Animal Nutrition and Feed Technology
Year : 2001, Volume : 1, Issue : 1
First page : ( 51) Last page : ( 60)
Print ISSN : 0972-2963.

Growth, survival and tissue composition of Macrobrachiurn rosenbergii (de Man) post larvae fed traditionally or with live feed

Nanda P.K.*, Sahu N.P.¹

Central Institute of Fisheries Education Versova, Mumbai-400 061, India

*Reprint request: Dr. P. K. Nanda, Division of Livestock Products Technology, Indian Veterinary Research Institute, Izatnagar-243 122, India. Tel: +91-581-440682; Fax: +91-581-447284; E-mail: nandapk@ivri.up.nic.in

¹Present address: Division of Animal Nutrition, Indian Veterinary Research Institute. Izatnagar-243 122, India.

Received:  21  July,  2000.

Abstract

Six hundred and thirty post-larvae (PL-10) of fresh water prawn, Macrobrachium rosenbergii weighing 48 to 50 mg with a body length of 18.0 to 18.3 mm were randomly distributed in three treatment groups having three replications each to study the comparative performance of PL fed with traditional (GNC:RB, 1:1) or live feeds (Moina and Artemia nauplio for a period of 30 days. Feeding was done twice a day at 08.00 and 17.00 hrs. The traditional feed was offered at 10% of the body weight of PL to D1 group while 250 numbers of Moina and Artemia nauplii were offered per PL to D2 and D3 groups, respectively, which ensured ad lib intake. The physico-chemical parameters of water like temperature, dissolved oxygen, free carbon dioxide, total alkalinity and pH were observed at every third day to monitor the water quality during the experiment. Sampling of biomass were done at every ten days interval to assess the growth performance of the PL and accordingly the per day increment in length, weight and percent weight gain were calculated. Body composition and survival rate were also worked out at the end of the experiment. After rearing for 30 days the average body weight, body length, percent weight gain and survival rate were significantly (P<0.01) higher in D2 and D3 groups than those of D1 group. Although, insignificant (P>0.05) but higher growth rate and survival rate was recorded in D3 group in comparison to D2 group. The tissue composition was least affected due to change in diet. However, an inverse relationship was recorded between moisture and fat, moisture and ash content of all the groups.

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Key words

M. rosenbergii, Artemia & Moina feeding, Growth, Tissue composition.

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Introduction

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Materials and Methods

Experimental design

Post larvae (PL-10) of M. rosenbergii were stocked @ 70 PL/tub having 35 L of bore well water (chlorine free) in 9 tubs where each treatment have three replications following a completely randomized design. No soil was used as the sub-stratum of the tubs. Experiment was carried out for a period of 30 days. The average length and weight of PL at the beginning of the experiment were 18–18.3 mm and 48–50 mg, respectively. Three treatment groups were fed with either traditional feed (D1), Moina sp (D2) or Artemia nauplii (D3).

Monoculture of Moina sp.

Mass culture of Moina was done in cement cisterns of 300L capacity. These cisterns were inoculated at 50 Moina/L to which slurry was applied. This slurry was prepared from a liquefied mixture of chicken droppings, GNC and single super phosphate @ 10:5:2 w/w per 300 L of fresh water. Before application, it was kept for 2 days and aeration was provided round the clock to release obnoxious gases such as hydrogen sulphide, ammonia etc. Peak density of Moina appeared after 5–7 days. The culture was maintained throughout the experimental period by application of slurry and replacing water.

Hatching of Artemia cysts

Artemia cysts were hatched in glass jar under controlled condition. Cyst at 5 g/L of water were incubated at 25–30°C in 30–36 ppt salinity of water with continuous aeration. The nauplii were hatched from the cyst after 15–20 hrs of incubation. Those nauplii were collected by concentrating them to a source of light. Traditional (control) feed was prepared by mixing equal proportion of GNC and RB.

Management practices

The required amount of feed (both traditional and live) per day was divided into two equal portions and offered at 08:00 and 17:00 hours. D2 and D3 groups were fed with Moina sp and Artemia nauplii @ 250 no/PL/day whereas control feed was given at 10% of initial body weight of D1 group. Before giving morning feed, tubs were cleaned manually. The waste materials were siphoned off and 50% of the tub water was replaced by equal volume of fresh borewell water. Aeration was provided round the clock to maintain good quality of water.

Growth and survival

Length and weight of PL were measured at 10 days interval. The mass weight of PL in each tub was measured for weight gain whereas ten PL were randomly taken from each tub for length measurement. Accordingly absolute gain in length, weight and their percent gain were calculated. Specific growth rate was also calculated. At the end of the experiment PL were counted to determine the survival rate.

Biochemical analysis of feed and tissues

The proximate analysis of feeds was done as per AOAC (1985). The calcium and inorganic phosphate (Pi) were estimated following the procedures of Talapatra et al (1940) and Fiske and Subba Row (1925), respectively. Similarly moisture, fat and ash contents of the prawn tissue were determined. Protein and carbohydrate content were estimated as described by Lowry et al (1951) and Hassid and Abraham (1957), respectively.

Water analysis

The physico-chemical parameters of water viz, temperature, pH, dissolved oxygen, total alkalinity, free carbon dioxide were analyzed on every third day as per the standard methods of APHA (1985).

Statistical analysis

Analysis of variance (ANOVA) technique was used to test the significance of means on various parameters as per the method prescribed by Snedecor and Cochran (1989).

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Results and Discussion

Physico-chemical parameters

In all tubs no considerable fluctuations were noted in the water temperature which ranged from 26.0 to 28.6°C. The pH of water ranged from 8.17 to 8.47 and dissolved oxygen from 6.1 to 7.2 ppm. Although free carbon dioxide was absent in all the tubs throughout the experimental period, the total alkalinity varied from 220–239 ppm. These observations were within the normal range for M rosenbergii as reported by New and Singholka (1982).

Growth parameters

The proximate and mineral composition of live feeds and the traditional feed are given in Table 1. The live feeds were rich sources of protein and fat but contained negligible amount of calcium and phosphorus compared to traditional feed. Growth in terms of length and weight and survival percentage of M. rosenbergii PL fed with different feeds such as D1, D2. and D3 have been presented in Table 2, Fig. 1 and Fig. 2. A significantly (P<0.01) higher weight gain were recorded in D2 and D3 groups than D1 group. However, D3 group registered a higher weight gain, though, it was not statistically significant (P>0.05), than D2 group. Similar trend was also observed for the gain in length. The D3 group recorded 80% more weight gain than the D1 group. Lower body weight and gain in length in D1 group may be due to lack of nutrient supply to the PL as per their requirement. This is quite evident from the nutrient composition of the feed as the live feeds contained more energy yielding nutrients than the traditional feed. The results obtained were more or less similar with the findings of Watanabe et al. (1983). Vay et al. (1993) also found the similar results while working on Penaeus japonicus larvae. They suggested that live feed might contribute extra digestible nutrients or some specific growth enhancing factors over artificial diet. Moreover, the live feeds especially Arternia (Ahmadi et al, 1994) and Moina cultured with poultry droppings (Alam et al, 1993) are reported to be rich in n-3 fatty acids which play a vital role for the growth of the post larvae.

Moller (1978) observed that PL of prawn must eat continuously to survive but should not actively search for feed. In this case due to mobility of the live feed, PL took the advantage of eating the live feed. Besides, due to elastic nature of the live feed, it is quite easy to swallow them as compared to rigid plant materials. Survival rate also followed the same trend as that of growth pattern indicating that the control feed (D1) failed to meet the nutritional requirements of PL as compared to live feed fed groups.

Biochemical composition

Body composition were similar in all the three groups irrespective of their growth rate (Table 3). This is in contrast to the findings of Sivakami and Ayappan (1991) who observed difference in body composition of fish species due to different feeds. In this regard New (1995) reported that change in body tissue composition is not only influenced by feed but also due to other factors like size, sex, age, environment and season etc.

Ash content of PL showed an increasing trend with increase in size of prawn. This may be due to accumulation of inorganic constituents as reported by Sriraman (1978). An inverse relationship (Y = 158.19 − 78.63 X) was observed between the ash and moisture content. This may be due to mineralization followed by advancement of age with concomitant fall of moisture content of tissue. Similarly, an inverse relationship (Y = 158.14 − 78.58 X) was observed between moisture and fat content of prawn tissue. Similar observation was also found by Brandes (1954).

From the above experiment it was concluded that live feeds were found to be superior than the traditional feed in the diet of M. rosenbergii post larvae. Though Artemia or Moina is found to be suitable for rearing at initial post larval period of M. rosenbergii, performance of former is found to be comparatively better. Body tissue composition is least affected by feeding different type of feeds during the growing period of M. rosenbergii post larvae.

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Figures

Figure 1: Average length of M. rosenbergii past larvae fed on different feeds TopBack

Figure 2: Average weight of M. rosenbergii post larvae fed on different feeds TopBack

Tables

Acknowledgements

Authors duly acknowledge the Director, Central Institute of Fisheries Education, Versova, Mumbai - 400 061 for providing the necessary research facilities for conducting the above work.

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