J/d)的模型: F=0.868C^(0.981+0.0346lnW-0.100lnT)通过讨论认为:温度对于南方鲇净能转化效率的正效应,主要是通过温度作用于消化率的机制而实现的。

The digestibilities of the yearlings were estimated by measuring their faecal productions of the southern catfish (Silurus meridionalis Chen) in laboratory from February, 1988 to February, 1989. The results showed that at 25℃ the mean values of the digestibilities as percentages of food energy in the fish fed ration levels of 1%, 2%,4% body weight per day and to satiation were 80.3% ,84.9%,88.4% and 87.3%, respectively; and that in the fish with mean initial weights of 8.72,25.43,45.16, 78.18 and 127.5g, the mean values were 86.6% ,81.1% ,90.4% ,86.9% and 81.1%, respectively. The mean digestibilities in the fish with similar initial weight (43.84-47.19g) at 15,20,25, and 30℃ were 78.1% ,82.0% ,85.2% and 90.0%, respectively. By regression analysis a model for prediction of the faecal production (F:J/day) with the food consumption (C:J/day), body weight (W:g) and temperature (T:℃) as independent variables was developed as following:p = 0.868C(0.981+0.0346 InW-0.100 InT)The discussion suggested that the positive effect of temperature on the efficiency in transforming food energy into net energy might occur on the basis of the relationship between the digestibility and temperature.