Efficacy of fennel (Foeniculum vulgare) and anise (Pimpinella anisum) essential oils as anaesthesics in common carp (Cyprinus carpio L. 1758).

In this study, the anaesthetic effects of fennel and anise essential oils were investigated on common carp. Fish (10 ± 0.45 g) were exposed to nine concentrations of essential oils (5, 10, 20, 50, 100, 200, 300, 400 and 500 mg L-1). Additionally, the histopathological effects on the fish tissues including gill, skin and hepatopancreas and physiological effects on some blood parameters (Na+, K+, Ca+2, Cl-, total plasma protein and glucose) of essential oils were investigated in carp. At the end of the experiment, fennel oil showed an anaesthetic effect at a concentration of 500 mg L-1 in carp (anaesthesia induction and recovery times were 308 and 472 s, respectively). Anise essential oil showed deep anaesthesia at a concentration of 100 mg L-1, but anaesthesia induction time was found to be very long (20 min). In addition, anise oil at concentrations above 100 mg L-1 caused 10% mortality in fish. Blood parameters except glucose level in both essential oils were unchanged during deep anaesthesia in carp. However, plasma glucose levels were found lower in fish anaesthetized with anise oil than control and fennel groups (P < 0.05). At the histopathological examination, no pathological findings were observed in any organ of fish in the fennel group. However, severe hyperemia and inflammatory cell infiltrations in gills, erosive lesions in the skin and slight inflammatory reactions in the skin were observed in the anise group. The present study demonstrated that fennel essential oil at 500 mg L-1 concentration can be used as an effective and safe anaesthetic in common carp, but anise essential oil is not suitable.

Effects of sage (Salvia officinalis) essential oil on growth, health and antioxidant capacity of common carp (Cyprinus carpio).

In the study, effects of S. officinalis essential oil on growth performance, health and antioxidant activity in C. carpio were investigated. The fish (13 ± 0.21 g) were fed with diet containing 1 and 3 ml kg- 1 of sage oil for 60 days. At the end of study, growth performance was not affected in fish fed with sage essential oil (p > 0.05). Superoxide dismutase (SOD) activity in hepatopancreas increased with addition of 1ml kg- 1 sage oil to the diet. However, Catalase (CAT) activity and malondialdehyde (MDA) values were not significantly altered in common carp. Total protein, albumin, glucose and hepatopancreas enzymes (aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP)) in blood serum were not affected by sage essential oil supplementation. At the histological examinations, no pathological findings were observed in hepatopancreas and intestine of carp. Goblet cells number and villi length in intestine increased with sage supplementation (p < 0.001). In addition, fertility, granulation and number of follicles increased in common carp fed with sage essential oil. Mortality after challenged with A. hydrophila was not observed in carp fed with 1ml kg- 1 concentration of sage essential oil. As a result, use of sage oil can be recommended in carp farming to improve gut health, provide disease resistance against A. hydrophila infection, and increase of fertility.

Reversible sterilization by supplementing turmeric (Curcuma longa) powder to diets of female Pseudotropheus socolofi.

This study was conducted to determine if diets supplemented with turmeric powder (Curcuma longa) affected the reversible sterilization of Pseudotropheus socolofi. Three experimental diets were formulated to contain 0%, 10%, and 14% turmeric powder. The fish (mean weight 13 g) were randomly divided into groups consisting of 1 male and 4 females for each aquarium and were kept together for 137 days. The control group was fed a diet without turmeric, while the others were fed diets with turmeric for the first 75 days. All groups were then fed the control diet from day 75 to 137. The results showed that turmeric powder supplementation did not affect growth performance (p Ëƒ 0.05). A histopathological examination of the ovaries, performed on two samples on days 75 and 137, revealed that high doses of turmeric decreased number of ovulated vitellogenic follicles and ovarian activity. Moreover, immature follicle density was excessive in groups fed turmeric powder. However, the number of ovulated vitellogenic follicles increased in groups fed diets containing 10% and 14% turmeric after feeding them with the turmeric-free control diet from day 75 to 137. In conclusion, the study revealed that supplementing diets with high ratios of turmeric can influence ovarian activity; however, these effects can be reversed by ceasing supplementation.

Subfertility effects of turmeric (Curcuma longa) on reproductive performance of Pseudotropheus acei.

This study was conducted to determine the effect of turmeric powder dietary supplementation on the histology of visceral organs and reproductive performance of Pseudotropheus acei. The fish were fed dietary additions of 0%, 1%, 3%, 5%, and 7% turmeric powder. Each treatment was replicated three times. There were one male and four female fish with a mean weight of 6 g in each replicate. The fish were fed ad libitum for 90 days. There were no differences in fertility rate, fecundity rate, hatching rate, egg diameter, and larvae survival rate among groups (P < 0.05). Ovulation frequency and the percent of spawning broodstock were less in the 7% and 5% turmeric-supplemented group (P < 0.05), while there were no effects of treatment in the 1%, and 3% groups compared with the control group. Observations in histopathological examinations indicated there were normal tissue structures in the control, 1% and 3% turmeric-supplemented groups, while the addition of 5% and 7% turmeric induced a degeneration of and decrease in number of observable ovarian follicles. In addition, there was a normal liver structure in the control and the 1% and 3% turmeric-supplemented groups and slight to severe lipidosis in the 5% and 7% turmeric-supplemented groups. Also, the supplementation of larger amounts of turmeric induced enteritis and the slight to severe side effects on the relevant organs. These results indicate that supplementing of diets with turmeric powder in amounts of 5% and 7% suppressed ovarian follicle development, and extended periods between times of spawning which resulted in subfertility of broodstocks.

Effect of ß-Mannanase and α-Galactosidase Supplementation to Soybean Meal Based Diets on Growth, Feed Efficiency and Nutrient Digestibility of Rainbow Trout, Oncorhynchus mykiss (Walbaum).

A 12-week feeding trial was conducted with 87 g rainbow trout to evaluate the effects on growth performances, feed efficiency and nutrient digestibility of adding ß-mannanase and α-galactosidase enzymes, solely or in combination. Seven diets were prepared by adding ß-mannanase, α-galactosidase and mixed enzyme at two different levels (1 g/kg and 2 g/kg) to control diet (without enzyme) including soybean meal. Mixed enzymes (1 g/kg, 2 g/kg) were prepared by adding ß-mannanase and α-galactosidase at the same doses (0.5+0.5 g/kg and 1+1 g/kg). At the end of the experiment, addition of ß-mannanase, α-galactosidase and mixed enzyme to diet containing 44% soybean meal had no significant effects on growth performance and gain:feed (p>0.05). In addition, adding ß-mannanase, α-galactosidase and mixed enzyme in different rations to trout diets had no affect on nutrient digestibility and body composition (p>0.05).