生物制剂作为饲料添加剂应用的研究进展

饲料添加剂是现代饲料业的重要组成部分。抗生素和激素类饲料添加剂的长期使用不仅使许多病原菌产生耐药性,而且会在畜产品中残留,严重影响动物疾病防治,危害人类健康。生物制剂能够作为抗生素替代品应用在饲料中,具有无残留、无耐药性、不易产生毒副作用等优点。对生物制剂作为添加剂应用于饲料中的研究进展进行了综述。     

微生态制剂对锦鲤生长及水质的影响研究

[目的]探讨微生态制剂对锦鲤生长及水质的影响.[方法]以锦鲤为试验对象,通过在饲料和水体中添加微生态制剂,研究其对锦鲤生长及水质的影响.[结果]微生态制剂对锦鲤的生长具有促进作用,最佳添加量为6％.试验组水体pH、氨氮含量、亚硝酸盐含量均低于对照组.[结论]复合微生态制剂在水产养殖业中有着广阔的应用前景.     

微生态制剂及其在水产养殖中的应用研究现状

论述了微生态制剂的种类、作用机理及其作为水质改良及饲料添加剂在水产养殖领域的应用现状。对微生态制剂在使用中的影响因子、存在问题以及发展趋势进行了初步分析。     

微生态制剂在猪生产中的应用

随着现代养殖业的发展,畜禽微生态制剂在世界范围内越来越受到人们重视。对微生态制剂的作用机理及其在猪生产中的应用进行了综述。     

多菌种复合益生素对三黄鸡的生产性能以及肠道主要菌群的影响

研究多菌种复合菌益生素对三黄鸡的生产性能和肠道主要菌群的影响。试验选用1560只1日龄的广西岑溪三黄肉仔鸡,随机分成2组,每组780只。对照组饲喂基础日粮,试验组日粮由基础日粮加0.1%的益生素组成。饲养时间为6周。试验结果表明:全期试验组的平均日增重比对照组高12.58%(P<0.01),料重比比对照组低9.23%(P<0.05);试验结束时,雏鸡空肠和盲肠大肠杆菌数量分别比对照组低27.61%(P<0.05)和25.57%(P<0.05),乳酸菌数量分别比对照组高16.12%(P>0.05)和11.28%(P>0.05)。     

牦犊牛源乳酸菌的筛选鉴定与体外益生特性评价

以3月龄健康牦犊牛胃肠道内容物作为菌源,筛选得到4株能够同时抑制大肠杆菌、沙门氏菌和金黄色葡萄球菌的乳酸菌,分别编号为XC3、DC1、DC8和A5。经16S rRNA序列分析鉴定,XC3为乳酸片球菌,DC8为罗伊乳杆菌,DC1为戊糖片球菌,A5为植物乳杆菌。经体外试验评价其益生特性,pH=3时,4株乳酸菌的活菌数均较高;在3 g/L的牛胆盐培养液中,菌株XC3的存活率为93.85%,菌株DC8和A5的存活率分别为51.59%和51.18%,但菌株DC1的存活率仅为6.77%;在人工胃液中培育0.5 h和3 h后,4株菌存活率均高于80%,在人工肠液中培育0.5 h和3 h后,存活率均高于70%。结果表明,乳酸菌XC3、DC8和A5具有潜在的益生作用,可作为牦犊牛专用益生菌制剂的添加对象。     

中草药与益生素对断奶仔猪生长和免疫作用的影响

试验选取54头25日龄三元杂交(杜×长×大)断奶仔猪,按性别、窝别和体重随机分为3组,每组3个重复,每个重复6头猪。各组基础日粮一致。对照组饲喂基础日粮;试验1组在基础日粮中添加0.05%中草药添加剂;试验2组在基础日粮中添加0.05%中草药与益生素混合添加剂。试验结果表明:试验2组效果最好,较对照组日增重提高了21.7%(P<0.05),饲料转化率提高了16.4%,腹泻率降低了69.2%;试验猪的血清球蛋白比对照组显著提高,尤其是免疫球蛋白IgA比对照组提高100%(P<0.01),证明了中草药与益生素饲料添加剂对断奶仔猪的免疫作用;两个试验组经济效益较高。     

Effect of a probiotic bacterium <Emphasis Type="Italic">Bacillus circulans</Emphasis> PB7 in the formulated diets: on growth,nutritional quality and immunity of <Emphasis Type="Italic">Catla catla</Emphasis> (Ham.)

Bacillus circulans PB7, isolated from the intestine of Catla catla, was evaluated for use as a probiotic supplement in the feeds for the fingerlings of Catla catla. The effect of supplement on the growth performance, feed utilization efficiency, and immune response was evaluated. Catla fingerlings (ave. wt. 6.48 ± 0.43 g) were fed diets supplemented with 2 × 10⁴ (feed C1), 2 × 10⁵ (feed C2), and 2 × 10⁶ (feed C3) B. circulans PB 7 cells per 100 g feed for 60 days at 5% of the body weight per day in two equal instalments in triplicate treatments. The control feed (CC) was not supplemented with the B. circulans. All the feeds were isocaloric and isonitrogenous. Fish fed with feed C2 displayed better growth, significantly (P ≤ 0.05) highest RNA/DNA ratio, a lower feed conversion ratio (FCR), and a higher protein efficiency ratio (PER) than the other experimental diets. Highest carcass protein and lipid was also observed in the fish fed C2 feed compared to the others. Significantly (P ≤ 0.05), highest protease was recorded in fish fed feed C2 (47.9 ± 0.016) and lowest in fish fed feed C3 (32.10 ± 0.009), where α-amylase activity did not differ significantly (P ≤ 0.05) beyond the lowest inclusion level. ALP, ACP, GOT, and GPT in the liver of Catla catla were the highest (P ≤ 0.05) in fish fed C2 feed. The highest TSP, albumin, and globulin was observed in fish treated with C2 feed after 60 days feeding trial, but the lowest glucose level was observed in the same treatment. After the feeding trial, the non-specific immunity levels and disease resistance of fish were also studied. Phagocytic ratio, phagocytic index, and leucocrit value were the highest in fish fed feed C2. After the feeding trial, the fish were challenged for 10 days by bath exposure to Aeromonas hydrophila (AH1) (10⁵c.f.u. ml⁻¹ for 1 h, and, after 7 days, 10⁷c.f.u. ml⁻¹ for 1 h). Highest survival percentage was observed in fish fed with feed C2 compared with only 6.66% in the controls, which indicated the effectiveness of B. circulans PB 7 in reducing disease caused by A. hydrophila.     

Effect of Customized Probiotics on the Physiological and Immunological Responses of Juvenile Western King Prawns (Penaeus latisulcatus Kishinouye, 1896) Challenged with Vibrio harveyi

Juvenile western king prawn P. latisulcatus were fed 10⁵ colony-forming units (CFU)/mL of two probiotics Pseudomonas synxantha and P. aeruginosa for 28 days. P. latisulcatus were then challenged with V. harveyi at 0 (control), 10³, 10⁵, and 10⁷ CFU/mL. During the seven days of challenge, disease resistance of the probiotic-fed prawns was compared with that of prawns not fed probiotics. The immunological responses of the prawns did not improve during the challenge period in terms of total haemocyte count, hyalinocyte, semi-ganulocyte, granulocyte, clotting time, bacteraemia, and intestinal bacterial load. Overall, when prawns were challenged with V. harveyi, the LT₅₀ values got shorter as V. harveyi concentration increased. LT₅₀ values of prawns fed probiotics were significantly longer (P < 0.05) than those not fed probiotics. At a V. harveyi concentration of 10³ CFU/mL, the 100% survival of the prawns fed probiotics was three times more likely than those of the prawns not fed probiotics.     

酪酸菌对种鸭生产性能的影响

选取10月龄的番鸭种鸭840只,随机平均分为对照组和试验组,试验组在对照组日粮基础上添加0.2%酪酸菌,以观察酪酸菌对种鸭生产性能和种蛋受精率的影响。结果表明,试验组平均产蛋率85.85%,比对照组高4.10个百分点(P<0.05);试验组受精率为100%,比对照组高28.58个百分点(P<0.01);蛋品质的相关指标则无显著差异(P>0.05)。试验结果表明,酪酸菌可以明显提高种鸭产蛋率和受精率。