减少营养损失和提高生长猪可持续性的饲养策略

多年来,利用营养物质养猪的效率有所提高。给猪饲喂能够满足其估算营养需要的饲料可以提高营养物质的利用率,利用率的提高相当于增加养猪生产的经济收益,同时最大限度地改善环境的影响。撰写本文的目的是回顾不同的日粮配伍法对动物营养物质利用率的影响,这些方法能向畜禽提供能够满足其所需营养水平的日粮,同时又能最大限度地减少营养物质的排泄量和温室气体的排放量。调整日粮配方来降低日粮中粗蛋白含量,可帮助畜禽最大限度利用日粮中氮和能量。减少动物生产碳足迹的重要技术是使用养殖场所在地的饲料原料和非人类食用产品(如菜籽粕),并在日粮中添加合成氨基酸。精准的饲喂和营养供给不仅可以通过每天定制畜禽所需的日粮,最大限度地提高动物对营养物质的利用率,还可以降低饲料成本,并提高日粮中氮的利用率。我们利用数学模型研究了减少日粮中粗蛋白水平对氮和能量利用率的影响。与不添加合成氨基酸的对照日粮相比,使用粗蛋白含量减少8%的试验日粮,可使氮利用率提高54%,同时使饲料成本降低11%。由于减少了由蛋白质脱氨基作用引发的能量损失,日粮中粗蛋白含量的同步减少意味着可利用能量有了较大的提高。与对照日粮相比,猪饲喂低蛋白日粮后,通过尿液和后肠发酵引发的能量损失降低了24%。与群体(group phase)饲喂相比,精准的饲喂和营养供给可以使畜禽减少30%的氮排泄量。用低蛋白日粮和精准饲喂技术可使养猪绩效具有相加性,产生61%的氮利用率。猪营养需要量的估算方法还有改进的空间。提高不同个体之间存在营养利用差异的认识,有助于进一步改善养猪生产对环境的影响。

Ochratoxin A:Carryover from animal feed into livestock and the mitigation strategies

This review aims to highlight the effects of ochratoxin A(OTA)in the feed of meat-producing animals.The accumulation of OTA in feed and its distribution in various farm animals were compared and evaluated.Primarily,the oral administration of OTA-contaminated feed and the predisposition in an animal's vital organ were critically examined in this work.The collated reports show that OTA directly associated with endemic nephropathy and its high concentration leads to degeneration of liver cells,and necrosis of intestinal and lymphoid tissues.At present,limited reports are available in the recent liter-ature on the problems and consequences of OTA in feed.Therefore,this review focused on the OTA carryover from feed to farm animals and the interaction of its secondary metabolites on their biochemical parameters.Hence,this report provides greater insights into animal health related to OTA residues in meat and meat products.This article also explores mitigation strategies that can be used to prevent the carryover effects of OTA in livestock feeds and the effects in the food chain.