大豆肽的生理功能和制备工艺

大豆肽是大豆蛋白质的水解产物,主要功能性营养物质包括多肽、寡肽、游离氨基酸和糖类,其相对分子质量低,易于消化吸收。丰富的小肽能调节矿物质、脂类代谢,降低胆固醇,提高免疫力。文章综述了大豆肽的生理功能和制备工艺。     

膨化大豆替代鱼粉对乌苏里貉毛皮质量的影响

选取150只健康乌苏里幼貉(Nyctereutes ussurienusis Matschie),随机分成1个对照组和4个试验组.各试验组按25%、50%、75%、100%比例用膨化大豆替代鱼粉饲料进行饲养试验,通过对针、绒毛的长度、粗细和皮板长度等反映毛皮质量各项指标的测定与分析得出:彭化大豆代替鱼粉能满足乌苏里貉冬毛生长的需要,不影响乌苏里貉毛皮质量.     

去皮豆粕在畜牧生产中的应用

去皮豆粕是经先去皮、后浸出工艺生产出的不带豆皮的豆粕，是国内市场上一种蛋白质饲料原料。本文着重介绍去皮豆粕的营养价值、质量标准及其在畜牧生产中的应用。     

Apparent Digestibility Coefficients of Nutrients and Nutritional Value of Poultry By-product Meals for Rainbow Trout Oncorhynchus mykiss Measured in vivo Using Settlement

Fish meal production is not growing worldwide, therefore, it is important to search for alternative protein sources. Three types of poultry by-product meals (feed grade, prime, and refined) and two fish meals (herring and menhaden) were mixed into a casein-gelatin purified reference diet at 30% to measure apparent digestibility coefficients (ADCs) for rainbow trout Oncorhynchus mykiss . A total of 90 fish (initial mean body weight 294.6 ± 10.7 g) were stocked into six 140-L fiberglass digestibility tanks at 15 fish per tank. Individual tanks were assigned randomly to each of the five experimental diets and the reference diet. Fecal collection by settlement lasted for 2 wk. Feces collected in each week represented a replicate, and they were analyzed separately. The ADCs of nutrients for herring meal, menhaden meal, feed grade poultry by-product meal, prime poultry by-product meal, and refined poultry by-product meal were: dry matter, 81.3, 70.9, 70.9, 71.5, and 74.5%, respectively ( P = 0.0168); crude protein, 89.8, 85.8, 83.1, 84.8, and 87.1%, respectively ( P = 0.0032); crude fat, 91.5, 90.7, 79.7, 82.7, and 79.9%, respectively ( P = 0.0004); ash, 76.6, 66.2, 74.1, 77.4, and 79.6%, respectively ( P = 0.2880); phosphorus, 58.2, 46.9, 49.4, 45.8, and 56.0%, respectively ( P = 0.0143); gross energy, 88.2, 84.0, 81.9, 83.4, and 79.8%, respectively ( P = 0.2466). Significant differences in ADCs of essential amino acid existed only for arginine, leucine, and tryptophan when comparing refined poultry by-product meal with herring meal. Results showed that refined poultry by-product meal had similar ADC values to herring meal, thus, it has a similar nutritional value and can replace portions of herring meal in rainbow trout feeds. Furthermore, differences exist in ADC values among grades of poultry by-product meals that should dictate appropriate use levels in rainbow trout feeds.     

Dietary Supplementation with Microencapsulated Lutein Improves Yolk Color and Lutein Content in Fresh and Cooked Eggs of Laying Hens

This study was conducted to compare the efficacy of diet supplemented with non-microencapsulated lutein (NL) and microencapsulated lutein (ML) in laying hens. A total of 270 Hy-line Brown laying hens (54 weeks old) were allocated to three groups with six replicates of 15 hens and were adapted to a wheat-soybean meal basal diet for two weeks. Next, the control birds were fed the basal diet, and the test birds were fed the basal diet supplemented with 600 mg/kg NL (12 mg/kg available lutein) or 90.1 mg/kg ML (10 mg/kg available lutein) for 35 days. Supplementation of lutein did not affect the productive performance of laying hens, but improved (P<0.05) the yolk color and red/green value (a*), with eggs from the ML group displaying improved color and a* values from the 15^th day of the experimental period. The blue/yellow value (b*) for the yolk showed an increase (P<0.05) through both NL and ML supplements. The yolk color of fried and boiled eggs and a* value of the yolk in fried eggs were improved (P<0.05) only through ML supplemented diet. Both NL and ML supplements resulted in lower (P<0.05) lightness and higher (P<0.05) a* values of yolk in boiled eggs, as well as higher (P<0.05) b* values in fried and boiled eggs. Yolk lutein content in fresh, fried, and boiled eggs was increased (P<0.05) in NL and ML groups with the latter being higher. In conclusion, ML improved yolk pigmentation and lutein retention in laying hens better than NL.     

膨化和膨胀加工技术及其对猪生产性能的影响

随着饲料原料资源的短缺和价格的上涨,加工工艺对降低生产成本,改善猪生产性能的作用日趋明显.传统的膨化工艺具有降低抗营养因子和有害菌数量,并提高营养物质消化率的作用.新型的膨胀工艺除了上述优点外,还能提高产能,降低能耗,并使原料释放营养物质,提高营养物质的消化率.膨胀工艺可破坏非常规原料的纤维成分,增加其应用范围和营养价值.大量的试验结果表明,膨化和膨胀工艺对仔猪、育肥猪和哺乳母猪的生产性能具有提升作用.膨化和膨胀工艺将会在饲料加工和动物营养领域发挥更大的作用.本文针对膨化和膨胀技术巨大的应用潜力及良好的实际效果作一简述.     

锅炉的高效操作及维护

饲料成本在畜禽生产的总成本中占有相当大的比例,约在60％～70％。饲料成本中原料是最主要的部分,但加工成本也不容忽视。饲料加工成本很大一部分和制备饲料制粒前调质或蒸汽压片谷物等环节所需的蒸汽有关,这部分成本往往被人所忽视直至导致重大问题。本文旨在综述蒸汽制备的一些基本原理,并提出一些改善锅炉操作效率的原则。     

挤压技术及其在饲料工业中的应用(2)

3挤压或膨胀饲料对猪生产表现的影响Fedal等人(1988)发现,用挤压大麦与大豆9:1混合料饲喂育肥猪(体重78kg),可以使回肠日粮干物质(D M)、总能(G E)、淀粉和氮(N)的消化率分别从55.6%、57.9%、83.7%和62.4%提高到62.0%、64.9%、96.9%和69.2%。H erkelm an等人(1990)报道,挤压玉米日粮使哺乳仔猪(体重20kg)的消化能从85.6%提高到87.7%(p<0.05),代谢能从83.7%提高到85.6%(p<0.05)。Jones等人(1990)发现,将饲喂豆粕日粮与饲喂挤压豆粉日粮的猪加以比较,其D M表观消化率分别是72.3%与76.1%,N的表观消化率是52.1%与54.1%。H ancock等人(1991a…     

去皮膨胀全脂大豆取代进口鱼粉对断奶仔猪生产性能的影响

本试验共选用PIC五元配套系商品代28d断奶仔猪100头,平均体重7.618kg。随机分成5个处理组,每组2个重复,每个重复10头。试验处理分别为:Ⅰ)5%鱼粉;Ⅱ)2.5%鱼粉 去皮膨胀全脂大豆;Ⅲ)去皮膨胀全脂大豆(无鱼粉);Ⅳ)2.5%鱼粉 去皮豆粕;Ⅴ)去皮豆粕(无鱼粉)。试验结果:终末头均增重处理组IV和III最高,由高到低依次为组IV、III、I、V、II,分别为10.842、10.409、9.886、9.416和9.340kg;料重比分别为1.227、1.363、1.507、1.527和1.653。结果表明用去皮膨胀全脂大豆完全取代断奶仔猪料中进口鱼粉,对仔猪的生产性能无不良影响。     

Effects of Microbial Phytase Supplementation and Dosage on Apparent Digestibility Coefficients of Nutrients and Dry Matter in Soybean Product-Based Diets for Rainbow Trout Oncorhynchus mykiss

Three experiments were conducted to evaluate the effects of microbial phytase (Ronozyme P(L) and dosage on apparent digestibility coefficients of dry matter, crude protein, amino acids, and minerals in soybean product-based diets for rainbow trout Oncorhynchus mykiss. In experiments 1 and 2, fish were fed soy protein concentrate and soybean meal-based semi-purified diets, respectively. In experiment 3, fish were fed soybean meal-based practical diets. A total of 900 fish (average body weight 100.1 ± 7.4 g) were stocked into 30 150-L fiberglass tanks with 30 fish per tank and two tanks per diet. Phytase was supplemented into soybean product-based diets at 0, 500, 1,000, 2,000, and 4,000 FTU/kg diet. Yttrium oxide (0.01%) was used as inert marker. Feces were collected by hand stripping three times at 3-d intervals. Results of experiments 1 and 2 showed that phytase supplementation significantly increased apparent digestibility coefficients of minerals (except copper and iron), but not dry matter. Experiment 3 showed that phytase supplementation significantly increased apparent digestibility coefficients of dry matter, crude protein, amino acids (except tryptophan and tyrosine), and minerals (except copper and iron). The optimum level of phytase supplementation in rainbow trout diets was approximately 500 FTU/kg diet.