van Houtert M F, Sykes A R
Animal and Veterinary Sciences Group, Lincoln University, Canterbury, New Zealand.
Int J Parasitol. 1996 Nov;26(11):1151-67. doi: 10.1016/s0020-7519(96)00120-8.
Resistance and resilience of the ruminant host to gastrointestinal (GI) parasitic nematode infections are influenced by many factors, including nutrition. This review examines the effects of host nutrition on the ability of ruminants to withstand GI nematode infections. Firstly the effects of infection on host metabolism are summarised briefly. An important factor in the pathogenesis is a reduction in feed intake by the host. Gut nematodes also increase endogenous protein losses, which result in net loss of amino acids to the parasitised host, though energy and mineral metabolism are also perturbed. The indications are that the major nutritional change is in protein metabolism. Resilience (the ability of an animal to withstand the effects of infection) can be enhanced markedly by increasing metabolisable protein supply and to a lesser extent metabolisable energy supply. Resistance to GI nematodes (ability of host to prevent establishment and/or development of infection) is also influenced by diet, particularly metabolisable protein supply. While there do not appear to be any effects of host nutrition on establishment of infective larvae, the rate of rejection of adult worms can be enhanced by improved nutrition. The exact nutritional requirements or the mechanisms involved are not known. It appears that the effects of improving nutritional status on host resilience are more clearly defined than effects on host resistance. The implication of changes in host resistance with nutritional state for host productivity need to be better described. Understanding the role of nutrition in improving both resistance and resilience of the host to GI parasites will be important if producers are to make better use of host acquired immunity and reduce dependence on pesticides for prophylaxis.
反刍动物宿主对胃肠道（GI）寄生线虫感染的抵抗力和恢复力受多种因素影响，包括营养。本综述探讨宿主营养对反刍动物抵抗胃肠道线虫感染能力的影响。首先简要总结感染对宿主代谢的影响。发病机制中的一个重要因素是宿主采食量减少。肠道线虫还会增加内源性蛋白质损失，这导致被寄生宿主的氨基酸净损失，尽管能量和矿物质代谢也会受到干扰。有迹象表明，主要的营养变化在于蛋白质代谢。通过增加可代谢蛋白质供应，并在较小程度上增加可代谢能量供应，可显著增强恢复力（动物抵抗感染影响的能力）。对胃肠道线虫的抵抗力（宿主预防感染建立和/或发展的能力）也受饮食影响，特别是可代谢蛋白质供应。虽然宿主营养似乎对感染性幼虫的建立没有任何影响，但改善营养可提高成虫的排出率。确切的营养需求或所涉及的机制尚不清楚。改善营养状况对宿主恢复力的影响似乎比对宿主抵抗力的影响更明确。宿主抵抗力随营养状态变化对宿主生产力的影响需要更好地描述。如果生产者要更好地利用宿主获得性免疫并减少对杀虫剂预防的依赖，了解营养在提高宿主对胃肠道寄生虫的抵抗力和恢复力方面的作用将很重要。
