不同蛋白质来源对早期断奶犊牛消化及血清生化指标的影响(一)

本文研究了不同蛋白质来源代乳品对早期断奶犊牛生长发育、常规营养物质消化率及部分血清代谢指标的影响.选取15头新生健康荷斯坦犊牛分为3组,分别饲喂乳蛋白和植物性蛋白质比例为80:20、50:50及20:80的代乳品,记为S20、S50及S80组.结果表明,S80组犊牛的总增重、平均日增重均低于其余2组,但统计上差异不显著(P>0.05);3组犊牛全程平均日增重分别为465、436和331 g/d.不同蛋白质来源对日粮常规营养素表观消化率无显著影响(P>0.05).但S80组略低.犊牛血清总蛋白(total protein,TP)含量在整个试验期内保持平稳,试验结束时S50组血清TP含量略高于其余2组,但差异不显著(P>0.05).3组犊牛血清尿素氮(serum u-rea nitrogen,SUN)含量随日粮植物性蛋白质含量的升高而上升,试验结束时S80组显著高于S20组(P<0.05).结果提示,利用植物性蛋白质代乳品饲喂早期断奶犊牛未对其增重产生不利影响,初生2～3周龄后的犊牛可以有效利用代乳品中的植物性蛋白质.     

不同蛋白质来源对早期断奶犊牛胃肠道形态发育的影响(二)

本文研究代乳品中不同蛋白质来源对早期断奶犊牛胃肠道形态结构发育的影响.选取15头2～8周龄的新生荷斯坦犊牛随机分为3组,分别饲喂乳蛋白和植物性蛋白比例分别为80∶20、50∶50及20∶80的代乳品,记为S20、S50、S80组.结果表明:蛋白质来源影响犊牛胃肠道器官与犊牛体重的比值,其中瘤网胃相对比重随日粮植物性蛋白含量升高而上升,皱胃则与之相反,但差异均不显著(P>0.05);肝脏、胰脏的相对比重随植物性蛋白含量升高而降低.日粮植物性蛋白含量增加可促进犊牛瘤网胃的发育,通过切片观察发现S80组犊牛瘤胃乳头高度较高、呈舌状或圆筒状、上皮颜色较深,该组犊牛瘤胃功能发育较好.不同蛋白质来源影响犊牛肠道的绒毛形态,但不显著影响肠道绒毛高度与隐窝深度的比值(P>0.05),小肠各段的比值均在3.0～4.7之间.上述结果表明,利用植物性蛋白代乳品饲喂早期断奶犊牛可以一定程度上刺激瘤胃发育,并未对肠道绒毛造成严重影响.     

淹水胁迫及胁迫解除对甜瓜幼苗呼吸等生理代谢的影响

以耐涝性稍强的脆禧和耐涝性较弱的世纪蜜甜瓜品种为材料,采用双套盆法研究半淹水、全淹水胁迫（1 d 和3 d） 及恢复（1、3、5 d）对甜瓜幼苗呼吸等生理代谢的影响。结果表明：与进行常规水分管理的对照相比,淹水胁迫降低了甜 瓜幼苗根系鲜质量、干质量和根系活力,且全淹处理的抑制作用更加显著。淹水胁迫提高了无氧呼吸乳酸脱氢酶（LDH）和 乙醇脱氢酶（ADH）活性,降低了有氧呼吸苹果酸脱氢酶（MDH）和琥珀酸脱氢酶（SDH）活性,耐涝性较弱的世纪蜜的 降低幅度大于耐涝性稍强的脆禧;淹水胁迫后2 个品种中超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT） 活性总体呈升高趋势。因此,淹水胁迫使甜瓜幼苗有氧呼吸受到阻碍,同时促进了无氧呼吸代谢,最终导致根系生长受到抑 制,且世纪蜜受到抑制程度大于脆禧。     

Effect of high-fructose diet on adipose tissue renin-angiotensin system in rats

AIM: To observe the effects of high-fructose diet on adipose tissue inflammation and renin-angiotensin system (RAS), and to reveal the role of Toll-like receptor 2 (TLR2) in this process.METHODS: Male SD rats (n=16) were randomly divided into control group, high fructose group, high fructose+siRNA negative control group, and high fructose+TLR2-siRNA group. The rats in control group were fed with a standard chow diet. The rats in high fructose group were fed with a diet with 60% fructose, and the rats in high fructose+TLR2-siRNA group and high fructose+siRNA negative control group were transfected with TLR2 siRNA and scrambled siRNA, respectively. Serum uric acid was measured and visceral adipose tissue was weighed at the 14th week. The levels of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), angiotensinogen (AGT), and angiotensin Ⅱ (Ang Ⅱ) were measured by ELISA. Infiltrating macrophages in the adipose tissues were measured with immunohistochemistry. The mRNA expression of IL-6, TNF-α, monocyte chemoattractant protein-1 (MCP-1), AGT, angiotensin-converting enzyme 1 (ACE1), angiotensin Ⅱ type 1 receptor (AT1R), and angiotensin Ⅱ type 2 receptor (AT2R) was detected by RT-qPCR. The protein level of TLR2 was determined by Western blot.RESULTS: High fructose-fed rats showed elevated serum uric acid, raising fat content, higher serum concentrations of IL-6, TNF-α, AGT and AngⅡ, and more infiltrating macrophages in the adipose tissues (P<0.05). Moreover, the mRNA levels of IL-6, TNF-α,MCP-1, AGT, ACE1, AT1R and AT2R in the adipose tissues were increased (P<0.05). When high fructose-fed rats were transfected with TLR2-siRNA, the dramatic decreases in TLR2 protein level and number of infiltrating macrophages in the adipose tissues were found. Both in serum and adipose tissues, the mRNA levels of inflammatory cytokines and RAS components were all significantly decreased (P<0.05).CONCLUSION: High-fructose diet up-regulates RAS in adipose tissues via activation of TLR2 inflammation signaling pathway.     

Effect of Zhengtian pills on P2X3 receptor expression in trigeminal gan-glion of migraine rats

AIM: To explore the effect of Zhengtian pills on P2X₃ receptor expression in trigeminal ganglion (TG) of migraine rat. METHODS: Sprague-Dawley (SD) rats were randomly divided into control group, migraine group, Zhengtian pills (ZTP) group and A-317491 group. After given corresponding drugs for 7 d, migraine rat model was established by subcutaneously injection of nitroglycerin (10 mg/kg), while the control rats were injected with saline. The beha-vioral manifestations of the rats were observed. The expression of P2X₃ receptor in rat TG was detected by the methods of immunofluorescence, Western blot and rea-time PCR. RESULTS: About 5 min after subcutaneousl injection, the behavioral manifestations such as scratching head and climbing cage were observed. The behavioral manifestations were observed within the first 30 min in control group, but the erythroid ears did not appear. After 2 h of molding, the behavioral manifestations disappeared in ZTP group and A-317491 group, while those in migraine group lasted for 3 h. Immunofluorescence results showed that the expression of P2X₃ receptor in TG was positive in each group. The expression level in migraine group was significantly higher than that in other groups. The P2X₃ receptor protein and mRNA levels in the TG of migraine group were higher than those in control group (P<0.01), while those in ZTP group were lower than those in migraine group (P<0.01). No difference of the P2X₃ receptor expression between ZTP group and A-317491 group was observed. CONCLUSION: Zhengtian pills may effectively alleviate migraine by inhibiting the expression of P2X₃ receptor in TG.     

北方高位池养殖模式存在的问题及发展方向

目前北方高位池养殖模式正处于发展阶段,借鉴南方高位池养殖模式的建设,北方高位池主要采用覆膜高位池养殖模式,具有高产量、高投入、高收益的特点.介绍了北方高位池养殖模式的发展,分析了高位池养殖模式发展中存在的问题.最后,根据北方地区的实际情况,提出了3种创新健康生态高位池养殖模式.     

甘氨酸对水貂GV期卵母细胞冷冻保存效率的影响

试验旨在探究玻璃化冷冻及培养过程中添加甘氨酸（glycine，Gly）对水貂GV期卵母细胞冷冻解冻后存活率、核发育、线粒体和皮质颗粒分布的影响。试验分为3组：对照组（没有进行冷冻处理）、冷冻组和Gly添加处理组（1 mmol/L Gly）。对玻璃化冷冻解冻后的水貂GV期卵母细胞分别进行平衡恢复3 h和体外成熟培养，采用免疫荧光标记法检测各组GV期卵母细胞线粒体分布的差异及MⅡ期皮质颗粒分布的变化。结果显示，Gly添加处理组卵母细胞在解冻后3 h的存活率与冷冻组相比差异不显著（P>0.05），但显著低于对照组（P<0.05）；Gly添加处理组卵母细胞的减数分裂恢复率显著高于冷冻组（P<0.05），但与对照组相比差异不显著（P>0.05）。免疫荧光结果显示，Gly添加处理组的GV期卵母细胞线粒体正常分布率显著高于冷冻组（P<0.05），但Gly添加处理组和冷冻组的GV期卵母细胞线粒体正常分布率均显著低于对照组（P<0.05）。皮质颗粒分布结果显示，水貂GV期卵母细胞在冷冻后体外成熟培养至MⅡ期时，Gly添加处理组皮质颗粒的正常皮质区分布比例显著高于冷冻组（P<0.05），但Gly添加处理组与冷冻组的正常皮质区分布比例均显著低于对照组（P<0.05）。结果表明，添加Gly可以提高冻融后水貂卵母细胞的减数分裂恢复率，降低冷冻对其线粒体及皮质颗粒的损失。     

"谷子糜子育种"专题导读:十五年区试数据分析展示谷子糜子育种现状

谷子（Setaria italica Beauv.）和糜子（Panicum miliaceum L.）是中国起源的古老粟类作物，在旱作生态可持续农业建设和种植业结构调整中具有重要作用，也是应对未来更加干旱环境的战略储备作物。自2001年到2015年，全国农技中心组织国家谷子糜子区域试验，对这个时期培育的谷子糜子品种的产量、适应性和品质进行综合鉴定，积累这个时期谷子糜子育成品种的产量和农艺性状表现的基础数据。本期《中国农业科学》发表了6篇对过去10—15年谷子糜子育成品种产量和农艺性状表现的分析评价文章，这些文章从整体上梳理了中国华北夏谷区、西北早熟区、西北中晚熟区、东北春谷区和糜子育成品种的产量水平、育种进步的性状和存在问题等，也提出了近期及将来的育种目标。本文是对这6篇文章进行的简评，希望能引导这6篇文章的深入研读。谷子糜子育种的突破有赖于关键性亲本的发现、创制和利用，以及有益产量性状累加育种技术的突破；商品性优质、食味优质、功能性优质专用和中矮秆适合机械化轻简化栽培应成为谷子糜子育种最应关注的重点方向。     

Process Optimization of Bacillus subtilis fermented Rose laevigata michx

The aim of this experiment was to study the optimum process of Rose laevigata michx fermented by Bacillus subtilis. The process of Bacillus subtilis fermented Rose laevigata michx was optimized by test method combining single factor and response surface.The Rosa laevigata michx polysaccharide content was chosen as indexes and the key factors which had greater impact on ferment effect were selected from carbon source,nitrogen source,water content,inoculation amout and fermentation time for further optimize by response surface. The results showed that water content,inoculation amount and fermentation time were the key factors among the five single factors. When the water content was 53.79%,inoculation amount was 5.74%,fermentation time was 2 days,the average content of Rosa laevigata michx polysaccharide was 15.47% which closed to predicted value (15.36%).Compared with the polysaccharide content in unfermented Rosa laevigata michx,that of fermented Rosa laevigata michx was increased 47.47%. The fermentation process was simple and easy to operate with remarkable fermentation effect,and it could provide theoretical basis for the development of the green feed additive.