December 22, 2024
Amin Oujifard

Amin Oujifard

Academic Rank: Associate professor
Address:
Degree: Ph.D in FISHERIES
Phone: 09173775889
Faculty: Faculty of Nano and Biotechnology

Research

Title
The effects of short-term starvation periods and re-feeding on the growth and feeding efficiency of (Acanthopagrus latus) and (Sparidentex hasta)
Type Thesis
Keywords
بازدهي تغذيه، آنزيم هاي كبدي، آنزيم هاي گوارشي ، نرخ رشد ويژه، سوپراكسيد
Researchers Saeed Hasanpour (Student) , Amin Oujifard (Primary advisor) , mansour tarfi (Advisor) , Omid Safari (Advisor)

Abstract

The compensatory growth response (CGR) and some selected physiological param- eters were evaluated in sobaity (Sparidentex hasta, 10 g) and yellowfin seabreams (Acanthopagrus latus, 4.3 g) juveniles subjected to a 2-week restricted feeding. Fish were first fed at 0%, 25%, 50% and 75% of the satiation level for a 2-week period, and then, they were refed for 6 weeks at the visual satiation level. The control group was fed to the satiation everyday for 8 weeks. Three hundred sobaty seabream juveniles were stocked into 15 tanks (20 fish tank−1 ), and 450 yellowfin seabream juveniles were allocated into 15 tanks (30 fish tank−1 ) and were fed on a commercial feed (500 g kg−1 crude protein and 150 g kg−1 crude fat). Survival rate was decreased in R0% group in S. hasta because of the cannibalism, which was triggered by feed restriction. After the 2 weeks of feed restriction, the control and R0% treatments in S. hasta (16.0 vs. 9.3 g) and A. latus (3.9 vs. 6.2 g) had the highest and lowest body weight, respec - tively. After the 6 weeks of refeeding trial, all the ration-restricted groups showed a full CGR in S. hasta. Regarding A. latus juveniles, except for R0%, the other groups showed a full CGR. Feed conversion ratio was improved in S. hasta that subjected to the 2-week feed restriction, but this parameter did not change in A. latus. Antioxidant enzyme activities in the liver of S. hasta juveniles, including glutathione-S-transferase, glutathione peroxidase, superoxide dismutase and catalase along with liver enzymes including alkaline aminotransferase, aspartate amino transferase, lactate dehydroge- nase and alkaline phosphatase gradually were decreased with reducing the severity of the feed restriction. Regarding A. latus, all mentioned antioxidant and the liver en- zymes in the feed-restricted groups were higher than the control. R75% and control groups in S. hasta had the greatest and the least trypsin and alkaline phosphatase activities. In A. latus, R25%, R50% and