Effects of melatonin on maturation,histone acetylation,autophagy of porcine oocytes and subsequent embryonic development

Melatonin (MLT) is an endogenous hormone with roles in animal germ cell development. However, the effect of MLT on porcine oocyte maturation and its underlying mechanisms remain largely unknown. Here, we investigated the effects of exogenous MLT on oocyte maturation, histone acetylation, autophagy and subsequent embryonic development. We found that 1 nmol/L MLT supplemented in maturation medium was the optimal concentration to promote porcine oocyte maturation and subsequent developmental competence and quality of parthenogenetic embryos. Interestingly, the beneficial effects of 1 nmol/L MLT treatment on porcine oocyte maturation and embryo development were mainly attributed to the first half period of in vitro maturation. Simultaneously, MLT treatment could also improve maturation of small follicle‐derived oocytes, morphologically poor (cumulus cell layer ≤1) and even artificially denuded oocytes and their subsequent embryo development. Furthermore, MLT treatment not only could decrease the levels of H3K27ac and H4K16ac in metaphase II (MII) oocytes, but also could increase the expression abundances of genes associated with cumulus cell expansion, meiotic maturation, histone acetylation and autophagy in cumulus cells or MII oocytes. These results indicate that MLT treatment can facilitate porcine oocyte maturation and subsequent embryonic development probably, through improvements in histone acetylation and autophagy in oocytes.     

吉林地区规模化猪场不同猪群繁殖与呼吸综合征的血清学调查

本试验应用ELISA法对吉林地区8个PRRS未免疫猪场和9个PRRS免疫猪场的后备母猪、生产母猪和5～10周龄的断奶仔猪三个猪群进行了PRRSV抗体检测。结果表明:吉林地区8个PRRS未免疫猪场均受到PRRSV感染,猪场抗体阳性率为100%,猪群抗体阳性率在50%～75%之间,平均阳性率为62.26%;吉林地区9个PRRS免疫猪场猪群PRRSV抗体阳性率在70%～100%之间,平均阳性率为87.78%。PRRS未免疫猪场与PRRS免疫猪场猪群抗体平均阳性率相比,差异极显著(P<0.01)。     

姜堰市桑园虫害多发原因及防治对策

近几年,姜堰市桑园害虫发生面广、量大、种类多,为害重,主要害虫有桑尺蠖、桑毛虫、桑象虫、野蚕、桑叶螨、桑蓟马、天牛等。从发生量看,这几年害虫属于偏重发生,并且各种害虫发生世代重桑较严重,发生为害时间延长,给养蚕生产带来了一定的威胁。为此,我们对桑园害虫发生的原因作调查分析并对今后的防治工作提出几点看法。     

Effect of chicken egg yolk immunoglobulins on serum biochemical profiles and intestinal bacterial populations in early‐weaned piglets

This study was conducted to test the hypothesis that dietary supplementation with anti‐E. coli, chicken egg yolk immunoglobulins (IgY), may affect early weaned piglet (EWP) intestinal functions and enteric micro‐organisms. One hundred and forty‐eight ([Landrace × Yorkshire] × Duroc) piglets, weaned at age day 21, were randomly assigned to receive one of three diets for 14 days. Treatment group one (control group) was fed the base diet. Treatment group two (antibiotics group) was fed the base diet which was supplemented with 100 ppm colistin sulphate and 15 ppm enramycin; treatment group three (IgY group) was fed the base diet which was supplemented with 500 mg/kg anti‐E. coli IgY. The study evaluated the effects on EWPs of IgY on growth, serum biochemical, inflammatory profiles and also digestion content intestinal bacterial populations. Results showed no significant difference in diarrhoea rates between IgY‐fed EWPs and antibiotic‐treated EWPs. Serum biochemical analysis showed that EWPs fed an IgY‐containing diet had both lower (p < 0.05) cholesterol and low‐density lipoprotein compared to antibiotic‐treated EWPs. Escherichia coli populations measured in IgY‐fed EWP ileal contents, compared to the control group, were significantly reduced (p < 0.05). Enterococcus, Lactobacillus, Clostridium and Bifidobacterium populations were unaffected by the IgY treatment. Larger (p < 0.05) Enterococcus populations and lower (p < 0.05) expression levels of heat‐stable enterotoxin b (STb) were observed in IgY‐fed EWP caecal digesta compared to the control group. Enteric Lactobacillus significantly decreased (p < 0.05) in EWPs fed antibiotics while it was unaffected by IgY treatment. Dietary supplementation with anti‐E. coli IgY has the potential to suppress enteric E. coli growth, but not Lactobacillus, Clostridium and Bifidobacterium. This promotes and maintains a healthy EWP intestinal environment. These findings suggest that IgY may be used as an alternative to antibiotics in EWP diets.     

The production of short chain fatty acid and colonic development in weaning piglets

Weaning process widely affects the small intestinal structure and function in piglets, while the responses of large intestine to weaning stress are still obscure. The purpose of this study was to determine the developmental changes (i.e., short chain fatty acids (SCFAs) concentrations, growth parameters, crypt‐related indices and antioxidant capacity) in colon of piglet during weaning. Forty piglets were weaned at day 21 and euthanized to collect colonic tissues and digesta samples on day 0, 1, 3, 7 and 14 post‐weaning (n = 8). Piglet growth performance was improved (p < .001) on day 7 and 14 post‐weaning. The concentrations of acetate, propionate, butyrate, valerate, isobutyrate, isovalerate and total SCFAs were higher (p < .001) during the late post‐weaning period. The mRNA abundances of SCFAs transporters were greater (p < .001) on day 7 and 14. The absolute and relative weights, absolute length and perimeter of colon were greater (p < .001) on day 7 and 14. Similarly, post‐weaning increases (p < .001) in colonic crypt depth and Ki67 positive cells numbers per crypt were observed during the same period. Colonic crypt fission indices decreased (p < .01), while total crypt numbers increased (p < .001) on day 14 after weaning. Moreover, total SCFAs concentration was significantly associated with colonic growth parameters and Ki67 cells/crypt (p < .001). In addition, catalase content was decreased on day 3, 7, and 14, whereas, the concentrations of total superoxide dismutase (T‐SOD) and manganese‐containing superoxide dismutase (MnSOD) were higher (p < .05) on day 1 and 3 post‐weaning. These results showed that weaning process has a significant effect on colonic growth and development, which might be associated with the change of SCFAs concentrations in colon.     

Combined microRNAome and transcriptome analysis of follicular phase and luteal phase in porcine ovaries

The aim of this study was to explore the expression difference of miRNAs and mRNAs between the follicular phase (FP) and luteal phase (LP) in porcine ovaries and provide a theoretical basis for the research on mammalian reproductive regulation. RNA‐Seq and miRNA‐Seq were used to identify differentially expressed genes (DEGs) and miRNAs (DEMs) between the FP and LP in ovaries of six sows (3‐year‐old Yorkshire pigs with similar weights and same parities). Bioinformatic analysis was used to screen potential genes and miRNAs related to porcine ovarian function. Real‐time qualitative PCR was used to validate the sequencing results. RNA‐Seq results showed that 3,078 genes were up‐regulated, and 1,444 genes were down‐regulated in the LP compared with the FP, and DEGs were significantly enriched in 242 Gene Ontology (GO) terms and 33 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. miRNA‐Seq identified 112 DEMs, of which 25 were up‐regulated and 87 were down‐regulated in the LP compared with the FP. We obtained 186 intersection genes (IGs) between the 4,522 DEGs and 2,444 target genes predicted from the 112 DEMs. After constructing a miRNA‐gene‐pathway network, we identified key miRNAs and genes including miR‐17‐3p, miR‐214, miR‐221‐5p, miR‐125b, FGF1, YWHAG, YWHAZ, FDFT1 and DHCR24, which are enriched in Hippo and PI3K‐Akt signalling pathways, and various metabolic pathways. These results indicate that these key genes and miRNAs may play important roles in the developmental transition from FP to LP in porcine ovaries and represent candidate targets for further study.     

咪唑苯脲缓释剂治疗温氏附红细胞体病的效果观察

咪唑苯脲(Imidocarb),又名双咪苯脲,属于均二苯基脲的衍生物,是一种动物专用的新型抗原虫的化学药物,目前是治疗奶牛附红细胞体病比较有效的药物,并能控制疫情,但不能彻底杀灭附红细胞体[1]。本试验用研制的咪唑苯脲缓释剂,用于临床治疗奶牛附红细胞体病,观察治疗效果,以期找到临床上治疗附红细胞体病更有效的药物。     

牛卵母细胞体外成熟技术研究

从两方面探讨了牛卵母细胞的体外成熟培养效果,即对不同级别和不同卵巢卵泡直径的卵丘卵母细胞复合体（COCs）进行成熟培养,测定其成熟率。COCs级别不同,培养成熟率之间存在很大差异,A级COCs成熟率为63．81％,B级为47．81％,显著高于C级和D级（P〈0．01）。卵母细胞的成熟率与采集COCs时的卵泡直径关系密切。中等卵泡的卵母细胞的成熟率为61．82％,显著高于小卵泡和大卵泡（P〈0．01）。试验结果表明：A级和B级COCs是卵母细胞体外培养的主要资源;在卵母细胞体外培养过程中,宜选择卵泡发育水平基本正常的中等卵泡采集COCs,而不宜选择发育过大或过小的卵泡。     

防止养殖环节的病死猪流向餐桌的对策

多年来,各级畜牧兽医主管部门及其所属的监督机构不断加强对病死猪的专项整治,有效防止了病死猪流向餐桌现象的发生。但各级财政仅在屠宰环节给予病死猪损失补贴和无害化处理费用补贴,而忽略了养殖环节病死猪的损失补贴;环保、保险、食安、工商、畜牧、公安等部门间没形成无缝协作机制,这些都是造成养殖环节病死猪流向餐桌的隐患。提示政府应尽快制定养殖环节病死猪的损失补贴财政政策,加大整治力度,建立多部门协作机制,以防止养殖环节病死猪流向餐桌。     

种子接种法测定紫花苜蓿不同品种对三叶草核盘菌的抗性

本试验采用种子接种法就10个紫花苜蓿(Medicago sativa L.)品种对三叶草核盘菌(Sclerotinia trifoliorum)的抗性进行了研究,根据接种后的种子萌发率、幼苗生长及幼苗干重三项指标的综合测定分析,供试品种中,游客和赛特受三叶草核盘菌影响最大,为高感品种;WL525和WL324受三叶草核盘菌影响最小,为高抗品种,其它6个品种介于两者之间,为中性材料。种子接种法便利、快捷,可以反映紫花苜蓿不同品种对三叶草核盘菌的抗性。