bacitracin-methylenedisalicylic-acid and Weight-Gain

The efficacy of bacitracin methylene disalicylate (BMD) in the management of necrotic enteritis (NE) when fed in combination with narasin was investigated in a floor-pen study of 2,000 broiler chickens using a Clostridium perfringens inoculum challenge model. Treatments consisted of 1) nonchallenged-nonmedicated; 2) challenged-nonmedicated; 3) challenged-narasin (70 ppm); 4) challenged-BMD (55 ppm); 5) challenged-narasin (70 ppm) + BMD (55 ppm). Medication was provided in the feed from Day 0 to trial termination on Day 41. C. perfringens challenge occurred from Day 14 to 16. BMD and narasin, fed alone and in combination, reduced (P < 0.05) mortality due to NE when compared to challenged-nonmedicated birds. NE lesion scores (Days 0 through 41) were lower among birds fed BMD and narasin, alone and in combination, compared to challenged-nonmedicated birds. Improvements in NE mortality and NE lesion scores were greatest for the BMD + narasin-medicated birds, followed by the BMD-alone, and then narasin-alone treated birds. BMD and narasin, alone and in combination, provided improvements (P < 0.05) in average daily gains over the entire study (Days 0 to 41). The results of this study demonstrate the effectiveness of BMD and narasin in the management of NE in broiler chickens.

Topics: Animals; Anti-Bacterial Agents; Bacitracin; Chickens; Clostridium Infections; Clostridium perfringens; Enteritis; Male; Necrosis; Poultry Diseases; Pyrans; Salicylates; Weight Gain

The intestine of the newly hatched chick is immature at hatch. Yeast contains nucleotides and β-glucans that enhance intestinal development and chick growth. Accordingly, a 14-d experiment was conducted to evaluate the efficacy of a novel yeast product and bacitracin methylene disalicylate in enhancing early growth and intestinal maturation in chicks obtained from young (26-27 wk old) and old (58 to 59 wk old) breeder hens. Chicks (384) were randomly assigned to 8 dietary treatments. Treatment 1 (YH) consisted of chicks, from young hens, fed corn-soybean meal (SBM) diet alone. Treatment 2 (YHB) consisted of chicks, from young hens, fed corn-SBM basal into which BMD was added at 0.055 g/kg. Treatment 3 (YHE) consisted of chicks, from young hens, fed corn-SBM basal into which yeast extract (YE) was added at 0.075% level. Treatment 4 (YHED) consisted of chicks, from young hens, fed corn-SBM basal into which YE was added at 0.15% level. Treatments 5 (OH), 6 (OHB), 7 (OHE), and 8 (OHED) consisted of chicks from old hens fed diets similar to those given to YH in treatments 1, 2, 3, and 4, respectively. Growth performance (body weight gain and feed conversion ratio) was evaluated on d 7 and 14. Intestinal tissue samples were also analyzed for alkaline phosphatase (ALP) activity as an indicator of intestinal maturation on d 4 and 13 of experiment. Results showed that by d 14 of experiment, only BMD treatments (YHB and OHB) improved body weight gain (P < 0.05). However, the body weight gains of chicks in the yeast-supplemented treatments (YHE, YHED, OHE, and OHED) were statistically similar (P > 0.05) to those of the BMD treatments. Ileal ALP activity was consistently enhanced by BMD and yeast product supplemented at 0.075% of the diet. It was concluded that antibiotic BMD and our novel yeast product supplemented at 0.075% of the diet improved early chick growth and maturation of the ileal segment of the small intestine.

Topics: Aging; Animal Feed; Animal Nutritional Physiological Phenomena; Animals; Bacitracin; Chickens; Diet; Dietary Supplements; Female; Intestines; Salicylates; Weight Gain; Yeasts