摘要
应用正交方法配制18种试验饲料,测其各营养素对鲮鱼的生长比速、肥满度及体蛋白质增重率作用的大小为:蛋白质>糖>混合无机盐>脂肪,其中蛋白质(P<0.005)和糖(除肥满度外,P<0.025)为主要的营养素;脂肪和混合无机盐,在本试验条件下,其作用并不明显(P>0.05)。每100克鱼(湿重),每日的最适生长的营养素需要量为:蛋白质0.70—0.80克、糖0.50克、脂肪0.10克,以及饲料中含14％的混合无机盐和17％的纤维素。虽体脂肪和水份的含量与营养素脂肪的水平有一定关系,但显著地受营养素蛋白质水平的影响(分别为P<0.025和P<0.01)。体脂肪随营养素蛋白质水平的增加而增高;水份则随营养素蛋白质水平的增加而下降。体脂肪(Y)与水份(X)之间存在负的相关关系,其关系式为:Y=60.3063-0.7643X。体脂肪和水份的含量,占鱼体重的78.33±0.25％。用无蛋白饲料饲养试验的结果,鲮鱼的体氮维持量为:14毫克氮/100克鱼(湿重)/日。
The nutritional requirements of protein, fat, carbohydrate, mineral mix and cellulose for the optimum growth of mud carp (average weight: 5.4±0.2 gm./fish) were studied. The L_(18)(6×3~6) table of orthogonal design method was employed to formulate eighteen diet combinations. Feeding experiments were conducted in 70×45×40 cm aquaria of 126 L in capacity under the following conditions: 1) water flow maintained at 62 L/hr; 2) water temperature averaged 30.8±1.2℃; 3) dissolved oxygen being 5.11 ±1.25 mg. O_2/L and pH, 7.8±1.0. The data of the experiments were analysed with the method of analyses of variance and the multiple method of Tukey's Q procedure.
The results of feeding experiment show that the effects of nutients on the specific growth rate, condition factor and body protein gain ratio ranked in the following order: protein>carbohydrate>mineral mix>fat. Thus, protein (P<0.005) and carbohydrate (P<0.025 except condition factor) were found to be the main nutrients, while the effects of fat and mineral mix were not so pronounced in the present experiment. The nutritional requirements for the optimum growth were protein: 0.70—0.80 gm., fat: 0.10 gm., carbohydrate: 0.50 gm. with an ingredient of 14% minerl mix and 17% cellulose in the diet per 100 gm. fish (wet weight)/day.
Although fat composition and moisture content fish boty show correlation with the fat content of the food, the nutritional protein levels do have a stronger effect on the fat and moisture contents of the body (P<0.025 and P<0.01 respectively.) When the fish was fed with increasing protein levels, body fat increased but body, moisture decreased. There wasa negative correlation between body fat (Y) and moisture (X), the; formula being Y=60.3063—0.7643X. Fat and moisture together amounted to 78.33± 0.25%. in the fish.
The maintenance nitrogen for metabolism was found to be 14 mg. N/100 gm. fish (wet wright)/day obtained from the experiments with protein-free diet.
