Pakistan Research Repository





The project" Influence of pond fertilization with broiler droppings on the growth performance and meat quality of major carps" was aimed to find-out an optimum level of nitrogen, from broiler droppings, for pond fertilization without any adverse effect on the quality of fish meat and limnology of ponds conducive for major carps growth. The experiment was conducted, with two replications for each of the treatments, in earthen ponds (0.012 ha each). After preliminary preparation of ponds, fingerling major carps, viz. Catla catla (25 %), Labeo rohita (60 %) and Cirrhina mrigala (15 %) were stocked in each of the ponds, separately, with the stocking density of 5333 fish per ha. Ponds were fertilized with broiler droppings (on the basis of nitrogen contents of broiler droppings) for one year at the rates of 0.10, 0.13, 0.16, 0.19 and 0.22g nitrogen per 100 g of wet fish weight daily and treatments were designated as T1, T2, T3, T4 and T5 respectively while the control ponds (T6) received no additives. After every 30-day interval, fish samples were captured randomly from each of the ponds and their morphometric characteristics, viz. wet body weight; fork and total lengths were measured and recorded. After obtaining the data, the fish were released back into their respective ponds. At the start of the experiment, the whole fish samples and at the end of the experimental period of one year fish meat samples (bone free fillet), of each fish species, were taken for the determination of chemical composition and organoleptic tests. Water samples, from ponds under each of the treatments, were analysed for physico-chemical and biotic variables to see the impact of pond fertilization, with broiler droppings, on the aquatic environment. The magnitude of contribution of all salient physico-chemical factors, in pond water, towards planktonic biomass production with subsequent nitrogen and biomass conversion into fish yield were computed also. The data on different parameters of fish growth, meat quality and pond limnology were subjected to statistical analysis. The comparison of mean values for various parameters and the significance of interactions were computed by using the analysis of variance and Duncan's Multiple Range test. Correlation and regression analyses were performed to find-out relationships and trends among various parameters. Under the above experimental conditions, following conclusions were drawn: 1. Broiler droppings added, on the basis of nitrogen contents, at the rate of 0.16 g nitrogen per 100 g of wet fish weight daily gave the best net fish yield of 3617.50 kg/ha/year, followed by 0.19, 0.13, 0.10 and 0.22g nitrogen levels. Among the three fish species, Catla catla grew the best in overall net weight gains, followed by Cirrhina mrigala and Labeo rohita. Water temperature was the only variable that affected the growth performance of fish significantly under all the treatments. 2. Significantly better growth performance of fish corresponded with the treatmental response towards higher planktonic productivity, especially zooplankton. However, the differential response of each treatment towards planktonic biomass production increased the growth rate of fish significantly with the concomitant increase in water temperature. 3. The fork length-weight relationships of three fish species, under five, fertilization treatments, followed almost isometric pattern of growth except for Labeo rohita under 0.10, 0.13 and 0.16 g nitrogen levels. However, among the three fish species Catla catla exhibited significantly higher weight gains against the fork length increments to follow the cube law of isometric growth. The fluctuations in the condition factor values of all the three fish species in relation to size was influenced by the status of ponds for their planktonic productivity indices which, in turn, regulated the standing planktonic productivity according to the feeding habits and age of the fish. 4. Increasing the level of nitrogen, from broiler droppings, decreased the conversion of nitrogen into fish body weight significantly. However, due to significantly better potential of treatments like T3 (0.16g nitrogen level) and T4 (0.19 g nitrogen level) towards planktonic productivity enhanced the fish yield significantly more than rest of the treatments. 5. Protein and fat contents of fish increased and that of ash and carbohydrates decreased among the three fish species after pond fertilization trials. With the increase of nitrogen level, the body protein and fat contents were found to increase upto 0.16g level of nitrogen. Both Catla catla and Labeo rohita had the highest fat (1.22+0.17 and 2.04+0.21 %) arid protein contents (18.04+0.46 and 19.49+0.54 %) under the influence of 0.16g nitrogen level while Cirrhina mrigala accumulated maximum fats (2.48+0.27%) and proteins (17.43+0.61 %) under 0.13 and 0.10 g nitrogen levels respectively. As regarded overall, performance of three fish species, under five fertilization treatments, both Labeo rohita and Cirrhina mrigala came up with the best species concerning their body proteins and fats. 6. Significantly higher growth of fish under different treatments affected the chemical composition of fish significantly for their fat and protein contents possibly due to differential response of treatments towards phytoplankton and zooplankton productivities for fish grazing. Increase in fish stroma proteins resulted in decreasing the softness of fish meat. However, myofibrillar proteins increased at the expense of sarcoplasmic proteins significantly in all the three fish species. 7. The meat bone ratios (meat/bone) in the three fish species under all the six treatments showed inverse relationship with their weights. However, 0.16g nitrogen level gave the best ratio of 23.98: 1. Among all the three fish species, Cirrhina mrigala exhibited the best meat bone ratio in all the treatments, followed by Labeo rohita and Catla catla. 8. Taste of fish was not affected by the five fertilization treatments, however, the control fish earned significantly less taste scores. Both Labeo rohita and Cirrhina mrigala came up as the best species in presenting quality meat to the judges particularly based on their meat/bone ratios. 9. The limnological environment of ponds, during this experiment, was conducive for fish rearing under all the treatments except for 0.22 g nitrogen level and the control. Increasing the nitrogen level beyond 0.16g showed a significant rise in the potassium contents of water and hence zooplanktonic productivity was affected negatively under both 0.19 and 0.22g nitrogen levels. The response of treatments towards the release of nutrients like nitrates and phosphates promoted the phytoplankton and zooplankton productivities of ponds that enhanced the fish growth significantly. This work may be extended to see the effect of potassium in water, on the planktonic productivity and fish growth in an integrated semi-intensive polyculture system to boost fish yield in earthen ponds.

Item Type:Thesis (PhD)
Uncontrolled Keywords:Pond Fertilization, Broiler Droppings, Major Carps, Fish Meat, Nitrogen Contents, Planktonic Productivity, Phytoplankton, Zooplankton,
Subjects:Biological & Medical Sciences (c) > Biological Sciences(c1) > Paleo-zoology(c1.10)
ID Code:298
Deposited By:Mr Ghulam Murtaza
Deposited On:17 Jun 2006
Last Modified:04 Oct 2007 21:00

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