Coated butyric acid and C12 monoglyceride supplementation of broiler feed to improve performance and gut health

Abstract

Due to the ban of antibiotics across the world there is pressure in finding alternative feed additives that can be used for food animals. The aim of this study was to determine the effect of butyric acid (Novyrate C) and monoglyceride (FRA®C12), with and without the addition of antibiotics (Zinc Bacitracin 15%) on the performance and gut health of broiler chickens. The study was conducted in an environmentally controlled commercial broiler house. The house contained ninety-six pens in total, divided into two rows consisting of forty-eight pens each over the length of the house. A total of two thousand three hundred and four male Ross 308 broiler birds were randomly distributed throughout the pens, 24 birds per pen at a stocking density of 22 kg/m2. All the birds received a typical South African maize-soya based diet throughout the trial. Dietary treatment combinations were implemented in a 3-phase feeding programme: Starter (0 to 14 d), Grower (14 to 28 d) and Finisher (28 to 35 d). This study was conducted using eight different dietary treatments. Treatment 1 was the positive control (Zinc Bacitracin 15% at 0.5 g/kg) and treatment 2 was the negative control (without the Zinc Bacitracin). Treatments 3, 4 and 5 consisted of Zinc Bacitracin together with either butyric acid (1 g/kg for starter, 0.75 g/kg for grower and 0.25 g/kg for finisher phase), mono-glyceride (1 g/kg) or a combination of the test products (butyric acid and monoglyceride). Treatments 6, 7 and 8 were the same as 3, 4 and 5 without the Zinc Bacitracin. Each treatment was repeated once within a block, resulting in 12 replications per treatment. The birds had ad libitum access to water and feed during the duration of the trial. A weekly numerical difference was recorded for body weight (BW), feed intake (FI) and feed conversion ratio (FCR). Two chicks per pen were sacrificed at the ages 20 and 33 days and duodenum, jejunum and ileum samples were sectioned from the gut. Results showed that growth was not significantly different between the treatments.The feed intake showed no significant difference either, but the birds that were not supplemented with the Zinc Bacitracin showed a lower FI (3747 g) compared to the group with Zinc Bacitracin inclusion (3767 g) at 35 days of age. The group of birds supplemented with Zinc Bacitracin resulted in a significantly lower FCR (P < 0.05) compared to the group without AGP at 7 days of age. The cumulative FCR of birds supplemented with both butyric acid and monoglycerides without the Zinc Bacitracin was significantly lower (1.47) compared to the same group with Zinc Bacitracin (1.51) from 0-35 days (P < 0.05). The viscera and wing weights expressed as a percentage of the carcass weight were significantly lower for birds that were supplemented with Zinc Bacitracin compared to the group of birds without AGP (P < 0.05), but no significant differences were reported for the thighs, drumsticks and breast weights relative to the carcass weight (P < 0.05) at 35 days of age. The supplementation of butyric acid, monoglycerides and their combination without AGP resulted in a significantly longer villi length in the duodenum, jejunum and ileum at 20 and 33 days. The combination of the two products resulted thus in a lower FI, FCR and increased villi height. The recommendation will be to use the products together as an alternative for antibiotic growth promoters in broiler feed.