利用IVM/IVF技术生产试管犊牛的研究

本研究利用卵母细胞体外成熟(IVM)、体外受精(IVF)技术,体外生产牛胚胎,以获得试管牛.结果表明:卵母细胞体外培养22～24h后,其成熟率为85％;体外受精率为83％.体外受精卵分别在颗粒细胞单层(GCM)和输卵管细胞单层(OCM)上培养,其胚胎最后产量(以授精时卵母细胞的数目为基数)分别为19％和29％,差异极显著(P<0.01).若体外受精卵先在GCM中培养72h后,再将已发生卵裂的(>4细胞)胚胎移到OCM中培养,其胚胎最后产量为35％.由此表明,早期胚胎在其发育过程中至少存在着3个发育相期,即1～8细胞、8～16细胞和16细胞～囊胚3个阶段,各阶段需要不同的培养环境.IVM/IVF胚胎移植到受体黄牛体内后,其足月时的妊娠率为15％.第一头试管犊牛已于1993年4月18日凌晨产出.     

后非洲猪瘟时期洋三元（DLY）商品母猪作种用的可行性分析及建议

自从2018年非洲猪瘟在中国暴发以来,为了尽快恢复产能,我国很多猪场在生产上开始采用洋三元商品母猪留作种用。通过收集某大型猪场的二元（（LY）母猪和洋三元（DLY）商品母猪的生产记录,统计两者在生产成绩上的差异,并综合其他文献来分析洋三元商品母猪留作种用的优缺点,给出改进的措施,为后非洲猪瘟时期养猪生产提供参考。     

Effects of berberine on the growth performance,antioxidative capacity and immune response to lipopolysaccharide challenge in broilers

This study evaluated the effects of berberine on growth performance, immunity, haematological parameters, antioxidant capacity, and the expression of immune response‐related genes in lipopolysaccharide (LPS)‐challenged broilers. We assigned 120 one‐day‐old male broilers (Ross 308) to two treatment groups; each group included two subgroups, each of which included six replicates of five birds per replicate. The experiment used a 2 × 2 factorial arrangement with berberine treatment (0 or 60 mg/kg dietary) and challenge status [injection of saline (9 g/L w/v) or LPS (1.5 mg/kg body weight)] as the main factors. On days 14, 16, 18 and 20, broilers were intraperitoneally injected with LPS or physiological saline. Blood and liver samples were collected on day 21. Dietary berberine supplementation significantly alleviated the compromised average daily gain and average daily feed intake (p < 0.05) caused by LPS. The LPS challenge led to increased lymphocyte and white blood cell (WBC) counts, malondialdehyde (serum and liver) content, and immunoglobulin G and M, tumour necrosis factor‐α (TNF‐α) and interleukin‐1β (IL‐1β) expression (p < 0.05) and significantly reduced serum total superoxide dismutase (T‐SOD) activity (p < 0.05). Dietary berberine significantly mitigated the LPS‐induced decreases in the mRNA expression of nuclear factor‐kappa B (NF‐κB), TNF‐α, IL‐1β, inducible nitrite synthase and cyclooxygenase‐2 (p < 0.05) in the liver. In conclusion, berberine supplementation has a positive effect on LPS challenge, which may be related to the increase in antioxidant enzyme activity and inhibition of both NF‐κB signalling and the expression of inflammatory mediators.     

维生素D_3疯狂上涨的背后

<正>1维生素D3价格的井喷也许没有多少人会想到,维生素D3———这个维生素大家族中的小品种会搅的整个饲料养殖行业如此躁动不安,突然无货可供,价格陡然飙升。2009年7月下旬,饲用级50万单位维生素D3粉的价格(下同)在50元/kg左右徘徊,虽显启动迹象,但市场关注度不高。当时有先见之明的市场人士预测,其价格可能在9月份升至300元/kg,但也     

Genetic differences in oestrous signs and oestrogen metabolism‐related genes between Chinese Mi and European Landrace‐Large White pigs

Oestrous signs affect timely mating and reproductive efficiency in swine breeding herds. To study the genetic difference of oestrous signs between Chinese and European pigs, 100 Landrace‐Large White (LLW) cross gilts and 50 Chinese Mi gilts were assessed for oestrous signs and the concentrations of serum estradiol‐17β and progesterone were determined. The genotype of 39 single nucleotide polymorphisms (SNPs) in 11 oestrogen metabolism and function‐related genes was determined by Sequenom iPLEX platform. Compared with LLW gilts, Mi gilts had longer time of standing reflex (p < .001), higher scores of vulva reddening (p = .001) and greater serum estradiol‐17β concentration (p < .01). Gilts with greater serum estradiol‐17β concentrations also had greater (p < .05) scores for oestrous signs. Genetic polymorphisms of nine genes in oestrogen metabolism pathways had significant differences (p < .05) between LLW and Mi gilts. There were three and six haploblocks of SNPs in LLW and Mi, respectively. Compared with LLW, the distribution of haplotypes was more centralized in Mi pigs. Genetic polymorphisms of oestrogen metabolism‐related genes have considerable differences between Chinese Mi and European LLW pigs. Because of the important roles of oestrogen during the oestrus, some genes of oestrogen metabolism pathway could be considered as candidate genes for oestrous signs.     

江西省萍乡市某羊场布鲁菌病的流行病学分析

江西省萍乡市某山羊场妊娠母羊散发流产,为了分析该羊场流产的发生是否与布鲁菌感染有关,同时掌握该羊场布鲁菌病的流行情况,随机抽样采血共分离得到100份山羊血清,首先使用虎红平板凝集试验进行初步鉴定,然后通过试管凝集试验重新检测阳性血清。结果表明,该羊场布鲁菌病阳性率为20％。由此可以得出,该羊场的布鲁菌病防控工作存在较严重的问题,应制定有效的防治措施,将山羊布鲁菌病的检测纳入日常疾病监测工作中,最终达到净化该病的目的。     

Association of polymorphisms for nuclear receptor coactivator 1 gene with egg production traits in the maternal line of Shaobo hens

1. The objectives of the study were to find polymorphic sites and elucidate the association between SNPs in the nuclear receptor coactivator 1 (NCOA1) gene and reproductive traits. 2. SNPs were detected by PCR-SSCP and DNA sequencing. Four SNPs were detected, including T10155007A, T10125838C, G10118492A and G10109315T. Three polymorphisms were associated with total egg production at the age of 300 d and the G10109315T polymorphism was associated with age at first egg. 3. In conclusion, the NCOA1 gene can be used as a molecular marker for reproductive traits in hens.     

DNA Methylation Pattern in Pronuclear-Stage Mouse Embryos: Effect of Oocyte Vitrification

This study was conducted to investigate the pattern of DNA methylation in pronuclearstage mouse embryos derived from vitrified-warmed oocytes.Mouse oocytes at metaphase Ⅱ (MⅡ) stage of meiosis were all...     

Green tea polyphenols supplementation alters immunometabolism and oxidative stress in dairy cows with hyperketonemia

Peripartal cows often experience negative energy balance, and are therefore prone to suffering from metabolic diseases such as hyperketonemia, which causes financial losses in dairy farms. This study aimed to investigate the effect of green tea polyphenol (GTP) supplementation during the periparturient period on production performance, oxidative stress and immunometabolism in dairy cows with hyperketonemia. One hundred Holstein cows were assigned to GTP (0.2 g/kg DM; n = 50) or control (without GTP; n = 50) group based on body weight, previous milk yield, and parity on d 15 before expected parturition. Subsequently, 10 cows with hyperketonemia were selected from each group, according to blood β-hydroxybutyric acid (BHBA) concentration between 1.2 and 2.9 mmol/L from 2 to 3 d postpartum. All cows were fed a close-up diet and a lactation diet with or without GTP supply from 15 d prepartum until 30 d postpartum. Milk and blood samples were obtained from 20 cows selected with hyperketonemia on 10, 20, and 30 d postpartum. Compared with control cows, greater milk yield and lower somatic cell count were observed in GTP cows. The GTP group had lower concentrations of BHBA, free fatty acids, cholesterol, triglyceride, reactive oxygen species, malondialdehyde, and hydrogen peroxide, greater concentrations of glucose, lower activities of aspartate aminotransferase, alanine aminotransferase, and glutamyl transpeptidase, alongside greater activities of superoxide dismutase, glutathione peroxidase, and total antioxidant capacity. Additionally, GTP supplementation up-regulated concentrations of interleukin-6 and interleukin-10, but down-regulated concentrations of tumor necrosis factor-α, interleukin-1β, interleukin-2, interleukin-8, and interferon-γ in plasma. Greater concentrations of plasma immunoglobulin G were also detected in the GTP group. Overall, the data suggested that GTP supplementation from 15 d prepartum to 30 d postpartum improved the milk yield and health status in cows with hyperketonemia during early lactation.     

饲用复合酶制剂酶学特性研究

饲用复合酶制剂的主要酶种包括纤维素酶、蛋白酶、脂肪酶和淀粉酶。利用高产菌株S6-5、Y7-6和B5-12混合发酵生产复合酶制剂,发现纤维素酶催化反应最适宜的酸碱度在pH=5.0,反应体系温度为60℃时,纤维素酶活力达到14293U/g;蛋白酶酶活在pH=6.0时酶催化能力最强;而脂肪酶和淀粉酶在50℃时催化能力最强,在60℃催化能力下降,但不明显。