The effects of different grain sources on gut evacuation rate and nutrient digestibility in common carp, Cyprinus carpio

The main objective of this study was to investigate whether dietary cereal grains of different carbohydrate sources can change nutrient digestibility, evacuation rate and the number of bacterial colony in gut. Common carp with an average weight of 244.7±6.3 g were divided randomly into sixteen 500-L tanks with a stocking density of 18 fish per tank. Four experimental diets were formulated by inclusion of four cereal grains (wheat meal, barley meal, corn meal and rice meal) in a basal diet in a ratio of 40%. The four experimental treatments with four replicates were assigned in 16 tanks. Inclusion of different types of cereal grain affected growth related parameters in C. carpio. Corn and wheat diets led to larger weight gains and better feed conversion ratios compared to barley diet (324 and 321 versus 305 g for final weight; 1.93 and 1.90 versus 2.25 for fed conversion ratio). Protein and dry matter digestibility in the common carp fed rice diet were lower in comparison to other cereal grains (73 and 58 versus 79-82 and 67-70%). The maximum and minimum bacterial colony numbers (133 and 63 cfu.gr-1×10-7) were observed in fish fed wheat and corn diets, respectively. Evacuation time showed a delay by feeding on barley diet and almost all dry matter left in part I of the intestine after 30 min (first sampling), but this rate was recorded 70% for corn diet .In conclusion, although dietary grains change evacuation time and bacterial colonial number in common carp, this condition does not have a great impact on nutrient digestibility

Effects of microwave irradiated canola meal on growth, nutrition performance, carcass characteristics and digestibility of nutrients in Huso huso fry

Effects of diets containing microwave-irradiated canola meal were evaluated on growth, nutrition performance, carcass composition and digestibility of nutrients in Huso huso fry with 31.18 ± 1.43 g in initial weight during 8-week experiment in a factorial design 4 × 2 with 8 treatments, each with 3 replications. Treatments included T1: %20 canola meal without irradiation; T2, T3 and T4: 20% irradiated-canola meal at 800 watts for 5, 10 and 15 min respectively; T5: 40% canola meal without irradiation; T6, T7, and T8: %40 800 watt – radiated canola meal at 5, 10 and 15 min respectively. At the end of the experiment, according to the results, the effects of diet containing microwave-irradiated canola meal on the final weight, weight gain, specific growth factor, feed conversion ratio and daily growth in H. huso fry were significant (p0.05), but showed significant effect on the carcass ash content (p0.05). So, it can be added to the diet up to 40% without any unfavorable effect on protein digestibility and growth rate