食品动物源沙门菌aac(6')-Ib-cr基因检测

为检测质粒介导的喹诺酮类耐药性aac(6')-Ib-cr基因在食品动物源沙门菌的分布状况.采用PCR结合BstC1酶切法,以及DNA测序法检测316株食品动物源沙门菌中aac(6')-Ib-cr基因;微量肉汤稀释法检测aac(6’)-Ib-cr阳性和阴性菌株对10种抗菌药物的耐药性;采用PFGE分析阳性菌株的亲缘关系.结果是aac(6')-Ib-cr基因检出率15.82％(50/316);aac(6')-Ib-cr阳性株对氨基糖苷类耐药率高于阴性株,但对环丙沙星、恩诺沙星和氧氟沙星的耐药率低于阴性株;aac(6’)-Ib-cr阳性菌株具有不同的PFGE谱型.结论:aac(6’)-Ib-cr基因在本次检测的食品动物源沙门菌中普遍存在,以水平和垂直传播方式在菌群间传播.     

如何减少畜禽强制免疫副反应的发生

免疫副反应客观存在,一定程度成为阻碍免疫工作顺利进行的"绊脚石"。我们深入调研,通过狠抓疫苗管理,规范免疫操作,增强畜禽体质,提高人员素质等措施,为有效减少免疫副反应的发生发挥了积极作用。     

苇状羊茅EST-SSR标记在草甸羊茅和多年生黑麦草的通用分析

草甸羊茅(Festuca pratensis Huds)和多年生黑麦草(Lolium perenne Lam)均是禾本科、多年生草本植物,是优良的牧草和草坪草.本研究采用40对苇状羊茅(Festuca arundinacea Schred)的表达序列标签-简单序列重复(Expressed sequence tags-s...     

Sedative and analgesic effects of intravenous xylazine and tramadol on horses

This study was performed to evaluate the sedative and analgesic effects of xylazine (X) and tramadol (T) intravenously (IV) administered to horses. Six thoroughbred saddle horses each received X (1.0 mg/kg), T (2.0 mg/kg), and a combination of XT (1.0 and 2.0 mg/kg, respectively) IV. Heart rate (HR), respiratory rate (RR), rectal temperature (RT), indirect arterial pressure (IAP), capillary refill time (CRT), sedation, and analgesia (using electrical stimulation and pinprick) were measured before and after drug administration. HR and RR significantly decreased from basal values with X and XT treatments, and significantly increased with T treatment (p < 0.05). RT and IAP also significantly increased with T treatment (p < 0.05). CRT did not change significantly with any treatments. The onset of sedation and analgesia were approximately 5 min after both X and XT treatments; however, the XT combination produced a longer duration of sedation and analgesia than X alone. Two horses in the XT treatment group displayed excited transient behavior within 5 min of drug administration. The results suggest that the XT combination is useful for sedation and analgesia in horses. However, careful monitoring for excited behavior shortly after administration is recommended.     

1～21日龄黄羽肉鸡棉籽粕傅里叶近红外及化学成分净能预测模型研究

本试验在用比较屠宰法实测25个棉籽粕样品净能(NE)值的基础上,旨在研究用傅里叶近红外( NIRS)和化学成分2种方法建立的NE预测模型的可行性,并比较2种预测模型的预测效果.1)棉籽粕NE值的测定采用维持NE (NEm)+沉积NE(NEp)的方法.其中NEm用回归法测定,设自由采食及限饲20％、40％、60％和80％...     

Effects of berberine on the growth performance,antioxidative capacity and immune response to lipopolysaccharide challenge in broilers

This study evaluated the effects of berberine on growth performance, immunity, haematological parameters, antioxidant capacity, and the expression of immune response‐related genes in lipopolysaccharide (LPS)‐challenged broilers. We assigned 120 one‐day‐old male broilers (Ross 308) to two treatment groups; each group included two subgroups, each of which included six replicates of five birds per replicate. The experiment used a 2 × 2 factorial arrangement with berberine treatment (0 or 60 mg/kg dietary) and challenge status [injection of saline (9 g/L w/v) or LPS (1.5 mg/kg body weight)] as the main factors. On days 14, 16, 18 and 20, broilers were intraperitoneally injected with LPS or physiological saline. Blood and liver samples were collected on day 21. Dietary berberine supplementation significantly alleviated the compromised average daily gain and average daily feed intake (p < 0.05) caused by LPS. The LPS challenge led to increased lymphocyte and white blood cell (WBC) counts, malondialdehyde (serum and liver) content, and immunoglobulin G and M, tumour necrosis factor‐α (TNF‐α) and interleukin‐1β (IL‐1β) expression (p < 0.05) and significantly reduced serum total superoxide dismutase (T‐SOD) activity (p < 0.05). Dietary berberine significantly mitigated the LPS‐induced decreases in the mRNA expression of nuclear factor‐kappa B (NF‐κB), TNF‐α, IL‐1β, inducible nitrite synthase and cyclooxygenase‐2 (p < 0.05) in the liver. In conclusion, berberine supplementation has a positive effect on LPS challenge, which may be related to the increase in antioxidant enzyme activity and inhibition of both NF‐κB signalling and the expression of inflammatory mediators.     

茬次和一天内不同收获时间对紫花苜蓿青贮发酵质量和体外发酵参数的影响

为了研究茬次和一天内不同收获时间对紫花苜蓿青贮饲料品质的影响,并进一步评价其饲用价值,本试验采用双因素设计,两茬紫花苜蓿于现蕾期同一天08：00（AM）,13：00（M）和18：00（PM）刈割并调制青贮饲料,室温下保存45 d后,取样分析并采用体外发酵法评价其饲用价值。结果表明,第1茬紫花苜蓿青贮饲料的相对饲喂价值（relative feed value,RFV）,干物质体外消化率（in vitro dry matter digestibility,IVDMD）及体外发酵挥发性脂肪酸（volatile fatty acids,VFA）、产气量均显著高于第2茬（P<0.05）。下午收获的紫花苜蓿青贮饲料有更高的干物质（dry matter,DM）含量及IVDMD （P<0.05）。因此,在实践生产中,要抓好第1茬的苜蓿生产,推迟刈割时间至中午或下午,可获得更高品质的紫花苜蓿青贮饲料。     

紫茎泽兰的生物学特点及其在畜牧生产中的应用

紫茎泽兰在我国分布范围广泛,是一种可利用的资源。目前有大量研究在探讨紫茎泽兰的生物学功能和提取其有效的活性成分,可以通过资源化利用提高紫茎泽兰的经济价值,变废为宝。论文综述了紫茎泽兰的生物学特点、生物学活性及其在动物抗寄生虫、抑制细菌、免疫调节和作为饲料原料的应用研究现状,为后期紫茎泽兰的研究提供参考。     

ADSL基因启动子区遗传变异与鸡肉冻藏新鲜度的相关性分析

试验旨在探究鸡腺苷琥珀酸裂解酶（adenylosuccinate lyase,ADSL）基因启动子区多态性及其与鸡肉冻藏新鲜度的相关性。以161只青脚麻鸡为研究对象,通过DNA混池测序法检测ADSL基因启动子区遗传变异。采用等位基因特异性PCR完成个体基因型分析,并分析了各基因型与鸡胸肌肉色、体重及胸肌冷冻60 d后新鲜度K值和pH的相关性。结果显示,在ADSL基因启动子区ATG上游1 670 bp处发现1个SNP位点（c.-1670 C>A）,其AA基因型个体肌肉冷冻60 d后新鲜度K值（23.61%）极显著低于CA（33.00%）和CC（33.56%）基因型（P<0.01）,即冻藏60 d后AA基因型个体肌肉较CA和CC基因型新鲜,CA和CC基因型间新鲜度K值差异不显著（P>0.05）;各基因型间鸡体重、胸肌肉色及胸肌冷冻60 d后pH均无显著差异（P>0.05）。生物信息学预测发现,c.-1670 C>A导致ADSL基因启动子区转录因子结合位点的显著改变,该突变位点可能造成ADSL基因的表达差异。综上,ADSL基因启动子区c.-1670 C>A与青脚麻鸡胸肌冷冻60 d后新鲜度K值具有显著相关性,该位点可作为青脚麻鸡肉品新鲜度的候选分子遗传标记。     

禽流感(H9)疫苗免疫间隔期探讨

通过在不同日龄对海兰褐蛋鸡进行禽流感(H9)灭活疫苗的免疫,探讨禽流感灭活疫苗的免疫间隔期。结果表明,开产以后不管防疫2次、3次、4次禽流感灭活疫苗,抗体水平均在6log2以上,且鸡的日龄越大,免疫次数越少,免疫抗体持续期越长。因此,建议从育成到鸡群淘汰的饲养全程中,四次时机恰当、搭配合理的禽流感(H9)疫苗免疫基本上能使得95%以上产蛋期抗体维持于7log2以上。