Interpopulation and intrapopulation maternal lineage genetics of the Lanyu pig (Sus scrofa) by analysis of mitochondrial cytochrome b and control region sequences

The Lanyu pig is an indigenous breed from the Lanyu Islet, which is southeast of Taiwan. Two herds of Lanyu pigs were introduced from the Lanyu Islet into Taiwan in 1975 and 1980. The current population of conserved Lanyu pigs consists of only 44 animals with unknown genetic lineage. The Lanyu pig possesses a distinct maternal genetic lineage remote from Asian and European pigs. The present study aimed to understand the phylogenetic relationship among conserved Lanyu, Asian, and European type pigs based on the cytochrome b coding gene, to ascertain the maternal lineage and genetic diversity within the conserved Lanyu pigs, and to address whether genetic introgression from exotic or Formosan wild pigs had occurred in the conserved Lanyu pigs. Entire mitochondrial genomes of both types of Lanyu pig comprised 2 ribosomal RNA, 22 transfer RNA, and 13 protein-coding genes. Only 2 haplotypes of the mitochondrial DNA (mtDNA) control region and cytochrome b were identified in the conserved Lanyu pig herds. When maximum likelihood trees were constructed, the Type I Lanyu mitochondrial genes formed a unique clade with a large pairwise distance of both cytochrome b and the control region from Asian and European type breeds, Formosan wild pigs, and exotic breeds. Significant loss of genetic diversity of mtDNA within the conserved Lanyu pigs was demonstrated by low haplotype and nucleotide diversities, supported by Fu and Li's D* neutrality test (1.44055; P < 0.05). The mtDNA control region sequences of extant pigs in the Lanyu Islet, however, showed high haplotype and nucleotide diversity, and clustered with exotic pigs. These results indicate no maternal lineage mtD-NA gene introgression from Formosan wild pigs and introduced exotic pigs to conserved Type I Lanyu pigs, and a severe loss of heterozygosity of mtDNA in conserved Lanyu pigs. The remaining extant pigs on the Lanyu Islet have been introgressed with exotic breeds. Strategies for future conservation of native Lanyu pigs are now even more urgent and important.     

当前美国蛋鸡疾病状况一瞥

<正>美国当前蛋鸡业面临的主要疾病包括大肠杆菌病、十二指肠局灶性坏死(FDN)、软骨病、传染性喉气管炎(ILT)和马立克氏病(MD)。当前,美国蛋鸡业正处于鸡群保健和疫病相对平静的一     

不同单酶制剂混合检测对比研究

试验以木聚糖酶、纤维素酶、淀粉酶和酸性蛋白酶为对象,首先研究了酸性蛋白酶分别和其他3种单酶进行混合后酶活测定值变化情况,结果表明,酸性蛋白酶对其他3种单酶的检测结果没有影响;试验第二部分研究了4种单酶整体混合在一起后各单酶测定值的变化情况,结果表明,木聚糖酶测定值出现很大偏高,其他3种单酶测定结果未出现显著偏差;进行进一步论证试验表明,淀粉酶可能是使木聚糖酶测定结果偏高的原因。     

Impact of Food Restriction on Ovarian Development,RFamide‐Related Peptide‐3 and the Hypothalamic–Pituitary–Ovarian Axis in Pre‐Pubertal Ewes

RFamide‐related peptide‐3 (RFRP‐3), the mammalian ortholog of gonadotropin‐inhibiting hormone, has been implicated as a mediator between reproduction and energy balance. This study aimed to investigate the physiological effects of RFRP‐3 on the process of ovarian development in food‐restricted pre‐pubertal ewes. The results showed that food restriction significantly inhibited the ovarian development and follicular growth. The data of qPCR in the hypothalamic–pituitary–ovarian (HPO) axis showed that food restriction not only upregulated RFRP‐3 mRNA expression but also downregulated the mRNA expression of gonadotropin‐releasing‐hormone receptor, follicle‐stimulating hormone receptor and luteinizing hormone receptor (LHR). Immunohistochemistry of RFRP‐3 in the ovaries suggested that RFRP‐3 may regulate the follicular development. These results suggested that the changes of RFRP‐3 in response to food restriction might influence the HPO axis and inhibit ovarian development.     

早期妊娠猕猴孕激素水平的检测

利用全自动化学发光免疫分析仪检测正常未妊娠的与不同孕期猕猴血清中雌二醇及孕酮的分泌水平。结果表明孕5d、10d、25d、30d血清孕酮比正常猕猴的分泌水平有非常明显的上升（P〈0.01）,孕15d也有显著的上升（P〈0.05）;孕15d、20d的雌二醇分泌水平比正常组有非常显著升高（P〈0.01）,而孕5d、10d、2...     

救必应水提取物对产ESBLs细菌的抑菌机理研究

为了探讨救必应水提取物的抑菌作用及抑菌机理,采用2倍微量稀释法和琼脂平板稀释培养计数法,测定救必应水提取物对产ESBLs(extended spectrum β-lactamases)细菌的最小抑菌浓度(minimal inhibitory concentration,MIC)和最小杀菌浓度(minimal bactericidal concentration,MBC),通过对细菌生长曲线、细菌超微结构、细胞壁和细胞膜通透性变化试验、核酸合成抑制试验研究救必应水提取物的抑菌机理。结果表明,与不添加提取物的对照组相比,救必应水提取物能够影响细菌的生长规律,使细菌破损严重,细胞壁和细胞膜通透性增加,细胞质外渗,菌液中AKP含量、可溶性蛋白含量增多、大肠杆菌DNA荧光强度明显减弱。研究表明,救必应水提取物的抑菌机理是通过细菌细胞壁和细胞膜通透性的变化,抑制细菌核酸的合成实现的。     

棘孢木霉(Trichoderma asperellum)固态发酵产纤维素酶及酶的性质

<正>纤维素酶具有破坏植物细胞壁,促进营养物质的消化和吸收,消除抗营养因子,提高饲料营养价值等多种功能,因而成为饲料工业研究的热点。目前用于纤维素酶生产和研究的菌株多为霉菌。棘孢木霉是我国新记录的木霉种[1],目前国内尚未见该菌种产纤维素酶的文献报道。     

动物副黏病毒感染与对策思考

尼帕病毒(Ni V)和亨德拉病毒(HeV)属于副黏病毒亚科的亨尼帕病毒属的成员。Ni V和HeV感染引起新的两种重要的人兽共患传染病。有关APMV-1(NDV)的发病和流行以及病原学研究认为APMV-1不断发生演化,新的基因型不断产生,对不同宿主的致病力不断变化,病毒感染的宿主谱不断扩大。本文简要介绍两种新的人兽共患传染病和APMV-1对鹅、鸭、猪的感染研究现状,就APMV-1宿主感染谱与演化加以分析,思考新的动物副黏病毒病防控对策。     

The effect of probiotic BioPlus 2B® on growth performance,dry matter and nitrogen digestibility and slurry noxious gas emission in growing pigs

For this study, 2 experiments were conducted to evaluate the effects of dietary BioPlus 2B^® supplements on growing pigs. In experiment 1, 64 crossbred pigs (26.70 ± 0.50 kg) were subjected to a 35-day feeding trial (2 pigs/pen, 8 pens/treatment) in which the effects of the following four corn-soybean meal based dietary treatments were compared: 1) CON (basal diet); 2) B0.05 (basal diet + 0.05% BioPlus 2B^®); 3) B0.1 (basal diet + 0.1% BioPlus 2B^®) and 4) B0.2 (basal diet + 0.2% BioPlus 2B^®). During the experimental period, average daily gain (ADG) tended to increase in a linear fashion (P = 0.08) with increasing levels of dietary BioPlus 2B^®. In addition, the average daily feed intake (ADFI) was found to increase (P < 0.05) as the levels of BioPlus 2B^® increased. However, no linear or quadratic effects were observed in the gain:feed ratio (G:F) or in the coefficients of total tract apparent digestibility (CTTAD) when dry matter (DM) and nitrogen (N) were considered. In experiment 2, 16 crossbred barrows (25.60 ± 0.10 kg) were randomly allotted to 1 of the 4 dietary treatments used in experiment 1 (1 pig/pen, 4 pens/treatment). The noxious gas emissions and pH of slurry waste were then measured daily for 120 h. Ammonia (NH₃) emission from the slurry samples obtained from pigs in the BioPlus 2B^® groups was lower than that of slurry obtained from pigs in the CON treatment (P < 0.05), however, hydrogen sulfide (H₂S) and mercaptan emission were not affected by supplementation with BioPlus 2B^®. In addition, the pH value decreased with time, and the pH values of slurry obtained from pigs subjected to the B0.1 and B0.2 treatments were lower than those of samples obtained from other groups after 48 h (P < 0.05). Taken together, these results indicate that supplementation with BioPlus 2B^® can reduce slurry NH₃ emission, but not H₂S and mercaptan emission in growing pigs without impacting growth performance.     

不同脱萼处理对‘华梨1号’梨脱萼率及果实品质的影响

以‘华梨1号’梨为试材,于梨花露白的花蕾期和盛花期喷施不同浓度的PBO和40%氟硅唑处理,研究不同脱萼处理对‘华梨1号’梨果脱萼率、座果率、单果重、果形指数和果实外观品质和内在品质的影响。结果表明：喷施不同浓度的PBO和40%氟硅唑处理对于‘华梨1号’梨幼果的萼片脱落及果实品质的影响差异显著。其中喷施12000 倍40%氟硅唑+600 倍PBO处理脱萼效果最为显著,幼果脱萼果率为92.53%;花朵座果率为97.58%,与清水对照处理差异不显著;果形指数为0.89,显著低于其他处理的果形指数,果形呈扁圆形,提高了果实的整齐度,改善了梨果外观品质;同时显著提高梨果的可溶性固形物和可溶性糖的含量,降低了梨果的果肉硬度,提高了‘华梨1号’梨果实的内在品质。