This study was designed to determine compensatory growth response of short-term starvation and refeeding cycles on Oreochromis mossambicus juveniles. A total of 360 juveniles were randomly divided into 12 tanks in triplicate groups. The control group (C) was fed three times a day to satiation. The feeding regimes of the other groups were designed as follows: 2 days deprivation /2 days refeeding (2DD2DRF), 2 days deprivation /3 days refeeding (2DD3DRF), and 2 days deprivation /4 days refeeding (2DD4DRF). After 60 days, only fish in 2DD4DRF group presented partial compensatory growth; no significant difference (P>0.05) was observed in the final weight (FW), and specific growth weight (SGR) compared to the control. Hepatosomatic index (HSI), viscerosomatic index (VSI), and condition factor (CF) was not affected by these feeding regimes. Furthermore, improved feed conversion ratio (FCR), and feed efficiency ratio (FER) were observed in 2DD4DRF fish, among groups. Feed intake (FI) was significantly lower (P<0.05) in starved fish compared to C. Meanwhile, muscle crude protein and lipid content in 2DD2DRF, and 2DD3DRF groups was significantly lower (P<0.05) compared to C and 2DD4DRF group. Compensatory growth response in 2DD4DRF presents possibilities for economic optimization in O. mossambicus production.

The estimation of melatonin in bovine plasma by radioimmunoassay is described and some aspects of specificity are discussed. Mean values for individual heifers ranged from 0.025 to 0.25 nmol/l during the day and were significantly (P less than 0.01) raised in each animal to mean values of 0.19 to 1.41 nmol/l at night. The hormonal changes after cloprostenol injections were not affected by the time of day at which the heifers were treated.