贵阳地区禽白血病的血清学调查

为了解和掌握禽白血病在贵阳地区发生和流行的基本情况,采用禽白血病A、B亚群抗体(ALV-A或B)和J亚群抗体(ALV-J)检测试剂盒,对贵阳市13个养鸡场中的15个肉鸡和商品蛋鸡共481份血清进行禽白血病抗体间接ELISA检测,结果 ALV抗体阳性率达到11.43%(55/481),其中9个鸡群172份血清样本A、B亚群抗体阳性率达到18.60%(32/172),13个鸡群309份血清J亚群抗体阳性率达到7.44%(23/309),结果表明该地区存在禽白血病病毒的感染。     

A peptide of foot-and-mouth disease virus serotype Asia1 generating a neutralizing antibody response, and an immunostimulatory peptide

The epitopes of the capsid of foot-and-mouth disease virus (FMDV) play important roles in the construction of highly immunogenic subunit vaccines. However few epitopes have been found for FMDV serotype Asia1. In this study we screened for epitopes of the VP1 and VP2 proteins of FMDV serotype Asia1 isolate, YNBS/58. Fragments consisting of amino acids 133-163 of VP1 and amino acids 1-33 of VP2 contained epitopes, and both induced lymphoproliferation in guinea pigs. Only the VP1 fragment induced neutralizing antibodies but the VP2 peptide dramatically increased the neutralizing antibody response induced by the VP1 peptide.     

两种蔗糖浓度对切割取样鼠胚冷冻解冻效果的研究

小鼠晚期桑椹胚、早期囊胚和扩大囊胚，经切割取样分别采用０．３６５Ｍ和０．２５Ｍ蔗糖浓度进一步细管和分步脱除甘油解冻后体外培养发育率分别为６５．５％、４６．４％和７５．４％，两种浓度间差异显著（Ｐ＜０．０５）；分步脱除甘油解冻瑟前者差异不显著（Ｐ＞０．０５），与后者差异极显著（Ｐ＜０．０１）。     

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.     

4种狂犬病病毒ELISA抗体检测试剂盒的评价

为评价国产狂犬病病毒ELISA抗体检测试剂盒的性能,选择4种国产品牌ELISA抗体检测试剂盒,分别检测463份已用荧光抗体病毒中和试验（FAVN）测知狂犬病病毒抗体效价的犬血清,用Kappa检验和配对卡方检验评价ELISA试剂盒与FAVN检测结果的一致性和差异性,计算ELISA试剂盒的诊断敏感性、诊断特异性、符合率和重复性等,并比较4种试剂盒的使用范围、样品稀释倍数等参数。结果显示：经Kappa检验,4种试剂盒与FAVN一致性均为弱;经配对卡方检验,A、B试剂盒与FAVN检测结果的差异不显著（P> 0.05）,而C、D试剂盒差异显著（P <0.05）。诊断敏感性,D试剂盒最高,B试剂盒最低;4种试剂盒诊断特异性均较低,为29.5%～57.7%;各试剂盒符合率相当,为71.3%～72.8%。综合敏感性、特异性、重复性等考量因素,得出C试剂盒更能满足免疫后抗体检测需求,A试剂盒也较好,两者可作为候选试剂盒。结果表明,4种国产狂犬病病毒ELISA试剂盒的诊断敏感性、诊断特异性、批间稳定性等性能需进一步提高,以满足基层免疫抗体监测需求。     

2022年度生猪产业营养与饲料领域发展趋势与建议

2021年,生猪产能全面恢复并持续在低位震荡,同时饲料原料供给不足及价格飙升,多重因素给生猪养殖业带来了前所未有的压力.本文总结了生猪营养与饲料领域2021年产业现状,分析了2022年度发展趋势,并从科学研究角度提出本领域相关建议.     

温湿度对亚洲小车蝗飞行能力及主要能源物质利用的影响

本研究采用昆虫飞行数据微机采集系统(飞行磨)吊飞方法,测定了温、湿度对10日龄亚洲小车蝗(Oedaleus asiaticus)雌雄成虫的飞行能力及主要能源物质利用的影响。结果表明,在环境温度为28℃、相对湿度(RH)为60%时,10日龄亚洲小车蝗成虫表现出最优的飞行能力,单个个体的最大飞行时间、最大飞行距离和最大飞行速度分别可达1.62h、9.87 km和2.03 km·h~(-1)。在温度16℃以下或28℃以上,其飞行能力明显降低。在40%~80%RH时,成虫均能进行正常的飞行活动。环境温、湿度会显著影响亚洲小车蝗成虫飞行能源物质的消耗情况(P0.05)。在最适的温、湿度条件下,小车蝗飞行所需的能源物质(甘油三酯)最少,其飞行单位距离消耗的甘油三酯也最低,能源利用效率最高。较高或较低的温、湿度条件,能源物质的消耗都显著高于最适条件。飞行能源物质利用效率的不同是导致其在不同温、湿度下飞行能力产生差异的主要原因之一。     

The localization and expression of epidermal growth factor and epidermal growth factor receptor in bovine ovary during oestrous cycle

Epidermal growth factor (EGF) is one of the important regulatory factors of EGF family. EGF has been indicated to effectively inhibit the apoptosis of follicular cells, to promote the proliferation of granulosa cells and the maturation of oocytes, and to induce ovulation process via binding to epidermal growth factor receptor (EGFR). However, little is known about the distribution and expression of EGF and EGFR in cattle ovary especially during oestrous cycle. In this study, the localization and expression rule of EGF and EGFR in cattle ovaries of follicular phase and luteal phase at different time points in oestrous cycle were investigated by using IHC and real-time qPCR. The results showed that EGF and EGFR in cattle ovary were mainly expressed in granulosa cells, cumulus cells, oocytes, zona pellucida, follicular fluid and theca folliculi externa of follicles. The protein and mRNA expression of EGF/EGFR in follicles changed regularly with the follicular growth wave both in follicular and in luteal phase ovaries. In follicular phase ovaries, the protein expression of EGF and EGFR was higher in antral follicles than that of those in other follicles during follicular growth stage, and the mRNA expression of EGFR was also increased in stage of dominant follicle selection. However, in luteal phase ovaries, the growth of follicles was impeded during corpus luteum development under the action of progesterone secreted by granular lutein cell. The mRNA and protein expressions of EGF and EGFR in ovarian follicles during oestrous cycle indicate that they play a role in promoting follicular development in follicular growth waves and mediating the selection process of dominant follicles.     

2019年我国部分地区屠宰生猪旋毛虫和弓形虫检测

为了解我国部分地区屠宰生猪旋毛虫和弓形虫感染情况,2019年在广东（5个）、山东（4个）、云南（6个）等省份的15个大型、中小型生猪屠宰场,采集猪膈肌样品315份,用PCR方法进行旋毛虫和弓形虫病原学检测;在以上3省15个大型、中小型生猪屠宰场（每省5个）,采集血清样品254份,用ELISA方法进行旋毛虫和弓形虫血清学检测。结果显示：经PCR检测,采样地区所有膈肌样品均为旋毛虫阴性,仅在云南省120份膈肌样品中检出1份弓形虫阳性;经ELISA检测,采样地区血清样品的旋毛虫和弓形虫抗体阳性率分别为1.97%和2.36%,不同省份的阳性率分布不一致,中小型屠宰场阳性率均高于大型屠宰场。结果表明,广东、山东、云南等省份屠宰生猪的旋毛虫和弓形虫携带率极低,基本可以保证猪肉的产品安全;部分地区屠宰生猪存在一定的弓形虫感染抗体,尤其是中小型屠宰场,表明此类猪群需要加强饲养环节的弓形虫感染控制。本研究为保障猪肉食品安全及饲养环节的猪旋毛虫和弓形虫感染控制提供了依据和指导。     

不同浓度大豆卵磷脂替代蛋黄对东佛里生奶绵羊精液冷冻保存效果的影响

本试验皆在研究添加不同浓度大豆卵磷脂（SL）冷冻保存东佛里生奶绵羊精液的效果。我们在Tris基础稀释液中,添加18%蛋黄为对照组,添加0.5%、1%、1.5%、2%、2.5%SL设为试验组,检测冷冻精液解冻后的精子活率和顶体完整率。结果显示,添加0.5%、2.5% SL冷冻稀释液稀释的精液,解冻后精子活率和顶体完整率与其他组之间存在显著差异（P<0.05）;添加18%蛋黄和1%～2% SL冷冻稀释液稀释的精液,冷冻解冻后精子活率和顶体完整率之间无显著差异（P>0.05）;添加18%蛋黄和1.0%～1.5% SL冷冻稀释液稀释后的精液,进行人工授精后母羊的妊娠率与对照组无显著差异（P>0.05）。因此,大豆卵磷脂可以作为冷冻保护剂用于东佛里生奶绵羊精液的冷冻保存,其最佳添加浓度为1～2%（g／L）。