The objective of the current study was to evaluate the impact of multiple copper supplements on male broiler growth performance and potential bile antimicrobial activity in corn-soy diets. A total of 2560 broilers were assigned randomly to 4 dietary treatments consisting of 16 replicates of 40 Cobb 500 broilers. The experiment was a 2x2 factorial (source x inclusion) design included two sources of copper (copper methionine hydroxyl analogue chelate (CMHAC) and copper chloride (CC)). Birds were fed a starter (d1-14), grower (d14-28), and finisher (d28-38). Average body weight (BW), body weight gain (BWG), mortality adjusted feed conversion ratio (FCR), feed consumption (FC) and mortality (%) were determined on days 14, 28, and 38. On day 38, 4 birds were randomly selected from alternating blocks (32 pens total) for collection of bile to evaluate any potential antimicrobial activity associated with varying copper source and level. Data was analyzed via a 2 x 2 factorial ANOVA with main effect means deemed significantly different a P ≤0.05. On d 28 and 38, broilers fed diets containing 120 ppm Cu significantly increased BW compared to the 30 ppm, additionally; BWG during the finisher phase was improved with the higher inclusion rate of copper. An impact of copper source was also observed as CMHAC fed broilers exhibited an elevated BW at day 28 (P=0.018) and 38 (P=0.031) compared to CC. This was associated with an increase (P=0.028) in BWG during the grower phase of production. Differences in BW and BWG were associated with a higher rate of FC as 120 ppm fed broilers consumed elevated (P=0.005) levels of feed as compared to 30 ppm and the CMHAC fed broilers consumed an elevated (P=0.027) level of feed compared to CC. Differences in FCR were observed only during the finisher phase of production as higher levels of copper decreased (0.043) FCR and the CMHAC fed broilers exhibited a lower FCR compared to CC. The bile collected from at the conclusion of the experiment did not result in any zone of inhibition when applied to plates of Salmonella Typhimurium, Staphylococcus aureus or Clostridium perfringens. These data suggest that copper level and source can impact broiler growth performance.
Key Words: copper, broiler, performance.
Coccidiosis and feed outage have been reported to be as common predispose factors for chronic necrotic enteritis. A floor pen study was conducted with 828 day-old male broilers to evaluate the effect of Eimeria challenge and feed outage on growth performance and gut health. The study consisted of 4 treatments – T1: Negative control with coccistat (NC), T2: NC+ feed outage, T3: Eimeria challenge, T4: Eimeria challenge+feed outage, each with 9 replicate pens of 23 birds each. T2 and T4 birds were subjected to 24-hr feed outage twice a week starting on d18. T3 and T4 birds were orally gavaged with a coccidiosis vaccine at 5X the recommended vaccination dose on d 14. A common nutritionally complete typical US corn soybean meal based broiler diets were formulated for starter (0-14 d), grower (14-29 d), and finisher (29-42 d) phases and fed for all birds. All diets were pelleted, and starter diet was crumbled after pelleting. Data were subject to one way ANOVA; means were separated by Fisher’s protected LSD test. A P-Value ≤ 0.05 was considered statistically different. Both Eimeria challenge and feed outage reduced BW on d21, 28 and 41, gain on d21 and d28, and increased FCR on d21 and 28. The growth performance of birds challenged with Eimeria and/or feed outage started to catch up during finisher phase. Eimeria challenge alone increased Eimeria acervulina lesions and serum lactose; reduced skin yellow color, jejunal FABP2, FABP6 and MUC2 gene expression at 1 week post challenge (d21). Feed outage after 1 week (d21) increased serum endotoxin regardless of Eimeria challenge and feed outage after 4 weeks (d41) reduced skin yellow color and duodenal FABP6 in the absence of Eimeria challenge. Combination of Eimeria challenge and feed outage increased serum α1 acid glycoprotein (d21 and d41) and duodenal IL1β gene expression (d41). In summary, combination of Eimeria challenge and feed outage induced more severe gut inflammation than either challenge alone, and both challenge conditions alone or in combination could be used to test the efficacy of feed additives in growth performance and gut health in broilers.
Key Words: Eimeria challenge, feed outage, inflammation, gut health, broiler.