本文从牛奶产量、乳制品产量、生鲜乳价格、饲料行情、奶牛生产性能测定、规模化牧场建设等几个方面分析了2021年山东省奶业整体发展情况,探讨了当前奶业发展面临的问题,并结合山东省奶业现状提出了促进奶业持续、健康发展的建议.

Dio3os is a significant lncRNA gene located in the Dlk1-Dio3 imprinted locus, and plays an important role in the body growth and development. However, there is relatively little information regarding the effects of this gene on reproductive activity in mice. Thus, the aim of this study was to investigate the effects of Dio3os on growth, development and reproductive activity in mice. Moreover, expression levels of associated genes were also monitored, using mouse endometrial stromal cells (ESCs). Firstly, qPCR and Western Blot were used to determine the expression levels of genes associated with Dio3os, using mouse ESCs. Then, RNA-seq was utilized to classify and annotate the activity of differentially expressed genes affected by Dio3os. Moreover, RNA pull-down and mass spectrometry were used to identify and analyze Dio3os-binding proteins. Additionally, 24 female mice were randomly divided into 4 equal groups (n=6 each), including LV3-Dio3os, LV3-NC, LV5-Dio3os and LV5-NC. Data of body weight, body length, tail length, occurrence rate of estrous cycle and organ coefficients for these mice were recorded. Results of qPCR and Western Blot showed that Dio3os affected the expression levels of Dlk1, Gtl2, Dio3 and genes related to development and apoptosis. Besides, Dio3os was highly expressed in mouse uterus and ovary. This gene also increased body weight and body length and affected the organ coefficients. Moreover, Dio3os increased the occurrence rate of estrus and correspondingly decreased the occurrence rate of diestrus. Together, these findings indicate that Dio3os affects growth, development and reproductive activity in mice. (c) 2021 PVJ. All rights reserved

It is well known that the dairy cow production is very sensitive to environmental factors, including high temperature, high humidity and radiant heat sources. High temperature-induced heat stress is the main environmental factor that causes oxidative stress and apoptosis, which affects the development of mammary glands in dairy cows. Dihydromyricetin (DMY) is a nature flavonoid compound extracted from Ampelopsis grossedentata; it has been shown to have various pharmacological functions, such as anti-inflammation, antitumor and liver protection. The present study aims to evaluate the protective effect of DMY on heat stress-induced dairy cow mammary epithelial cells (DCMECs) apoptosis and explore the potential mechanisms. The results show that heat stress triggers heat shock response and reduces cell viability in DCMECs; pretreatment of DCMECs with DMY (25 μM) for 12 h significantly alleviates the negative effects of heat stress on cells. DMY can provide cytoprotective effects by suppressing heat stress-caused mitochondrial membrane depolarization and mitochondrial dysfunction, Bax and Caspase 3 activity, and modulation of oxidative enzymes, thereby preventing ROS production and apoptosis in DCMECs. Importantly, DMY treatment could attenuate heat stress-induced mitochondrial fragmentation through mediating the expression of mitochondrial fission and fusion-related genes, including Dynamin related protein 1 (Drp1), Mitochondrial fission 1 protein (Fis1), and Mitofusin1, 2 (Mfn1, 2). Above all, our findings demonstrate that DMY could protect DCMECs against heat stress-induced injury through preventing oxidative stress, the imbalance of mitochondrial fission and fusion, which provides useful evidence that DMY can be a promising therapeutic drug for protecting heat stress-induced mammary glands injury and mastitis.

运用多重PCR同时检测肉鸽病原(圆环病毒、腺病毒及疱疹病毒Ⅰ型)的方法,分别设计与合成3种病毒基因扩增引物,并提取疑似病鸽的肝脏样品DNA、进行单一PCR扩增及基因序列测定,结果分别获得了大小为239、418、618 bp的DNA产物.通过摸索多重PCR反应条件,应用多重PCR同时检测3种病毒基因片段,同时获得了鸽疱疹病毒Ⅰ型、鸽圆环病毒及鸽源腺病毒的基因片段.再对疑似混合感染这3种病毒的肝脏样品进行检测,发现50％(6/12)样品存在3种病毒的混合感染、25％(3/12)样品存在鸽圆环病毒和鸽源腺病毒的混合感染、8.3％(1/12)样品存在鸽源腺病毒和Ⅰ型鸽疱疹病毒的混合感染、8.3％(1/12)样品存在鸽圆环病毒和Ⅰ型鸽疱疹病毒的混合感染、8.3％(1/12)样品未发生任何感染.结果表明,多重PCR可快速检测鸽疱疹病毒Ⅰ型、鸽圆环病毒及鸽源腺病毒的混合感染,表明运用三重PCR检测3种病毒混合感染有很好的应用价值.

Heat stress-induced oxidative stress in bovine mammary epithelial cells (BMECs) threatens the normal growth and development of bovine mammary tissue, resulting in lower milk production of dairy cows. The aim of the present study is to investigate the protective effects of S-allyl cysteine (SAC), an organosulfur component extracted from aged garlic, on heat stress-induced oxidative stress and apoptosis in BMECs and to explore its underlying mechanisms. Our results showed that heat stress treatment considerably decreased cell viability, whereas SAC treatment dose-dependently restored cell viability of BMECs under heat-stress conditions. In addition, SAC protected BMECs from heat stress-induced oxidative damage by inhibiting the excessive accumulation of reactive oxygen species (ROS) and increasing the activity of antioxidant enzymes. It also inhibited heat stress-induced apoptosis by reducing the ratio of Bax/Bcl-2 and blocking proteolytic the cleavage of caspase-3 in BMECs. Interestingly, we found that the protective effect of SAC on heat stress-induced oxidative stress and apoptosis was dependent on the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway. SAC promoted the Nrf2 nuclear translocation in heat stress-induced BMECs. The results were also validated by Nrf2 and Keap1 knockdown experiments further demonstrating that Nrf-2 was indeed involved in the protective effect of SAC on heat stress-induced oxidative damage and apoptosis. In summary, our results showed that SAC could protect BMECs from heat stress-induced injury by mediating the Nrf2/HO-1 signaling pathway, suggesting that SAC could be considered as a therapeutic drug for attenuating heat stress-induced mammary gland diseases.

为进一步优化细胞外基质,建立胚胎干细胞(embryonic stem cells,ESCs)稳定的体外培养体系,试验分别采用小鼠胚胎成纤维细胞(mouse embryonic fibroblasts,MEFs)饲养层、基质胶(Matrigel)和贴附因子(attachment factor,AF)细胞培养板,以N2B27为基础培养基,评估和比较不同处理对小鼠ESCs(mESCs)自我更新及多能性维持的影响.结果表明:在KSR浓度为5％的N2B27培养基中,MEFs饲养层的mESCs形态立体,边缘清晰,呈规则的圆顶状;Matrigel、AF细胞培养板培养的mESCs形态立体,呈集落样生长.MEFs饲养层培养的mESCs传代后黏附快,集落形成显著快于Matrigel、AF细胞培养板,AF细胞培养板培养的mESCs黏附少,集落形成慢.免疫荧光染色结果显示,3种处理的mESCs均表达Oct4和Sox2蛋白,但AF细胞培养板培养的mESCs中Oct4、Sox2和Nanog的转录表达水平低于Matrigel细胞培养板,其中Sox2和Nanog差异显著或极显著(P<0.05或P<0.01).说明AF可用于mESCs培养,但在细胞黏附、增殖速率及多能因子表达上与MEFs、Matrigel有差异.

Heat stress–induced reductions in milk yield and the dysfunction of mammary glands are economically important challenges that face the dairy industry, especially during summer. The aim of the present study is to investigate the effects of heat stress on mitochondrial function by using dairy cow mammary epithelial cells (DCMECs) as an in vitro model. Live cell imaging shows that the mitochondria continually change shape through fission and fusion. However, heat stress induces the fragmentation of mitochondria, as well as the decreased of ATP level, membrane potential, and anti-oxidant enzyme activity and the increased of respiratory chain complex I activity. In addition, the cytosolic Ca2+ concentration and cytochrome c expression (Cyto-c) were increased after heat stress treatment. Both qRT-PCR and western blot analysis indicate that mitofusin1/2 (Mfn1/2) and optic atrophy protein-1 (Opa-1) are downregulated after heat stress, whereas dynamin-related protein 1 (Drp1) and fission 1 (Fis-1) are upregulated, which explains the observed defect of mitochondrial network dynamics. Accordingly, the present study indicated that heat stress induced the dysfunction of DCMEC through disruption of the normal balance of mitochondrial fission and fusion.

从江苏北部某牛场共采集26头经四环素治疗1周的患乳房炎奶牛的奶样31份,从生牛乳中分离鉴定出病原菌12株,其中大肠杆菌3株,肺炎克雷伯菌2株,停乳链球菌、鲍曼不动杆菌、肠球菌、松鼠葡萄球菌、产色葡萄球菌、短小芽孢杆菌和铜绿假单胞菌各1株.药敏试验结果显示:3株大肠杆菌和2株肺炎克雷伯菌对青霉素、氨苄西林和林可霉素均显示出多重耐药性;铜绿假单胞菌菌株W9对青霉素、氨苄西林、林可霉素、四环素、土霉素和头孢喹肟均表现出多重耐药;产色葡萄球菌菌株W12对林可霉素、四环素和土霉素多重耐药;松鼠葡萄球菌菌株W11对林可霉素、链霉素、卡那霉素、四环素、土霉素、庆大霉素和头孢喹肟均耐药.在9种常用的兽用抗生素中,12株分离菌对林可霉素的耐药率最高,达到83.3％(10/12);对卡那霉素和庆大霉素的耐药率最低,均仅为8.3％(1/12).

[目的]本试验旨在探究乳腺炎奶牛乳腺组织中是否存在细胞程序性坏死. [方法]采集健康和乳腺炎奶牛乳腺组织,HE染色后进行形态学观察,实时荧光定量PCR( RT-qPCR)检测炎性相关因子基因( IL-1β、IL-6、TNF-α)和程序性坏死相关因子受体相互作用蛋白基因(RIPK3、RIPK1)、混合谱系激酶结构域样蛋白基因( MLKL)和Caspase8基因表达,Western blot检测MLKL和磷酸化 MLKL蛋白( p-MLKL)表达. [结果]程序性坏死标记蛋白 MLKL 在乳腺炎乳腺组织中表达;IL-1β、IL-6、TNF-α和RIPK1 mRNA的表达量极显著升高( P<0.001),RIPK3 mRNA 表达量显著升高( P<0. 01),Caspase8 mRNA表达量极显著降低(P<0.001);MLKL mRNA和蛋白表达量差异均不显著(P>0.05),但p-MLKL蛋白表达量显著增加(P<0.05). [结论]根据程序性坏死相关因子的表达变化,可以推断出在乳腺炎乳腺组织中存在细胞程序性坏死.

[目的]本试验旨在探讨去乙酰化蛋白7(sirtuin 7,SIRT7)对奶牛乳腺上皮细胞(DCMEC)合成乳蛋白、乳脂和乳糖关键基因表达的影响.[方法]以体外原代培养的中国荷斯坦奶牛DCMEC为试验材料,纯化后转染质粒pCDNA3.1-SIRT7,继续培养48或72 h后收集细胞.采用RT-qPCR和Western blot法检测乳蛋白、乳脂和乳糖合成关键基因mRNA和蛋白的表达;通过特异性试剂盒检测胞内和培养基中甘油三脂(TG)含量.[结果]1)乳蛋白:与对照组相比,过表达SIRT7可显著提高αs1-酪蛋白基因(CSN1S1)、β-酪蛋白基因(CSN2)和ETS转录因子基因(ELF5)mRNA水平,促进CSN2蛋白合成,激活雷帕霉素靶蛋白(mTOR)磷酸化;2)乳脂:与对照组相比,过表达SIRT7可显著提高乳脂合成关键因子过氧化物酶增殖体激活受体γ(PPARγ)、固醇调节元件结合蛋白1(SREBP1)mRNA和蛋白水平,显著增加细胞内甘油三酯(TG)含量;3)乳糖:与对照组相比,过表达SIRT7可显著提高乳糖合成关键因子葡萄糖转运蛋白1(GLUT1)mRNA表达.[结论]在体外培养条件下,过表达SIRT7可促进DCMEC中乳蛋白、乳脂和乳糖合成关键基因的表达.

Mastitis, a major infectious disease in dairy cows, is characterized by an inflammatory response to pathogens such as Escherichia coli and Staphylococcus aureus. To better understand the immune and inflammatory response of the mammary gland, we stimulated bovine mammary gland epithelial cells (BMECs) with E. coli-derived lipopolysaccharide (LPS). Using transcriptomic and proteomic analyses, we identified 1019 differentially expressed genes (DEGs, fold change ≥2 and P-value < 0.05) and 340 differentially expressed proteins (DEPs, fold change ≥1.3 and P-value < 0.05), of which 536 genes and 162 proteins were upregulated and 483 genes and 178 proteins were downregulated following exposure to LPS. These differentially expressed genes were associated with 172 biological processes; 15 Gene Ontology terms associated with response to stimulus, 4 associated with immune processes, and 3 associated with inflammatory processes. The DEPs were associated with 51 biological processes; 2 Gene Ontology terms associated with response to stimulus, 1 associated with immune processes, and 2 associated with inflammatory processes. Meanwhile, several pathways involved in mammary inflammation, such as Toll-like receptor, NF-κB, and NOD-like receptor signaling pathways were also represented. NLRP3 depletion significantly inhibited the expression of IL-1β and PTGS2 by blocking caspase-1 activity in LPS-induced BMECs. These results suggest that NLR signaling pathways works in coordination with TLR4/NF-κB signaling pathways via NLRP3-inflammasome activation and pro-inflammatory cytokine secretion in LPS-induced mastitis. The study highlights the function of NLRP3 in an inflammatory microenvironment, making NLRP3 a promising therapeutic target in Escherichia coli mastitis.

Compared with conventional identification methods, DNA-based genetic approaches such as single nucleotide polymorphisms (SNPs) and satellites are much more reliable for pig identification and meat traceability. In this study, multiallelic amplification fragments with multiple SNPs, incorporating the advantages of both SNPs and microsatellites, were explored for the first time for pig identification and meat traceability. Primer pairs for multiallelic fragments and their optimal SNPs were successfully selected and used for identification of individuals from Suzhong and Duroc populations. Meanwhile, the combined panel of the above mentioned primer pairs together with their optimal SNPs for Suzhong and/or Duroc pigs were validated for identification of the hybrids (Suzhong×Duroc). Therefore, we have successfully selected multiallelic amplification fragments with multiple SNPs to identify pigs and their meat samples from Suzhong, Duroc or their hybrids. Our study demonstrates that our method is more powerful for pig identification or meat traceability than SNPs or microsatellites.

The polycomb group (PcG) proteins are key epigenetic regulators in stem cell maintenance. PcG proteins have been thought to act through one of two polycomb repressive complexes (PRCs), but more recent biochemical analyses have challenged this model in the identification of noncanonical PRC1 (nc-PRC1) complexes characterized by the presence of Rybp or Yaf2 in place of the canonical Chromobox proteins. However, the biological significance of these nc-PRC1s and the potential mechanisms by which they mediate gene repression are largely unknown. Here, we explore the functional consequences of Yaf2 disruption on stem cell regulation. We show that deletion of Yaf2 results in compromised proliferation and abnormal differentiation of mouse embryonic stem cells (mESCs). Genome-wide profiling indicates Yaf2 functions primarily as a transcriptional repressor, particularly impacting genes associated with ectoderm cell fate in a manner distinct from Rybp. We confirm that Yaf2 assembles into a noncanonical PRC complex, with deletion analysis identifying the region encompassing amino acid residues 102-150 as required for this assembly. Furthermore, we identified serine 166 as a Yaf2 phosphorylation site, and we demonstrate that mutation of this site to alanine (S166A) compromises Ring1B-mediated H2A monoubiquitination and in turn its ability to repress target gene expression. We therefore propose that Yaf2 and its phosphorylation status serve as dual regulators to maintain the pluripotent state in mESCs.

An increasing number of studies have revealed that histone deacetylase (HDAC) mediated histone deacetylation is important for mammalian oocyte development. However, nonselective HDAC inhibitors (HDACi) were applied in most studies; the precise functions of specific HDAC classes during meiosis are poorly defined. In this study, the class IIa-specific HDACi MC1568 was used to reveal a crucial role of class IIa HDACs in the regulation of histone deacetylation during porcine oocyte meiosis. Besides, the functions of HDACs and histone acetyltransferases in regulating the balance of histone acetylation/deacetylation were also confirmed during oocyte maturation. After the validation of nontoxicity of MC1568 in maturation rate, spindle morphology, and chromosome alignment, effects of MC1568 on developmental competence of porcine somatic cell nuclear transfer (SCNT) embryos were evaluated, and data indicated that treatment with 10 μM MC1568 for 12 hours following electrical activation significantly enhanced the blastocyst rate and cell numbers. Moreover, results showed that optimal MC1568 treatment increased the H4K12 acetylation level in SCNT one cells and two cells. In addition, MC1568 treatment stimulated expression of the development-related genes OCT4, CDX2, SOX2, and NANOG in SCNT blastocysts. Collectively, our investigation uncovered a critical role of class IIa HDACs in the regulation of histone deacetylation during oocyte meiosis. Furthermore, for the first time, we showed that MC1568 can improve the in vitro development of porcine SCNT embryos. These findings provide an alternative HDACi for improving animal cloning efficiency and may shed more light on nuclear reprogramming.

[Objective] This study aimed to clone C4B gene in Siji goose and detect its expression level in different tissues. [Method] cDNA sequence of C4B gene was cloned with RACE-PCR method. Amino acid sequences in multiple species were aligned in GenBank, and a phylogenetic tree was constructed for homology analysis. [Result] C4B gene in Siji goose shared relatively high homology with chicken and quail; Siji goose C4B gene was expressed highly in liver and lung of adult geese and expressed lowly in epididymis, seminiferous duct, brain, kidney, testis, heart, oviduct and smal intestine. [Conclusion] In the present study, mRNA expression lev-el of C4B gene in different tissues and organs of Siji goose was determined by flu-orescence quantitative PCR, which provided basis for rapid diagnosis of specific an-imal diseases.

Suzhong swine is a hybrid breed derived from Taihu sows and Landrace boars. To identify individual Suzhong swine and trace the source of pork product, 52 single nucleotide polymorphisms ( SNP) were developed in the Suzhong swine genomic DNA fragments using 7 pairs of primers out of 29. Among the SNPs, 41 with heterozygosities more than 0. 1 were selected for Suzhong pigs swine genotyping. By converting the genetic loci with sequences of AA, TT, GG, CC, AT, AG, AC, TG, TC, and GC into digital number of 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9, respective-ly, 96 digital barcodes, unique for each individual pig&nbsp;produced, were generated for 96 Suzhong swine derived from 7 boars and 12 sows. Theoretically, the barcodes based on 41 SNPs amplified by the 7 primer pairs can be used for distinguishing about 5 000 000 individual pigs.

To set up pig archives, identification of individual Duroc pigs using DNA barcode was performed. Totally 8 pairs of PCR primers that were able to amplify genomic DNA fragments were successfully isolated from pig genomes from 31 pairs of primers. 39 SNP loci were identified with the 8 primers. 16 SNP loci with heterozygosities≥0. 1 were chosen for writing the DNA barcodes recognizing individual Duroc pigs. The DNA barcodes were then translated into corresponding digital barcodes by converting base letters into digital numbers. Using the digital barcodes, a total of 68 pigs from 10 litters was identified. Accordingly, 2, 10, 9, 3, 3, 9, 3 and 3 kinds of alleles were identified with the 8 primers, respectively. Theoretically, the different alleles would give 131 220 (2×10×9×3×3×9×3×3) kinds of genotypes if they were randomly&nbsp;combined in the population, which were sufficient for the medium-scale Duroc farm to distinguish each individual pig completely.

The study was conducted to investigate the polymorphisms of estrogen receptor(ESR) gene,prolactin receptor(PRLR) gene and follicle-stimulating hormone β subunit(FSHβ) gene using PCR-RFLP in Shan pigs.The results showed that the predominant alleles of ESR and PRLR genes were B(frequency=0.817) and A(frequency=0.550),respectively,and only genotypes AA and AB were found in FSHβ gene.Correlation analysis indicated that pigs with BB genotype in ESR gene had more total number born(TNB) and number born alive(NBA) of first-and second-parity sows than those with AA one(P<0.01).Pigs with genotypes AA and AB in PRLR gene had more TNB and NBA than those with BB one(P<0.01).Pigs with AA genotype in FSHβ gene had more TNB and NBA than those with AB one.Pigs with genotype AA in ESR had higher birth weight(BW) than those with AB and BB ones among the first-and secondparity sows(Pccc0.05),and higher weaning weight(WW) than those with BB ones(P<0.05).Pigs with genotype BB in PRLR had higher WW than those with AB and AA ones among the first-and second-parity sow groups(P<0.05).Genotype AB in FSHβ was a dominant one in improving birth weight and weaning weight traits.

本文回顾了近二十年来催乳素在调控家禽繁殖活动方面的研究进展,这些进展包括催乳素分泌的神经内分泌调控机制,催乳素促进就巢发生和抑制产蛋的下丘脑和垂体的中枢内分泌调控机制,以及促进家禽繁殖产蛋的卵泡局部调控机制.催乳素对禽(鸟)类季节性繁殖的调控也分为两种,一种是在依赖年度光照变化调控季节性繁殖的家禽,其年度季节性繁殖周期的形成也是由催乳素和促性腺激素LH分泌的交替消长调控,而对于某些依赖温度而非光照调控的鸟类,催乳素而非LH是启动和终止繁殖季节的主要因素.从催乳素具有抑制和促进禽(鸟)类繁殖产蛋性能的双重调控作用来看,对催乳素作为研究对象而开展的家禽产蛋性能的遗传基础和基因聚合选育研究,还需要继续在理论和实践方面进一步完善.

选择胎次、日龄和体重基本相近的杜长大三元杂交仔猪48头,平均体重约20 kg,按体重和性别分为4组,分别为自制中药1、2、3组和抗生素组,进行饲养对比试验,猪重约60 kg时结束.结果表明,中药1、2、3组的猪日增重分别较抗生素组高8.53％、13.91％、8.16％,饲料消耗分别较抗生素组降低了4.0％、7.1％、4.3％；中药1、2、3组和抗生素组的IgA、IgG、IgM、C3和C4均较试验前有不同程度提高,其中以中药2组提高幅度较大.综合比较增重、饲料消耗、免疫球蛋白和补体含量等各项指标,均以中药2组的配方效果最佳.