The effects of different levels of boron supplementation to feed on the growth parameters of rainbow trout (Oncorhynchus mykiss) were investigated for the first time using four diet variations (0.01%, 0.05%, 0.10%, and 0.20% of boron in feed) in addition to a control diet (without boron). After 120 days of feeding, the final weight (FW), weight gain, condition factor, feed intake, feed conversion rates, specific growth rate, protein efficiency ratio, survival rates, economic conversion rate, and economic profit index were calculated for each treatment and compared with the control as growth parameters. The initial weight was 17.89 ± 1.12 g; at the end of feeding, the FWs were determined as 89.91 ± 2.11 g for the control and 90.56 ± 1.34 g, 99.21 ± 3.76 g, 88.14 ± 2.43 g, and 78.74 ± 1.47 g for 0.01%, 0.05%, 0.10%, and 0.20% of boron feed treatments, respectively. The results of this study show that feeding rainbow trout with 0.05% boron-supplemented feed stimulates the growth parameters, but 0.20% of boron supplementation inhibits the growth of rainbow trout.

Gamete activation in fish is an important step in terms of artificial fertilization of oocytes, cryopreservation studies and other experimental manipulations. Salinity and pH differences in activation media affect to sperm motility and fertilizing ability. These experiments were therefore designed to investigate the combined effects of pH (range 5.0–9.0) and salinity (20, 30, 37, and 45‰) of activation media on sperm motility of European sea bass Dicentrarchus labrax. The best results were obtained at salinity 37‰ and a pH of 9.0. Our results also demonstrated that non-progressive motility at salinity 45‰ was observed in the range of 5.0–9.0 pH. In conclusion, spermatozoa can be motile at a wide range of pH and salinity values although the percent of motile spermatozoa and motility duration are negatively affected by low pH values.

In this study, different amounts of glutamine were added to the diet of rainbow trout, and they were then fed for a period of 90 days. The current research investigated the effects of glutamine on various aspects of rainbow trout, including growth performance, condition factor, viscerosomatic index, hepatosomatic index, carcass composition, fatty acid profile, hematological parameters, and biochemical parameters. The study's findings revealed that adding glutamine to the diet of rainbow trout had a beneficial impact on their growth features. The rainbow trout group that was fed a 2% concentration of glutamine experienced the most notable increase in growth rate. A statistically significant difference in growth was observed among all groups (p < 0.05). Adding glutamine to the diet increased the amount of protein and decreased the fat content in the flesh of the fish. Glutamine exerted an influence on the blood and biochemistry parameters of fish, as well as their fatty acid composition. In conclusion, the inclusion of glutamine in the diet of fish could potentially enhance their immune system, improve the quality of their muscles, and enhance their growth performance.