Improving the growth, feed efficiency and hematological indicators of Nile tilapia fingerlings Oreochromis niloticus using dietary lactic acid supplementation with different feeding routines

: A 42-day trial 2 × 2 factorial study was conducted to investigate the importance of using lactic acid (LA) as a feed additive in different feeding regimes on the growth, feed and blood indicators of Nile tilapia fingerlings Oreochromis niloticus . Two levels of feed additives 0% and 1% Lactic acid with two feeding systems—1) half of the daily meal was offered in the morning and the other half in the afternoon and 2 ــــ ) 3/4 (75 %) of the daily meal was offered in the morning and the other 1/4 (25%) in the afternoon. Fingerlings were stocked in 12 plastic aquaria (60 liters), with 10 fish/ aquaria. A commercial diet of 30% crude protein was used with a feeding rate of 3% of the biomass. The results showed, dietary LA had a positive impact on fish performance compared with feeding regimes. Fishes that were fed dietary LA with 50% of daily meal in the morning were the best in growth and blood parameters followed by fishes that were fed a diet without LA with 75% of their meal in the morning.