Development of improved disease monitoring tools and management strategies to promote health in finishing pigs

Abstract

This thesis investigated strategies to improve detection and control of disease in finishing pigs. It was found that a disinfection routine in finisher pig housing reduced bacteria on pen surfaces. All-in/all-out systems had lower concentrations of airborne bacteria and ammonia than continuous flow systems, however pig health and productivity did not differ between systems. Serum acute phase proteins (APPs) were significantly related to a reduced average daily gain (ADG) of pigs in the two weeks before slaughter. The lifetime growth of >700 pigs was monitored to explore consequences of early growth on lifetime health and performance. The probability of pigs showing illness later in life was associated with litter size and early growth rate. Early stage differences existed between the growth rate of light and heavy birth weight groups. Oral fluid (OF) was utilised for measurement of APPs, to determine the presence of subclinical disease in pigs. C-reactive protein (CRP) and Haptoglobin (Hp) in the OF of individual pigs was negatively related to their ADG over the finishing period and lifetime respectively. CRP within a pooled OF was negatively related to pen finishing ADG. To collect pooled OF samples from groups of pigs, a single length of rope in a pen of ≤ 25 pigs generated >80% chewing, in 60 minutes. A higher proportion of pigs chewed the rope when housed in a fully slatted system than in a straw system. An interaction occurred between the housing system and the number of ropes provided. Daily water use patterns of finisher pigs were evaluated for early disease detection. The mean daily quantity of water consumed per pig within a given week differed in relation to the severity of scour observed in the following week at a level approaching significance. These findings demonstrate possible techniques to identify disease in the sub-clinical stage.