Reproductive and Endocrine Characteristics of Delayed Pubertal Ewe-Lambs after Melatonin and l-Tyrosine Administration

The investigation was carried out to study the impact of melatonin and L-tyrosine administration on the onset of cyclicity in delayed pubertal ewe-lambs. Fifteen delayed pubertal ewe-lambs (age >16 months) were used in this study after being assigned randomly into three groups. In the first group (melatonin treated group, n = 5), each lamb was administered 3 mg melatonin orally at 16:00 hours from 1 July to 15 September while in the second group (L-tyrosine treated group, n = 5), each lamb was administered L-tyrosine at the level of 100 mg/kg b.w. as a single oral dose. The third group (n = 4) served as control. Lambs were exposed to mature, fertile rams daily and blood samples were collected twice weekly. The progesterone concentrations (P4 evaluations) were significantly higher (p < 0.05) in treated groups than the control group. Ovarian activity, assessed by P4 evaluations, showed that all animals in the first group came in oestrus and from them four got pregnant (80%) while in the second group, only three lambs came in heat and from them two became pregnant (40%). On the contrary, none of the control lambs showed oestrus. In conclusion, this study confirmed that the oral administration of melatonin and L-tyrosine played an essentially physiological roles to induce cyclicity in delayed pubertal ewe-lambs and improved their reproduction.     

美国瑞士褐牛在塔城地区舍饲条件下的适应性研究

[目的]通过对美国瑞士褐牛在塔城地区舍饲条件下适应性的研究,为新类型的培育提供科学依据。[方法]对美国瑞士褐牛犊牛和母牛进行为期三年的饲养观察,对其生长情况、泌乳、繁殖性能、耐粗饲、耐热抗寒性能及疾病项目进行测定及统计分析。[结果]在舍饲条件下,初生重平均为35.23 kg,6月龄平均日增重为719.81 g;12月龄平均日增重为724.16 g,生长发育良好。平均繁殖成活率为81.72%;一胎平均泌乳量为3 561 kg,二胎平均泌乳量为4 267 kg,三胎平均泌乳量为4 579 kg。[结论]美国瑞士褐牛在塔城地区舍饲饲养条件下其生长发育良好,表现出了良好的适应性。     

肉牛早期断奶试验研究

[目的]旨在研究早期断奶技术对不同品种肉用犊牛生长发育的影响,[方法]本试验在草原牧区应用犊牛代乳料产品开展了不同品种犊牛的早期断奶工作,[结果]表明:安杂牛、新褐杂牛、荷斯坦牛三组间日增重差异不显著(P>0.05),安杂组增重成本8.25元/kg,新褐杂增重成本组9.27元/kg,荷斯坦组增重成本9.62元/kg,但...     

Pyloric outflow obstruction secondary to sclerosing encapsulating peritonitis in a dog

A 6-year-old, male neutered mixed breed dog was presented emergently with a three-week history of hyporexia, vomiting, diarrhoea and weight loss. Upon examination, the patient was dull, had generalised muscle atrophy, moderate abdominal pain and a mild amount of peritoneal effusion. A fluid-filled, distended, corrugated small bowel with marked gastroparesis and moderate peritoneal effusion was noted on abdominal ultrasonography. Endoscopy revealed hyperaemic and friable mucosa and a subjectively narrowed pylorus. Emergency exploratory celiotomy was performed due to worsening patient condition and revealed thick, diffuse, fibrous adhesions of the abdominal cavity. Based on these findings, sclerosing encapsulating peritonitis (SEP) was suspected. A large mass of omentum adjacent to the greater curvature of the stomach had caused a pyloric outflow obstruction. Adhesiolysis was attempted but was unsuccessful due to the friability of the small intestines. The dog was humanely euthanased under anaesthesia. A diagnosis of SEP was confirmed via necropsy. No underlying cause was identified. This is the first known case of a pyloric outflow obstruction secondary to SEP in a dog. Although rare, this condition should be considered as a differential for dogs with signs of a pyloric outflow obstruction with concurrent ascites and abdominal pain, hyporexia, vomiting and diarrhoea.     

猪流行性腹泻病毒S2基因B细胞表位嵌入型S-层蛋白在副干酪乳杆菌中的表达与鉴定

【目的】构建新型猪流行性腹泻病毒(Porcine epidemic diarrhea virus, PEDV)乳酸菌活菌疫苗载体。【方法】应用DNA重组技术将嗜酸乳杆菌S-层蛋白(SLP)基因及PEDV S2基因B细胞表位(EpitopeS2)融合基因(SLP-EpitopeS2)克隆到乳酸杆菌表达载体pTRK892中,构建重组载体pTRK-SLP-EpitopeS2,通过电转化方法将重组质粒导入副干酪乳杆菌中,获得重组副干酪乳杆菌。分别用SDS-PAGE、Western blotting和免疫荧光试验(IFA)鉴定目的蛋白在副干酪乳杆菌中的表达。【结果】PCR结果显示,成功扩增出大小为1 400 bp的目的条带,与插入融合基因大小一致,双酶切结果出现大小分别为1 400和4 700 bp的2条带,基因测序结果显示无碱基缺失和突变等,从而确定重组质粒pTRK-SLP-EpitopeS2构建正确。SDS-PAGE、Western blotting结果显示,在48 ku处出现与理论值大小一致的目的蛋白条带,表明融合基因SLP-EpitopeS2在副干酪乳杆菌中得到有效表达。IFA结果显示,...     

不同施肥时间及施氮水平对高寒草甸生物量和土壤养分的影响

采用随机区组设计,探讨了不同施肥时期及氮肥用量对三江源区高寒草甸初级生产力、植物养分及土壤养分的影响。结果表明:在施肥时间为7月10日,施肥量为150 kg·hm^-2时,地上生物量为最大值,较对照增加了2.06倍(P <0.05)。而植物氮素含量在施肥时间为7月10日,尿素用量为300 kg·hm^-2时达到最大值,较对照增加了31.18%(P <0.05)。相关性分析表明,地上生物量与植物全氮成显著正相关,施氮量与植物全氮成线性相关。施肥时间为7月10日左右时,尿素施用水平为150~300 kg·hm^-2,该类型高寒草甸初级生产力和土壤全氮都达到最大值,可作为优先氮素添加量来推荐。     

Detection and isolation of Toxoplasma gondii from fresh semen of naturally infected dogs in Southern Brazil

The aim of this study was to isolate Toxoplasma gondii and determine the viability of the parasite in fresh semen samples of clinically healthy adult dogs naturally infected. Eleven seropositive dogs with T. gondii IgG antibodies from southern Brazil were selected to confirm the presence and viability of T. gondii in fresh semen samples using in vitro isolation in Vero cell culture, polymerase chain reaction (PCR) and sequencing analysis. The presence of viable T. gondii was confirmed by in vitro isolation and PCR in five semen samples. The ITS1 region of the isolated protozoa (TG S4) was amplified and sequenced. The nucleotide sequence obtained was 99% compatible with the T. gondii DNA sequences stored in the GenBank. It has been shown that T. gondii tachyzoites may be isolated in vitro from fresh semen samples of clinically healthy dogs seropositive for T. gondii.     

Bluetongue virus infection in sheep: haematological changes and detection by polymerase chain reaction

SUMMARY Eight sheep vaccinated with 10⁶ pfu of attenuated Australian bluetongue virus serotype 23 (BTV-free sheep were challenged with virulent BTV 23. There was little subsequent variation in the mean clinical score, or in the mean lymphocyte and platelet concentrations in the peripheral blood of the eight vaccinated sheep. There was a marked thrombocytopenia and lymphopenia in the naive sheep as the mean lymphocyte and platelet concentrations fell to a minimum at days 8 and 11 after inoculation, respectively. Similar changes were observed in three other naive sheep inoculated with field isolates of BTV 1, 9 or 23. BTV was detected by nested polymerase chain reaction in whole blood of these sheep between days 6 and 28, in mononuclear leukocytes between days 3 and 14, and in platelets between days 6 and 21.