Universities Research Journal 2011, Vol. 4, No. 2 Effect of Different Feeds on the Reproductive Performance of Clarias Batrachus (1758) Aye Aye Cho Abstract Two types of dietary feed were prepared to evaluate on the reproductive potential of Clarias batrachus (1758). The first dietary feed was thrash fish feed (A) containing protein 30%, Fat 9.08%, Ash 14.99%, Moisture 9.50% and the second was pellet from feed (B) containing protein 40%, Fat 10.53%, Ash 13.86%, Moisture 9.49%.The fish of uniform size and age were given to two group of spawners each contain 20 pairs. Mean body weight of fishes in group (A) and (B) after three month, just before, induction was recorded as 83.7 ±1.66g and 88.1 ±0.87g, respectively. Feed (B) produced better result in body weight than feed (A) (t 6.071, P < 0.05). Induction was carried out by giving pituitary hormone to the two groups. Greater Development of ovary were observed in the female breeder fed with feed (A) than those breeder with feed (B) (t=4.09, P<0.05). The number of eggs produced was also significantly higher in group (A) than group (B) (t=12.33,p<0.05). Those fishes fed upon feed (A) could produce significantly high numbers of healthy larvae with high survival rate (A=81.01%, B=72.01%). Keywords : Clarias batrachus, Feed (A), Feed (B) Introduction Clarias batrachus is a native species of Myanmar. Locally known as NgaKhoo. The flesh of this fish is considered excellent by indigenous people. The fish is hardy enough to survive varying conditions of freshwater ranging from non-polluted to polluted. (Khin Hnin Lwin 1982) Nutrition plays a main role in the life of an organism for its growth, health and reproduction etc. By manipulating the feed and its ingredients, the fishes kept in the fish farm can be managed to produce as either for breeders or for flesh (Khin Hnin Lwin 1982). So that, present study was carried out to investigate the two different feed formulations on. 1. Body weight gain 2. Maturity of ovary 3. Production of eggs 4. Development of eggs into healthy larvae Lecturer, Department of Zoology, University of Yangon.
136 Universities Research Journal 2011, Vol. 4, No. 2 Materials and Methods Preparation of feed To evaluate the different in reproductive potential of Clarias batrachus, two feed formulations were prepared based on the different protein contents. One feed was designated as feed (A) which mainly included thrash fish containing 30% protein and another was feed (B) in the form of pellets, containing 40% protein (Vet Assay Lab 2002). Feed A was prepared from raw fishes of high protein content with low price. They were collected from the Kyee Myin Dine fish market. Collected fishes were thoroughly cleaned and poached at 50 C, then the poached fishes were stored under the temperature of 5-10 C for one week. Prepared feed was given to fishes at the rate of 510% of the fish body weight, twice a day. Feed (B) was in pellet form provided by Myanmar Arr Marn fish and shrimp food manufactory company. It contains 33.33% of rice bran, 19.99% of ground nut cake, 19.99% of sesame cake, and 26.66% of minced thrash fish. This fed B was given twice daily with the rate of 5-10% of body weight. The fishes receiving two different types of feed were weighed monthly for three months until they could be used as breeders in induce breeding. Then, the female fishes were injected with pituitary extract and records were made on the weight of ovary and the number of eggs that were stripped off. Then, the eggs were fertilized artificially with the milt suspension of the testes obtained from the injected male spawners. Development of fertilized eggs into normal healthy larvae was studied, recorded and analysed. Results Growth rate based on body weight of female breeders Mean body weight of each fish was recorded as 56.9±1.80 g in the beginning of feeding with feed (A). Then, the average weight of the female fishes was gradually increased to 61.5±2.07 g, and 73.9±3.38 g in the 2 nd and 3 rd month, respectively. Just before the injection of hormone, each female weighed 83.7±1.66 g. Just after injection each female breeder weighed 91±5.85g. Initially, the weight of each female fish provided with feed B was recorded as 57.3±1.77 g. Afterward, the mean body weight of female fishes were recorded as 64.5±3.40 g and 78.9±1.6 g in the 2nd and 3rd months,
Universities Research Journal 2011, Vol. 4, No. 2 137 respectively. Just before the injection of hormone, each female breeder weighed 88.1±0.87 g (Table 1, Fig. 1). Mean body weight of each breeder fish just after injection of hormone was recorded as 95.2±6.4 g. Growth of ovary by weight Those female fishes provided with feed (A) after injection of hormone produced minimum ovary weight of 35 g and maximum ovary weight of 50 g. Meanwhile, those female fishes fed upon feed (B) produced 32 g and 49 g of minimum and maximum ovary weight, respectively. On average, 43.8±3.93 g and 39.15±4.38 g of ovary weight were recorded from feed (A) and feed (B), respectively. Statistically also found to be the feed (A) better than feed (B) in the growth of ovaries (t=4.09, P<0.05) (Table 2, Fig. 2). Number of eggs produced from ovaries Minimum and maximum number of egg produced from those female fishes fed with feed A was 205 eggs and 474 eggs, respectively. Meanwhile, those female fishes received feed (B) produced minimum of 152 eggs and maximum of 445 eggs. On average, 368±69.71 eggs were produced from feed (A) fishes and 297.8±69.71 eggs were produced from feed (B) fishes (t=12.33, P<0.05) (Table 2, Fig. 2). Effect of two feeds on survival of larvae Those breeder fishes lived on diet (A) produced average of 368.0 eggs, out of which average of 307.15 eggs hatched out to normal larvae and average of 60.85 were found to be abnormally developed and dead (16.53% dead). Mean numbers of 297.8 eggs were laid from breeders feeding on diet (B). Out of that average of 215.9±57.27 eggs were successfully hatched out, and average of 78.4±36.65 eggs could not hatched and died (26.32% dead). Feed (A) was found to be significantly superior over feed (B) in production more number of healthy larvae (t=6.016, P<0.05) (Table 2, Fig. 2).
138 Universities Research Journal 2011, Vol. 4, No. 2 Discussion Comparison of two feeds It was found that feed (B) which contain more protein content was found to give better results then feed (A) in gaining body weight (Table 1). This may be due to the high protein content of feed (B). Which made those fishes in giving more weight than feed (A). similar reports was given by (De Silva, 1993) that fishes getting feed of high protein content gain more weight than those fishes receiving lesser protein content. In the production of eggs, the breeder receiving feed (A) could produce more number of eggs then those breeders receiving feed (B) (Table 2). So that, feed (A) with low protein content was good for high fecundity. In the development of ovary and production of eggs, feed (A) which contains less protein was found to be better then feed (B). This can be assumed that ovarian development, production of egg and normal larvae do not require high protein content. It was also agreeable with the report of (De Silva, 1993) that high fecundity of fishes could be resulted from low protein diet feed. Table 1 Comparison of two feed formulations in the development of female spawner fishes (by body weight) Feed formulations Initial weight Monthly mean body weight of fishes After one month After two month three month (before injection) after injection Feed A 56. 9±1.8 61.5±2.07 73.9±3.38 83.7±1.66 91±5.85 Feed B 57.3±1.77 64.5±3.4 78.9±1.6 88.1±0.87 95.2±6.4
Universities Research Journal 2011, Vol. 4, No. 2 139 Fig. 1 Comparison of two feed formulation in the development of female spawner fishes (by body weight) Table 2 Comparison of two feed formulations in the production of eggs and survival of larvae Feed formulations Ovary by weight Mean data Number of eggs Percentage of normal larvae Feed A 43.8±3.93 368±69.71 81.01 Feed B 39.15±4.38 297.8±69.71 72.01
140 Universities Research Journal 2011, Vol. 4, No. 2 Fig. 2 Comparison of two feed formulation in the production of eggs and survival of larvae Acknowledgements I am greatly indebted to Professor Dr. Maung Maung Gyi, Head of Zoology Department, University of Yangon for his valuable supervision, editing, of this paper. References Anonymous (2002). The compositions of Myanma Arr Morn Fish and Shrimp Feeds. De Silva, S.S. (1993). Supplementary feeding in semi-intensive aquaculture systems. In Farm-Made Aquafeeds, Published by Proceedings of the FAO/AADCP Regional Expert Consulation on Farm-Made Aquafeeds. FAO- RAPA/AADCP, Bangkok. 24-60. Khin Hnin Lwin (1982), Some Aspects on the Biology of the Freshwater Catfish, Clarias batrachus (Linnaeus, 1758), M.Sc., Thesis, University of Yangon, Myanmar. 46.