COMPENSATORY GROWTH IN INDIAN MAJOR CARP, ROHU, LABEO ROHITA (HAM.)

摘要

Rohu, Labeo rohita (Ham.) fingerlings weighing 7.36 +- 0.06 gm (Mean +- SE) were reared in circular plastic tub of 50L capacity at 24 to 26 deg C for 60 days during the period between 17th February and 17th April, 2001. The control group was fed commercial pellet feed (Epic Feed) @ 5% of body weight once a day in the morning (8 A.M.) throughout the experiment. The other two groups were restricted of feed at 50% and 75% levels of control and fed the same feed @ 2.5% of body weight and 1.25% of body weight respectively, once a day in the morning (8 A.M.) for 30 days (restriction period) and for next 30 days (re-alimentation period), both the restricted groups were fed @ 5% of body weight once a day in the morning (8A.M.) like control. At the end of experiment, fish restricted of feed had statistically (P<0.05) similar but numerical by higher body weight than the numerically control. During re-alimentation period, weight gain, specific growth rate, feed intake, absolute growth rate (AGR), gross growthefficiency (CGE) or feed efficiency ratio( FER) and -protein and energy retention efficiency were significantly (P>0.05) higher in restricted fish than in the control indicating compensatory response in these fish. Restricted fish also showed hyper feedconsumption activity during re-alimentation period. No significant (P<0.05) differences were found in digestibility of dry matter (DM), protein and energy and protein gain : lipid gain between restricted and control fish during re-alimentation period, but the tendency of restricted fish was found to have higher values of protein gain : lipid gain than the control, suggesting that hyperphagia due to hyperactivity ,of feed consumption was the mechanism for increased growth rate. Growth efficiency and protein and'energy retention efficiency might be due to lower maintenance requirement during compensatory growth of Rohu and this also suggested that .compensatory growth obtained might be due to the protein growth rather than increased gut fat deposit or increased water uptake, because body length proportionately increased with the body weight. Numerically complete compensation of body weight of Rohu was obtained perhaps due to the ability of Rohu restricted of food to catch up in the body weight of control fish probably resulted from relative strong capacity for compensatory growth.