强化兽药GSP后续监管 保障兽药产品质量安全

随着兽药GSP认证工作的全面结束,兽药GSP的日常监管工作越来越凸显其重要性。本文综合论述了在兽药GSP日常监管过程中发现的诸多问题,以及今后如何做好兽药GSP后续监管工作所采取的措施。     

精氨酸的抗热应激作用及在母猪上的应用

精氨酸是一种条件性必需氨基酸,在生理调节方面具有重要的功能。在正常情况下,成年动物对精氨酸的需求可以通过内源性合成满足,但在应激条件下,内源合成的精氨酸不足以满足机体的需求。精氨酸代谢可合成一氧化氮(NO),NO在体内发挥着重要的生理作用。文中综述了高温热应激对母猪的影响、精氨酸在体内的代谢过程及在抗氧化应激方面的作用,以促进高温热应激条件下精氨酸在母猪中的应用及研究。     

不同品系杜洛克后代商品猪胴体性状的比较分析

为研究不同品系杜洛克作为终端父本对其后代商品猪胴体性状的影响,选取214和108头分别由美系和加系杜洛克公猪配种、出生时间相近(±2 d)和体重相近(35±5 kg)的后代三元商品猪进行育肥饲养,结束饲养后开展屠宰试验,测定背膘厚度、眼肌厚度、瘦肉率和肋骨数.结果显示:加系杜洛克商品后代的背膘厚度、眼肌厚度显著(P<0...     

J亚群禽白血病病毒与禽网状内皮增生症病毒共感染对肉鸡生长和免疫功能的抑制作用

1日龄网鸡感染J亚群禽白血病病毒(ALV-J)以及共感染禽网状内皮增生症病毒(REV)后,肉鸡生长发育明显受阻,体重增重明显下降(P＜0.05),法氏囊、胸腺明显萎缩(P＜0.05),在用新城疫疫苗免疫后,感染组血清中新城疫抗体效价显著低于对照组(P＜0.05);在ALV-J和REV共感染后,这种抑制作用更为明显(P＜0.01).ALV J单独感染后,鸡对传染性法氏囊病病毒(IBDV)弱毒疫苗免疫后的抗体反应与对照组没有明显差别,但ALV-J与REV的共感染可明显延缓鸡对IBDV弱毒疫苗免疫的抗体反应.     

Effect of dietary Schizochytrium microalga oil and fish oil on plasma cholesterol level in rats

The purpose of the study was to test the hypothesis that the dietary oils with different content of n‐3 polyunsaturated fatty acids (PUFA) eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) affect plasma lipid level in rats in a different degree. The diets with 6% of fish oil (FO) and Schizochytrium microalga oil (SchO; EPA+DHA content in the diets 9.5 + 12.3 and 2.6 + 29.5% of the sum of total fatty acids, respectively) were used; the diet with 6% of safflower oil (high content of n‐6 PUFA linoleic acid, 65.5%; EPA+DHA content 0.7 + 0.9%) was used as a control. The difference between FO and SchO was established only in the case of plasma triacylglycerol (TAG) level: plasma TAG of the FO‐fed rats did not differ from the control rats (p > 0.05), while SchO decreased (p < 0.05) plasma TAG to 46% of the control. On the other hand, FO and SchO decreased (p < 0.05) total plasma cholesterol (TC) in rats in the same extent, to 73% of the control. Regarding the underlying mechanisms for the TC decrease, both SchO and FO up‐regulated hepatic Insig‐1 gene (181 and 133% of the control; p < 0.05), which tended (p = 0.15 and p = 0.19 respectively) to decrease the amount of hepatic nSREBP‐2 protein (61 and 66% of the control). However, neither SchO nor FO influenced hepatic 3‐hydroxy‐3‐methyl‐glutaryl‐CoA reductase gene expression (p > 0.05); SchO (but not FO) increased (p < 0.05) low‐density lipoprotein receptor mRNA in the liver. It was concluded that the decrease of total plasma cholesterol might be caused by an increased cholesterol uptake from plasma into the cells (in the case of SchO), but also by other (in the present study not tested) mechanisms.     

高山草原绵羊放牧生态及消化代谢的研究：Ⅰ放牧绵羊嗜食性研究

利用植物显微技术镜检法和食道瘘管法对放牧绵羊采食的高山草原植物成分与嗜食性指数进行分析。结果表明,绵羊在黄草期采食植物成分比青草期多,其嗜食性指数在不同时期变幅较大,随着冬季来临,绵羊对草地植物的嗜食性不如青草期强烈,至某些植物嗜食性是相对稳定的。     

断乳前后乳猪消化道(胰、小肠内容物)几种消化酶活性变化的研究

测定乳猪胰脏、小肠内容物中淀粉酶、胰蛋白酶、胰凝乳蛋白酶的活性以观察年龄对其影响。10头乳猪从21、28、35、42、49日龄分别被屠宰，乳猪在28日龄断奶。胰、小肠内容物中的淀粉酶，胰蛋白酶和胰凝乳蛋白酶的总活性从21日龄至35日龄均呈逐渐上升趋势；35日龄后出现下降，断奶可能会造成多数消化酶的活性降低。但随着进食刺激则酶活会很快恢复并呈上升趋势。     

草原生态系统的土壤微生物生态

1980～1998年,在内蒙古锡林河流域等草原地区开展了土壤微生物生态学方面的系列研究. "干重换算法"为草原土壤微生物不同类群的生物量测定提供了一个较实用的方法;内蒙古不同草原和荒漠区土壤微生物活性具有不同的地理分布特征;锡林河流域六种植物群落下土壤微生物的区系组成及生物量分布亦有所不同;羊草等牧草具有明显的根际效应;不同放牧率及退化草场围栏恢复、落地油污染、施用稀土元素等人为因素会对土壤微生物数量及活性产生不同的生态效应;微生物多样化变化亦符合"中度干扰理论";土壤微生物在草原生态系统物质转化和能量流动中起着非常重要的作用;植物残体分解过程中微生物类群存在明显的优势更替现象.     

Characterization of polymorphisms of transferrin receptor and their association with susceptibility to ETEC F4ab/ac in pigs

Diarrhoea caused by enterotoxigenic Escherichia coli (ETEC) expressing F4 (F4ab, F4ac and F4ad) fimbriae is a significant cause of mortality and morbidity in newborn and weaned pigs. The locus controlling susceptibility towards ETEC F4ab/ac has been mapped to SSC13q41, in which TFRC (transferrin receptor) was localized and considered as a positional candidate gene for ETEC F4ab/ac receptor. In this study, we determined susceptibility/resistance to ETEC F4ab/ac in a total of 755 F2 animals from a White Duroc x Erhualian intercross using a microscopic enterocyte adhesion assay. We identified two TFRC polymorphisms (SNPs 591 A>G and 632 A>G) in a single exon after comparative sequencing analysis of 2371-bp amplicons containing the complete coding region of TFRC using RNA of eight full-sib F2 animals with susceptible and resistant phenotypes. The intron sequences flanking the two exon polymorphisms were obtained, revealing an intron polymorphism (SNP 291 C>T). We genotyped the 19 founder animals of the White Duroc x Erhualian intercross for the identified polymorphisms, showing that only the 291 C>T polymorphism is a highly informative marker. We further genotyped all 59 F1 and 755 F2 animals for the 291 C>T polymorphism, and the association of this polymorphism with susceptibility/resistance to ETEC F4ab/ac in these F2 animals was evaluated by the transmission disequilibrium test. The result showed that the 291 C>T polymorphism is not a causal mutation, however, has a significant linkage disequilibrium with the ETEC F4ab/ac, especially F4ac receptor locus.     

The organic acid profiles in the feces of pigs at Brachyspira hyodysenteriae- or B. pilosicoli-positive farms

We observed a significant difference in the organic acid profile of diarrheal feces between pigs infected with and free from pathogenic spirochetes. Diarrhea and loose feces were collected from growing pigs, held at 15 different commercial farms. A total of 106 samples were measured for organic acid concentration by HPLC and were checked for the presence of B. hyodysenteriae and B. pilosicoli by PCR. B. hyodysenteriae was detected in 3 samples collected from one farm. B. pilosicoli was detected in 5 samples collected from another farm. Lower concentrations of iso-butyrate and iso-valerate were likely associated with development of pathogenic spirochete infection.