Odour Emissions in Broiler Production: Influence of Nutrition, Necrotic Enteritis and Litter Condition

Abstract

<p>Odour emissions have been identified as a potential threat for the sustainable development of the broiler industry. Few of the methods examined to reduce odour emissions from poultry operations have proved effective. The methods including biofilters, litter treatments, neutralising agents, air scrubbers, ozone treatment are either impractical to apply or too costly to use in commercial farms. If diets could be formulated to more closely meet nutrient requirements, there would be reduced excretion of undigested components and lower level of substrates available for microbes to metabolize them to odorous compounds. Diet affects water intake, water to feed intake ratio, litter moisture, litter pH and litter water activity all of which may have an impact on the emission of odorants from the litter. This thesis details the role of diet composition, necrotic enteritis and litter condition on odour emission from broiler production. This thesis includes a comprehensive review on key odorants from broiler production, their origin, analytical techniques for odour measurements and nutritional factors affecting odour emissions. The five chapters that follow investigate the role of phytase enzyme (chapter 2), protein sources (chapter 3), protein levels (chapter 4), probiotic and saponin (chapter 4), litter condition (chapter 4 and 5), necrotic enteritis and high sodium diet (chapter 5) and the effect of <i>Clostridium perfringens</i> culture (chapter 6) on odour emissions. Nutritional strategies such as increasing meat meal in the diet, decreasing dietary protein levels and the addition of a <i>Bacillus subtilis</i> based probiotic and saponin blend may lower odour emission from broiler production. The results also indicate that odour is related to litter condition and if litter moisture content and water activity can be reduced and necrotic enteritis prevented, odour problems can be alleviated in broiler sheds.</p>