Effect of the Feeding on Artificial Diet or Alfalfa Plant on the Growth of Grass Carp Ctenopharyngodon idella (Val. 1844) Fingerlings Cultivated in the Earthen Ponds

The current study aims to compare the growth of young grass carp Ctenopharyngodon idella fed on either artificial diet or alfalfa. The experiment was carried out in the earthen ponds of the Aquaculture Unit in the Agricultural Researches and Experiments Station (College of Agriculture, University of Basrah), which is located in the Al-Hartha district, approximately 16 km north of Basra (300 65' 64.6''N, 470 74' 79.5''E). The experiment begun from 26 July 2019 to 10 December 2019. Six ponds with an area of 600 square meters each were used for treatments. Fish were distributed equally to the culture ponds (600 fish per pond) at average individual weight of 6.3±0.28 g. Fish in artificial diet treatment were fed 5 % of the body weight and in alfalfa treatment 50 % of the body weight. Samples of fish were weighed every twenty days for the purpose of controlling growth parameters subsequently adjusting the daily feed provided based on the new weight. The growth criteria (final weight, weight gain, daily growth rate, specific growth rate, relative growth rate, feed conversion ratio and protein efficiency ratio) were calculated. Results of the current study showed that the water temperature is the most variable factor, for example, the highest temperature was 27.2oC in July, while the lowest temperature was 18.7oC in December. Results of growth criteria of the current study showed that grass carp in earthen ponds preferred alfalfa rather than the artificial diet, as the final average weight were 97.35, 47.18 g, the weight gain rate were 91.73, 40.75 g fish-1, the daily growth rate were 1.27, 0.42 g day-1, relative growth rate 1707.77, 629.99 %, specific growth rate were 3.92, 2.04 % day-1, feed conversion ratio were 11.75, 2.51and protein efficiency ratio were 1.75, 0.45 for fish fed on alfalfa plant and the artificial diet respectively.