Van Eenige M J E M, Counotte G H M, Noordhuizen J P T M
InterACT Agrimanagement BV, Elahuizen, The Netherlands.
Tijdschr Diergeneeskd. 2013 Feb 1;138(2):86-97, 99.
Drinking water can be considered an essential nutrient for dairy cattle. However, because it comes from different sources, its chemical and microbiological quality does not always reach accepted standards. Moreover, water quality is not routinely assessed on dairy farms. The microecology of drinking water sources and distribution systems is rather complex and still not fully understood. Water quality is adversely affected by the formation of biofilms in distribution systems, which form a persistent reservoir for potentially pathogenic bacteria. Saprophytic microorganisms associated with such biofilms interact with organic and inorganic matter in water, with pathogens, and even with each other. In addition, the presence of biofilms in water distribution systems makes cleaning and disinfection difficult and sometimes impossible. This article describes the complex dynamics of microorganisms in water distribution systems. Water quality is diminished primarily as a result of faecal contamination and rarely as a result of putrefaction in water distribution systems. The design of such systems (with/ without anti-backflow valves and pressure) and the materials used (polyethylene enhances biofilm; stainless steel does not) affect the quality of water they provide. The best option is an open, funnel-shaped galvanized drinking trough, possibly with a pressure system, air inlet, and anti-backflow valves. A poor microbiological quality of drinking water may adversely affect feed intake, and herd health and productivity. In turn, public health may be affected because cattle can become a reservoir of microorganisms hazardous to humans, such as some strains of E. coli, Yersinia enterocolitica, and Campylobacter jejuni. A better understanding of the biological processes in water sources and distribution systems and of the viability of microorganisms in these systems may contribute to better advice on herd health and productivity at a farm level. Certain on-farm risk factors for water quality have been identified. A practical approach will facilitate the control and management of these risks, and thereby improve herd health and productivity.
饮用水可被视为奶牛的一种必需营养素。然而，由于其来源不同，其化学和微生物质量并不总是能达到公认标准。此外，奶牛场通常不会对水质进行常规评估。饮用水源和分配系统的微生态相当复杂，目前仍未被完全了解。分配系统中生物膜的形成会对水质产生不利影响，生物膜会成为潜在致病细菌的持久储存库。与这类生物膜相关的腐生微生物会与水中的有机和无机物质、病原体甚至彼此相互作用。此外，水分配系统中生物膜的存在使得清洁和消毒变得困难，有时甚至无法进行。本文描述了水分配系统中微生物的复杂动态。水质下降主要是粪便污染的结果，而在水分配系统中因腐败导致水质下降的情况很少见。此类系统的设计（有无防回流阀及压力情况）以及所使用的材料（聚乙烯会促进生物膜形成；不锈钢则不会）会影响其所提供水的质量。最佳选择是开放式漏斗形镀锌饮水槽，可能配备压力系统、进气口和防回流阀。饮用水微生物质量差可能会对采食量、畜群健康和生产力产生不利影响。反过来，公共卫生也可能受到影响，因为牛可能成为对人类有害的微生物的储存宿主，例如某些大肠杆菌菌株、小肠结肠炎耶尔森菌和空肠弯曲菌。更好地了解水源和分配系统中的生物过程以及这些系统中微生物的生存能力，可能有助于在农场层面就畜群健康和生产力提供更好的建议。已经确定了一些农场层面影响水质的风险因素。一种切实可行的方法将有助于控制和管理这些风险，从而改善畜群健康和生产力。
