Effects of dry whey powder alone or combined with calcium butyrate on productive performance, duodenal morphometry, nutrient digestibility, and ceca bacteria counts of broiler chickens

- Dry whey, calcium butyrate, and their mixture were evaluated in broiler chickens.
- Feeding with the mixture increased nutrient digestibility and reduced cecum pH.
- Feeding either with the mixture or without additives improved weight and feed intake.
- Dry whey or calcium butyrate alone in feed improved feed conversion ratio.
- The mixture of additives in feed enhanced duodenal histomorphometry.

Prebiotics and organic acids have been proposed as safe additives in poultry feeding to promote performance and health. The purpose of this study was to assess the influence of supplementing corn-soybean diets of broiler chickens with dry whey powder (WP), fat-coated calcium butyrate (CaB), and a mixture of both on apparent ileal digestibility (AID), pH of gastrointestinal content at various segments, productive performance, duodenal histomorphometry, and ceca microbial counts. The experiment consisted of a 2 × 2 factorial arrangement, with 2 WP inclusion rates (0 and 60 g/kg of diet) and 2 CaB rates (0 and 1 g/kg of diet). One-day-old male broiler chickens were randomly allocated to floor pens and assigned to 1 of 4 treatments. In Trial 1, 120 broiler chickens were allocated to 4 treatments with 3 pens per treatment and 10 broiler chickens per pen during 21 d. With the addition of WP, the AID of dry matter, crude protein, Ca, and P increased, and cecum pH decreased only when CaB was also added (CaB × WP, P < 0.046). In Trial 2, 1200 broiler chickens were allocated to the 4 treatments with 10 pens per treatment and 30 broiler chickens per pen during 42 d. With the dietary supplementation of WP, average daily gain and feed intake of broiler chickens increased during starter, grower-finisher periods, and the entire feeding period only when CaB was also added (P < 0.047). However, with addition of WP, feed conversion ratio (FCR) decreased in broiler chickens fed the diet without CaB, but it increased in those fed with CaB during the grower-finisher and entire feeding periods (P < 0.001). Duodenal histomorphometry measurements were evaluated using hematoxylin and eosin stains, and cecal microbial counts were determined by selective culture media. With the addition of WP, villus height, villus height to crypt depth ratio, and villus surface area were increased only when CaB was also added (CaB × WP, P < 0.017), while the supplementation of WP increased Bifidobacterium spp. counts only when CaB was not added (CaB × WP, P = 0.049). Results obtained in the present study indicate that the supplementation of WP without CaB addition improved the FCR of broiler chickens. However, the supplementation of WP together with CaB improve duodenal development, increases nutrient AID, and the weight and ingestion of broiler chickens.