畜禽养殖场环境微生物致病性和耐药性调查研究

为了解掌握养殖场中环境微生物对养殖业和公共卫生造成的影响,初步对我国养殖场环境微生物进行了研究。对吉林、湖北等省份的部分养猪场和养鸡场环境采样,并进行大肠杆菌和沙门氏菌分离鉴定,同时对从鸡舍和猪舍内分离大肠杆菌和沙门氏菌进行动物致病性实验及对13种抗生素的耐药性实验。实验结果表明,所有实验的沙门氏菌和90.7%的大肠杆菌菌株对小白鼠有致病性;所有分离菌株对磺胺类药物的耐药性非常严重,其次是对四环素,对其他药物也有不同程度的耐药性。     

黄霉素、肉碱对草鱼生长性能、肌肉成分和血清生理生化指标的影响

将平均体重(134.3±12.1)g的草鱼(Ctenopharyngodon idella)分成3组,饲喂在基础饲料(对照组)中分别添加8mg/kg黄霉素和200mg/kgDL-肉碱的饲粮,养殖8周后,各组鱼体增重率分别为156.29%、165.46%、167%,黄霉素、肉碱组较对照组提高了5.87%、6.85%(P<0.05);与对照组相比,饲料中添加黄霉素降低草鱼肌肉蛋白含量3.92%(P<0.05),提高血清丁酰胆碱酯酶活性43.49%(P<0.05),对草鱼血清非特异性免疫指标无显著影响(P>0.05);与对照组相比,添加肉碱组血清胆固醇含量降低11.54%(P<0.05)。     

日粮不同蛋白质水平对三元肥育猪生产性能和胴体品质的影响

本文旨在研究不同日粮蛋白质水平对三元肥育猪生产性能、血液参数、胴体性状和肉质性状的影响.试验选取36头杜长大三元杂交猪,体重约为(47±4.2)kg,随机分为3个处理,每个处理12个重复,各处理分别饲喂低(12.9%)、中(15.4%)、高(18.7%)3个蛋白质水平日粮.试验第46天后,分别检测血液生化指标、激素水平、胴体品质和肉质性状.结果显示,3个日粮蛋白质水平对日增重、采食量、料重比及胴体品质和肉质性状均无影响(P>0.05);血清碱性磷酸酶、低密度脂蛋白、甘油三酯、胆固醇、谷丙转氨酶、谷草转氨酶、血清尿素氮以及生长激素均以中蛋白质水平组最高;随着日粮蛋白质水平的增加,肥育猪血清胰高血糖素有降低的趋势(P=0.089).以上结果表明,日粮蛋白质水平降低到12.9%并不影响肥育猪生长性能、胴体品质和肉质性状.     

In vivo characterization of inflammatory biomarkers in swine and the impact of flunixin meglumine administration

Non-steroidal anti-inflammatory drugs (NSAID) are a family of chemicals that function to reduce pain, fever, and inflammation, and they are commonly used in people and animals for this purpose. Currently there are no NSAIDs approved for the management of inflammation in swine due to a lack of validated animal models and suitable biomarkers to assess efficacy. A previous in vitro study examining biomarkers of inflammation identified fourteen genes that were significantly altered in response to Escherichia coli lipopolysaccharide (LPS)-induced inflammation. In the present study, five of those fourteen genes were tested in vivo to determine if the same effects observed in vitro were also observed in vivo. Plasma levels of prostaglandin E(2) (PGE(2)), an essential mediator of fever and inflammation, were also determined. Two groups of swine were stimulated with LPS with the second group also treated with flunixin meglumine. Blood was collected at 0, 1, 3, 6, 8, 24, and 48h post LPS-stimulation. The RNA was extracted from the blood and quantitative real-time-PCR (qRT-PCR) was utilized to determine the expression patterns of CD1, CD4, serum amyloid A2 (SAA2), Caspase 1, and monocyte chemoattractant protein 1 (MCP-1). The LPS-stimulated animals demonstrated a statistically significant alteration in expression of SAA2 and CD1 at 3h post-stimulation. Flunixin meglumine treated animals' demonstrated reduced expression of CD1 in comparison to the LPS-stimulated swine at 24 and 48h post LPS-stimulation. Flunixin meglumine treated animals exhibited reduced expression of SAA2 at 48h post-stimulation compared to LPS-stimulated swine. Swine treated with LPS demonstrated statistically significant increases in plasma PGE(2) at 1h post-stimulation. Swine treated with flunixin meglumine had no increase in plasma PGE(2) levels at any time. These results demonstrate that PGE(2) production, along with two out of five genes (SAA2 and CD1) have the potential to serve as early biomarkers of inflammation as well as indicators of NSAID efficacy.     

不同营养状态大鼠胃和小肠ERα的表达

为探讨不同营养应激对大鼠胃和小肠内雌激素受体α(ERα)表达的影响,本试验用免疫组织化学SP法分别对标准营养、高营养和低营养条件下健康雄性SD大鼠胃和小肠内ERα阳性细胞的分布和数量变化进行研究.结果发现,ERα阳性细胞在大鼠的胃和小肠内均有分布,以胃的黏膜固有层胃底腺区和小肠的固有层及黏膜下层分布为主.低营养组ERα的表达量显著低于其他组(P＜0.01);低营养恢复标准营养后,胃中ERα的表达量无明显变化,小肠中ERα的表达量极显著升高(P＜0.01);高营养组恢复到标准营养后,胃中ERα表达量显著减少(P＜0.05),十二指肠和空肠中ERα表达量极显著减少(P＜0.01),回肠无明显变化.表明ERα参与食物应激反应中胃肠道的消化和吸收和免疫调节活动.     

Density-Dependent Ecohydrological Effects of Piñon–Juniper Woody Canopy Cover on Soil Microclimate and Potential Soil Evaporation

Many rangeland processes are driven by microclimate and associated ecohydrological dynamics. Most rangelands occur in drylands where evapotranspiration normally dominates the water budget. In these water-limited environments plants can influence abiotic and biotic processes by modifying microclimate factors such as soil temperature and potential soil evaporation. Previous studies have assessed spatial variation in microclimate and associated ecohydrological attributes within an ecosystem (e.g., under vs. between woody canopies) or across ecosystems (e.g., with differing amounts of woody canopy cover), but generally lacking are assessments accounting systematically for both, particularly for evergreen woody plants. Building on recently quantified trends in near-ground solar radiation associated with a piñon–juniper gradient spanning 5% to 65% woody canopy cover, we evaluated trends in soil temperature and associated estimates of potential soil evaporation as a function of amount of woody canopy cover for sites overall and for associated canopy vs. intercanopy locations. Quantified soil temperature trends decreased linearly with increasing woody canopy cover for intercanopy as well as canopy patches, indicating the coalescing influence of individual canopies on their neighboring areas. Notably, intercanopy locations within high-density (65%) woody canopy cover could be as much as ～10°C cooler than intercanopy locations within low-density (5%) cover. Corresponding potential soil evaporation rates in intercanopies within high-density woody canopy cover was less than half that for intercanopies within low density. Our results highlight ecohydrological consequences of density-dependent shading by evergreen woody plants on soil temperature and potential soil evaporation and enable managers to rapidly estimate and compare approximate site microclimates after assessing amounts of woody canopy cover. Such predictions of microclimate have general utility for improving management of rangelands because they are a fundamental driver of many key processes, whether related to understory forage and herbaceous species or to wildlife habitat quality for game or nongame species.     

The Impact of Egg Ozonation on Hatching Success,Larval Growth,and Survival of Atlantic Cod,Atlantic Salmon,and Rainbow Trout

The direct exposure of fish eggs to ozonated water has generated interest as a means of ensuring pathogen-free eggs without the use of harsh chemicals. However, there are numerous knowledge gaps, including safe contact times, exposure levels, and potential long-term effects on aquaculture species in both freshwater and seawater. The effect of different ozone (O₃) doses (0.5–1.0, 1.5–2.0, and 2.5–3.0 mg of O₃/L for 90 s) on recently fertilized eggs of Atlantic Cod Gadus morhua and eyed eggs of Atlantic Salmon Salmo salar and Rainbow Trout Oncorhynchus mykiss was evaluated in comparison with the effects of two commercial disinfectants: Perosan (0.004 mg/L) and Ovadine (100 mg/L). The impact of ozone application was evaluated based on hatching success, larval nucleic acid concentration, larval growth, and survival. Overall, results indicated that ozonation of Atlantic Cod eggs at a dose less than 3.0 mg/L for 90 s produced no negative effect on the larvae up to 30 d posthatch. Furthermore, ozonation of Atlantic Salmon and Rainbow Trout eggs generated no negative effect on the larvae, based on monitoring until 85% yolk sac re-absorption (16 d posthatch).

Received May 6, 2014; accepted October 24, 2014     

2个猪品种的ATP2B1基因表达与ETEC F4粘附性关联分析

以ATP2B1基因作为仔猪腹泻相关的候选基因,在2个品种63头猪的小肠组织中,采用实时荧光定量PCR技术对肠毒素大肠杆菌(ETEC)F4受体不同黏附表型个体进行表达量的比较分析,以验证其基因功能和作为仔猪腹泻相关候选基因的可能性.结果表明:ATP2B1基因在不同黏附表型间的表达量有显著的差异,可望作为F4ab受体的相关...     

The pre-emptive effect of epidural ketamine on wound sensitivity in horses tested by using von Frey filaments

Objective To evaluate the pre‐emptive analgesic effect of pre‐incisional epidural ketamine. Study Design A blinded, randomized experimental study. Animals Sixteen mixed breed mares, 7.6 ± 2.8 years old, weighing 352 ± 32 kg. Methods In a pilot study, an incision was made on one lateral thigh using a lidocaine block and no further analgesics, and it was verified that the nociceptive threshold was lower on the incised side than nonincised side (p ≤ 0.05), and that von Frey filaments evoked a pain response. The 16 animals were divided into group A (ketamine, n = 9) and B (saline, n = 7). An epidural catheter was inserted 24 hours before the trials. The thigh was shaved bilaterally, and the right side was blocked (incised side) using lidocaine. Twenty‐five minutes later, ketamine (A) or saline (B) was administered epidurally. Five minutes later, a 10‐cm skin incision was made on the right side, and then sutured. Nociceptive threshold was determined with von Frey filaments at 1, 3, and 5 cm around the incision at 15‐minute intervals for 2 hours, then at 4, 6, and 8 hours. Behavioral alterations, heart and respiratory rates were recorded. Nociceptive thresholds from these points were averaged to obtain mean values at each time, converted to a logarithmic scale, and submitted to a nonparametric analysis (Mann–Whitney and one‐way repeated measures anova test, p ≤ 0.05). Results After 8 hours, the global range score revealed reduced hyperalgesia (p < 0.01) around the incision in 92% (4.65–4.27) of evaluated intervals in group A (ketamine). There were no significant changes in behavior, heart and respiratory rates. Conclusions It was concluded that pre‐emptive epidural ketamine reduced post‐incisional pain in the horse, and that von Frey filaments were able to quantify cutaneous sensitivity after tissue damage. Clinical relevance Epidural ketamine injection can reduce post‐incisional sensitivity in the horse.