Propolis extract as a feed additive of the Nile tilapia juveniles

ABSTRACT This study was conducted to investigate the effects of dietary propolis alcohol extract supplementation on growth performance, digestibility, intestinal morphometry, and physiologic parameters Nile tilápia (Oreochromis niloticus L.) juveniles. For performance experiment and intestinal morphometry, 120 fish averaging 1.41±0.3g were randomly distributed into 24 tanks (70L each) in a closed recirculation water system with constant aeration and biofilter. The animals were distributed into four treatments using a completely randomized design with six replicates per treatment. The treatments consisted of four pellet feeds with different alcohol propolis concentrations extract (AEP) (0.0, 0.5, 1.0 and 1.5gkg-1). The performance experiment period was conducted for 45 days. For the digestibility experiment, an inert marker in the feed and the adapted Guelph feces collecting system were used. The results showed no differences in the performance parameters, crude protein apparent digestibility and dry matter of the feeds, intestinal morphometry, and physiologic parameters. However, there was an increasing linear effect on the energy digestibility with increasing PAE concentrations in the fish feed. The usage of the propolis extract supplementation levels of 1% is recommended for optimum effect on villus morphometry in Nile tilapia.