Effects of dietary neutral detergent fibre on production performance, nutrient utilization, caecum fermentation and fibrolytic activity in 2- to 3-month-old New Zealand rabbits

An experiment was conducted to determine the effects of different dietary neutral detergent fibre (NDF) levels on growth performance, nutrient utilization, caecum development, caecal fermentation, slaughter performance, immune organ and fibrolytic activity in 2- to 3-month-old New Zealand meat rabbits. Eighty 2-month-old rabbits were allocated in individual cages for five treatments in which they were fed each diet with NDF at 240, 270, 300, 330 and 360 g/kg respectively. The results are as follows: the average daily gain of 300 g/kg NDF group was the highest (30.09 g/day) and higher than that of 240 g/kg NDF group (p < 0.05). The feed/gain ratio of 300 g/kg NDF group was the lowest (4.27) and lower than those of 240 and 360 g/kg NDF groups (p < 0.05). The coefficient of total tract apparent digestibility (CTTAD) of energy, crude protein, crude fibre and ether extract decreased when dietary NDF increased (p < 0.05); CTTAD of NDF increased when dietary NDF increased (p < 0.01). Digestible nitrogen and retained nitrogen of 240, 270, 300 and 330 g/kg NDF groups were higher than that of 360 g/kg NDF group (p < 0.05). The caecum weight, the proportion of caecum weight to body weight and the acetic acid ratio of volatile fatty acid rose when dietary NDF concentration increased (p < 0.05). The NH(3)-N concentration of caecum dropped when dietary NDF increased (p < 0.05). The fibrolytic activity increased when the dietary NDF increased (p < 0.01).     

紫花苜蓿品种比较试验

通过对26个紫花苜蓿（Medicago sativa）品种的生育期、株高、产量、越冬率等指标的试验比较，结果表明：公农一号、保丰、陇东、德福等几个品种的表现优于其他参试品种，适宜在辽西北风沙地地区推广种植。     

单宁对反刍动物养分利用的营养机制

植物饲料中适量的单宁含量对反刍动物养分利用有其积极作用。本文从分析单宁的理化性质入手,详细综述了植物饲料中单宁的营养作用机制、抗营养作用、去除措施以及研究展望,以期为有效利用含单宁的植物饲料提供理论参考。     

类胡萝卜素吸收研究进展

关于类胡萝卜素的吸收机制说法不一,目前体外培养的细胞模型被广泛用于类胡萝卜素的吸收研究。本文主要从细胞水平上讨论了类胡萝卜素的吸收研究进展,并详细讨论了类胡萝卜素吸收机制方面研究较多的选择性吸收及吸收过程中的相互影响。细胞对β-胡萝卜素的摄入和分泌表现出浓度依赖性、时间依赖性和饱和性;对不同类胡萝卜素的吸收表现出选择性;类胡萝卜素在吸收过程中表现出相互影响。上述研究结果表明,类胡萝卜素的吸收可能是一个有载体参与的易化运输过程。     

Preparation of Pectin/Chitosan Synbiotic Microcapsules and Its Study on Simulated Gastrointestinal Environments and Storage Stability

Pediococcus acidilactici and inulin were used as wall cores,with pectin and chitosan as the shell material.The conditions of microencapsulation were optimized by analyzing the embedding rate,particle morphology,the mechanical strength,gastrointestinal tolerance in vitro and storage performance.The experimental group was divided into three groups:Free Pediococcus acidilactici group (PA),microcapsule group made by embedding Pediococcus acidilactici alone (PC(PA)MCs),synbiotic microcapsule group made by embedding inulin and Pediococcus acidilactici (PC(PA-I)MCs).The results showed that the appearance,particle size,mechanical strength and embedding rate of microcapsules were better when the mass concentration of pectin was 5 g/100 mL,the content of inulin was 25 mg/mL and the mass concentration of chitosan was 0.8 g/100 mL.Through the gastrointestinal tolerance test in vitro, it was found that PC(PA-I)MCs group was relatively stable in the artificial gastric juice in vitro (P<0.05).At the same time,it began to release rapidly in the artificial intestinal fluid in vitro at 30 min and it was almost completely disintegrated after 2 h.It was found that the cell survival rate of PA group decreased significantly at cold and room temperature through the storage test for 4 weeks.While the cell survival rate of PC(PA-I)MCs group decreased slightly.And the cell survival rate of PC(PA-I)MCs group was higher than that of PC(PA)MCs group (P>0.05).At room temperature,the cell survival rate of PC(PA-I)MCs group was higher than that of PC(PA)MCs group (P>0.05).In summary,pectin/chitosan microcapsules with inulin as probiotics had a better embedding effect on Pediococcus acidilactici.     

鹅观草属三个物种及其居群间核型变异研究

报道了鹅观草属3个物种,毛叶鹅观草、竖立鹅观草和纤毛鹅观草及其居群间的核型,其中R. amurensis的核型2n=4x=28=24m(2SAT) 4sm为首次报道.结果表明,3个物种绝大多数由中部和近中部着丝点染色体组成,具1对随体,几乎都位于第14对染色体上.核型类型为2A.但在核型公式、平均臂比、臂比大于1.7的染色体比率等方面,不仅3个物种的种间存在一定的差异,而且R. ciliaris和R. japonensis的种内不同居群间也存在差异,表明R. ciliaris和R. japonensis种内具有较大的遗传多样性.     

山羊催乳素基因PCR-SSCP分析

设计5对引物，采用PCR SSCP技术检测催乳素（prolactin，PRL）基因外显子1~外显子5在高繁殖力山羊品种（济宁青山羊、波尔山羊、文登奶山羊）和低繁殖力山羊品种（内蒙古绒山羊）中的单核苷酸多态性，同时研究该基因对济宁青山羊高繁殖力的影响。通过克隆测序首次获得了山羊PRL基因外显子全序列。结果表明PRL基因在研究的4个山羊品种中都不存在单核苷酸多态性，提示检测的PRL基因座位对济宁青山羊高繁殖力没有显著影响。     

酶制剂在畜禽生产中的应用研究进展

酶制剂作为3大绿色饲料添加剂（益生素、中草药、酶制剂）之一，能够部分解决饲料资源不足的难题，它的研究、开发与应用已成为动物营养界关注的一个热点；作者综述了酶制剂在畜牧生产应用中的最新研究进展，并初步提出酶制剂开发利用的研究重点。     

猪呼吸道疾病综合征的防治

猪呼吸道疾病综合征(PRDC),又称“猪复合性肺炎”“、多因子猪呼吸道病”等,是近几年来集约化养猪场或养猪专业户常见的疾病,给养殖业带来严重的经济损失。本病的特点是致病原因复杂,多因子共同作用,临床症状不一,病程长,疗程久,猪增重速度下降,尤其是保育猪和育肥猪多发。通常需联合用药才能控制。1病因猪呼吸道疾病综合征的致病原因相当复杂,目前尚存在争议,但共同认为是一种多因子复合型疾病。1.1原发性病原经常是几种病原同时存在。常见的主要病原有:1.1.1猪繁殖与呼吸综合征病毒本病毒引起猪繁殖与呼吸综合征,俗称“兰耳病”。其典型…     

肉鸡生产HACCP管理体系的研究与建立

HACCP是一个管理体系,它是一种如何组织具体科学技术在生产中应用并落到实处的学问,属于管理学的范畴。HACCP管理体系实施的关键是要建立一个有效的操作程序和监控体系,制定本企业的技术标准操作程序。同时需要培养一支技术过硬、经验丰富、责任心强的技术人员和监管队伍,建立监控记录,定期检查分析,不断预测潜在危害,不断提高企业控制关键点的能力和水平,对企业的质量管理进行持续改进,最终形成一套适合企业饲养过程的HACCP计划,并推广应用,达到质量安全的效果。