A Survey of Farm Management Practices Relating to the Risk Factors, Prevalence, and Causes of Lamb Mortality in Ireland

SIMPLE SUMMARY: A reduction in lamb mortality would benefit farmers both economically and ethically. The major causes of lamb mortality are similar worldwide. Targeting the specific causes can result in reduced lamb mortality. This involves identifying underlying factors associated with lamb mortality and subsequently recommending changes to management practices. The objective of this study was to investigate the risk factors associated with lamb mortality on Irish sheep farms to provide a greater understanding of the necessary management practices required to reduce lamb mortality. This was achieved by identifying relationships between on-farm practices and risk factors of lamb mortality associated with these practices. Predators, lamb birth weight, and diseases were perceived by farmers to be the main causes of lamb mortality. Individual lambing pens were used on most sheep farms but were not cleaned and/or disinfected on 26% of them. Lamb mortality tended to be lower on farms that used best-known practices. Full-time farmers that used hospital and individual pens had a higher gross margin (€18/ewe). Management systems affect both lamb mortality and flock gross margin. Every 1% decrease in average lamb mortality across Irish flocks is worth ~€3 million annually to the Irish sheep sector. ABSTRACT: Lamb mortality is a key factor influencing ewe productivity and profitability. The current study investigated risk factors associated with and management practices implemented on sheep farms to reduce lamb mortality. A survey consisting of 13 multiple-part questions (57 separate questions) was administered to all sheep farmers participating in the Teagasc National Farm Survey, representative of the Irish national population of sheep farms. A total of 60% of respondents identify mating or lambing date, and this practice tended to be associated with reduced lamb mortality (1.2%, p = 0.08). Individual lambing pens were used by 88% of farmers, but 26% did not clean or disinfect them. A total of 79% and 9.5% of farmers applied iodine to all lambs’ navels and administered antibiotics to all lambs to treat and/or prevent diseases, respectively. Most farmers vaccinated their ewes (86%) and lambs (79%) against clostridial diseases and/or pasteurellosis; 13% vaccinated against abortion agents. Lamb mortality tended to be lower (Kruskal–Wallis (KW) = 2.749; p = 0.09) on farms that used stomach tubing, heat box, iodine, hospital, and individual pens compared with farms that do not implement all those practices. Predators, lamb birth weight, and diseases were perceived by respondents to be the three main causes of live-born lamb mortality. The gross margin is significantly higher on lowland farms by €37 per ewe compared with hill farms (Kruskal–Wallis (KW) = 4.056; p < 0.001). The combination of full-time farming and the use of hospital and individual pens improved gross margin (€18/ewe, p = 0.028). It is concluded that on-farm management practices affect both lamb mortality and flock gross margin.