The production of short chain fatty acid and colonic development in weaning piglets

Weaning process widely affects the small intestinal structure and function in piglets, while the responses of large intestine to weaning stress are still obscure. The purpose of this study was to determine the developmental changes (i.e., short chain fatty acids (SCFAs) concentrations, growth parameters, crypt‐related indices and antioxidant capacity) in colon of piglet during weaning. Forty piglets were weaned at day 21 and euthanized to collect colonic tissues and digesta samples on day 0, 1, 3, 7 and 14 post‐weaning (n = 8). Piglet growth performance was improved (p < .001) on day 7 and 14 post‐weaning. The concentrations of acetate, propionate, butyrate, valerate, isobutyrate, isovalerate and total SCFAs were higher (p < .001) during the late post‐weaning period. The mRNA abundances of SCFAs transporters were greater (p < .001) on day 7 and 14. The absolute and relative weights, absolute length and perimeter of colon were greater (p < .001) on day 7 and 14. Similarly, post‐weaning increases (p < .001) in colonic crypt depth and Ki67 positive cells numbers per crypt were observed during the same period. Colonic crypt fission indices decreased (p < .01), while total crypt numbers increased (p < .001) on day 14 after weaning. Moreover, total SCFAs concentration was significantly associated with colonic growth parameters and Ki67 cells/crypt (p < .001). In addition, catalase content was decreased on day 3, 7, and 14, whereas, the concentrations of total superoxide dismutase (T‐SOD) and manganese‐containing superoxide dismutase (MnSOD) were higher (p < .05) on day 1 and 3 post‐weaning. These results showed that weaning process has a significant effect on colonic growth and development, which might be associated with the change of SCFAs concentrations in colon.     

Characterization of Mycobacterium avium subspecies paratuberculosis disseminated infection in dairy cattle and its association with antemortem test results

Mycobacterium avium subspecies paratuberculosis (MAP) disseminated infection in dairy cattle affects animal health and productivity and is also a potential public health concern. The study objectives were to characterize MAP disseminated infection in dairy cattle and to determine the role of antemortem tests in detecting cattle with disseminated infection. Forty culled dairy cows representing a variety of serum enzyme-linked immunosorbent assay (ELISA) results and body conditions were selected for the study. The physical condition of the cows was assessed via clinical examination prior to euthanasia and blood and feces were collected and tested by serum ELISA and fecal culture, respectively. Fifteen tissues were aseptically collected from each cow during necropsy and cultured for isolation of MAP. Disseminated infection was diagnosed when MAP was isolated in tissues other than the intestines or their associated lymph nodes (LNs) and was distinguished from infection found only in the gastrointestinal tissues and from absence of infection. Of the 40 cows in the study, 21 had MAP disseminated infection. Results showed that 57% (12/21) of cows with disseminated infection had average to heavy body condition and no diarrhea. Cows with disseminated infection had no to minimal gross pathologic evidence of infection in 37% (8/21) of cases. Only 76% (16/21) of cows with disseminated infection had positive historical ELISA results and only 62% (13/21) had a positive ELISA at slaughter. Thus, antemortem evidence of MAP infection was lacking in a high proportion of cows where MAP disseminated infection was confirmed.     

不同添加剂对紫花苜蓿拉伸膜裹包青贮饲料品质的影响

为明确葡萄糖、红糖、果渣对紫花苜蓿拉伸膜裹包青贮饲料青贮品质的影响,探明最适合添加于紫花苜蓿裹包青贮的有机添加剂,按照紫花苜蓿原料重量的0.2%、0.4%、10%分别添加葡萄糖、果糖、果渣进行90 d青贮。结果表明:添加葡萄糖可保留紫花苜蓿中更多的干物质,有效提高青贮饲料中的乳酸含量,降低乙酸和丙酸含量;添加红糖不利于青贮饲料pH值的降低和乳酸积累,能产生较高的氨态氮、乙酸和丙酸含量;添加果渣虽然可以降低青贮饲料的pH值,但会造成显著的粗蛋白损失。综合分析认为,添加葡萄糖对提高紫花苜蓿拉伸膜裹包青贮饲料青贮品质效果较好。     

瘤胃灌注不同比例的混合VFA对肉牛瘤胃发酵、能量和氮代谢的研究

以装有瘤胃瘘管的肉牛（３９０±３０ｋｇ）饲喂全羊草的基础日粮,瘤胃灌注４种不同摩尔比例的混合ＶＦＡ（乙酸：丙酸：丁酸为７５∶１５∶１０,６５∶２５∶１０,５５∶３５∶１０和４５∶４５∶１０）,按４×４拉丁方试验设计测定了灌注后代谢产热率（ＨＰ／ＭＥ）,ＶＦＡ转化为体脂肪的效率（Ｋｆ）和可消化氮转化为沉积氮的效率。结果表明,随着灌注混合ＶＦＡ中丙酸比例超过２５％,ＨＰ／ＭＥ明显降低（Ｐ＜００５）,Ｋｆ值极显著地增加（Ｐ＜００１）;可消化氮转化为沉积氮的效率显著增加（Ｐ＜００５）;ＨＰ／ＭＥ与瘤胃中乙酸比例、Ｋｆ值与瘤胃液中丙酸比例均呈线性正相关。     

简析跨国企业的兽药产品及市场特点

本人长期跟踪研究国外上市的兽药新产品,不断研究跨国公司的产品线、研发思路和产品周期等,现总结如下,视作抛砖引玉。1 重点产品数量少,剂型多,销售额巨大目前全球排名第一位的动物保健品公司是梅里亚公司,为什么是梅里亚公司?如果简单分析一下产品,便可知道。1997年,默克公司动物保健部与罗纳梅里厄公司(50:50)合并组成梅里亚公司。1999年,梅里亚公司的总销售额为14.48亿美元,其中阿维菌素类药物的销售额为6.54亿美元,占总销售额的39%(详见表1);非泼罗尼(Fipronil)的销售额为3.15亿美元,占总销售额的21.8%。仅此两种药物,就占1999年总销…     

菊芋的功能及其在食品中的应用

菊芋是一种具有多种生理功能的天然绿色食品,极具开发价值。论述了菊芋的营养功能、生理功能、生态功能及其在食品中的应用。     

雪凝灾后厩肥和尿素对新植鸭茅鲜草产量的影响

2007－2008年进行了厩肥和尿素配合施用对新植鸭茅Dactylis glomerata栽培草地鲜草产量的影响研究,结果表明,在经历了2008年年初持续20多天雪凝灾害之后,6个厩肥和尿素处理组合的鲜草产量差异显著,施厩肥30 000 kg/hm2与施尿素75、175、275 kg/hm2的处理组合的鲜草产量均极显著高于对照,厩肥施用量30 000 kg/hm2的处理组合鲜草产量较高,其中,鲜草产量最高的施肥组合为厩肥30 000 kg＋尿素175 kg/hm2,而最经济的施肥组合应该是厩肥30 000＋尿素75 kg/hm2。     

饲料中添加发酵中药对文昌鸡肝毒性研究

中药渣经微生物发酵可减少抗营养因子,增强功效,试验旨在研究饲料添加发酵中药渣对文昌鸡肝脏毒性影响。试验选用体重、日龄相近文昌鸡(43日龄,母)192只,随机分为4组,每组8个重复,每个重复6只。发酵中药渣添加水平为0%、0.5%、1.0%、1.5%,试验为期4周。结果显示,与组1相比,2、3、4组血清中谷草转氨酶(AST)、总胆红素(TBIL)、葡萄糖(GLU)含量均显著降低(P<0.05)。与组1相比,2、3组肝脏组织AST含量显著升高(P<0.05);3组谷丙转氨酶(ALT)含量显著升高(P<0.05),4组ALT含量显著降低(P<0.05);2、3、4组碱性磷酸酶(AKP)含量显著升高(P<0.05);3、4组肝脏组织中GLU和总蛋白(TP)显著升高(P<0.05)。表明,饲料中添加发酵中药渣可减少文昌鸡肝细胞损伤,促进肝脏的合成代谢和贮备功能,其中以1.0%添加量最适。