AUSTRALIAN POULTRY CRC - Poultry Hub

The ARDRA and partial 16S rRNA gene sequencing revealed four distinctive groups of lactobacilli:L. salivarius group (group I), L. crispatus group (group II), unidentified Lactobacillus species (groupIII), and L. johnsonii (group IV) (Table 3.6). These Lactobacillus species are dominant in the ileal andcaecal digesta of broilers. The L. johnsonii group was mainly detected in the ileal and caecal digesta ofthe Acacia extract-supplemented group. The Ph-48 generalized PhenePlate system was used to test thefermentation characteristics of the four groups of lactobacilli. All four groups fermented themonosaccharide; galactose at varying levels and disaccharides; sucrose, trehalose, and palatinose(Table 3.7). Sucrose was the substrate which was the most fermented by isolates from all four groups.3.1.5 Natural plant extracts and prebiotic compounds as alternatives toantibiotics in broilers in a necrotic enteritis challenge modelThe final experiment under Strategy A was conducted to determine the effects of two different watersolublecarbohydrate extracts (Rengarenga lily extract and Acacia extract), and two commerciallyavailable prebiotic compounds, Fibregum® and Raftifeed®-IPE, with similar chemical compositionsto the plant extracts on performance, gut microflora composition, gut morphology and humoralimmune responses of broiler chickens subjected to a necrotic enteritis (NE) challenge model involvingoral inoculation with C. perfringens (Cp). The plant extracts and prebiotic compounds were added (10g/kg) to a wheat-based diet.Table 3.8: Mean body weight gain (BWG), feed intake (FI) and feed conversion ratio(FCR) of broiler chickens fed diets supplemented with plant extracts and prebioticcompounds 2Body weight gain(BWG; g/bird)Feed Intake (FI;g/bird)Feed conversionratio (FCR)d 1 to 21 d 1 to 35 d 1 to 21 d 1 to 35 d 1 to 21 d 1 to 35Unchallengedcontrol837 1993 1177 3551 1.41 1.78(UC)Negative-control 690 1741 1055 3366 1.53 1.94(NC)Positive-control 805 1998 1092 3296 1.36 1.65Acacia extract 725 1817 1099 3611 1.52 1.99Fibregum 713 1841 1069 3534 1.50 1.92Lily extract 692 1740 1087 3533 1.57 2.03Raftifeed 684 1712 1036 3300 1.51 1.93S.E.M. 1 14.35 44.47 23.59 112.43 0.02 0.05Orthogonal contrastsUC vs. NC