酵母富集微量元素铜的研究

酵母细胞具有富集某些微量元素的能力,它能将富集的无机态铜转化为有机态形式。采用富集培养方法,从22株酵母菌株中筛选出2株富集高含量铜的酵母菌,对其铜含量进行测定。结果表明：铜含量分别达到7．7mpdkg和7．9mpdkg,适宜的铜盐为氯化铜,其添加的离子浓度为90mpdkg。     

富铜酵母发酵条件优化的研究

利用酵母菌具有较强的富集微量元素的特性,试验研究了酵母菌富集微量元素铜的条件优化。从6株酵母菌中筛选出耐铜能力和富集铜能力均较强的J5作为试验菌株。试验结果显示:500ml摇瓶中装入50ml培养基,pH值为4.0～5.5,接种量为4%,30℃条件下摇床培养,最适宜的无机铜源为氯化铜,适宜氯化铜浓度120μg/ml。在此条件下培养所得酵母菌体生物量能达到1.00g/100ml以上,有机铜含量能够达到5000μg/g左右。     

酵母富集微量元素锌的研究

酵母能够将无机态微量元素锌转化为有机态的微量元素。采用富集培养方法,从22株酵母菌株筛选出2株富集高含量锌的菌株,并对酵母菌在不同锌离子浓度条件下最适生长条件、pH、含锌化合物的筛选进行研究。结果表明,锌含量为4000～5000mg/kg,适宜的含锌化合物为硫酸锌,锌离子添加浓度为60～120mg/kg。     

猪铜中毒的诊治

铜是动物不可缺少的微量元素,用高浓度铜饲料喂猪,具有抑制细菌效能和明显的促生长作用,能保证猪体健康、加快猪的生长速度、提高饲料报酬。一些猪场将硫酸铜作为生长促进剂,但过量食入或过量加入仔猪饲料导致但高剂量     

铜作为猪生长促进剂的应用综述

1955年Dr.Braude首先发现高浓度铜日粮具有促进猪生长的作用,此后国内外许多研究者对铜的作用及其代谢等进行了广泛的研究.现将铜对猪的日增重、饲料转换效率和胴体品质的影响及其毒性等问题进行综述与分析,便于对此进行深入的研究.     

酵母铜对仔猪生长性能及抗氧化作用的影响

将平均体重(18.23±3.03)kg的24头健康的松辽黑仔公猪随机分为4组,每组6头,试验1组饲喂硫酸铜250mg/kg,试验2、3、4组分别饲喂酵母铜10、50、100mg/kg,研究酵母铜和硫酸铜对7～10周龄仔猪的生长性能及抗氧化酶活性的影响。结果表明:日粮中添加50mg/kg酵母铜,在提高仔猪的生长性能及抗氧化酶活性方面与添加250mg/kg硫酸铜具有相同的作用效果。随着酵母铜浓度的增加,血清中CuZn-SOD、铜兰蛋白的活性相应提高。随着日龄的增加,CuZn-SOD、铜兰蛋白的活性逐渐增强。     

酵母产品对母猪繁殖性能的影响研究

酵母菌是单细胞真核微生物,目前酵母产品已普遍运用于饲料中,酵母产品主要包括酵母培养物、活性干酵母、酵母细胞壁多糖和酵母微量元素。本文综述了这些酵母产品在影响母猪繁殖性能方面的研究进展,为酵母产品在母猪生产中的运用提供参考。     

酵母在畜禽业中的研究与应用

酵母是一类单细胞微生物,属真菌类。目前已知的酵母菌有９５余种。由于酵母菌个体大、蛋白质含量高易分离、杂食性强易培养、生长期短、代谢产物多、综合利用广等特点而倍受关注。随着科技的发展和人们对养殖业需求的不断上升,     

富铁酵母对家兔红细胞免疫功能的影响

为探讨富铁酵母对家兔红细胞免疫功能的影响,将32只家免随机分成富铁酵母高、低剂量组,FeSO4组及空白对照组,分别灌服富铁酵母(Fe元素8 mg/kg、4 mg/kg)、FeSO4(Fe元素4 mg/kg)及空白生理盐水;连续5 d后,检测红细胞C3g受体花环率和复合物(IC)花环率.结果:富铁酵母较FeSO4及空白组能显著提高红细胞C3h受体花环和红细胞复合物(IC)花环的百分率,但高、低剂量间无显著性差异.结论:富铁酵母能显著提高红细胞免疫功能.     

Effect of dietary astaxanthin rich yeast,Phaffia rhodozyma,on meat quality of broiler chickens

We evaluated effects of dietary supplementation with astaxanthin (Ax)‐rich yeast, Phaffia rhodozyma (Xanthophyllomyces dendrorhous), on broiler chicken meat quality. Fourteen‐day‐old female Ross broilers were divided into three groups: control group, Ax‐free diet; Ax 10 group, 10 mg/kg Ax diet; and Ax 20 group, 20 mg/kg Ax diet for 28 days. At 42 days old, chickens were slaughtered, and then growth performance, meat quality and sensory attributes were analyzed. Compared with the control, a* values increased significantly after slaughter and 48 h postmortem for Ax 20 samples (P < 0.05) and for b* values in Ax 20 and Ax 10 groups (P < 0.05). Cooking loss decreased in the Ax 20 group (P < 0.05). After 120 h aging, contents of several free amino acids and total free amino acid content of Ax 20 group were significantly higher than the control (P < 0.05). In sensory evaluation, meat texture attributes improved significantly in the Ax 20 group (P < 0.01). No significant changes occurred in flavor attribute scores of meat soup from the Ax 20 group compared with the control even though most assessors preferred meat soup from the Ax 20 group. Overall, Ax‐rich yeast in the diet improves broiler chicken meat quality.     

富硒酵母对肉鸡生产性能的影响研究

试验选择富硒酵母,在肉鸡饲料中添加4个水平的富硒酵母(硒添加水平0、0.1、0.2、0.3mg/kg),以确定富硒酵母在肉鸡饲料中的适宜添加量。结果表明:添加后,肉仔鸡生产性能无显著差异,但可显著提高42日龄肉仔鸡的增重和耗料量。本试验中,饲料中硒的适宜添加水平为0.1mg/kg。     

啤酒酵母多糖提取工艺条件的研究

试验研究了从啤酒酵母中提取胞壁多糖的提取工艺。提取工艺路线为:酵母溶解→冻融→超声波破碎→碱溶→中和→沉淀→洗涤→烘干。通过正交试验对酵母破壁和碱溶条件进行优化,寻求最佳的工艺条件,多糖得率为19.4%,用苯酚-硫酸法测定多糖的含量为51.9%。     

利用甘蔗糖蜜生产饲料酵母发酵条件的研究

以甘蔗糖蜜为碳源发酵生产高生物量饲料酵母,通过单因素正交试验设计,确定优化的培养条件为:温度28℃,pH5.0,装液量200mL/500mL,摇床转速180r/min,培养时间84h。在优化的培养条件下酵母菌株的总蛋白质含量可达到6.01g/L。     

Effect of supplemental yeast culture and physiological factors on colostrum and milk composition of Pelibuey ewes

The effects of supplemental yeast culture, litter size, stage and number of lactation on milk composition were studied in Pelibuey ewes. Twenty ewes were randomly assigned to one of two dietary treatments. Ten control ewes grazed on guinea grass (Panicum maximum) and were supplemented with concentrate. A further ten ewes received the same diet with 14 g/head/day of yeast culture (Saccharomyces cerevisiae). Colostrum was collected within 24 h after parturition, and subsequently, milk samples were collected at fortnightly intervals (7, 21, 35, and 49 days). Total solids content averaged 32% in colostrum and 12.5% in milk. Colostrum of primiparous ewes had higher total solids content than that of ewes with more than five lactations. However, ewes with more than five lactations produced milk with higher net energy, total solids, protein, and casein than ewes with fewer lactations. Milk at 7 days had a significantly higher content of energy, total solids, and fat than milk at 21, 35, and 49 days. Total solids content was lower for ewes rearing one lamb than larger litter sizes. Supplementation with yeast culture did not affect the composition of colostrum and milk, which was mainly affected by the stage and number of lactation.     

混菌发酵生产富肽蛋白饲料工艺条件的研究

利用枯草芽胞杆菌和产朊假丝酵母菌混合发酵生产富肽蛋白饲料,通过单因素和响应面分析试验对其工艺条件进行了研究,选择接菌比例(枯草芽胞杆菌:产朊假丝酵母)为3:1,发酵36h。最佳发酵条件为:发酵温度33℃,装料量40g,原料初始含水率为62%,拌料水的pH值为自来水的自然pH值。在此条件下测得三氯乙酸可溶性氮(TCA-NSI)含量达到33.61%。