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121.
乌鸡黑色素在果蝇体内排铅解毒的研究 总被引:2,自引:0,他引:2
以黄体果蝇为实验动物,研究2种乌鸡黑色素添加水平(0.02mg/mL和0.2mg/mL)对果蝇在高铅(2mg/mL)条件下平均寿命和体内铅含量的影响。结果表明:乌鸡黑色素能显著提高果蝇的平均寿命(P<0.05),延寿率达70.2%和54.9%。与阳性对照(1262.0±363.1)μg/g相比,添加0.2mg/mL黑色素能显著(P<0.05)降低果蝇体内铅含量(949.7±38.4)μg/g达32.9%。因此,乌鸡黑色素对果蝇具有一定排铅解毒作用。 相似文献
122.
本试验旨在以玉米为样本筛选用绵羊小肠液冻干粉测定精饲料瘤胃非降解残渣淀粉小肠消化率的最佳培养条件。分别研究了小肠液冻干粉用量(0.2、0.3、0.4、0.5和0.6g)对16h玉米瘤胃非降解残渣干物质和淀粉小肠消化率的影响;离体培养时间(4、8、12、16、20和24h)对16h玉米瘤胃非降解残渣干物质和淀粉小肠消化率的影响。结果表明,在本试验条件下,绵羊小肠液冻干粉测定玉米瘤胃非降解残渣淀粉小肠消化率的最佳用量为0.45g小肠液冻干粉/0.56g玉米瘤胃非降解残渣,最佳培养时间为12h。利用绵羊小肠液冻干粉测定常用饲料过瘤胃残渣淀粉小肠消化率的方法是可行的。 相似文献
123.
124.
经过对加利福尼亚兔进行3个世代纯种选育后,繁殖性能有了明显的改善。三世代窝产仔数、产活仔数、35日龄断奶窝重分别为7.73只、7.33只、3733.64g,分别较零世代提高10.4%、11.6%和69.8%,在CP16.13%、CF14.5%的中等偏下营养条件下,四世代77日龄体重达1915g,35~77日龄日增重为27.11克,屠宰率达56.2%,兔群整齐度有明显的改善。 相似文献
125.
从5000余只杂种兔中,按公母比例1∶8选择300余只体重大、产毛量高的个体进行横交固定,经过4个世代的选育,兔只(11月龄)平均体重达5386克,年产毛量1424克,粗毛率11.74%,结块率2.24%,胎产活仔7.26只,料毛比43∶1。种兔外貌特征一致,遗传性能稳定。现有核心群种兔1200只,繁殖群7200只,生产群2.5万余只,向省内外推广繁育28万只,各项生产指标均达到或超过预定标准及全国家兔育种委员会制定的“德系长毛兔种兔鉴定标准”和“粗毛型长毛兔的选育指标”。 相似文献
126.
H.W. Brooks G.A. Hall A.J. Wagstaff A.R. Michell 《Veterinary journal (London, England : 1997)》1998,155(3):263-274
This paper examines the possibility that treatment of diarrhoea with conventional oral rehydration solutions (ORSs) may be detrimental to villus structure by imposing nutrient deprivation and that such detrimental effects may be reduced or avoided by using a nutrient ORS. A conventional WHO-type ORS (W) was compared with two nutrient solutions (N and G) both containing high glucose concentrations and the latter containing glutamine; their effects on enteric structure were assessed by morphometric analysis of samples obtained from diarrhoeic calves after 96h treatment. Comparisons were also made with samples from controls and diarrhoeic calves at the stage where oral rehydration would have begun in the treated groups. As in our previous ORS studies, diarrhoea was induced with enterotoxigenic Escherichia coli (09:K30:K99). We measured villus length and width, crypt depth and width and calculated villus surface area in proximal, mid and distal small intestine (PSI, MSI, DSI), using standard morphometric techniques. Proximal and distal spiral colon samples (PC, DC) were examined for crypt depth and width; mitoses per crypt were counted in samples from all regions. Non-diarrhoeic calves showed the expected gradient of villus length through PSI, MSI and DSI, hence data for each region are normalized as a percentage of the control value for that region. PSI showed the greatest loss of villus length and surface area (50%) with diarrhoea. In MSI and DSI the villus loss was greater with solution W and N or G, as were increased mitoses and crypt depth. Crypt depth and mitoses also increased in the colon with solution W. Colonic crypt width increased with diarrhoea and conventional oral rehydration but less so with G; there is reason to believe that such changes have functional significance. Crypt changes in colon, MSI and DSI were least with solution G. The changes developing in diarrhoeic calves prior to treatment were thus less apparent in those treated with a nutritional ORS, particularly if it contained glutamine. 相似文献
127.
The experiment was conducted to study the effects of yeast culture on growth performance, meat quality and intestinal microflora of broilers. A total of 432 1-day-old AA commercial broiler chicks with initial body weight of (41.73±0.15)g were randomly divided into 4 groups with 6 replicates per group and 18 broilers per replicate,receiving diets supplemented with 0,0.1%,0.2% and 0.3% yeast culture, respectively. The trial lasted for 42 days which was divided into two periods with 1 to 21 d and 22 to 42 d,respectively.The feed intake,body weight,death and culling rate were recorded in each period. At the end of the experiment,1 chickens in each replicate with the weight close to the average value were slaughtered after fasting for 12 h. The slaughter performance and intestinal microflora counts were determined.The results showed that compared with control group,the supplementation of 0.2% and 0.3% yeast culture significantly increased the body weight at 42 d and the average daily gain (ADG) during the whole trial (P< 0.05).The diet supplemented with 0.2% yeast culture significantly improved the ADG,decreased the F/G of broilers during 22 to 42 d (P< 0.05),and it also significantly increased the average daily feed intake (ADFI) and ADG (P< 0.05),decreased the F/G of the whole period (P< 0.05).Moreover,the supplementation of 0.2% yeast culture significantly decreased the drip loss of meat and the count of Escherichia coli (P< 0.05),and significantly increased the count of Bifidobacterium(P< 0.05). In summary, the supplementation of 0.2% yeast culture could significantly improve the growth performance and the muscle quality of broilers.The intestinal microflora in broiler cecum were effectively optimized after inclusion of yeast culture in the study. 相似文献
128.
比较了热激、酸化和隔绝氧气3种处理对木薯采后生理性变质的影响,结果显示,热激和酸化都能在一定程度上延缓木薯PPD的发生,隔绝氧气是最为理想的抑制木薯PPD发生的方法。因此,通过过量表达或者干扰某些基因表达,降低以至于去除伤口处的氧气的方法将是防治木薯采后生理性变质的有效途径。 相似文献
129.
提出了利益均衡机制的构造框架:研究目标、政企分开的基础研究,政企分开时银行、企业、政府三方决策过程研究,政企分开后的效果评价、实证研究、关键问题,提出了相应的构建思路. 相似文献
130.
南方鲇源豚鼠气单胞菌胞外产物活性与致病性研究 总被引:4,自引:0,他引:4
采用琼脂扩散法测定了南方鲇源豚鼠气单胞菌胞外产物酶活性和溶血活性,同时对胞外产物的细胞毒性和其致病性进行了研究。结果显示:南方鲇源豚鼠气单胞菌胞外产物具有蛋白酶、脂酶、明胶酶和脲酶活性,但不具有淀粉酶和卵磷脂酶活性,具有很强的溶血活性和细胞毒性。肌肉注射感染发现,其对南方鲇有强致病性,其LD50为每千克鱼体重0.802 mg;注射后的南方鲇肌肉、心、肝、肾、脾、肠和胃等组织发生了严重组织病理变化,骨骼肌和心肌坏死断裂,炎症细胞浸润;肝脏严重空泡变性;肾小管上皮细胞变性、坏死、间质内大量炎症细胞浸润;脾充血、出血,淋巴细胞减少,胃肠黏膜上皮细胞变性、坏死、脱落。 相似文献