肉鸡饲用酶

酶是在生物化学反应中起催化作用的化合物的泛称。酶参与完成化学反应之后可以恢复原状。这种循环可以解释为什么1吨饲料中必须添加1千克酶。酶是天然发酵产物,将其用于肉鸡生产得到了认可。 酶具有高度特异性。比如,某种酶只能对某     

理性认识饲用酶的酶活

正酶制剂是一种催化剂,也是一种活性蛋白质。饲料酶制剂发展20多年,逐渐广泛应用在各种饲料中。然而,在实际的应用中存在一些对酶制剂的误解,从而导致酶制剂应用效果的发挥产生偏差,如高酶活不一定有高的酶解效果。1饲用酶作用的环境影响酶活性的发挥酶活是比较酶水解能力大小的一个重要指标,大家通常认为高酶活意味着更好的水解能力,从而偏向于选择高酶活的产品。酶活是酶活力的度量单位。1个酶活力单位是指在特定条件(如37℃,     

饲用酶产品的新动态

开发和应用非药物饲料添加剂是保证畜产品质量的一项有效措施。其中饲用酶是当前国内外动物营养界研究的热点之一。本文简要介绍饲用酶的作用机理、克服酶热不稳定性和饲用酶新用途等方面的研究进展。1　饲用酶的作用机理酶是具有生物活性的蛋白质 ,按其作用性质可分为氧化还原酶、转移酶、水解酶、裂合酶、异构酶及连接酶。常见的饲用酶产品都属于水解酶类 ,如淀粉酶、蛋白酶、纤维素和半纤维素酶、甘露聚糖酶、植酸酶、戊聚糖酶等 6类。一般认为 ,饲用酶的作用机理是降解饲料中的大分子聚合物(如纤维素、淀粉、蛋白质等 ) ,改善动物对葡萄…     

论饲用酶的稳定化

近十年来各国注册的饲用酶产品越来越多。将酶加到饲料中，能提高畜禽对营养成分的利用率，改善饲养环境和畜禽质量，产生良好的经济效益和社会效益。饲用酶中的纤维素酶、果胶酶等可分解来自植物细胞壁的非淀粉多糖，提高其营养价值，增加被胞壁保护的营养成分释放量；酸性蛋白酶等可帮助消化利用蛋白质等营养物质，降低料肉比；β—葡聚糖酶能分解大麦中的抗营养物β—葡聚糖，降低畜禽肠道的粘滞性，促进营养成分的有效吸收；植酸酶可消除植酸的抗营养性，减少无机磷的使用量和排泄量。饲用酶大多以复合酶的形式添加到雏鸡、仔猪饲料中或…     

国内饲用玉米需求探析

10月12日,国内玉米市场价格仍比较混乱,东北地区新玉米仍未大量上市,仍以消耗陈玉米为主。优质比较少;南方销区仍在等待华北玉米大量上市,华北地区阴雨天气偏多,导致近期玉米价格难以有效回落,玉米价格仍居高不下。吉林地区出库价格1470元/t,沈阳地区玉米出库价格1540元/t。潍坊入厂价格1600元/t,中等质量。石家庄地区玉米价格1600元/t,蛇口港成交1720元/t,四川地区玉米到站价格1690元/t,南方销区到货开始增多。     

饲用酶制应用研究进展

制约饲料产业发展的主要因素是饲料原料玉米大豆的不足,而利用其它作物来提供饲料中所需的蛋白质与能量,却又因为所含有的各种抗营养因子而难以代替玉米和大豆的地位,但随着生物技术的发展,酶制剂的广泛运用在一定程度上缓解了这个问题。使得饲料资源来源得到新的途径,促进了我国饲料工业的发展,同时先一步掌握先进的酶制剂在饲料中的使用,也将大大提高饲料商品的市场竞争力。本文将对现在的酶制剂的使用及存在问题进行探究。     

影响饲用酶应用的因素

综述了饲用酶在生产、加工、贮存及饲喂过程中影响其应用及效果的因素。作为饲用抗生素替代产品之一，酶制剂在畜牧生产上的应用越来越广泛。其无毒副作用、无残留、无抗药性，在改善环境的同时，经济有效地提高畜禽生产性能及饲料利用率和产品品质，且增强机体免疫功能，提高动物抗应激能力，实际生产中常常要求酶制剂的生产成本低、产量高、活力高、性能稳定，但酶为生物活性物质，在生产、加工、贮存及饲喂过程中极易受到破坏而失活或活性降低，现将在上述过程中影响其应用的因素作一总结，期望能引起人们的重视。     

饲用酶高产菌株的筛选

饲用复合酶是一类新型的活性饲料添加剂．不但能补充动物内源酶的不足,而且有效降低了饲料中的抗营养因子,从而提高饲料的营养价值．促进动物对营养物质的消化吸收,使饲料转化率明显提高,降低料肉比,从而降低了饲料成本。本文以菌株米曲霉M-4．11为供试菌株,经定向诱变、筛选到蛋白酶和纤维素酶两株突变株,并考察了培养基质配比对产酶的影响。     

饲用酶的应用及发展趋势

对饲用酶的种类、特点、作用机理、存在问题和应用前景等进行了综述。     

评价饲用酶质量的指标

本文主要探讨了饲用酶的质最评价指标,包括不同条件下的酶活力和稳定性,为广大饲用酶制剂使用者提供了一定的参考价值,从而进一步推动酶制剂在饲料中的广泛应用.     

雉鸡育成期的饲养管理技术

雉鸡脱温后至性成熟前的这一段时间为雉鸡的育成期。这一阶段正是雉鸡长肌肉、长骨骼和增重速度最快的时期。雉鸡育成期的饲养和管理是否得当，将直接关系到雉鸡能否早日作为商品上市或其作为种用性能的好坏。为此，笔者现将雉鸡育成期阶段的饲养管理经验介绍如下：１饲养方式１．１立体笼养法适用于以肉用为目的大批饲养雉鸡，在育成期采用立体笼养法，可以获得良好效果。与立体笼养育雏相比，育成期雉鸡的饲养密度应适当降低，３０日龄时脱温，结合分群疏散密度，使其饲养密度控制在２０～２５只／m２，以后每两周左右疏散一次，使其密度…     

华芬复合酶对猪生长性能的影响

复合酶制剂作为绿色饲料添加剂已经在饲料企业和养殖企业中得到了广泛的应用。试验在以玉米、豆粕为主的高品质口粮中添加0．1％复合酶制剂，小猪和中猪日增重分别比对照组提高6．31％和3．32％；料重比分别比对照组下降6．03％和3．42％；腹泻发病率分别比对照组降低40．91％和4．55％。为在以后养猪生产中推广使用，提供了依据。     

直面食品安全,广东家禽行业在行动

2009年2月28日，全国人大常委会以158票赞成、3票反对、4票弃权表决通过了食品安全法。该法将于今年6月1日起施行。     

Efficiency of utilisations of food energy by female growing minks

The efficiency of utilisation of food energy by female growing minks, from weaning to adult age, was studied. The food given, pelleted according to an original technology, has the following chemical composition on a DM basis: 87.0% organic matter, 37.1% crude protein, 11.7% crude fat, 2.6% crude fiber, 35.6% nitrogen-free extractives and 13.0 per cent ash. Young minks had a feed intake, in relation to body weight, warying from 11.6 g to 58.6 g DM/d. Maximum feed intake related to kg0.75 was recorded at 700 g body weight (approximately 98 g DM/kg0.65). Digestibility of the given food expressed in DE, averaged 87.7 +/- 1.2%, while metabolizability, 82.3 +/- 1.1%. Total heat production related to the intaked gross energy, was 48.0 +/- 3.0%, and the retained energy, 34.3 +/- 4.0 per cent. The net efficiency of the metabolizable energy used for maintenance and production could not be accurately determined. However, taking to account the calculated values required for maintenance, of 649 kJ/kg0.75 in 300 to 600 g young minks, and of 607 kJ/kg0.75 in 600 to 1100 g young minks and also the maintenance efficiency, Km = 0.75, the coefficient for ME utilisation in protein and fat synthesis, of 0.50 and 0.75, respectively, it was able to determine the average ME efficiency used as net energy for maintenance and production: 70%. The highest values of nictemeral metabolism were recorded in the evening, and the lowest ones, at noon; the difference between the maximal and the minimal value did not exceed 6 per cent.     

Rapamycin administration during an acute heat stress challenge in growing pigs

Study objectives were to determine the effects of rapamycin (Rapa) on biomarkers of metabolism and inflammation during acute heat stress (HS) in growing pigs. Crossbred barrows (n = 32; 63.5 ± 7.2 kg body weight [BW]) were blocked by initial BW and randomly assigned to 1 of 4 environmental-therapeutic treatments: 1) thermoneutral (TN) control (n = 8; TNCon), 2) TN and Rapa (n = 8; TNRapa), 3) HS control (n = 8; HSCon), or 4) HS and Rapa (n = 8; HSRapa). Following 6 d of acclimation to individual pens, pigs were enrolled in two experimental periods (P). During P1 (10 d), pigs were fed ad libitum and housed in TN conditions (21.3 ± 0.2°C). During P2 (24 h), HSCon and HSRapa pigs were exposed to constant HS (35.5 ± 0.4°C), while TNCon and TNRapa pigs remained in TN conditions. Rapamycin (0.15 mg/kg BW) was orally administered twice daily (0700 and 1800 hours) during both P1 and P2. HS increased rectal temperature and respiration rate compared to TN treatments (1.3°C and 87 breaths/min, respectively; P < 0.01). Feed intake (FI) markedly decreased in HS relative to TN treatments (64%; P < 0.01). Additionally, pigs exposed to HS lost BW (4 kg; P < 0.01), while TN pigs gained BW (0.7 kg; P < 0.01). Despite marked changes in phenotypic parameters caused by HS, circulating glucose and blood urea nitrogen did not differ among treatments (P > 0.10). However, the insulin:FI increased in HS relative to TN treatments (P = 0.04). Plasma nonesterified fatty acids (NEFA) increased in HS relative to TN treatments; although this difference was driven by increased NEFA in HSCon compared to TN and HSRapa pigs (P < 0.01). Overall, circulating white blood cells, lymphocytes, and monocytes decreased in HS compared to TN pigs (19%, 23%, and 33%, respectively; P ≤ 0.05). However, circulating neutrophils were similar across treatments (P > 0.31). The neutrophil-to-lymphocyte ratio (NLR) was increased in HS relative to TN pigs (P = 0.02); however, a tendency for reduced NLR was observed in HSRapa compared to HSCon pigs (21%; P = 0.06). Plasma C-reactive protein tended to differ across treatments (P = 0.06) and was increased in HSRapa relative to HSCon pigs (46%; P = 0.03). Circulating haptoglobin was similar between groups. In summary, pigs exposed to HS had altered phenotypic, metabolic, and leukocyte responses; however, Rapa administration had limited impact on outcomes measured herein.