猪瘟野毒感染抗体阻断ELISA检测方法的建立与初步评价

以猪瘟野毒E2蛋白为包被抗原、辣根过氧化物酶标记的猪瘟野毒单抗作为酶标抗体,建立检测猪瘟野毒抗体的阻断ELISA方法。猪瘟野毒E2最适包被浓度为0.03μg/mL,待检血清最适稀释度为1∶4,酶标猪瘟野毒单抗稀释度为1∶1 000。用建立的阻断ELISA方法检测369份临床阴性血清,计算阻断率,确定临界值,阻断率>40%为猪瘟野毒抗体阳性,阻断率≤40%为猪瘟野毒抗体阴性。用建立的ELISA方法检测84份血清,其中78份为免疫猪瘟疫苗的血清,6份为猪瘟病毒感染血清。结果显示,78份免疫血清均检测为猪瘟野毒抗体阴性,6份猪瘟感染血清均检测为猪瘟野毒抗体阳性。因此可初步判定该方法可用于鉴别诊断猪瘟病毒自然感染动物和C株疫苗免疫动物的血清抗体,并为临床检测猪瘟野毒抗体提供便捷、快速,精准的检测工具,对猪瘟的临床诊断、预防以及猪瘟净化工作具有非常重要的参考意义。     

Treatment of contaminated radial fracture in Sprague-Dawley rats by application of a degradable polymer releasing gentamicin

Fracture-related infections remain a leading cause of morbidity and mortality. We aimed to establish a simple contaminated radial osteotomy model to assess the efficacy of a biodegradable polymer poly(sebacic-co-ricinoleic acid) [p(SA-RA)] containing 20% w/w gentamicin. A unilateral transverse osteotomy was induced in Sprague-Dawley (SD) rats, followed by application of Staphylococcus aureus suspension over the fracture. After successfully establishing the contaminated open fracture model, we treated the rats either systemically (intraperitoneal cefuroxime), locally with p(SA-RA) containing gentamicin, or both. Control groups included non-contaminated group and contaminated groups that were either untreated or treated with the polymer alone. After 4 weeks, the bones were subjected to micro-CT scanning and microbiological and histopathology evaluations. Micro-CT analysis revealed similar changes in the group subjected to both local and systemic treatment as in the non-contaminated control group. Lack of detectable bacterial growth was noted in most animals of the group subjected to both local and systemic treatment, and all samples were negative for S. aureus. Histopathological evaluation revealed that all treatment modalities containing antibiotics were highly effective in reducing infection and promoting callus repair, resulting in early bone healing. While p(SA-RA) containing gentamicin treatment showed better results than cefuroxime, the combination of local and systemic treatment displayed the highest therapeutic potential in this model.     

饲料中动物源性成分微流控检测芯片的研究

试验以"LAMP+微流控"技术为基础,开发饲料动物源性成分检测芯片。针对牛、羊、猪、鸡的16srRNA靶序列,根据LAMP引物设计软件进行4种肉类LAMP引物设计。在LAMP优化试验、芯片优化测试、特异性验证试验和芯片应用测试中,进行最佳引物筛选测试和特异性测试。结果显示,筛选出的4种肉类最佳引物特异性强,最佳反应温度为65℃。芯片特异性验证试验的归一化荧光曲线显示,试验结果准确、特异性稳定。对饲料市场购买的16份样本中检测出的动物源性成分,采用中华人民共和国农业行业标准验证,符合率100%。微流控检测芯片的开发与应用为饲料中动物源性成分检测提供新方法,为饲料产品质量安全提供保障。     

Black soldier fly and yellow mealworm live larvae for broiler chickens: Effects on bird performance and health status

The commercial broiler chicken strains are the result of successful selection programmes. Most of the problems related to welfare arise from the high growth rate and body weight. The use of environmental enrichments in intensive farming could have a positive effect on birds by increasing animal welfare. The aim of the study was to evaluate the effects of Hermetia illucens (HI) and Tenebrio molitor (TM) live larvae in the diets of broiler chickens on growth performance, carcass yield and health status. A total of 180 four-day-old male broiler chickens (Ross 308) were randomly allotted to 18 pens. Each pen was assigned to one of the three dietary treatments (6 replicates/treatment, 10 birds/replicate) as follows: (i) control diet (C): commercial feed (two feeding phases: starter [4–11 days] and grower [12–38 days]), (ii) HI: C + 5% of the expected daily feed intake (DFI) HI live larvae (calculated on dry matter [DM]) and (iii) TM: C + 5% of DFI TM live larvae (DM). At 39 days of age, birds were slaughtered. Growth performance parameters were overall not affected by dietary treatments, except for the grower phase feed conversion ratio (FCR) and the overall FCR being better in the TM broilers than the others (p < 0.01). No differences were observed for slaughtering performance and haematological and serum parameters, except for the spleen relative weight being higher (p < 0.01) in the birds administered with larvae when compared to the C group. Gut morphometric indexes and histopathological alterations were not influenced by insect larvae administration. In conclusion, the administration in limited quantities of HI and TM live larvae as environmental enrichment has no negative effects on broiler chicken growth performance and health status. A behavioural study could confirm that live insect larvae represent a novel natural environmental enrichment in broiler farming.     

AR regulates porcine immature Sertoli cell growth via binding to RNF4 and miR-124a

Sertoli cells are the only somatic cells in the seminiferous epithelium which directly contact with germ cells. Sertoli cells exhibit polarized alignment at the basal membrane of seminiferous tubules to maintain the microenvironment for growth and development of germ cells, and therefore play a crucial role in spermatogenesis. Androgens exert their action through androgen receptor (AR) and AR signalling in the testis is essential for maintenance of spermatogonial numbers, blood–testis barrier integrity, completion of meiosis, adhesion of spermatids and spermiation. In the present study, we demonstrated that AR gene could promote the proliferation of immature porcine Sertoli cells (ST cells) and the cell cycle procession, and accelerate the transition from G1 phase into S phase in ST cells. Meanwhile, miR-124a could affect the proliferation and cell cycle procession of ST cells by targeting 3′-UTR of AR gene. Furthermore, AR bound to the RNF4 via AR DNA-binding domain (DBD) and we verified that RNF4 was necessary for AR to regulate the growth of ST cells. Above all, this study suggests that AR regulates ST cell growth via binding to RNF4 and miR-124a, which may help us to further understand the function of AR in spermatogenesis.     

Effects of dietary Bacillus coagulans and yeast hydrolysate supplementation on growth performance,immune response and intestinal barrier function in weaned piglets

The present study investigated the effects of Bacillus coagulans and yeast hydrolysate supplementation on growth performance, immune response and intestinal barrier function of weaned piglets. Twenty-four weaned piglets with an average body weight (BW) of 6.89 ± 0.15 kg were divided into four diets for 28 days. The treatments were basal diet (control), basal diet supplemented with antibiotic (20 mg/kg colistin sulphate and 40 mg/kg bacitracin zinc, AT), probiotics (400 mg/kg Bacillus coagulans ≥5 × 109 CFU/g, BC) or yeast hydrolysate (5000 mg/kg yeast hydrolysate, YH). Average daily gain (ADG) and average daily feed intake (ADFI) were improved by AT and YH diets (p < 0.05), while BC diet only increased ADG (p < 0.05). The complement 3 (C3), lysozyme (LZM) and tumour necrosis factor-α (TNF-α) concentrations in serum were increased in BC diet (p < 0.05). Feeding AT and YH caused the increase of jejunal villus height (p < 0.05), and a higher ratio of villus height/crypt depth was observed in AT, BC and YH groups (p < 0.05). The mRNA expression of zonula occludens-1 (ZO-1) in jejunal mucosa was up-regulated by AT, BC and YH diets (p < 0.05). Dietary AT, BC or YH inclusion decreased the interleukin-1β (IL-1β) concentration and TNF-α mRNA expression (p < 0.05), and YH supplementation even down-regulated toll-like receptor 4 (TLR4) and CD14 expressions (p < 0.05). In summary, the dietary administration of BC or YH both improves growth performance through promoting the intestinal barrier function, indicating both of them can serve as potential alternatives to antibiotics growth promoters for the piglet production.     

口感化及颗粒化开食料对早期断奶羔羊生长和胃肠道发育的影响

分析探讨口感化及颗粒化开食料对早期断奶羔羊生长和胃肠道发育的影响。选取新生健康的双羔湖羊公羔42只,随机分为两组,分别饲喂颗粒化和口感化开食料,试验期42 d。两组羔羊21日龄之前的采食量、体重和绝对生长的变化趋势相似。21日龄以后,口感化开食料组羔羊的采食量、体重、绝对生长和相对生长均明显高于颗粒化开食料组,42日龄体重、后两周的采食量及15～21日龄的相对生长率在两组间有显著差异(P < 0.05)。口感化开食料还显著提高(P < 0.05)了羔羊42日龄时的育肥指数、体长指数、胸围指数、管围指数和断奶前的瘤胃质量和瘤胃/胴体。以上结果表明,与颗粒化开食料相比,口感化开食料更有利于羔羊早期断奶前后的瘤胃发育、采食量提高、体重和体尺的发育,但对其他胃室及肠道发育没有影响。     

HPLC法测定天然植物粗提物中芍药苷含量

建立高效液相色谱法检测天然植物粗提物饲料原料中芍药苷的测定方法。用十八烷基硅烷键合硅胶色谱柱,以乙腈-0.1%磷酸溶液(14:86)为流动相,检测波长230nm,流速：1.0 mL/min;柱温：30 ℃;进样量：10μL。结果显示,芍药苷的线性方程为Y=10.6017X－14.8514,(r=0.99966,n=6),本方法的回收率为100.4~102.1%,RSD均小于2.0%。结果表明,本方法准确,可靠,适用于天然植物粗提物饲料原料中芍药苷的测定。     

非班太尔对照品的定值研究

(目的)本文旨在联合使用质量平衡法与差示扫描量热法2种定值方法测定非班太尔对照品的含量。(方法)采用高效液相色谱法测定非班太尔的纯度,采用卡尔费休氏容量滴定法、炽灼残渣检查法、气相色谱法分别测定其水分、灰分和残留溶剂,由质量平衡法公式计算非班太尔对照品的含量;采用差示扫描量热法对非班太尔对照品含量加以佐证。(结果)质量平衡法和差示扫描量热法测定结果经科克伦判定互为等精度,取其算术平均值作为最终定值结果,即非班太尔对照品含量为99.66%。(结论)质量平衡法与差示扫描量热法对非班太尔对照品的定值结果基本一致,2种方法能够更好地保证非班太尔对照品赋值的准确性。     

基于AHP-CRITIC法的正交设计优选贞芪颗粒提取工艺及促生长作用初步研究

（目的）开发一种具有促生长作用的新中兽药贞芪颗粒,优化其提取工艺并对其促生猪生长作用进行初步研究,为其工业化生产提供参考。（方法）以总多糖、黄芪甲苷、毛蕊异黄酮葡萄糖苷、特女贞苷、红景天苷、干膏得率作为评价指标,采用层次分析法（AHP）、基于指标相关性的权重确定方法（CRITIC）、AHP-CRITIC混合加权法确定各评价指标的权重系数,根据其正交试验结果优化贞芪颗粒提取工艺参数。将100头保育猪随机分为5组,通过在日粮中添加不同剂量的颗粒,连续喂养30天,与空白组和阳性对照组对比,计算平均日增重（ADG）、平均日采食量（ADFI）和料肉比（F: G）。（结果）AHP-CRITIC混合加权法科学优选出最佳提取工艺参数为复方药材加12-13倍质量的水提取3次（第一次13倍）,每次2.5 h。3批验证试验综合评分均值为98.91,RSD为0.79%。经过30天饲喂,高、中、低剂量组和阳性对照组的料重比无显著性差异（P>0.05）,但都显著低于空白对照组（P<0.05）,其中中剂量组的料重比最低。（结论）AHP-CRITIC混合加权法确定的权重系数客观、真实,优选出的贞芪颗粒提取工艺经验证,合理、稳定,重复性好,此工艺条件下制备的颗粒对生猪具有促进生长的作用。