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Abstract
Brassica spp. meal especially canola, rapeseed, and carinata are protein source that could partially replace soybean meal (SBM). The poultry industry is heavily dependent on SBM as a protein source. Today, that industry has limited feed ingredients, fluctuating feedstuffs prices, along with other challenges as exploration of antibiotic substitute and diseases outbreak. This dissertation explores the interaction between SBM alternative Brassica feed ingredients or bioactive compounds on Salmonella or Eimeria infection, and intestinal health of chickens. A series of studies are included in this dissertation. In the first study, the novel feed ingredient, carinata meal was evaluated for its nutrient profile, digestibility, and effect of its inclusion on chicken growth performance, tight junction gene expression and intestinal morphology. The nitrogen-corrected true metabolizable energy (TMEn) for low glucosinolate carinata meal (LGCM) and high glucosinolate carinata meal (HGCM) were 1,814 and 1,690 kcal/ kg on an as is basis. This study found that LGCM and HGCM could be included at 12% and 8% respectively, without deleterious effect on growth. In the second study, the influence of rapeseed, canola meal and allyl isothiocyanate (AITC) as potential antimicrobials: effects on growth, and gut health in Salmonella Typhimurium challenged chickens were investigated. The in vitro result showed that MIC and MBC of AITC was at 80 and 200 ppm, respectively. An in vivo study showed that rapeseed at 30% inclusion and AITC at 1,500 ppm can reduce Salmonella shedding in the excreta and to other organs. Lastly, the third experiment investigated the effects of rapeseed, canola meal, and AITC inclusion on growth performance, intestinal-permeability, oocyst shedding, lesion score, histomorphology, gene expression, and short chain fatty acids (SCFA) production in broilers challenged with Eimeria maxima. Results suggests that 40% canola meal could be good alternative to SBM during Eimeria infection. AITC also showed beneficial effect on gut health during E. maxima challenge period. In cecal excreta, broilers fed diet supplemented with AITC at 500 ppm and canola at 40% had highest butyrate and valeric acid, respectively.