猪繁殖与呼吸综合征病毒Nsp2蛋白纳米抗体的筛选及其鉴定

为制备猪繁殖与呼吸综合征病毒(PRRSV)非结构蛋白2(Nsp2)的纳米抗体,本研究将截短表达的Nsp2重组蛋白免疫骆驼后分离骆驼外周血淋巴细胞,利用RT-PCR扩增其VHH基因,将VHH基因插入pCANTAB5E噬菌体载体,构建双峰驼重链抗体可变区文库。利用噬菌体展示技术经过3轮淘选,共筛选得到44株Nsp2特异性纳米抗体;经ELISA检测,结果显示44株Nsp2特异性纳米抗体均能与Nsp2蛋白特异性反应。本研究首次筛选到PRRSVNsp2特异性纳米抗体,为Nsp2蛋白的相关研究提供了必要的研究工具,同时为开发新型抗PRRSV药物奠定一定的基础。     

Hair cortisol concentration in pre‐ and postpartum dairy cows,and its association with body condition,hock health,and reproductive status

The objective of this study was to investigate the profiles of hair cortisol concentrations as an index of chronic stress in dairy cows in association with their health, nutrition, and reproductive parameters. For 25 Holstein dairy cows, hair was collected from the tail switch ?19.2 ± 11.4, 44.8 ± 11.9, 103.0 ± 9.9, and 168.0 ± 9.7 days postpartum (L0, L1, L2, and L3, respectively). Body condition scores were negatively correlated with hair cortisol concentrations (r = ?0.255), and hock health scores were positively correlated with hair cortisol concentrations (r = 0.236, p < 0.05). Hair cortisol concentrations during the postpartum period showed different patterns according to the time of first artificial insemination (AI) and fertility. Cows that were submitted to first AI by 86 days postpartum showed a peak hair cortisol concentration at L1, whereas cows with delayed first AI had a peak at L2. The hair cortisol concentrations of subfertile (≥168 days) cows were significantly higher at L1 and L2 compared with L0, whereas hair cortisol concentrations of fertile cows (<168 days) were not different among the sampling times. These results indicate that cows with health problems appear to experience greater chronic stress, which may impair their reproductive function.     

Preliminary findings of altered follicular activity in Holstein cows with coagulation factor XI deficiency

Factor XI (F XI) deficiency is an autosomal recessive coagulopathy found in Holstein cattle. Affected animals have a 50% greater prevalence of repeat breeding. Therefore, several parameters describing ovarian function were studied. Daily blood sampling revealed that progesterone concentrations were slower to decline from a peak at day 16 (p<0.01) to values less than 3 nmol/L in F XI-deficient cows (5.14±0.69 days (mean ± SD) versus 4.05±0.63 days in control animals), resulting in an oestrous cycle length of 24.7±2.1 days compared to 22.9±3.0 days, respectively. This was not due to an alteration in the availability of prostaglandin F₂ (PGF₂) or oxytocin (OT) involved in luteolysis. No significant differences (p>0.05) were seen between normal (n=7) and F XI-deficient (n=7) cows in the peak values or the area under the curve for the pulse in 13,14-dihydro-15-keto PGF₂ in response to OT challenge or in the parameters describing the pulse of ovarian OT secretion after PGF₂ injection (n=7 for each) between days 12 and 14. Ovulatory follicular development was assessed by ultrasound monitoring and plasma 17-oestradiol values at 8-h intervals after a luteolytic injection of cloprostenol (n=6 for each). Follicular diameter was smaller (p<0.05) and accompanied by lower peak oestradiol values near the time of ovulation in F XI-deficient cows. The results suggest that the oestrous cycle in F XI-deficient cows is characterized by a slower process of luteolysis that may be associated with smaller follicular development.Abbreviations F XI factor XI - OT oxytocin - PGF₂ prostaglandin F₂ - PGFM 13,14-dihydro-15-keto-prostaglandin F₂ - i.m. intramuscularly     

Effect of dystocia on subsequent reproductive performance and functional longevity in Holstein cows

The objective of this study was to evaluate the effect of dystocia on the reproductive performance and functional longevity in Iranian Holsteins. Data consisted of 1 467 064 lactation records of 581 421 Holstein cows from 3083 herds which were collected by the Animal Breeding Center of Iran from April 1987 to February 2014. Reproduction traits in this study included interval from first to second calving, days open and days from first calving to first service. The generalized linear model was used for the statistical analysis of reproductive traits. Survival analysis was performed using the Weibull proportional hazards models to analyse the impact of dystocia on functional longevity. The incidence of dystocia had an adverse effect on the reproductive performance of dairy cows. Therefore, reproductive traits deteriorated along with increase in dystocia score (p < 0.05). The culling risk was increased along with increase in the score of dystocia (p < 0.0001). The greatest culling risk was observed in primiparous cows, small herds and low‐yielding cows (p < 0.0001). Also, the lowest culling risk was found for cows calving at the youngest age (<27 months), and cows with age at first calving >33 months had the greatest risk (p < 0.0001). The results of current study indicated that dystocia had important negative effects on the reproductive performance and functional longevity in dairy cows, and it should be avoided as much as possible to provide a good perspective in the scope of economic and animal welfare issues in dairy herds.     

荒漠草地地区伊犁绢蒿分枝数目对放牧强度的响应

试验于2012-2013年在新疆昌吉阿什里乡进行,以新疆荒漠草地典型植物种伊犁绢蒿(Seriphidium transiliense)为研究对象,研究了不放(CK)、轻度放牧(LG)、中度放牧(MG)和重度放牧(HG)下伊犁绢蒿各级分枝数、营养枝和生殖枝的变化规律,通过在生长季内多次采样方法(每30d采样一次),比较不同放牧梯度下各级分枝数数目,营养枝与生殖枝的数目,以揭示伊犁绢蒿构件数目对放牧强度的响应机制。结果表明,各放牧梯度下伊犁绢蒿各级分枝数在CK区表现为二级分枝数一级分枝数,在LG、MG和HG区则表现为分枝级数越高,分枝数越低;营养枝数目也在LG区表现有最大值,占全株分枝数的20.5%以上,营养枝数目的变化趋势为LGCKMGHG;生殖枝数在各放牧处理间与不放牧条件下大部分差异显著(P0.05),变化趋势为CKLGMGHG。     

玉米赤霉烯酮和脱氧血腐镰刀菌烯醇对雌性动物的生殖毒性及作用机制

镰刀菌毒素玉米赤霉烯酮(ZEA)和脱氧血腐镰刀菌烯醇(DON)广泛存在于受污染的谷物和饲料中。体内和体外研究表明,ZEA和DON均可影响雌性动物的繁殖性能,引起生殖器官、胎儿形态,生殖细胞成熟率,性激素分泌的改变。本文综述了ZEA和DON对雌性动物繁殖性能的影响及潜在的作用机制。     

饲粮中添加中链脂肪酸甘油三酯对母猪繁殖性能、血清生化指标及初乳成分的影响

本试验旨在研究母猪妊娠后期和泌乳期饲粮中添加中链脂肪酸甘油三酯(MCT)对母猪繁殖性能、血清生化指标及初乳成分的影响。试验选取120头纯种大白妊娠母猪(3~5胎),根据母猪预产期相近,胎次、体况、历史繁殖成绩均衡分布的原则分为3组,每组40个重复,每个重复1头母猪。对照组饲喂基础饲粮(含3.17%豆油),油剂组以0.6%纯油剂MCT替换基础饲粮中0.6%的豆油(含2.57%豆油),粉剂组在基础饲粮中添加0.5%微胶囊粉剂MCT。试验从母猪妊娠第85天开始至仔猪断奶结束。结果表明:1)与对照组相比,油剂组和粉剂组母猪产程分别提高了17.58%(P0.05)和9.21%(P0.05),母猪泌乳期平均日采食量分别提高了5.92%和10.07%(P0.05),母猪断奶后7日发情率分别提高了6.52%和4.25%(P0.05);饲粮中添加MCT对母猪其他繁殖性能指标无显著影响(P0.05)。2)饲粮中添加MCT对母猪血清生化指标均无显著影响(P0.05)。3)与对照组相比,油剂组和粉剂组母猪初乳乳脂含量分别提高了18.09%和19.09%(P0.05),饲粮中添加MCT对母猪初乳成分均无显著影响(P0.10)。由此可见,在母猪妊娠后期及泌乳期饲粮中添加MCT未能改善母猪的生产性能、血清生化指标及初乳成分,但添加油剂型MCT可显著缩短母猪产程。     

Lipid droplet distribution of immature canine oocytes in relation to their size and the reproductive stage

This study investigated the distribution of lipid droplets (LD) in immature canine oocytes in relation to their size and the reproductive stage. Oocytes were collected from the ovaries of bitches at different estrous stages, divided according to their size (110‐120 µm; >120 µm), and stained with Nile Red to detect lipid droplet distribution. At the follicular phase most of the oocytes displayed a diffuse pattern of LD distribution, whereas at anestrus and luteal phase oocytes showed LD mainly in a peripheral/ perinuclear LD distribution. A significantly higher intensity of LD has been recorded in the oocytes > 120 µm compared to those of smaller size (110 ‐ 120 µm) at all stages of the estrous cycle. At follicular phase, oocytes > 120 µm displayed LD intensity similar to that of oocytes > 120 µm at luteal phase and higher compared to the oocytes of the other groups.     

Zoledronic acid inhibits proliferation and induces apoptosis in U937 cells

AIM: To study the antiproliferation and proapoptotic effects of zoledronic acid(ZOL) on human acute myeloid leukemia cell line U937. METHODS: The viability of U937 cells was detected by CCK-8 assay. The cell cycle of the U937 cells was analyzed by flow cytometry with PI staining. Apoptotic rate was assessed by flow cytometry with Annexin V-PI and Hoechst 33342 staining. Mitochondrial membrane potential was detected by JC-1 assay. Methylcellulose was used to assess colony formation. The protein levels of p21, Bcl-2 and Bax were determined by Western blot. RESULTS: ZOL inhibited the viability of U937 cells. ZOL induced S-phase cell cycle arrest in the U937 cells. The results of flow cytometry analysis with Annexin V-PI and Hoechst 33342 staining showed that ZOL also induced apoptosis in a dose- and time-dependent manner. Mitochondrial membrane potential assay was also used to verify the apoptosis. The apoptotic rate was consistent with the reduction of mitochondrial membrane potential. Colony formation assay showed that ZOL significantly inhibited the colony formation capacity of the U937 cells. This was achieved by the induction of S-phase cell cycle arrest, and up-regulation of Bax and p21, and down-regulation of Bcl-2. CONCLUSION: ZOL inhibits cell proliferation by regulating the expression of cell cycle-related protein, and induces apoptosis via the mitochondrial apoptotic pathway.