生长猪粉状高铜饲料中添加不同剂量甜味剂对生长性能的影响

试验共分4个处理,其甜味剂的添加量分别为0、200、300、400g/t,试验选用20头体重为30kg左右的三元(DХLХY)杂交猪,试验期为20d,试验期间考察猪的平均日增重、日均采食量、料肉比三个生长性能指标。结果表明:甜味剂的添加量为常规添加量200g/t时,可显著的提高生长猪粉状高铜饲料的适口性,在200g/t的基础上提高甜味剂的添加量,饲料适口性和日增重均没有得到进一步显著的提高,各处理组料肉比差异均不显著,表明甜味剂的添加对饲料的利用率无显著的影响,因此,在生长猪粉状高铜配合饲料中甜味剂的添加量以常规用量为宜,过高的添加甜味剂并不能起到进一步提高生长猪生长性能的作用。     

粉状高铜饲料中添加不同剂量食盐对生长猪生长性能的影响

研究生长猪粉状高铜饲料中添加不同剂量食盐对生长性能的影响,试验共分5个处理,每个处理组添加铜250mg/kg。试验共分5个处理,其食盐添加量分别为0.3%、0.35%、0.40%、0.45%、0.50%,试验选用25头体重为30kg左右的三元(DХLХY)杂交猪,试验期为30d,试验期间考察猪的平均日增重、日均采食量、料肉比3个生长性能指标。结果表明:生长猪粉状高铜配合饲料中为了提高饲料适口性,食盐的添加量以0.4%为宜。     

加酶益生素对育肥猪的效果

本试验旨在探讨加酶益生素在生长育肥猪日粮中的应用效果。试验表明,在120天试验期间,添加饲喂加酶益生素的试验组,每头猪平均日增重789．25g,未添加加酶益生素的对照组,每头猪平均日增重为673．4g,试验组比对照组提高日增重17．2％,差异极显著（P＜0．01）试验组料肉比为2．91：1,对照组料肉比为3．18：1,试验组比对照组提高饲料报酬8．5％,差异显著（P＜0．05）。     

抗菌肽替代部分醋酸锌对仔猪生长性能及血液生化指标的影响

试验旨在研究日粮中添加5g/t抗菌肽替代100g/t醋酸锌对仔猪生长性能和血液生化指标的影响。选用30日龄平均体重无显著差异的荣昌仔猪48头,随机分为3组,每组4个重复,每个重复4头仔猪(公母各半),试验期为30d。期间观察仔猪的生长及腹泻情况。试验结束时每个重复随机选择2头健康仔猪进行前腔静脉空腹采血制备血清。采用全自动生化分析仪测定血液生化指标。试验表明,添加5g/t抗菌肽替代100g/t醋酸锌能显著降低仔猪腹泻率及饲料增重比(P<0.05),显著提高仔猪日增重(P<0.05),抗菌肽能提高血液中锌的含量,对血液中酶的影响不大,但能显著提高血液中免疫球蛋白含量(P<0.05)。     

微生物发酵饲料对仔猪生产性能的影响

应用含酵母菌、乳酸菌和芽孢菌等益生菌发酵饲料饲喂仔猪,研究微生物发酵饲料对仔猪生产性能的影响。选择品种为杜×长×大三元断奶仔猪共46头进行试验,随机分成2组,其中试验组23头,对照组23头。试验组采用仔猪基础料+5%微生物发酵饲料,对照组只用仔猪基础料,试验期15d。结果表明,试验组平均日增重为326g,对照组平均日增重为267g,试验组比对照组每日多增重59g,提高22%,差异极显著(P<0.01);试验组日均采食量为554g,对照组日均采食量为555.3g,差异不明显(P>0.05)。试验组料肉比为1.70:1,对照组为2.08:1,试验组比对照组减少0.38,显著提高了饲料利用率(P<0.01);试验组增重成本每公斤为4.00元,对照组为4.78元,试验组每公斤增重少花0.78元。实验结果表明,微生物发酵饲料能提高仔猪生长性能,节约饲料成本,增加养猪的经济效益。     

饲料中添加新肥素220对断奶仔猪生产性能的影响

选用180头杜×长×大28日龄断奶仔猪随机分成3组，每组设3个重复，每个重复20头仔猪，试验期39d。结果表明，对照组不添加新肥素220仔猪日增重为41g，料肉比为1.66，饲料中添加0.5％的新肥素220仔猪日增重为449g，料肉比为1.59，与对照组相比，增重率提高了7.7％（P＞0.05），料肉比改善了4.2％；添加1％新肥素220仔猪日增重为457g，料肉比为1.63，与对照组相比，增重率提高了9.6％（P＞0.05），料肉比改善了1.8％。0.5％新肥素组和1％新肥素组仔猪腹泻频率分别比对照组降低了1.6％和2.7％。     

低蛋白浓缩饲料中添加苏氨酸对仔猪生长性能的影响

选取42日龄同批次、初始体重相近的DLY三元杂交商品猪25头作为试验动物,将试验群体随机分成5个处理组,每组5头,分别饲喂不同苏氨酸水平的低蛋白浓缩饲料,比较各试验组,得出应用于凉山州地区的浓缩饲料中宜添加适量的苏氨酸以提高仔猪的日增重和饲料的利用率,综合考虑仔猪的生长性能和饲料成本因素,在浓缩饲料占配合饲料为25%的低蛋白浓缩饲料中,苏氨酸的添加量以2kg/t为宜。     

复合酶制剂对仔猪生长性能及饲料消化率的影响

目的 探究复合酶制剂对仔猪生长性能及饲料消化率的影响。方法 试验选用80头28日龄断奶仔猪，随机分为4组，即空白对照组、试验Ⅰ组、试验Ⅱ组和试验Ⅲ组，在基础日粮中根据体质量分别添加0、200、400、600 mg/kg的复合酶制剂，试验为期30 d。结果 与对照组相比，试验组Ⅱ和试验组Ⅲ仔猪的终测体重、平均日增重和平均日采食量显著升高(P<0.05),料重比显著降低(P<0.05)。与对照组相比，试验组Ⅱ和试验组Ⅲ仔猪对饲料中干物质、粗脂肪、粗蛋白、粗纤维和粗灰分的消化率显著升高(P<0.05)。结论 在基础日粮中添加复合酶制剂可以有效提高断奶仔猪的生长性能，改善仔猪对饲料中营养物质的消化，提高营养物质吸收率，且在该试验条件下，复合酶制剂的最适添加剂量为600 mg/kg。     

日粮中添加甲基-天冬氨酸、胍基乙酸、γ-氨基丁酸和甾醇对中猪生产性能和饲料成本影响的研究

目的:为了开发甲基-天冬氨酸、胍基乙酸、γ-氨基丁酸和甾醇绿色饲料添加剂,确定其实际使用效益。方法:采用98头平均体重(50.48±3.89)kg的杜长大中猪分成5组,分成对照组、甲基-天冬氨酸100 g/t组、胍基乙酸500 g/t组、γ-氨基丁酸100 g/t组、甾醇20 g/t组,饲养42 d,研究四种添加剂对中猪生长性能和经济效益的影响。结果:各组日增重、料肉比、价/肉比(元/kg)都差异不显著(P>0.05),但是有潜在的影响。结论:甲基-天冬氨酸、胍基乙酸、γ-氨基丁酸和甾醇的适宜添加量需要深入研究。     

浓缩饲料与不同处理方式玉米配合使用效果试验

将初始体重相近5周龄DLY三元杂交断奶仔猪18头,随机分成3组,每组6头,进行为期30d饲养对比试验.试验组I将玉米炒熟后混合相应比例的浓缩饲料饲喂仔猪。试验组II的浓缩饲料配方与试验组I一致,将玉米用90℃水糊化待温度降至45℃左右时再混入相应比例的浓缩饲料饲喂仔猪。试验组III的浓缩饲料配方与组I、II一致,玉米面不经熟化处理混入相应比例的浓缩饲料饲喂仔猪。通过三组试验得出:II组仔猪在生长速度和料肉比方面优于其他组,I组饲料适口性为最佳组。     

Effects of Dietary Digestible Protein and Energy Levels on Growth Performance,Feed Utilization,and Body Composition of Juvenile Permit,Trachinotus falcatus (Linnaeus, 1758)

A 9‐wk study was conducted to evaluate the effect of dietary protein and energy on growth performance of juvenile permit, Trachinotus falcatus, growing from approximately 30 to 150 g. Nine experimental diets were formulated to contain three levels of crude protein (400, 450, and 500 g/kg dry matter [DM]); and three levels of crude lipid (100, 200, and 300 g/kg DM) in a 3 × 3 factorial design. Growth rate and feed efficiency were significantly improved with increasing dietary protein levels from 400 to 500 g/kg and with dietary lipid levels from 100 to 200 g/kg. Fish body protein content was positively correlated with dietary ratio of digestible protein (DP) to digestible energy (DE) (P < 0.01, R² = 0.83), while body lipid was negatively correlated with dietary DP/DE (R² = 0.55, P < 0.05) but positively correlated with dietary DE levels (R² = 0.66, P < 0.01). Results showed a protein‐sparing effect, as protein retention was significantly increased by increasing dietary lipid level. In conclusion, the diet containing DP of 392.7 g/kg and DE of 18.8 MJ/kg (DM), corresponding to a DP/DE of 20.9 g/MJ, is suggested as an optimal feed for growth and feed efficiency in juvenile permit.     

Nutritional value of frass from black soldier fly larvae,Hermetia illucens,in a channel catfish,Ictalurus punctatus,diet

Frass is the by‐product of the larval meal industry and includes larval waste, exoskeleton sheds and residual feed ingredients. Experimental frass was derived from the larvae of black solder flies fed distillers' dried grains with solubles and had a protein and fat content of 216 and 60 g/kg, respectively. A 10‐week study was conducted to evaluate the effect of dietary levels of frass on growth, feed utilization, and body proximate and mineral composition of channel catfish, Ictalurus punctatus. Five diets containing 0, 50, 100, 200 and 300 g frass per kg diet were fed to channel catfish (5.24 ± 0.04 g) in quadruplicate aquaria to apparent satiation twice daily. Final weight gain was significantly increased in fish fed diets containing frass at levels from 100 to 300 g/kg. Fish fed diets without frass, and with 300 g/kg frass, showed the lowest and highest feed intake, respectively. Feed and protein efficiencies, however, were significantly lower in fish fed frass at levels of 200 g/kg and higher compared to the control diet. Survival, whole‐body composition and mineral content were not affected by frass. In summary, black soldier fly larval frass has potential as a protein source or just an ingredient for enhancing palatability of catfish diets.     

国产鱼粉替代进口鱼粉饲养牙鲆试验报告

以国产鱼粉和进口鱼粉 ,分别设计成两种等蛋白、等能量的干粉料 ,与小杂鱼按一定的比例混合制成软颗粒饲料 ,投喂南方池养牙鲆进行饲养对比试验 ,经过 2 0 4天的饲养 ,投喂A料、B料的尾相对增重率分别为 2 4 0 1 %、 2 4 83% ,尾平均日增重分别为 2 .1 8g、1 .4 6 g ;饲料系数分别为 2 .0 5、 2 .6 0 ,牙鲆增重 1kg所需饲料成本分别为 9.6 6 元和 1 3.6 5 元。牙鲆鱼肌肉粗蛋白、粗脂肪含量差异不显著 (P >0 .0 5 ) ,5种鲜味氨基酸的含量很接近     

Effects of restricted feeding regimes on growth and feed conversion on juvenile green sea urchin,Strongylocentrotus droebachiensis

Groups of juvenile green sea urchin, Strongylocentrotus droebachiensis (average wet weight = 3.3 g), were fed five different dry feed rations (0.2%, 0.4%, 0.8%, 1.2% and 2.4% of their body weight per week) under constant light and temperature conditions for 160 days (Experiment I) in groups to examine growth effects, and for 40 days as individual treatments (Experiment II) to examine feeding efficiency. There was 100% survival of the sea urchins during both experiments. In Experiment I, the lowest ration group (0.2%) had significantly lower growth than the rest of the groups. There was no significant differences in growth between the sea urchin fed ration over 0.4% dry feed of the body wet weight per week. In Experiment II, the lowest feed ration groups (0.2%) had significant lowest growth but had the best feed conversion ratio (FCR), using 0.5 g of feed of dry feed per gram of sea urchin wet weight body growth. The FCR increased with increasing feed ration and the 2.4% group had the poorest FCR, using 1.3 g of feed per gram weight gain. Results from Experiments I and II illustrate that juvenile green sea urchin can grow at a restricted feed ration that is under maximum feed intake, without reduction in growth.     

膨化饲料水库网箱养殖牛蛙试验

选择环境安静,水质清新,水面开阔的库湾设置网箱(2 a=10 mm)养殖牛蛙,放养体重50~100 g的牛蛙160~200只/m2,100 g以上的牛蛙80~100只/m2,探索解决牛蛙常规养殖存在的污染环境和疾病严重等问题。结果表明:牛蛙的成活率为94.3%,日均增重1.33~2.97 g,网箱新增产值178元/m2,显著高于牛蛙常规养殖和鱼塘网箱养殖效益,为牛蛙养殖和综合提高水体养殖效益提供新的发展途径。     

Feed intake and growth performance of Senegalese sole (Solea senegalensis Kaup, 1858) fed diets with partial replacement of fish meal with plant proteins

To be able to study nutrient requirement and utilization in any species, a diet supporting normal feed intake and growth equally well as a traditional fish meal‐based diet is needed. Additionally the formulation of the diet should allow low levels of the nutrient under study. When studying the amino acid metabolism and requirements, one cannot rely on the fish meal‐based diets as fish meal are nicely balanced according to requirements. Therefore the current study aimed to develop a plant protein‐based diet (with low fish meal inclusion) to be used in the nutritional studies of Senegalese sole juveniles supporting feed intake and growth close to that obtained in a fish meal‐based control feed. Two experiments were conducted to evaluate whether Senegalese sole juveniles would accept and utilize diets containing high plant protein inclusion. For testing the acceptance of high plant protein inclusion, two diets were formulated: a reference diet that contained fish meal as the main protein source (450 g kg^?1 dry matter) whereas in the test diet, fish meal was substituted by a mixture of plant ingredients (soybean meal, corn and wheat gluten) with l ‐lysine supplementation. In order to improve the palatability, 50 g kg^?1 squid meal was added to both diets. The indispensable amino acids (IAA) profile of the test diet was made similar to the control diet by adding crystalline amino acids. Further, automatic feeders were used to improve the feed intake. Fish (24 g initial body weight) were fed the diets for a period of 4 weeks. As fish accepted both diets equally well, a second study was undertaken to test the growth performance. Fish (6 g initial BW) were fed the diets for a period of 12 weeks. The use of automatic feeders to deliver the feed and the addition of both squid and balancing the indispensable amino acids resulted in growth performance and accretion not differing from the fish meal fed control. It can be concluded that juvenile Senegalese sole are able to grow and utilize high plant‐protein diets when both diet composition and feeding regime are adequate for this species.     

Prediction of culture performance of juvenile Litopenaeus vannamei by in vitro (pH-stat) degree of feed protein hydrolysis with species-specific enzymes

Rapid in vitro methods for measuring digestibility may be useful in analysing aqua feeds if the extent and limits of their application are clearly defined. The pH‐stat protein digestibility routine with shrimp hepatopancreas enzymes was previously related to apparent protein digestibility with juvenile Litopenaeus vannamei fed diets containing different protein ingredients. The potential of the method to predict culture performance of shrimp fed six commercial feeds (T3, T4, T5, T6, T7 and T8) with 350 g kg^?1 declared crude‐protein content was assessed. The consistency of results obtained using hepatopancreas enzyme extracts from either pond or clear water‐raised shrimp was further verified in terms of reproducibility and possible diet history effects upon in vitro outputs. Shrimps were previously acclimated and then maintained over 56 days (initial mean weight 3.28 g) on each diet in 500‐L tanks at 114 ind m^?2, clear water closed system with continuous renewal and mechanical filtering (50 μm), with four replicates per treatment. Feeds were offered four times daily (six days a week) delivered in trays at feeding rates ranging from 4.0% to 7.0% of stocked shrimp biomass. Feed was accessible to shrimp 4 h daily for 1‐h feeding period after which uneaten feed was recovered. Growth and survival were determined every 14 days from a sample of 16 individuals per tank. Water quality was monitored daily (pH, temperature and salinity) and managed by water back flushing filter cleaning every 7–10 days. Feeds were analysed for crude protein, gross energy, amino acids and pepsin digestibility. In vitro pH‐stat degree of protein hydrolysis (DH%) was determined for each feed using hepatopancreas enzyme extracts from experimental (clear water) or pond‐raised shrimp. Feeds resulted in significant differences in shrimp performance (P < 0.05) as seen by the differences in growth rates (0.56–0.98 g week^?1), final weight and feed conversion ratio (FCR). Shrimp performance and in vitro DH% with pond‐raised shrimp enzymes showed significant correlation (P < 0.05) for yield (R² = 0.72), growth rates (R² = 0.72–0.80) and FCR (R² = ?0.67). Other feed attributes (protein : energy ratio, amino acids, true protein, non‐protein nitrogen contents and in vitro pepsin digestibility) showed none or limited correlation with shrimp culture performance. Additional correlations were found between growth rates and methionine (R² = 0.73), FCR and histidine (R² = ?0.60), and DH% and methionine or methionine+cystine feed contents (R² = 0.67–0.92). pH‐stat assays with shrimp enzymes generated reproducible DH% results with either pond (CV ≤ 6.5%) or clear water (CV ≤ 8.5%) hepatopancreas enzyme sources. Moreover, correlations between shrimp growth rates and feed DH% were significant regardless of the enzyme origin (pond or clear water‐raised shrimp) and showed consistent R² values. Results suggest the feasibility of using standardized hepatopancreas enzyme extracts for in vitro protein digestibility.     

Feed management for Pacific white shrimp Litopenaeus vannamei under semi‐intensive conditions in tanks and ponds

To improve feed management strategies for the semi‐intensive culture of Litopenaeus vannamei, outdoor tank and pond trials were conducted. In the tank trial, shrimp (35 shrimp/m², n = 4) were offered feed for 6 weeks based on a standard feeding protocol (SFP, designed as T100) with five variations (T80:90:100, T90, T90:100, T100:110, T110) of this protocol produced by varying the feed inputs and expressing the treatments as a percentage. Results demonstrated no significant differences in survival rate and feed conversion ratio (FCR) among treatments. The mean final weight and final biomass in the treatments T100:110 and T110 were significantly higher than those in treatment T90 but were not different from the other treatments. In the pond trial, juvenile shrimp (28 shrimp/m², n = 4) were stocked into twelve 0.1‐ha ponds over a 16‐week period. Three feeding protocols were evaluated including a SFP, a 10% reduction in the SFP (SFP:90), and a variable feed input (SFP:80:90:100), which included 80% SFP at week 4th–8th, 90% SFP from week 9th–12th and 100% SFP for week 12th–16th. There were no significant differences in growth performance and economic return among treatments. Based on previous studies, in which higher feed inputs were evaluated, and results of this study, it does not appear to be economically beneficial to use high feed inputs. Instead, feed input could be either applied at a standard ration to optimize growth and economic return or at restricted rations to reduce FCR (feed cost) albeit at the expense of some growth.     

The energy requirements of Eurasian perch (Perca fluviatilis L.) in intensive culture

Fish feed constitutes one of the largest costs in aquaculture, therefore inefficient feed management will have a negative impact on fish farm economics. Eurasian perch (Perca fluviatilis L.) is a relatively new candidate for freshwater aquaculture, however little is known about the energy requirements of this species. The aim of this study was to develop an energy requirement model for intensive culture of Eurasian perch reared at rational temperatures. Data on growth (the thermal unit growth coefficient, TGC, ³√g · (°C · days)^?1) and digestible energy need (DEN, kJ DE · g^?1) of Eurasian perch at a size range of 20–180 g and at temperatures of 17–23 °C were used. Regression analysis revealed that both TGC and DEN were affected significantly by fish size (P < 0.001) but not by temperature (P > 0.05). Two models including body size of the fish were developed: (i) an inverse TGC model for evaluation of the daily theoretical weight increment (TWi, g · day^?1) and (ii) a linear DEN model. The TGC model was validated by comparing theoretical data with data obtained from a commercial growth trial. By combining the TWi and the DEN, a model describing the daily theoretical energy requirement (TER, kJ · day^?1) at different temperatures and for Eurasian perch of different sizes was successfully developed.