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Clostridium perfringens, an α-toxin producing gram-positive bacterium, is an enteric pathogen for poultry. Because subclinical C. perfringens infections often result in damage of the intestinal mucosa, decreased nutrient digestion, and poor performance, efforts should be taken to find an effective strategy that controls overgrowth of C. perfringens. For this purpose, the efficacy of a sodium lauroyl lactylate (LauL) as a feed additive to prevent C. perfringens colonization in broilers was determined. First, the effect of LauL was compared with capric and lauric mono- and diglycerides (MDG) and capric and lauric free fatty acids in Clostridium-infected chickens. Clostridial lesion scoring at d 16 showed that MDG and LauL were both effective in reducing the severity of lesions. When taking into account results on BW gain and mortality, LauL was more effective than MDG. For this reason, a dose response study was made to determine the optimal dietary dosage of LauL. In this experiment, it was shown that a LauL dose higher than 0.15% should be used to expect positive effects on lesion severity and mortality. None of the LauL doses led to a significant better response on growth performance. In a third trial, efficacy of LauL was compared with commercial products that limit bacterial activity in the intestinal tract (Aromabiotic Poul 60) or coccidiosis (chemical coccidiostat, Clinacox). None of the products were able to reduce the number or severity of lesions, and no effect on production performance was observed. Thus, despite the clear positive effect seen in experiment 1, and in experiment 2 with LauL doses higher than 0.15%, supplementing this lactylate to the diet does not consistently reduce C. perfringens colonization in broiler chickens because no such effects were observed in experiment 3. These results, however, provide a scientific basis for future studies to further investigate lactylates as potential additives to reduce the severity of necrotic enteritis in broilers in a C. perfringens challenge model.

2015. Effect of nutritional interventions with quercetin, oat hulls, β-glucans, lysozyme or fish oil on immune competence related parameters of adult broilers. Wageningen Livestock Research Report 977.The purpose of this experiment was to evaluate the effects of five nutritional interventions, provided during d 14 -28, including inclusion of a plant extract (quercetin); an insoluble fiber (oat hulls); a prebiotic (β-glucan); an anti-microbial protein (lysozyme), and ω-3 fatty acids from fish oil, on growth performance, composition of the intestinal microbiota, and morphology and gene expression of small intestine of broilers. Despite the different types of interventions, parameters related to immune competence were only marginally affected by the tested products. It seemed that in this study inclusion of oat hulls, and probably β-glucans, had perspective to improve immune competence. It is recommended to revaluate some of the tested interventions, especially dietary inclusion of oat hulls and β-glucans, in broilers starting from day-old onward.This report can be downloaded for free at http://dx. References 37Appendix 1 Calculated composition of the diets 48 Appendix 2 Calculated composition of the starter and finisher diets 49 Appendix 3 Chemical and nutritional composition of the rapeseed extract used in the present experiment comparing with canola meal (Khajali and Slominski, 2012) 50Limited effects of nutritional interventions were observed on gene expression of the gut tissue, and the genes differently expressed between dietary treatments do not seem to be directly involved in immune related processes. Despite the different types of interventions, parameters related to immune competence were only marginally affected by the tested products. It seemed that in this study inclusion of oat hulls, and probably β-glucans, had perspective to improve immune competence. It is recommended to revaluate some of the tested interventions, especially dietary inclusion of oat hulls and β-glucans, in broilers starting from day-old onward.