Comparative Study between the Performances of Nile Tilapia Oreochromisniloticus during and Out of the Normal Spawning Season

During the production season (2010-2011), this work was carried out at a commercial tilapia hatchery in Motobas, Kafr El-Sheikh Governorate- Egypt. Two experiments were managed using the same design to make a comparison between spawning of Nile tilapia Oreochromisniloticusbroodstock off-season (the winter) and on-season (the summer). The two experiments were tested by studying the effects of using feed additive (Nuvisol hatch P® 0.1%), different broodstocksizes (350, 200, 150 and mixed up to 250 g/fish) and stocking densities (50, 55, 60 female/pond-24m2) on growth performance, feed utilization, reproductive performance and economical profitability parameters of Nile tilapia, O.niloticus spawned in the summer and in the winter. Comparing the results of the economic analysis of the two experiments showed that the total production of Nile tilapia fry per each spawning pond, 24 square meters, is 28,090 within the natural spawning season, an increase of 2.23% from that was spawning outside the normal season (27478 fry). Though total revenue and net income under hatchery conditions in the out off-season (February 2010) much higher than that in natural spawning season (April 2011) by 22.01%. This is of course due to the price of tilapia fry in the winter months is higher than the summer to supply shortages in winter and increased demand at the same time. This is due to the farmers need to start the growing season early, March/April, in order to harvest their fish before temperatures drop in the next winter, which adversely affect the life of the fish

Comparative Study between the Performances of Nile Tilapia Oreochromisniloticus during and Out of the Normal Spawning Season

During the production season (2010-2011), this work was carried out at a commercial tilapia hatchery in Motobas, Kafr El-Sheikh Governorate- Egypt. Two experiments were managed using the same design to make a comparison between spawning of Nile tilapia Oreochromisniloticus broodstock off-season (the winter) and on-season (the summer). The two experiments were tested by studying the effects of using feed additive (Nuvisol hatch P® 0.1%), different broodstock sizes (350, 200, 150 and mixed up to 250 g/fish) and stocking densities (50, 55, 60 female/pond-24m2) on growth performance, feed utilization, reproductive performance and economical profitability parameters of Nile tilapia, O.niloticus spawned in the summer and in the winter. Comparing the results of the economic analysis of the two experiments showed that the total production of Nile tilapia fry per each spawning pond, 24 square meters, is 28,090 within the natural spawning season, an increase of 2.23% from that was spawning outside the normal season (27478 fry). Though total revenue and net income under hatchery conditions in the out off-season (February 2010) much higher than that in natural spawning season (April 2011) by 22.01%. This is of course due to the price of tilapia fry in the winter months is higher than the summer to supply shortages in winter and increased demand at the same time. This is due to the farmers need to start the growing season early, March/April, in order to harvest their fish before temperatures drop in the next winter, which adversely affect the life of the fish

Effects of herbal supplements on milk production quality and specific blood parameters in heat-stressed early lactating cows

The present study explored the influence of supplemental herbal mixtures on cow milk production, quality, and blood parameters in dairy cows under high ambient temperatures. Thirty Holstein cows were randomly assigned into three experimental groups of 10 each. The first control group was supplied with the commercial basal diet, whereas two treatment groups were provided with the commercial basal diet supplemented with 50 and 100 g/head/day of the herbal mixture, respectively. The results showed that the mixture of herbal supplementation did not influence weekly milk production. Milk total fat, triglyceride, and total protein values were not affected (p < 0.05) in cows fed on basal diets supplemented with herbal mixture; however, milk cholesterol was decreased significantly by 100 mg/head/day of the herbal mixture. On the other hand, lactose has increased significantly by adding 100 mg/head/day of herbal mixture. Furthermore, the total cholesterol level in serum was decreased by adding 100 mg/head/day of the herbal mixture, while plasma prolactin, cortisol, GOT, and GPT were unaffected. Regarding fatty acids (C18, C18:1 (c9), 18:1 (c11), 18:2 (c9, c12), 18:2 (t9, t12), and CLA (c9, t11)), there was no significant variation between the groups. Meanwhile, both C19:00 and 18:3 (c6, c9, and c12) were noticeably higher (p < 0.05) in the group that received 100gm, followed by 50 mg, compared to the control. In conclusion, the supplement with a herbal mixture positively affected milk quality by decreasing total cholesterol and increasing lactose, milk fatty acid profile by increasing unsaturated fatty acids content, and plasma cholesterol levels

Dietary effect of soybean lecithin on the growth performance, digestive enzyme activity, blood biomarkers, and antioxidative status of striped catfish, Pangasianodon hypophthalmus.

Soybean lecithin (SBL) is usually added to aquafeed as a lipid source because aquatic animals cannot synthesize phospholipids. Hence, this study aimed to investigate the role of SBL on the growth, nutrient consumption, digestive enzyme activity, blood parameters, and antioxidant capability of striped catfish. The fish were fed on five experimental diets with five grading levels of SBL (0, 2, 4, 6, and 8%) for 60 days. The final weight, weight gain, specific growth rate, feed intake, and protein efficiency ratio were markedly higher in striped catfish treated with 2-4% SBL than the control level (0% SBL). However, the lowest feed conversion ratio was in the fish-fed groups of 4-6% SBL. The carcass lipid content was significantly higher in fish fed 2-4% SBL compared to the control level (0% SBL). The lipase, amylase, and protease activities were significantly increased in the fish fed 2-6% SBL compared to 0% SBL-fed group. The gradually increased levels of SBL improved the structural appearance and increased the intestinal villi length and branching appearance. The triglycerides and total cholesterol were increased in the fish fed with 4, 6, and 8% compared to the control level, with the highest being in the fish fed with 8%. The lysozyme activity was higher in the fish fed with 2, 4, and 6% of SBL compared to the control level, with higher activity in the fish fed with 2 and 4% than 6%. Superoxide dismutase, glutathione peroxidase, and catalase activities were increased in the fish fed with 2, 4, and 6% SBL. The malondialdehyde level was lower in the fish fed with 4-6% SBL compared to the control level. The regression analysis revealed that the optimum dose of SBL is required at 3.65-4.42% for better productivity and health performances in striped catfish

Fig 1 -

Polynomial regression analysis (Pn = 9).</p

Formulation and composition of the basal diet.

Soybean lecithin (SBL) is usually added to aquafeed as a lipid source because aquatic animals cannot synthesize phospholipids. Hence, this study aimed to investigate the role of SBL on the growth, nutrient consumption, digestive enzyme activity, blood parameters, and antioxidant capability of striped catfish. The fish were fed on five experimental diets with five grading levels of SBL (0, 2, 4, 6, and 8%) for 60 days. The final weight, weight gain, specific growth rate, feed intake, and protein efficiency ratio were markedly higher in striped catfish treated with 2–4% SBL than the control level (0% SBL). However, the lowest feed conversion ratio was in the fish-fed groups of 4–6% SBL. The carcass lipid content was significantly higher in fish fed 2–4% SBL compared to the control level (0% SBL). The lipase, amylase, and protease activities were significantly increased in the fish fed 2–6% SBL compared to 0% SBL-fed group. The gradually increased levels of SBL improved the structural appearance and increased the intestinal villi length and branching appearance. The triglycerides and total cholesterol were increased in the fish fed with 4, 6, and 8% compared to the control level, with the highest being in the fish fed with 8%. The lysozyme activity was higher in the fish fed with 2, 4, and 6% of SBL compared to the control level, with higher activity in the fish fed with 2 and 4% than 6%. Superoxide dismutase, glutathione peroxidase, and catalase activities were increased in the fish fed with 2, 4, and 6% SBL. The malondialdehyde level was lower in the fish fed with 4–6% SBL compared to the control level. The regression analysis revealed that the optimum dose of SBL is required at 3.65–4.42% for better productivity and health performances in striped catfish.</div

Blood immunity and antioxidative responses of striped catfish fed dietary soybean lecithin for 60 days.

Blood immunity and antioxidative responses of striped catfish fed dietary soybean lecithin for 60 days.</p

Blood biochemical indices of striped catfish fed dietary soybean lecithin for 60 days.

Blood biochemical indices of striped catfish fed dietary soybean lecithin for 60 days.</p

Fig 2 -

Histomorphology of the middle intestine of striped catfish in the control fish (A; 0%) and gradually increased levels of soybean lecithin (B, C, D, E; 2, 4, 6, 8% respectively) showing evident enrichment and branching of intestinal villi (blue arrowhead) by increased levels of soybean lecithin in the supplemented diet. Stain H&E. Bar = 100 μm.</p

Growth performance of striped catfish fed dietary soybean lecithin for 60 days.

Growth performance of striped catfish fed dietary soybean lecithin for 60 days.</p