以遗传潜力推算最佳生长及经济效益的生猪饲料配方及自动化饲喂计划

饲养策略是针对整个猪群,这必然会导致自然资源的低效利用,甚至可能会扩大猪在屠宰时的个体差异。通过管理猪群均匀度做到精准饲喂有助于提高动物生产系统的效率。这个解决办法依赖于对营养供给与动物生产性能之间的精准预测、生产性能的持续监测和调节营养供给的饲喂系统。     

第三章 用采食行为评估动物福利(续完)

正4知识缺口和未来研究需求4.1反刍动物目前,人们对反刍动物放牧时的行为需求知之甚少。因此,在不考虑营养方面的条件时,反刍动物不进行放牧,而在室内向其提供全价混合日粮(Total Mixed Ration,TMR)日粮,这种方式是否对动物福利来说会更好,还需要进一步研究。反刍动物在采食习惯上具有天生的选择性,并且在某些情况下能够选择混合饲料中的某些成分,以最大限度提高自身的健康和生产力。研     

两种欧盟批准的动物饲料添加剂在商业养殖条件下对断奶后仔猪的作用比较

试验旨在研究二甲酸钾(KDF)和苯甲酸(BA)对断奶后仔猪生产性能的影响。两种添加剂都被欧盟批准作为动物饲料添加剂用于猪。KDF (添加量0.6%)和BA(添加量0.5%)分别用于2×240头断奶后仔猪(断奶日龄28 d,大白×长白×皮特兰)直至42日龄。自由采食(饲料含17.8%粗蛋白)和饮水。仔猪圈栏饲养,每处理组10栏(始重7.8 kg)。试验数据统计分析以P0.05作为显著性水平。结果表明:试验结束时二甲酸钾处理组仔猪日均采食量极显著多于正对照组(分别为346 g和294 g),同时平均日增重也显著提高了40 g (分别为315 g和273 g)。但两组的饲料转化率没有发现统计学差异。由此可见,与正对照组相比,二甲酸钾更能促进仔猪的生长性能。     

Changes in various metabolic parameters in blood and milk during experimental Escherichia coli mastitis for primiparous Holstein dairy cows during early lactation

Background:The objective of this study was to characterize the changes in various metabolic parameters in blood and milk during IMI challenge with Escherichia coli(E.coli) for dairy cows during early lactation.Thirty,healthy primiparous Holstein cows were infused(h = 0) with-20-40 cfu of live ? coli into one front mammary quarter at ~4-6wk in lactation.Daily feed intake and milk yield were recorded.At-12,0,3,6,12,18,24,36,48,60,72,96,108,120,132,144,156,168,180 and 192 h relative to challenge rectal temperatures were recorded and quarter foremilk was collected for analysis of shedding of E.coli.Composite milk samples were collected at-180,-132,-84,-36,-12,12,24,36,48,60,72,84,96,132 and 180 h relative to challenge(h = 0) and analyzed for lactate dehydrogenase(LDH),somatic cell count,fat,protein,lactose,citrate,beta-hydroxybutyrate(BHBA),free glucose(fglu),and glucose-6-phosphate(G6P).Blood was collected at-12,0,3,6,12,18,24,36,60,72,84,132 and 180 h relative to challenge and analyzed for plasma non-esterified fatty acids(NEFA),BHBA and glucose concentration.A generalized linear mixed model was used to determine the effect of IMI challenge on metabolic responses of cows during early lactation.Results:By 12 h,E.coli was recovered from challenged quarters and shedding continued through 72 h.Rectal temperature peaked by 12 h post-challenge and returned to pre-challenge values by 36 h post-IMI challenge.Daily feed intake and milk yield decreased(P 0.05) by 1 and 2 d,respectively,after mastitis challenge.Plasma BHBA decreased(12 h;P 0.05) from 0.96 ± 1.1 at 0 h to 0.57 ±0.64 mmol/L by 18 h whereas concentration of plasma NEFA(18 h) and glucose(24 h) were significantly greater,11 and 27%,respectively,after challenge.In milk,fglu,lactose,citrate,fat and protein yield were lower whereas yield of BHBA and G6 P were higher after challenge when compared to pre-challenge values.Conclusions:Changes in metabolites in blood and milk were most likely associated with drops in feed intake and milk yield.However,the early rise in plasma NEFA may also signify enhanced adipose tissue lipolysis.Lower concentrations of plasma BHBA may be attributed to an increase transfer into milk after IMI.Decreases in both milk lactose yield and%after challenge may be partly attributed to reduced conversion of fglu to lactose.Rises in G6 P yield and concentration in milk after challenge(24 h) may signify increased conversion of fglu to G6 P.Results identify changes in various metabolic parameters in blood and milk after IMI challenge with E.coli in dairy cows that may partly explain the partitioning of nutrients and changes in milk components after IMI for cows during early lactation.     

Carbon stock and rate of carbon sequestration in Dipterocarpus forests of Manipur,Northeast India

We examined the carbon stock and rate of carbon sequestration in a tropical deciduous forest dominated by Dipterocarpus tuberculatus in Manipur,North East India.Estimation of aboveground biomass was determined by harvest method and multiplied with density of tree species.The aboveground biomass was between18.27–21.922 t ha-1and the carbon stock ranged from9.13 to 10.96 t C ha-1across forest stands.Aboveground biomass and carbon stock increased with the increase in tree girth.The rate of carbon sequestration varied from1.4722 to 4.64136 t ha-1year-1among the dominant tree species in forest stands in tropical deciduous forest area.The rate of carbon sequestration depends on species composition,the density of large trees in different girth classes,and anthropogenic disturbances in the present forest ecosystem.Further work is required to identify tree species having the highest potential to sequester CO2 from the atmosphere,which could lead to recommendations for tree plantations in a degraded ecosystem.     

环境强化增加结肠癌模型的周细胞和IgA依赖型伤口修复能力和寿命长度

环境强化(Environmental enrichment,EE)多次被证实具有身心治疗作用,通过为实验动物提供复杂的居住条件,能够改善它们的活跃度、行为和交互能力。使用Tcf4Het/+ApcMin/+介导的结肠肿瘤发生模型,发现EE显著改善了肿瘤小鼠的存活率,EE对小鼠肿瘤负荷的影响性别差异。Tcf4Het/+ApcMin/+雄性小鼠的循环型炎性细胞因子和诱导型核激素受体(NHR)信号表达显著降低,这两者都是伤口修复过程中的常见因子。有趣的是,EE激活了肿瘤伤口修复能力,该过程是通过血运重建,浆细胞募集和IgA分泌,在伤口修复过程中利用周细胞更换腺体肿瘤结构,使肠道微生物菌群正常化。EE依赖性变化可能是Tcf4Het/+ApcMin/+介导的结肠肿瘤雄性小鼠存活率显著改善的重要基础。本研究凸显了EE在未来设计结肠癌患者治疗策略中的重要作用。     

稻米壳发电用于印度最贫困省

印度贫困地区发现一种新的发电方式,并从中得到安慰。一位名叫Manoj Shinha的可再生能源企业家,开拓性地使用废弃稻米壳作为生物给料来为印度最贫穷的省邦之一比哈尔邦提供电力。