Trehalose in glycerol-free freezing extender enhances post-thaw survival of boar spermatozoa

Cryopreservation of boar semen is still considered suboptimal due to lower fertility as compared with fresh samples when glycerol, a permeating cryoprotectant, is used. Trehalose is a non-permeable cryoprotectant and nonreducing disaccharide known to stabilize proteins and biologic membranes. The aim of this study was to evaluate the cryosurvival and in vitro penetrability of boar spermatozoa when glycerol was replaced with trehalose in a freezing extender. Ejaculated Berkshire semen samples were diluted in egg yolk-based freezing extender containing glycerol (100 mM) or trehalose (0, 50, 100, 150, 200 and 250 mM) and cryopreserved using a straw freezing procedure. Thawed samples were analyzed for motility, viability, mitochondrial membrane potential (MMP), and acrosome integrity. In experiment 2, penetrability of spermatozoa cryopreserved with 100 mM glycerol or trehalose was examined. Replacement of cryoprotectant glycerol (100 mM) with trehalose had no effect on sperm viability, but replacing it with 100 mM trehalose improved motility, MMP and acrosome integrity significantly. Sperm motility and MMP were considerably higher in 100 mM trehalose, whereas the acrosome integrity was substantially higher in 100–250 mM trehalose. The in vitro penetration rate was also significantly higher in spermatozoa cryopreserved with trehalose (61.3%) than in those cryopreserved with glycerol (43.6%). In conclusion, 100 mM non-permeable trehalose can be used to replace glycerol, a permeating cryoprotectant, for maintenance of better post-thaw quality of boar spermatozoa.     

阿莫西林混悬注射液在猪体内的生物等效性研究

为了研究阿莫西林混悬注射液在猪体内的药代动力学和生物等效性,采用双处理、双周期随机交叉试验设计,将24头健康猪随机分成2组,按15 mg/kg体重肌肉分别单剂量注射受试制剂和参比制剂,采用高效液相色谱法测定血浆中阿莫西林的浓度,利用Win Nonlin6.4软件计算主要药动学参数,并评价两种制剂的生物等效性。结果显示,受试制剂和参比制剂的Tmax分别为(3.45±2.49)h,(1.34±1.74)h;Cmax分别为(6.94±4.73)mg/L,(4.39±2.87)mg/L;AUC0-t分别为(37.00±11.48)mg·h·L-1,(30.02±8.93)mg·h·L-1;AUC0-∞分别为(40.26±13.36)mg·h·L-1,(38.46±15.38)mg·h·L-1。阿莫西林混悬注射液受试制剂和参比制剂的AUC0-t、AUC0-∞、Cmax、Tmax均有显著性差异,双单侧t检验结果显示两种制剂生物不等效,试验为兽医临床给药方案的制定以及合理用药提供参考。     

In growing pigs, chlortetracycline induces a reversible green bone discoloration and a persistent increase of bone mineral density dependent of dosing regimen

We studied in growing pigs the effects of exposure to dietary chlortetracycline on bone mineral density (BMD) and bone color. Pigs were randomly allocated to a drug-free diet (n = 48) or a diet fortified with 800 ppm of chlortetracycline, starting either at 28- or 84-d of age, and for either a 28- or 56-d duration (n = 16 pigs/group). The lumbar vertebral discoloration and BMD of randomly chosen pigs were evaluated at 28-d intervals up to 168-d of age. The odds of bone discoloration increased with dosing duration and age at treatment onset, and decreased with the withdrawal time and age at treatment onset interaction (p ? 0.001). The measured trabecular BMD linearly increased with age and squared treatment duration (p ? 0.005). Therefore, TC-induced bone discoloration is reversible, and may be prevented with proper dosing regimen design. Moreover, TC induces a persistent increase on BMD that could be detected with quantitative computed tomography.     

Respiratory function and pulmonary lesions in pigs infected with porcine reproductive and respiratory syndrome virus

Pulmonary dysfunction was evaluated in pigs infected with porcine reproductive and respiratory syndrome virus (PRRSV, isolate VR-2332) and compared to clinical and pathological findings. Infected pigs developed fever, reduced appetite, respiratory distress and dullness at 9 days post-inoculation (dpi). Non-invasive pulmonary function tests using impulse oscillometry and rebreathing of test gases (He, CO) revealed peripheral airway obstruction, reduced lung compliance and reduced lung CO-transfer factor. PRRSV-induced pulmonary dysfunction was most marked at 9–18 dpi and was accompanied by a significantly increased respiratory rate and decreased tidal volume. Expiration was affected more than inspiration. On histopathological examination, multifocal areas of interstitial pneumonia (more severe and extensive at 10 dpi than 21 dpi) were identified as a possible structural basis for reduced lung compliance and gas exchange disturbances.     

Transmission of methicillin resistant Staphylococcus aureus among pigs during transportation from farm to abattoir

The prevalence of methicillin resistant Staphylococcus aureus (MRSA) in pigs at abattoirs is higher than in pigs sampled on farms. This study investigated whether MRSA negative pigs can become MRSA positive during transportation from the farm to the abattoir after exposure to other pigs and environmental sources of MRSA. Nasal swabs were collected from four batches of pigs during loading at the farm, on arrival at the abattoir and after stunning. Environmental wipes were taken from lorries after transporting pigs and from lairages after holding pigs. All pigs (n = 117) tested MRSA negative before transportation. On arrival at the abattoir, 12/117 (10.3%) pigs in two batches tested MRSA positive. In lorries that tested positive after transportation, the prevalence of MRSA positive pigs was 21.1%, whereas no MRSA was detected in pigs that had been transported in lorries that tested negative after transportation. At stunning, all batches and 70/117 (59.8%) pigs tested MRSA positive. Pigs can become MRSA positive in the short period of time during transportation from the farm to stunning at the abattoir.     

利用山东地方猪种培育新品种和专门化母系研究

以莱芜黑猪、烟台黑猪为育种素材,采用继代选育法培育而成了ZML专门化母系和鲁烟白猪新品种。ZML专门化母系和鲁烟白猪新品种具有繁殖哺育率高、适应性抗逆性强和肉质优良等突出性状。ZML专门化母系窝均产仔14.82头,70日龄育成率90.90%,肌内脂肪9.78%。利用ZML筛选的“ZFD♂Х（ZFY系♂ХZML系♀）♀”配套系育肥猪日增重742g,料重比2.99：1,胴体瘦肉率（58.39±4.40）%,肌内脂肪4.01%。鲁烟白猪窝均产仔13.02头,70日龄育成率95.01%,育肥期日增重782g,料重比2.57：1,瘦肉率62.67%。推广应用结果表明ZML专门化母系和鲁烟白猪新品种适宜于黄淮海区域饲养,尤其适宜于该区域中小型规模饲养。     

基于DANP法识别影响养殖户病死猪处理行为的关键因素

为了规范养殖户病死猪处理行为,保障猪肉安全与公共健康,以及保护生态环境。在借鉴国内外现有研究成果的基础上,归纳总结了可能影响生猪养殖户病死猪处理行为的四个维度和17个主要因素,运用决策实验分析法(Decision Making Trial and Evaluation Laboratory,DEMATEL)和网络层次分析法(Analytic Network Process)相结合的DANP法(DEMATEL-based ANP),定量分析影响生猪养殖户病死猪处理行为维度及因素间的相互关系,识别关键因素。研究结果表明,生产经营特征是最重要的维度,相关法律法规认知、生猪疫情与防疫认知、成本与收益、养殖规模和养殖模式是五个关键因素。证实了DANP的方法能有效识别影响养殖户病死猪处理行为的关键因素,且结论可为政府规范生猪养殖户病死猪处理行为提供了有益的决策参考。     

海南猪杂交效果及海南猪H-FABP基因和MyoG基因5′上游区域的遗传变异研究

测定了海南猪、海南猪母猪与杜洛克公猪杂交后代的胴体性状、肉质性状,并对脂肪酸结合蛋白(H-FABP)和肌细胞生成素(MyoG)基因的5′上游区域的遗传变异进行了分析。结果表明:杂交黑猪与其母本海南猪相比,活体重、胴体重、屠宰率、胴体长、瘦肉率均有提高,且差异显著(P0.05),表现出较好的杂种优势;骨率、皮率降低,脂肪沉积性能提高,而眼肌面积、皮厚变化不大。另外,海南猪与杂交黑猪肉质均符合优良肉质标准,杂交黑猪肉在滴水损失、大理石纹、水分、粗蛋白含量等方面优于海南猪,表现出较好的杂种优势。海南猪H-FABP基因5′上游区域和MyoG基因5′上游区域遗传变异的基因型和等位基因频率,为海南猪优良肉质性状的形成提供了遗传学依据。     

猪NCOA1基因PCR-RFLP多态性分析（摘要）（英文）

[目的]研究猪NCOA1基因的PCR-RFLP多态性,为猪的分子育种和标记辅助选择提供理论依据。[方法]以81头山东寿光六和原种猪场的长白猪为研究对象,采取常规酚-氯仿抽提法从猪耳组织提取基因组DNA,以基因组DNA为模板进行PCR扩增获得440 bp的NCOA1基因目的片段,利用限制性内切酶RsaⅠ对PCR产物进行酶切和琼脂凝胶电泳检测,并计算各等位基因频率和基因型频率。[结果]琼脂糖电泳检测酶切产物出现3种基因型：AA型（1条带：440 bp）、AB型（3条带：440、282、158 bp）、BB型（2条带：282、158 bp）;基因型频率分别为0.54、0.43和0.03;A和B 2个等位基因的基因频率分别为0.76和0.24。[结论]该研究猪群中,A为优势等位基因,AA基因型频率较高。     

肌肉苹果酸酶活性与猪肉品质关系的研究

[目的]探讨肌肉苹果酸酶活性与猪肌肉品质的关系,为提高猪肌肉品质提供理论依据。[方法]选取3个不同品种的猪（鄂西黑猪、长野鄂杂交猪和长大二元杂交猪）,比较了肌肉苹果酸酶活性以及肉质性状之间的差异。[结果]结果表明,鄂西黑猪的肌肉苹果酸酶活性和肌内脂肪显著高于长野鄂（三元）杂交猪和长大二元杂交猪（P〈0.05）;长大二元杂交猪的肌肉pH2值、滴水损失和剪切力显著高于鄂西黑猪（P〈0.05）。[结论]猪肌肉苹果酸酶活性对猪肉品质存在一定的影响。其中,肌肉苹果酸酶活性与肌内脂肪含量呈显著正相关,与肉色呈正相关,而与滴水损失和剪切力呈显著负相关。