Effects of the addition of oak (Quercus robur L.) and yucca (Yucca schidigera) on the water quality and growth performance of pacific white shrimp (Litopenaeus vannamei) cultured intensively in concrete tanks

The application of mixed natural extracts from oak (Quercus robur L.) and yucca (Yucca Schidigera) (OY) in an intensive culture system for Pacific white shrimp (Litopenaeus vannamei) was able to improve the growth performance of shrimp and the quality of its rearing media. Twelve tanks sized 8 × 8 × 1.3 m were stocked with 500 post-larvae m−2 per tank and treated with 2, 2.5, and 3 Kg Ha−1 of OY. Physical and chemical water parameters, including pH, dissolved oxygen, temperature, and salinity, were measured 4 times day−1 during the trial. Measurements of other chemical parameters, including Ammonia (NH3-N), Nitrite (NO2-N), and Nitrate (NO3-N), were performed the second and sixth day after the addition of OY. The same measurements were conducted in the control treatment every seventh-day post water exchange during the 90 days of the culture period. The growth performance parameters (biomass, final body weight, feed conversion ratio, survival rate, and percentage weight gain) and nutrient retention rate were evaluated after 90 days of shrimp culture. The utilization of OY significantly increased the final body weight (FBW), percentage weight gain (PWG), feed conversion ratio (FCR), survival rate (%), and the final biomass of shrimp. Different dose applications of OY significantly reduced the accumulation of ammonia (NH3-N), nitrite (NO2-N), and nitrate (NO3) in the rearing media compared to the control. However, there were no significant differences in protein, fat, ash, dry fiber, and water content among the shrimp treated with different addition levels of OY. This research concludes that the application of OY could maintain a safe level of ammonia and other nitrogen metabolites in the rearing media and enhance the growth performance of shrimp cultured in intensive production systems using commercial concrete tanks.