【作者】 仲维玮；

【导师】 文华；

【作者基本信息】 华中农业大学 ， 水产养殖， 2010， 硕士

【摘要】 本研究以罗非鱼(Oreochromis niloticus)为试验对象,评价混合植物蛋白源替代鱼粉对罗非鱼幼鱼生长、体组成、生化指标和消化率的影响,以及研究不同脱毒处理方法对棉粕中棉酚的影响,及脱毒处理棉粕的使用效果,以期提高罗非鱼饲料植物蛋白源的利用率,为生产实践提供依据。研究的内容和结果如下：1.混合植物蛋白源替代鱼粉对尼罗罗非鱼幼鱼生长、体组成及表观消化率的影响选用初始体重为(7.16+0.81)g的尼罗罗非鱼幼鱼为试验对象,以混合植物蛋白源(棉粕／菜粕／玉米蛋白粉／蚕豆质量比=1/1/1/1)分别替代0%、25%、50%、75%、100%鱼粉,配制成五组等氮(粗蛋白为30%)、等能(总能为20 KJ/g)的饲料,探讨混合植物蛋白源替代鱼粉对尼罗罗非鱼幼鱼生长、体组成及消化率的影响,试验期为10周。结果表明：混合植物蛋白源替代25%-75%鱼粉时,罗非鱼的增重率、特定生长率、蛋白质效率和饲料系数与对照组无显著差异(P>0.05),替代100%鱼粉时,罗非鱼的增重率、特定生长率和蛋白质效率显著低于其他处理组,饲料系数显著高于其他处理组(P<0.05)；混合植物蛋白源替代鱼粉对鱼体的肝体比、脏体比无显著影响(P>0.05)；随着混合植物蛋白源替代比例的升高,罗非鱼全鱼粗蛋白质、灰分含量显著降低,粗脂肪含量显著升高(P<0.05),但肌肉的营养组成不受影响(P>0.05)；除组氨酸含量随替代比例的增加而升高外,混合植物蛋白源替代鱼粉对鱼体肌肉的必需氨基酸、总氨基酸无显著影响,100%替代组的肌肉呈味氨基酸占总氨基酸比例显著低于对照组(P<0.05),而其他处理组与对照组无显著差异(P>0.05)；100%替代组的蛋白质和氨基酸消化率显著低于25%、50%、75%替代组和对照组(P<0.05),但各处理组的脂肪消化率差异不显著(P>0.05)。因此,本试验条件下,以生长、体组成及消化率为评价指标,罗非鱼饲料中混合植物蛋白源替代75%鱼粉是可行的。2.饲料中利用不同脱毒处理的棉粕适量替代豆粕对尼罗罗非鱼幼鱼生长、体组成及血清转氨酶活性的影响试验采用硫酸亚铁和高温两种方法对棉粕进行脱毒处理,以不同脱毒处理的棉粕替代豆粕(33%,67%),配制成7组等氮(粗蛋白为33%)等能(总能为19 KJ/g)的饲料,在室内饲养尼罗罗非鱼幼鱼(平均体重为7.27±0.25 g)10周,探讨脱毒处理对棉粕中游离棉酚含量以及对尼罗罗非鱼幼鱼生长、体组成和肝功能的影响。试验结果表明,脱毒处理对降低游离棉酚含量有显著效果,硫酸亚铁处理组和加热处理组饲料游离棉酚含量(44.80 mg/kg,70.02 mg/kg;32.43 mg/kg,43.23 mg/kg)显著低于未处理组(198.14 mg/kg,267.02 mg/kg),脱毒处理可显著降低鱼体肝脏和肌肉中游离棉酚含量(P<0.05)；不同脱毒处理棉粕替代豆粕对罗非鱼的增重率、特定生长率及成活率无显著影响(P>0.05)；不同脱毒处理棉粕替代豆粕对鱼体蛋白质、脂肪含量无显著影响,未处理组鱼体灰分含量显著高于空白组(P<0.05),脱毒处理组鱼体灰分含量与空白组无显著差异(P>0.05)；各处理组肝体比和脏体比无显著性差异(P>0.05),但未处理组谷草转氨酶和谷丙转氨酶活性显著高于脱毒处理组和空白组(P<0.05),这表明棉粕中游离棉酚过高可引起鱼体肝功能异常。因此,在本试验条件下,棉粕中游离棉酚对罗非鱼幼鱼肝功能有显著影响,对棉粕进行脱毒处理可降低游离棉酚含量,提高棉粕的利用率。更多还原

【Abstract】 The study was conducted to Oreochromis niloticus, the effects of fish meal replacement by plant protein sources on growth performance, body composition and apparent digestibility, and using cottonseed meal treated with two methods for detoxification of gossypol as a partial substitution of soybean meal. The contents and results are as follows:1.A study with increasing levels of a plant protein mixture (PM) replacing fish meal (FM) in diets for juvenile Nile tilapia, was conducted to elucidate effects on growth performance, body conposition and digestibility. The PM was consisted of 25% cottonseed meal,25% rapeseed meal,25% corn gulten meal and 25% broad bean. Five isonitrogenous (crude protein 30%) and isoenergetic (20 KJ/g) diets replacing 0% (control),25% (PM25),50% (PM50),75% (PM75) and 100% (PM100) of the FM with PM were formulated. Each experimental diet was fed to triplicate groups of 30 Nile tilapia juveniles (initial body weight 7.16±0.81 g) in 400 L aquaria for 10 weeks.The water temperature was (21±0.5)℃,and dissolved oxygen was approximately 5.0 mg/L during the experimental period. The results showed that weight gain rate (WGR),specific growth rate (SGR), feed conversion ratio (FCR) and protein efficiency ratio (PER) of fish fed diets PM25,PM50, PM75 were not significantly different from those of fish fed control diet (P>0.05), while fish fed PM100 had significant difference with those of fish fed the other diets.No significant differences in HSI and VSI were observed among dietary treaments.The whole body proximate analysis showed that protein and ash contents significantly decreased with increasing dietary PM levels, while the whole body lipid content showed increased. Except hisidine content was increased with increasing dietary PM levels, there were no significant effects on muscle indispensable amino acid (IAA) and total amino acid contents.Taste amino acid to total amino acid ratio decreased with increasing dietary PM levels, and no effect on total amino acid content was observed (P>0.05).PM substitution up to 75% of the FM protein did not result in differences in the apparent digestibility of protein and total amino acid compared with the control(P>0.05), whereas in the PM100 group digestibility was significantly lower than the other groups (P<0.05);no significant effects were found on lipid digestibility (P>0.05).These results suggest that 75% FM replacement by PM caused no significant effect on the growth, body composition and digestibility of Nile tilapia.2.The cottoseed meal used in this experiment was treated with ferrous sulfate and heated for detoxification of gossypol, then was used to replace 33%,67% soybean meal. The objective was to study the effect of different treatments on the reduction of gossypol level. Seven isonitrogenous (33% crude protein) and isoenergetic(19 KJ/g) diets were formulated. Each experimental diet was fed to triplicate groups of 30 Nile tilapia juveniles (initial body weight 7.27±0.25 g) in 400 L aquaria for 10 weeks.The water temperature was (21±0.5)℃,and dissolved oxygen was approximately 5.0 mg/L during the experimental period. The result showed that the detoxification treatments were beneficial for the reduction of free gossypol, the free gossypol content of diets treated with ferrous sulfate and heated (44.80 mg/kg,70.02 mg/kg; 32.43 mg/kg,43.23 mg/kg) were significantly lower than the untreated diet(198.14 mg/kg,267.02 mg/kg). Detoxification treatment markedly reduced the free gossypol contents of liver and kidney (P<0.05);No significant differences were observed in weight gain rate (WGR),specific growth rate (SGR),survival rate (SR) among dietary treatments (P>0.05);Detoxification treatments had no significant effects on protein and lipid contents, while, the ash content of untreated group was significantly higher than that of control group (P<0.05), the ash content of detoxification treated group was similar with the control group (P>0.05);No significant differences in HSI and VSI were observed among dietary treaments (P>0.05), however, aspartate aminotransferase and alanine aminotransferase activities of untreated group were significantly higher than detoxification treated and control groups (P<0.05), which showed that the free gossypol content of cottonseed meal can bring the abnormity of liver function. In conclusion, the free gossypol content of cottonseed meal had significant effect on liver function, the detoxification treatment was beneficial to reduce the content of free gossypol, improve the utilization of cottonseed meal.更多还原