A comparative study on the effect of commercial fish feeds on the growth of Thai pangas, Pangasius hypophthalmus

A 70 day long experiment was carried out to evaluate three commercial pangas feeds available in Bangladesh viz. Quality Feeds Ltd. (QF), Aftab Bohumukhi Farm Ltd. (ABF) and Saudi-Bangla Fish Feed Ltd. (SBFF) (designated as treatment_T1 T2 and T3) on the growth of Pangas, Pangasius hypophthalmus. Each treatment had two replicates using six experimental ponds of each 80m2 size. The stocking density was 250 fish/80m2. At the beginning, the fish were fed twice daily at 15% of their body weight which was gradually reduced to 10 and 6%, respectively for the rest of the period. The ranges of water quality parameters observed were: temperature 29.0°C- ~5.1 °C, pH 6.85 - 8.52, DO 1.71 - 7.65 mg/1 and transparency or Secchi depth 14.5 - 30.0 em. The mean weight gain of fish was significantly (~<0.05) higher in T3 followed by T2 and T. The specific growth rate (SGR) ranged. between 4.09 and 5.06, feed conversion ratio (FCR) values between 1.54 and 1.61 with treatment T1 showing the lowest FCR. Protein efficiency ratio (PER) values ranged between 2.03 and 2.11. The survival of fish varied between 90.4 and 91.6%. The significantly (P<0.05) highest production of fish (kg/ha/70 days) and profit (Tk/ha/70 days) was observe in T3 (SBFF) followed by T2 (ABF) and T1 (QF), respectively. The result of the study showed that on the basis of nutritive value and growth performance of pangas, feed from Saudi-Bangla Fish Feed Ltd. is the best.

Effect of salinity on food consumption and growth of juvenile Nile tilapia (Oreochromi niloticus L.)

The effect of salinity (0, lO and 20%o, water temperature 28 ± l oC) on food consumption and growth of juvenile Nile tilapia, Oreochromis niloticus L. (9.94 ± 0.15 g) were investigated by feeding group of 20 fish at 2% body weight day. Individual food consumption was measured using X-radiography. There were no significant differences in growth or white muscle protein concentrations among groups. During feed deprivation, weight loss was similar for fish held at O%o and 10 %o salinity, but after 7 days over 50% of the fish maintained at 20%o salinity developed lesions covering 5-25% of the body. No significant relationships were observed between individual specific growth rates and food consumption rates within the groups. The fish in all salinity groups showed a negative correlation between specific growth rate and food conversion ratio. The coefficient of variation for wet weight specific food consumption and the mean share of meal for each fish were used as a measure of social hierarchy strength. A negative correlation was observed between coefficient of variation in food consumption and mean share of meal. The social hierarchy structure was similar in all salinities; 25% of the fish were dominant (18.29% above an equal share of meal) and 30% were subordinate (16.19% below an equal share of meal) and the remainder 45% fish fed theoretical share of meal (MSM, 5.26%).

Growth performance and morphological variations of local and Thai climbing perch (Anabas testudineus, Bloch)

Climbing perch locally known as koi (Anabas testudineus) is a popular food fish in our country. Thai climbing perch was introduced in Bangladesh from Thailand. To explore the variation in growth performance and orphological features of local and Thai climbing perch a study was undertaken. The highest gain in length, weight and SGR were found in Thai koi 12.23±0.38 cm, 55.83±0.53 g and 7.92±0.11 %/day respectively. Fourteen morphometric characters were studied where eleven (TL, SL, HL, HBD, LBD, DFL, PECFL, PELFL, AFL, UJL and LJL) showed significant difference (p<0.01) in Thai koi from the local ones. Of the meristic characters no. of dorsal fin rays (hard), anal fin rays (hard), caudal fin rays and scale along lateral line (upper and lower) as recorded from the Thai koi were significantly higher (p<0.01) than that of the local koi. The no. of dorsal fin rays (soft) in Thai koi were also significantly higher (p<0.05) from that of local koi. The number of vertebra were also variable in local and Thai climbing perch (25 in case of local koi and 26 in case of Thai koi). Hence, the results obtained form the present study satisfy the characteristics of A. testudineus which reveals that both the local and Thai koi belongs to the same species. Growth performance of Thai koi was better compared to local koi reared in same conditions.

Effect of feeding frequency on the growth of common carp (Cyprinus carpio L.) fry

A laboratory-feeding trail was conducted for 45 days with fry of common carp Cyprinus carpio L. (0.45±0.03g) in aquaria in a static indoor fish rearing system. The fry were fed on a pelleted diet containing 33% crude protein having fishmeal as major protein source. The fish fry in five treatments A, B, C, D, and E, each with two replicates were fed on 5% daily ration divided into different feeding frequencies of 2, 3, 4, 5 and 6 times a day respectively in order to observe the growth performance. Each replicate contained 15 fry having total initial weight of 6.87±0.31g. At the end of the feeding trial, significantly different and higher (p<0.05) growth response was observed in treatment C having a feeding frequencies of 4 times a day. Significantly the highest and the lowest percent growth of 334.30 and 218.91% were observed in fish fed on the diet (Treatment C) with 4 times and (Treatment A) 2 times feeding frequencies per day, respectively. Food conversion ratio (FCR) of 1.78 was significantly higher (pgrowth parameters viz, specific growth rate (SGR), apparent protein digestibility (ADP) were also higher in treatment C than the other treatments. The results of the present study demonstrated that the growth performance of C. carpio was the best at 4 times feeding in a day using 33% dietary protein containing fish meal as major protein source.

Length-weight relationship and relative condition factor in Oreochromis mossambicus (Peters) of Bhima River

Oreochromis mossambicus (Peters), a common freshwater fish of Bhima river, has high economic value and considerable fishery importance. The length-weight relationship in the logarithmic way for this fish can be written as: Log W = - 4.50241627 + 2.884822741 log L. This is close to the cubic law indicating the isometric growth of the fish in its natural habitat. The correlation coefficient (r) was found to be 0.9865 which showed a good relationship between the two parameters. The mean relative condition factor (K sub(n)) was 1.00 suggesting the well-being of the fish.

Length-weight relationship and condition factor of Perna viridis (Linnaeus, 1758) and Meretrix meretrix (Linnaeus, 1758) from Mumbai waters

Length weight relationship of the two commercially important molluscs P. viridis and M. meretrix was found to be W=-0.40263L super(2.044719) & W=-0.04359L super(2.2315498) respectively. Condition factor was recorded to be less than 1.0 for most part of the year in P. viridis and for M. meretrix it ranged from 0.39 to 4.61. The present study reveals that there was allometric growth in both the species and the growth was not satisfactory since it showed lower K-value during most part of the year.

Influence of formulated diets with varying protein levels on growth and ammonia excretion in the fry of Indian major carp, Cirrhina mrigala

The influence of formulated isocaloric diets of different protein levels (30, 35, 40, 45 and 50%) on the growth and ammonia excretion of the Indian major carp Cirrhina mrigala fry was studied for a rearing period of four weeks in the laboratory. Fishmeal, groundnut oilcake and silkworm pupae formed the source of protein in all the diets. As the dietary protein level increased from 30 to 40%, the growth and conversion efficiency increased significantly. Further increase in the protein level resulted in decrease in growth and conversion efficiency. Growth rate, weight gain (%), and gross and net feed conversion efficiencies were maximum at 40% dietary protein level. Ammonia excretion was directly proportional to the level of protein in the diet.

Recovery, growth and carcass composition following periods of restricted ration and full feeding in indian major carp, Rohu (Labeo rohita H.)

A 90-day experiment was conducted to determine the effect of restricted ration and full feeding on the recovery growth and carcass compositions of fingerlings (average weight - 20.74 ± 0.13 g) of rohu, Labeo rohita (H.). Rohu fingerlings procured from a local fish breeder were fed with commercial pelleted feed (27% crude protein) during the two-week acclimatization in the laboratory condition. Experimental pelleted diet (30% crude protein) was prepared and the control group (T sub(CFR)) was fed at 3% of body weight for the 90-day trial period. The experimental group T sub(1FR) was fed for three days at 1% of body weight and the next three days at 3% of body weight, T sub(2FR) was fed for seven days at 1% of body weight and the next seven days at 3% of body weight, T sub(3FR) was fed for 15 days at l% of body weight and the 15 days at 3% of body weight and T sub(4FR) was fed for 25 days at 1% of body weight and the next 25 days at 3% of body weight, alternating between 1 and 3% for the specified period during the 90-day trial period. Daily rations were divided into two equal meals per day at 09.00 and 16.00 hours. Average percent survival rate of rohu during the 90-day trial period was more than 90. Percent live weight gain (98.90 ± 0.34, 113.0 ± 5.93, 125.71 ± 11.01 and 141.90 ± 2.89), specific growth rate (1.53 ± 0.01 1.68 ± 0.06, 1.80 ± 0.10 and 1.96 ± 0.02%/d) and absolute growth rate (1.33 ± 0.13, 1.38 ± 0.07, 1.39 ± 0.04 and 1.44 ± 0.07g/d) of the experimental groups (T sub(1FR), T sub(2FR), T sub(3FR) and T sub(4FR) respectively) increased with the advancement of the experiment in comparison to those in control, T sub(CFR) (90.92 ± 5.81%, 1.44 ± 0.07%/d and 1.34 ± 0.20g/d, respectively) and were proportionately correlated with the degree of deprivation probably through the mechanism of increased feed intake (hyperphagia), feed efficiency ratio or gross growth efficiency, protein efficiency ratio and the superior feed conversion ratio reflecting in better performance index. The body length and muscle composition of fish indicated that recovery growth happened due to protein growth but certainly not due to fat deposition in the gut. Feeding at 1 and 3% of body weight alternating over a period of 25 days might economize the culture operation of rohu.

Growth performance and nutrient utilization of catfish Clarias gariepinus fed varying inclusion level of fermented unsieved yellow maize

This study was conducted using 150 fish of Clarias gariepinus to investigate the growth performance and nutrient utilization of Clarias gariepinus fed five treatment diets containing varying inclusion level of fermented unsieved maize. The diets were grouped into CT, T1, T2, T3, and T4 with inclusion levels of 25%, 50%, 75%, and 100% of fermented unsieved maize respectively. Highest weight gain was recorded in T4 with value of 10.24 and lowest weight was recorded in CT with 9.17. High FCR were observed in T2 with value of 0.70 and lower value was observed in T4 with value of 0.62. While, T2, T3, and T4 have highest survival rates with values of 90% in each treatment CT and T1 recorded 80% and 70% respectively. There was a significant (p< 0.05) difference between the food conversion ratios treatment T4 with the best value and other treatments. There was a significant (p< 0.05) difference between the levels of fermented unsieved maize inclusion and the specific growth rate of the experimental fish. The highest value of protein level and feed efficiency were observed in T4 at significant difference level (p< 0.05) than other treatments. It was concluded that fermentation of maize in fish feed has positive effects on the nutritional value of the feed. It is recommend that fermented maize can replace raw maize in fish feed diet for growth performance. KEYWORDS: Fermentation, yellow maize, Clarias gariepinus, Fish, Feed.

Growth performance and nutrient utilization of catfish Clarias gariepinus fed varying inclusion level of fermented unsieved yellow maize

This study was conducted using 150 fish of Clarias gariepinus to investigate the growth performance and nutrient utilization of Clarias gariepinus fed five treatment diets containing varying inclusion level of fermented unsieved maize. The diets were grouped into CT, T1, T2, T3, and T4 with inclusion levels of 25%, 50%, 75%, and 100% of fermented unsieved maize respectively. Highest weight gain was recorded in T4 with value of 10.24 and lowest weight was recorded in CT with 9.17. High FCR were observed in T2 with value of 0.70 and lower value was observed in T4 with value of 0.62. While, T2, T3, and T4 have highest survival rates with values of 90% in each treatment CT and T1 recorded 80% and 70% respectively. There was a significant (p< 0.05) difference between the food conversion ratios treatment T4 with the best value and other treatments. There was a significant (p< 0.05) difference between the levels of fermented unsieved maize inclusion and the specific growth rate of the experimental fish. The highest value of protein level and feed efficiency were observed in T4 at significant difference level (p< 0.05) than other treatments. It was concluded that fermentation of maize in fish feed has positive effects on the nutritional value of the feed. It is recommend that fermented maize can replace raw maize in fish feed diet for growth performance.

Estimation of RNA/DNA ratio in two north-Indian natural populations of mahseer (Tor tor) and its relationship with growth and hydrobiology

Samples of Tor tor were collected from Bari Reservoir of Udaipur and Narmada River at Hoshangabad (India), in the months of July and November 2005, respectively. Twenty-five samples were collected from each location. Bari Reservoir samples ranged from 17.0 to 24.5 cm in total length and from 75 to 155 g in weight, while Narmada samples ranged from 20.0 to 42.0 cm in length and 90 to 425 g in weight. The nucleic acid content in body muscle of Tor tor and the RNA/DNA ratio were estimated. The age of fishes was estimated by the scale study method and specimens were classified into four age groups. RNA/DNA ratio showed significant linear increase with increase in weight and age till the age of three years after which, the growth rate reduced. The 1-2 year group was the only one common between the two water bodies and a comparison of RNA/DNA ratios showed higher growth rate in Bari Reservoir. The gross primary productivity was also higher in Bari Reservoir being 551 mg cmˉ³ dˉ¹ compared to 404 mg cmˉ³ dˉ¹ observed for Narmada River. The condition factor (K) was found to be higher (1.21) in the fish from the Bari Reservoir compared to those of Narmada River (1.14). The growth rate was higher in females compared to males in >100 g specimens.

Effect of feed quality restriction followed by realimentation on growth, nutrient utilization, biochemical changes and haematological profiles of Indian major carp, rohu (Labeo rohita H.)

To investigate the effect of protein restriction with subsequent re-alimentation on nutrient utilization, hematological and biochemical changes of Indian major carp, Rohu (Labeo rohita H.), 150 acclimatized Rohu fingerlings (average 20.74 ± 0.13 g) divided into five experimental groups (30 fingerlings in each groups with three replications with 10 fingerlings in each) for experimental trial of 90 days using completely randomized design. Control group (T sub(CPR)) was fed with feed having 30% crude protein at 3% of body weight for 90 days trial period. Other experimental groups T sub(1PR) was alternatively 3 days fed with feed having 20% CP and 30% CP at 3% of body weight, T sub(2PR) was alternatively 7 days fed with feed having 20% CP and 30% CP at 3% of body weight, T sub(3PR) was alternatively 15 days fed with feed having 20% CP and 30% CP at 3% of body weight and T sub(4PR) was alternatively 25 days fed with feed having 20% CP and 30% CP at 3% of body weight during 90 days trial period with daily ration in two equal halves at morning and afternoon. It was noticed that retention of different nutrients was almost similar among all treatment groups indicated improvement of digestibility of nutrients might not be the mechanisms for recovery growth in carps. Increased percent feed intake of body weight (hyperphagia) (4.14 ± 0.30 or 4.94 ± 0.46 and 3.33 ± 0.29), improved specific growth rate (1.86 ± 0.09 or 2.26 ± 0.05 and 1.43 ± 0.01), absolute growth rate (1.57 ± 0.08 or 1.84 ± 0.18 and 1.36 ± 0.12), protein efficiency ratio (1.19 ± 0.11 or1.16 ± 0.12 and 1.05 ± 0.09) were the important mechanism showing better performance index (21.60 ± 1.09 or 23.80 ± 0.21 and 19.45 ± 0.37) through which the experimental groups which were protein restricted and re-alimented at 3 or 7 days alternatively during 90 days trial period could able to compensate the growth retardation and to catch up the final body weight of control (128.68 ± 11.53 g/f) but other experimental groups failed to compensate during 90 days trial period. Result of the present study indicated that deprived fish i.e., fish received alternate 3 or 7 days protein restriction and re-alimentation showed recovery growth had still lower values of Hb (10.21 ± 0.02, and 9.88 ± 0.04 g/dl), hematocrit value (30.62 ± 0.05 and 26.64 ± 0.11%), total erythrocytic count (3.40 ± 0.01 and 3.29 ± 0.01 X10super(6) mm³), plasma glucose (126.93 ± 0.20 and 126.67 ± 0.05 mg/dl), total plasma lipid (1.04 ± 0.01 and 1.02 ± 0.01 g/dl) and liver glycogen (290.10 ± 0.80 and 288.99 ± 0.95 mg/kg) in comparison to control (10.56 ± 0.08 g/dl, 31.68 ± 0.24%, 3.52 ± 0.03 X10super(6) mm³, 128.23 ± 0.25 mg/dl, 1.07 ± 0.01g/dl and 292.00 ± 0.23 mg/kg) at the end of 90 days trial but total plasma protein in deprived group was compensated with advancement of trial period. All hematological and biochemical parameters studied were proportionately lowered in the experimental group got higher degree of deprivation. These findings suggested that with the increase of trial length complete compensation of hematological and biochemical profiles of rohu might be achieved. The results indicated that the implementation of alternative 7 days low and high protein diet feeding during aquaculture of carps could make economize the operation through minimizing the feed input cost.

Length-weight relationship in freshwater cat fish Clarias batrachus (Linn.)

Clarias batrachus (Linn.), a common freshwater cat fish of Bhima River, has high economic value and considerable fishery importance. The length-weight relationship in the logarithmic way for this fish can be written as: Log W = 4.503717819 + 2.70681765 Log L. This is close to the cubic law indicating the isometric growth of the fish in its natural habitat. The correlation coefficient (r) was found to be 0.9824 which showed a good relationship between the two parameters.

Substitution of live feed by formulated diet: effect on the growth and survival of Betta splendens (Regan) fry

The present work evaluates the effectiveness of partial or total replacement of live feed (LF) (Tubifex) together with formulated diet (FD) for Betta splendens. Three hundred Betta splendens fry of uniform size (mean weight 0.19±0.01g) were equally distributed in five treatment groups with three replicates in glass aquaria of 351itre capacity. Fishes were given diets at different ratio of LF and FD viz. T1(C) 100% LF; T2 75% LF, 25% FD; T3 50% LF, 50% FD; T4 25% LF, 75% FD and T5 100% FD and the experiment continued for 105 days. T2 group registered highest (P<0.05) % body weight gain (125.61±0.26) and specific growth rate (2.34±0.02), which was similar to T1 and T3 groups. Lowest FCR was recorded in T2 (2.40±0.11) group, which was similar to Tl, T3 and T4 groups. Highest (P<0.05) PER was observed in T4 (1.00±0.03) group, which was similar to T3 and T5 groups. At the end of experiment, highest % survival was recoded in T1, T2 and T3 groups (96.67±1.67), which was similar to T4 group. From the study, it is concluded that LF can be successfully replaced up to 75% by FD without any adverse effect on the growth and survival of Betta splendens.

A nerve growth factor from the venom of Chinese cobra (Naja naja atra) and its effects on male reproductive system in rats

A nerve growth factor (NGF) was isolated from the venom of Chinese cobra (Naja naja ntr a) by ion exchange chromatography, gel filtration and fast protein liquid chromatography (FPLC). The N-terminal sequence of 22 amino acid residues was identical with other NGFs previously purified from the venom of the same genus. The NGF monomer molecular weight was estimated to be 13 500 by reducing SDS-PAGE and the isoelectric point was determined to be 7.2 by isoelectric focusing electrophoresis. NGF improved the epididymal sperm motility of male rats and increased the pregnancy rate and fetus number of mated female rats. The serum levels of luteinizing hormone (LH) and follicle stimulating hormone (FSH) of male rats administrated NGF + gossypol was lower than that of male rats administrated gossypol. Histological sections of testes and epididymides showed that NGF reduced the destructive effects of gossypol on rat testes. (C) 1999 Elsevier Science Inc. All rights reserved.