Impacts of a freedom farrowing pen design on sow behaviours and performance

The limited space in farrowing crate imposes many challenges, such as prolonged farrowing duration and high piglet stillbirth rate. Although the features of farrowing pens compensate for the drawbacks of farrowing crates, they are associated with high piglet crushing mortality caused by the greater space afforded to sows and their rolling-over behaviour. Therefore, a freedom farrowing pen was designed to overcome the drawbacks of both farrowing crates and farrowing pens. The main features of the freedom farrowing pen are its left anti-crushing bar and detachable right anti-crushing bar on the sides of the sow lying area. It also has a 10 cm-high anti-crushing bar in the non-lying area. Eighteen healthy, multiparous Yorkshire sows (3-7 parity) were averaged and randomly assigned to farrowing crates, farrowing pens, and freedom farrowing pens to compare the effects of the farrowing systems on sow behaviour and performance. Results showed that the farrowing duration and the mean piglet birth intervals were longer for the sows in farrowing crates than for those in farrowing pens and freedom farrowing pens (P<0.05), but there was no difference between the sows in farrowing pens and those in freedom farrowing pens (P>0.05). The piglet stillbirth rate was higher for the sows in farrowing crates than for those in farrowing pens and freedom farrowing pens (P<0.001). Crushing mortality was higher among piglets in farrowing pens (P<0.001), but there was no difference between piglets in freedom farrowing pens and those in farrowing crates (P>0.05). The freedom farrowing pen and the farrowing pen allowed sows to turn around and move freely, but because of the different structures of their anti-crushing bars, the increase in sow movement did not cause higher piglet crushing mortality (P>0.05). Sows in freedom farrowing pens were found to be more protective of their piglets.     

The 16MΔvjbR as an ideal live attenuated vaccine candidate for differentiation between Brucella vaccination and infection

Brucellosis brings great economic burdens for developing countries. Live attenuated vaccines are the most efficient means for prevention and control of animal Brucellosis. However, the difficulties of differentiating of infection from vaccine immunization, which is essential for eradication programs, limit their applications. Therefore, the development of a vaccine that could differentiate infection from immunization will overcome the limitations and get extensive application. VjbR is a quorum sensing regulator involving in Brucella's intracellular survival. The vjbR∷Tn5 mutants have been proven effective against wild type strain challenge, implying its possibility of use in vaccine candidate development. To further evaluate this candidate gene, in the present study, the antigenicity of purified recombinant VjbR protein was analyzed. Antibodies to Brucella melitensis VjbR could be detected in sera from patients and animals with brucellosis but not in control ones, implying the potential use of this protein as a diagnostic antigen. Then a vjbR mutant of B. melitensis 16M was constructed by replacing the vjbR with kanamycin gene. The mutant showed reduced survival in macrophage and mice. Vaccination of BALB/c mice with 16MΔvjbR conferred significant protective immunity against B. melitensis strain 16M challenges, being equivalent to which induced by the license vaccine Rev.1. The vjbR deletion mutant elicited an anti-Brucella-specific immunoglobulin G response and induced the secretion of gamma interferon and interleukin-10. The most importance is that, the use of vjbR mutants as vaccines in association with diagnostic tests based on the VjbR antigen would allow the serological differentiation between infected and vaccinated animals. These results suggest that 16MΔvjbR is an ideal live attenuated vaccine candidate against B. melitensis and deserves further evaluation for vaccine development.     

绵羊催乳素受体基因外显子10多态性及其与产羔数相关分析

采用PCR-SSCP技术检测催乳素受体(PRLR)基因外显子10在湖羊、小尾寒羊、洼地羊和阿勒泰羊中的单核苷酸多态性,研究该基因与湖羊高繁殖力的关联性。结果表明:4个绵羊品种在P2引物扩增区域均符合Hardy-Wenberg平衡,但P3引物只有阿勒泰羊符合Hardy-Wenberg平衡。P2扩增片段的不同基因型分布频率在4个品种间差异不显著(P0.05);而除阿勒泰羊P3扩增片段的基因型分布与其余3个品种间存在极显著差异(P0.01)外,其余各品种间基因型分布差异不显著(P0.05)。4个绵羊品种间产羔数存在极显著差异(P0.01),但不同基因型间产羔数差异不显著(P0.05);湖羊不同引物不同基因型产羔数的差异亦均不显著(P0.05)。本研究表明,PRLR基因不能作为湖羊高繁殖力的候选基因。     

发酵法在死猪无害化处理中的研究及应用展望

我国生猪出栏量已连续3年超7亿头,每年产生约7千万具猪尸体,约合2百万吨的废弃物.大量死猪若不能被及时有效地处理,将会污染环境,带来食品安全问题,危害到公共卫生安全,造成巨大经济损失.死亡动物无害化处理问题日益引起人们的广泛关注.目前,无害化处理方法众多,笔者简述了较受关注的发酵法的概念和分类、 研究与应用现状,并展望了其应用前景.     

不同腐熟剂接种下肉牛粪污腐熟进程的比较研究

通过肉牛粪污好氧堆肥发酵,对接种不同腐熟剂与空白处理堆肥过程进行物理化性质分析比较,研究不同腐熟剂接种对堆肥过程的影响。结果表明：向堆肥物料中添加腐熟剂可加快堆肥升温速度,提高水分散失率、有机质降解速率,加快粪污腐熟进程,缩短堆肥周期;自主研发腐熟剂和市售腐熟剂堆肥效果相似,项目组自主研发腐熟剂具有加速肉牛粪污腐熟进程的功效。     

不同蛋白质水平日粮对肥育猪肠道氨基酸转运载体CAT1 mRNA表达量的影响

本试验旨在研究不同蛋白质水平日粮对肥育猪肠道氨基酸转运载体CAT1 mRNA表达量的影响.选取36头杜×长×大二三元杂交阉公猪,平均体重(55.6±7.0)kg,随机分为3个处理,分别饲喂13%(低蛋白质组)、16%(对照组)和19%(高蛋白质组)的蛋白质水平日粮,每个处理12个重复(单栏饲养).于饲喂后第45天,每组随机屠宰5头,分离肠道(十二指肠、空肠和回肠),运用Real-Time PCR技术,以β-actin为内参基因,研究CAT1 mRNA相对于β-actin的表达量.结果表明,在饲喂高蛋白质日粮时,与对照组相比,氨基酸转运载体CAT1 mRNA相对于内参β-actin mRNA的表达量,在肥育猪十二指肠、空肠和回肠中分别提高了58.4%、23.2%和24.5%,但差异不显著(P>0.05);而饲喂低蛋白质日粮时,CAT1 mRNA相对表达量在肥育猪十二指肠和空肠中则分别提高93.1%和122.6%,差异显著(P<0.05),而在回肠中降低了14.3%,差异不显著(P>0.05).高蛋白质水平日粮对肥育猪肠道CAT1 mRNA相对表达最的影响不大,而低蛋白质水平日粮对肥育猪肠道CAT1 mRNA相对表达量的影响较大,尤其是对空肠CAT1 mRNA的相对表达量.     

12个多年生牧草品种在迪庆高寒地区的引种评价

为筛选出适宜云南迪庆高寒地区种植的多年生牧草品种,本研究开展了12个多年生牧草品种引种适应性的比较,并采用灰色关联度综合评价法对其生产性能进行了综合评价。结果表明,12种牧草生产性能的高低顺序为紫花苜蓿牧歌401+Z(Medicago sativa cv.Amerigraze401+Z)菊苣将军(Cichorium intybus cv.Commander)鸭茅安巴(Dactylis glomerata cv.Anmba)多年生黑麦草雅晴(Lolium perenne cv.Yatsyn)白三叶铺地(Trifolium repens cv.Prop)红三叶(T.pratense)白三叶海法(T.repens cv.Haifa)紫花苜蓿游客(Medicago sativacv.Eureka)紫花苜蓿WL-525(Medicago sativacv.WL-525)扁穗雀麦草地麦特(Bromus catharticus cv.Grasslands Matua)紫花苜蓿猎人河(M.sativacv.Hunterriver)老芒麦同德(Elymus sibiricus cv.Tongde)。其中,牧歌401+Z紫花苜蓿、将军菊苣、安巴鸭茅、雅晴多年生黑麦草、铺地白三叶、普通红三叶、海法白三叶在当地适应性较好,生产性能相对较高,可作为当地建植栽培草地及改良天然草地的优选品种。研究结果对解决当地饲草匮乏、促进当地草地畜牧业的可持续发展具有重要的意义。     

"黑麦草-水稻”草田轮作系统的研究V.稻田冬种黑麦草的优质高产栽培技术

黑麦草（ＩＲＧ）的栽培方式、播种量、施肥种类和施肥量是影响ＩＲＧ优质高产的主要因素。研究结果表明,高播量（２２．５ｋｇ／ｈｍ＾２）稻底撒播方式可以获得优质高产的ＩＲＧ,干物质产量９１８３．４５ｋｇ／ｈｍ＾２,粗蛋白质产量达１６６８．００ｋｇ／ｈｍ＾２,因其节省劳力,且可以有效利用稻田水分,因此可作为稻田冬种ＩＲＧ的主要方式。中等播量（１５．０ｋｍ／ｈｍ＾２）育苗移栽方式也获得了较高的产量（９７６５     

诱导猪肺泡巨噬细胞CD163受体表达的细胞因子筛选

猪肺泡巨噬细胞(porcine alveolar macrophages,PAM)中的CD163受体作为明星分子不仅参与正常的生理活动,而且作为重要的病毒受体介导猪繁殖与呼吸综合征病毒(Porcine reproductive and respiratory syndrome virus,PRRSV)入侵宿主靶细胞,因...     

高寒牧区栽培毛苕子多次刈割生产性能研究

对毛苕子不同刈割时间与次数的生产性能进行了对对比,发现其生产能力有很大差别,试验证明,在高寒牧区栽培毛苕子,在整个生育期内刈割２次可获得最高产草量,一茬草与二葜最佳刈割期分别为初花期和结荚初期。