Studies of the effect of different diets on fish performance and the water quality changes in fertilized fish ponds

Two experiments were conducted for 6 months to declare to what extent the artificial feed could serve in addition to the optimum fertilizer dose [urea and superphosphate] in polyculture fish ponds. The water quality parameters of different ponds were monitored and analyzed every twenty weeks during the growing period. The results showed a significant differences in fish performance of Tilapia. The high values were obtained from the fish fed balanced diet with fertilizers. Moreover, the high protein efficiency ratios [PER] were obtained from fish fed wheat bran with or without fertilizers, as the feed efficiency decreased linearly with increasing protein level in the diet. In case of carp, significant differences were found in fish performance. The high values were obtained from fish fed balanced diet with or without fertilizers. The highest PER values were obtained from fish fed wheat bran without fertilizers. Concerning the water quality, obvious changes in the nutrient salts and dissolved oxygen were observed. Nitrogen as nitrate proved to be phytoplankton limiting growth, however phosphorus as orthophosphate showed the opposite. These changes can be attributed to phytoplankton blooms and crashes. Economically, highest net revenue was obtained by using balanced diet with optimnum doses of fertilizers, followed by balanced diet only

Some studies on behavioural, physiological and productive aspects in Egyptian goslings kept under two systems of management

The behavioral and physiological performance of 20 young Egyptian goslings were studied under two systems of management [confined and open systems]. Birds were divided into 2 equal groups, each of 10, 6-week old goslings. The study was conducted for 6 consecutive weeks in the Department of Hygiene and Animal Ethology. Obtained results revealed that goslings kept in open system and showed a marked increase in feed consumption [kg] have good feathering and obtained a 2.19 kg final body weight. While goslings kept in confinement showed less feed consumption, poor feathering and they obtained 1.696 kg final body weight. Goslings in open system were more active, feed searching, ground pecking, playful, contented, sleeping and sunbathing, more performing comfort movements than do goslings in confinement. The ethogram of goslings in open system was timed by nature than the ethogram of those in confinement. No significant differences in RBCs [million/ml], Hb% MCV, MCH, PCV and MCHC [P <0.01] were found between goslings of the two systems of management