Determination Of Feed Digestibility And Growth Performance Of Indian Major Carps (Catla Catla, Cirrhinus Mrigala And Labeo Rohita) Reared Under Similar Feeding Conditions
Material type: Book ; Format:
Publisher: 2010 Dissertation note: Artificial feed plays an important role in semi-intensive fish farming, where density of fish is high. Fish feed development is the least developed sector in aquaculture, particularly in third world countries. The formulation of nutritionally balanced and acceptable diet for fish feed is possible only if information regarding its digestibility is available. It is well known that these two parameters, nutritionally balanced diet and its digestibility, play a key role for the development of artificial feed for fish. Determination of nutrient digestibility is the first step in evaluating the potential of an ingredient for use in the diet of reared species. Information on digestibility coefficients of feed ingredients is very useful not only to enable formulation of diets that maximize fish growth by providing appropriate amounts of available nutrients but also to reduce fish wastes.
The present study was therefore, designed to find out the digestibility of nutritionally balanced diet that contains cheap and easily available ingredients. The experimental and reference diets were evaluated for comparative growth and diet utilization efficiency in three Indian major carps (Catla catla, Labeo rohita and Cirrhinus rnrigala). The highest weight gain was observed in the Cirrhinus miri gala (20.57 ± 2.8 g & 0.7 ± 0.4 cm) followed by Labeo rohita (19.17 ± 3.02g & 1.1 ± 0.4 cm) and Catla catla (19.23 ± 3.Og & 0.4 ± 0.3cm), with the experimental or test diet (TD). The lowest growth was also observed in the Catla catla (14.6 ± 3.8 g & 0.2 ± 0.1cm) with reference diet (RD). Growth, FCR and digestibility of nutrients (Protein, EE, DE) were assessed. Proximate analysis (i.e., crude protein, gross energy, dry matter and marker estimation) of feed ingredients and formulated diets was also done. The highest protein digestibility was observed in Labeo rohita (83.4±3.5%) followed by Cirrhinus mn gala (82.2 ± 4.2) and Catla catla (81.8± 4.6%) The over all digestibility's of nutrients was higher for experimental diet in three fish species i.e. crude protein (84.4 ± 2.1), dry matter (33.3 ± 8.4), crude fat (82.1± 3.1) and gross energy (61.0 ± 5.1). Nutrient digestibility of reference diet were lower (crude protein 77.2 ± 1.3, dry matter 53.0 ± 3.0, crude fat 78.7 ± 0.58 and gross energy 58.3 ± 4.5) as compared to the experimental diet.
Similarly the FCR and FCE values for experimental diet (3.1 ± 0.12 and 32.4 ± 0.69) were better than the reference diet (3.8 ± 0.06 and 25.6 ± 0.58). Among three fish species the Cirrlzinus miri gala has better FCR and FCE (3.4 ± 0.57 and 29.6 ± 5.1) followed by Cat/a catla (3.5 ± 0.42 and 29 ±.0 4.2) and Labeo rohita (3.5 ± 0.49 and 28.5 ± 4.95), respectively. FCR and FCE ratios for reference diet was the lowest in the Labeo rohita (3.9 and 25.0), whereas Cirrhinus mrigala and Cat/a cat/a showed similar ratios (3.8 0 and 26.0), respectively.
Key physico-chemical parameters viz, temperature, dissolved oxygen (DO), pH, conductivity, total dissolved solids, were regularly monitored during the study period. All the parameters showed positive significant correlation with each other except DO which showed negative significant correlation. The correlation of physico-chemical parameters with growth was negatively significant whereas positive correlation was observed between DO and growths indicating that DO have a significant effect on the growth.
The over all results showed that the experimental diet (40% protein level) has better growth and nutrient digestibility as compared to the reference diet (24.5% protein level) which resulted poorer growth and digestibility values.
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Prevalence And Effects Of Lernaea Spp. (Anchor Worm) On The Growth, Skin Histopathology And Hematology Of Catla
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Publisher: 2010 Dissertation note: The experiment was conducted for the duration of three months in four earthen ponds each having dimension 21 xl 3. 5x2. I m (length x width x depth) to evaluate the prevalence of Lernaea spp. and its effects on the growth of Catla catla (Thaila) and hematology and skin. The data regarding the growth performance, Lernaea and ulceration prevalence of fish was recorded on fortnightly basis. The parasite was individually collected from each fish in all four ponds after fifleen days and a detailed microscopic examination of all individuals was done. The species found in the pond fish was identified as the Lernaea cyprincaea.
Our results show the highest weight gain was observed in the pond 4 (413.7 g) followed by pond 2 (378.7 g) and pond 1 (359.8 g), and pond 3 showed the lowest weight gain (357.8 g). There was no significant difference between weight gains of Catla catla irrespective of the prevalence of lernaea species. The highest length increment was observed in the pond 2 (17.5 cm) followed by pond 1 (14.04 cm) and pond 3 (12.1). The lowcst length increment was in pond 4 (11.89 cm). There was no significant difference between initial and final length gain of Catla caila irrespective of the prevalence of lernaea species infestation in all ponds.
At the start of studies there was no infestation of lernaea on thaila. Fish was healthy and fast growing but after fifteen days of stocking L. cyprincaea infestation was observed. infestation was observed in all ponds. There was gradual increase in the rate of infestation till half of the experimental duration irrespective of the environmental changes in all ponds. Increase in the L. cyprincaea percentage in first half of the study was from 20.51% - 36.25% in pond no.1, 17.75% -25.25% in pond no.2, 6.5% - 10% in pond no.3 and 14.75% - 13.1% in pond no.4. In the second half of the experiment fish was treated with KMnO4 @ 1 ppm and common salt @ 1% of total water volume in the second half of the experiment there was a gradual decrease in the lernaea percentage due to treatment. However, the proliferation of the lernaea remained after some time of the treatment, although the lernaea percentage was decreased at the end of study. Decrease in the second half of the study was from 6.9%-5% in pond no.1, 5% - 6.45% in pond no.2, 10.83% -5% in pond no.3 and 5.7% - 5% in pond no. 4. The percentage of L. cyprinacea infestation was compared and there was significant increase in the percentage of Lernaea with the passage of time. However, after the treatment there was a significant decrease in the Lernaea percentage at the end of study. The ulceration percentage in fish was also studied in relation to the Lernaea prevalence and it showed good correspondence and higher the prevalence with higher the ulceration was observed. The ulceration percentage showed a significant difference with respect to time.
The histopathological studies of thaila showed a vast difference b/w healthy and lernaeid fish skin. Healthy thaila skin has no change and variation in its structure while lernaeid thaila skin showed deep variation and ulceration. Skin burst from epidermis and cutis till lower connective tissues.
Study of hematological parameters of lernaeid and non lernaeid fish blood exhibited a significant decreased in Neutrophils, Eosinophils, Lymphocytes, Basophils, Monocytes and Thrombocytes count duration of the blood collection was four months. With respect to duration of exposure to parasites significant increase in the Hb and ESR and decrease in TEC, TLC, PCV and DLC show significant severity of parasitic infection.
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