Nasrollah Mahboobi Soofiani, Fatemeh Shir-Mohammad, Javad Pour-Reza,
Volume 2, Issue 1 (spring 1998)
Abstract
A 46-day feeding trial was conducted with rainbow trout (Oncorhynchus mykiss) to examine the effects of partial substitution of plant protein sources with fish meal in diets. Three different sources of plant protein including soybean, sunflower and cottonseed meals were substituted by fish meal at four levels of 10, 20, 30 and 40 percentages. Each diet was assigned to triplicate groups of fish in a completely randomized design as a 3×4 factorial arrangement, with a control diet. Seven hundred and eighty fish were used in this trial. Twenty fish were randomly assigned to each of 39 pens and were acclimated in these pens to the experimental conditions two weeks before treatments began. This substitution caused no significant differences in all the criteria measured with control diet. Fish fed diets of 30 and 40 percent soybean meal substitution showed greater weight gain and better growth performance, lower FCR and higher PER values in comparison with the fish receiving other diets, although the differences were not significant. Irrespective of substitution levels, comparison of fish fed by three different sources of plant protein in their diets showed that the fish fed diet containing sunflower meal had significantly (p<0.0l) lower final mean weight and growth performance, higher FCR and lower PER than the fish receiving soybean and cottonseed meal diets. Relative liver weight of fish receiving soybean meal diets was significantly (p<0.0l) higher than those fed with cottonseed meal diets, but the difference was not significant when compared with the fish fed with the sunflower meal diets. Partial replacement of cottonseed meal resulted in a higher energy availability to fish and also better performance of fish. However, diets containing soybean meal showed not much effects on performance of rainbow trout. These results indicate that cottonseed and soybean meals can be recommended as a suitable and fish meal-sparing ingredient in diets for rainbow trout.
F. Shir-Mohammad, N. Mahboobi Soofiani, J. Pourreza,
Volume 8, Issue 4 (winter 2005)
Abstract
In order to investigate the effect of phytase and copper supplementaion on growth and carcass composition of common carp (Cyprinus carpio L.), in a completely randomized design with 3 ×2 factorial arrangement with three replicates the experimental diets including three levels of phytase 0, 500 and 1000 (FYT) kg-1 and two levels of copper 0 and 15 mg/kg were tested. Diets contained 0.72 percent total phosphorus. One hundred and forty four carps with a mean weight of 207±23 g were selected and allocated in eighteen cages (8 fish per cage). The experiment was carried out for 8 weeks and 2 weeks for acclimatization. Phytase supplementation caused no significant differences in weight gain (WG), feed conversion ratio (FCR), carcass index (CI), protein efficiency ratio (PER), liver, carcass and blood composition but increased apparent phosphorous digestibility (APD) significantly (P<0.04). Copper supplementation also caused no significant differences in WG, FCR, CI, PER, APD, liver copper, carcass composition, cholesterol (Ch), triglycride (TG), phosphorus of serum but decreased liver fat significantly (P<0.004) and increased high density lipoprotein (HDL) of serum (P<0.02). Interactions between phytase and copper on WG (P<0.01), FCR (P<0.04), PER (P<0.03), liver copper (P<0.02) and TG of serum (P<0.001) were significant. This experiment suggests the presence of antagonistic effect between phytase and supplemental copper. Phytase enzyme improved some parameters of growth and carcass composition of common carp without supplemental copper but addition of copper to the diets with phytase enzyme impaired the improved performance of carp.
