Swine veterinarians are exposed to sustained noise levels in swine confinement units, in which noise levels of 95 to 104 decibels (dBA) may be generated during feeding.1 Although research has documented noise-induced hearing loss in pig producers,2 no research has been done to measure the effect of occupational noise on hearing in swine veterinarians. Among the several studies in New York dairy farmers,2–4 two suggest that older males who work on livestock farms without hearing protection are at a higher risk of hearing loss.2,3

Introduction: Interest in assessing the significance of lung lesions in ruminants at slaughter has only recently emerged. Early reports examined the prevalence and effects of lung lesions on cattle performance (Wittum et al., 1995, Bryant et al., 1996). These reports concluded that lung lesions in cattle could be reliably diagnosed by observation at slaughter, and are associated with decreased performance and product quality (Gardner et al., 1999). Only very recently has the biological effect of lung lesions been assessed in fed lambs. These studies indicate that, depending on severity, lung lesions can decrease animal performance. The presence of lung lesions negatively impacts the growth performance of lambs. Lambs with severe lung lesions had reduced daily gain during the last month of the finishing period, a 510% decrease (Goodwin et al., 2001). Affected lambs usually have no history of respiratory disease prior to slaughter, therefore lung lesions represent subclinical (silent) respiratory disease. Lung lesions have been shown to negatively impact growth performance of lambs and eliminate a lamb carcass from the highly valuable Kosher lamb market. Of lambs presented for Kosher slaughter, 2030% are rejected due to lung lesions. Carcasses qualifying for kosher have $5-10 per head in added value, therefore rejection of 20-30% of lambs represents a significant loss to the sheep industry. The cause, timing, and predisposing conditions for development of the lung lesions are unknown, thus limiting the development of intervention plans to prevent lung lesion formation. At present, lung lesions can only be diagnosed at slaughter. Lung lesions are a common condition in lambs, which lower growth performance and potentially decreasing carcass value, thus reducing profits for sheep producers. It is important that work be done to describe and attempt to limit lung lesions in lambs. We have planned a series of studies to determine the microbes associated with lung lesions and the time frame of lesions formation. The risk factors for lung lesion formation and management systems to reduce the incidence of lung lesions will also be investigated. This work features a lifetime approach, starting observations and measurements early in life and concluding at slaughter. We plan to find cost effective strategies to implement on commercial farms/ranches that would limit the effects of lung lesions in lambs. The initial studies described here assess the incidence and effect of lung lesions in lambs produced at the SDSU Sheep Unit.