Introduction

The feed cost accounts for 65-70% of total cost of broiler chicken production. To overcome this problem, continuous research is on to find low cost non-competitive newer feed resources for economizing cost of production. One such feed resources is fish waste a by product of fishery industry, which hitherto wasted, can be converted to wholesome poultry feed, if treated properly (Tanuja et al., 2014). India is the second largest producer of fish in the world, contributing 5.68% of the global production. Fish processing for human consumption yields around 40% of edible meat while remnant 60% is fishery by product composed of bones, skin, head, viscera, meat scraps and scales (Gilberg, 1993), which are discarded as waste all over the world that causes serious environmental problems and economic losses (Kjos et al., 2000; Barroga et al., 2001). The fish by products could be not only a valuable protein source in poultry feed but also prevents the environmental pollution if processed properly into edible form. Fish silage is a liquid product made from whole fish or parts of fish that are liquefied by the action of natural enzymes in the fish, in the presence of an added organic acid. There is little information on the utilization of fish waste as poultry feed. Therefore, the present study was undertaken to assess the dietary incorporation of acid treated fish silage on performance and economics of broiler chicken production.

Materials and Methods

One hundred eighty, day-old broiler chicks (Vencobb) were randomly distributed into 3 treatment groups with 3 replicates in each group. The chicks were placed in 9 pens, with 20 chicks in each pen in deep litter system using rice husk as bedding materials. All the chicks were kept under uniform managerial conditions throughout the experimental period. Control starter (0-3 wk) and finisher (4-6 wk) diets were formulated to meet all the nutrient requirements. Subsequently two test diets were prepared by incorporating acid treated fish silage at 5 and 10% level. All the diets formulated were isonitrogenous and isocaloric. Each diet was offered ad libitum to 3 pens of 20 chicks each throughout the experimental period. The composition of starter and finisher diet is presented in Table 1. Dressing waste (intestine and gills) of fresh water fishes were collected from a local fish market in Bhubaneswar, Odisha, India. The waste was washed with clean water, chopped and grounded into paste using meat grinder for silage preparation following the method of Tanuja et al. (2014).

The body weight of chicks was recorded individually at weekly intervals. The body weight gain at six weeks of age was calculated as the difference in sixth week body weight and the initial weight of chicks (day old chick body weight).  Feed consumption was recorded on individual pen basis. Feed conversion ratio was calculated as the ratio of feed consumed and body weight gain. The cost of feed was calculated based on the prevailing market price of each ingredient included in the feed. The cost of fish silage was arrived by including the cost of chemicals used and processing cost. Data were subjected to statistical analysis under completely randomized design employing one-way analysis of variance (Snedecor and Cochran, 1989). The means of different treatments were compared with Duncan’s multiple range tests (Duncan, 1955). Significance was considered at P <0.05 levels.

Table 1: Ingredients (%) and nutrient composition of starter and finisher diet

Result and Discussion

The day old body weight of broiler chicks in different treatments ranged from 48.07g   to 48.51 g and did not vary significantly, indicating uniform distribution of chicks at the beginning of experiment. Dietary incorporation of fish silage at either 5 or 10 % level had no influence on body weight of broilers during 0-6 weeks of age.  However, feed consumption was significantly higher in the birds fed diet incorporated with 5% fish silage compared to that of 10%.  Dietary inclusion of fish silage had no influence on feed conversion ratio (FCR) of broiler during 0-6 weeks of age.

The findings of the present study suggested that dietary incorporation of acid treated fish silage upto 10% in the diet of broiler chickens had no adverse affect on body weight in broiler chickens. Similar to the finding of the present study, no influence in body weight on inclusion of either acid silage meal or fermented fish silage meal up to a level of 10% in the diet of broilers was reported earlier (Johnson et al., 1985).

Table 2: Effect of dietary incorporation of fish silage on body weight, feed consumption and feed conversion ratio of broiler chickens

Means with different superscripts in a row differ significantly (P<0.05)

Another observation of the present study was a significant reduction in feed consumption, when fish silage level in the diet was increased from 5 to 10%.  However, the reduced feed consumption did not affect the body weight of broilers. Similar to the finding of the present study, many workers reported reduced feed consumption due to dietary incorporation of higher level of fish silage (20%) in the diet of broiler chickens (Magana et al., 1999; Darsan et al., 2009 and Ai-Marzooqi et al., 2010). The cumulative FCR of birds was also statistically comparable (P>0.05) in different groups. Reports of Epse et al. (1992), Magana et al. (1999) and Smitha (2005) are in agreement with the results of the present study where in no influence on FCR was noticed due to incorporation of fish silage up to 30% in the diet.

Considering the composition of three rations (0, 5 and 10% fish silage), the calculated cost per kg feed was found to be Rs. 28.24, Rs. 27.45and Rs. 26.07,  respectively during starter phase (0-3 weeks) and  Rs. 27.24, Rs. 26.36 and Rs. 25.33 during finisher phase (4-6 weeks). Dietary inclusion of fish silage at 5 and 10% level reduced the feed cost  by Rs. 0.79 per and Rs. 2.17 per kg feed during starter phase and  Rs 0.88 per kg feed and Rs. 1.91 per kg of feed during finisher phase compared to control diet. The cost of feed consumed per bird was significantly higher (P<0.05) in the dietary group containing 5% fish silage compared to control diet and 10% fish silage group.

Table 3: Cost of feed ingredients and additives

The feed cost per kg live weight gain was significantly (P<0.05) lower in the dietary group containing  10% fish silage compared to control diet and 5% fish silage group during 0-6 weeks of experimental period. The present finding is in agreement with Vedhanayakam et al. (1976) who reported lower feed cost per kg gain in birds fed diets containing fish silage. Similarly, Sakthivel et al. (2005) reported that fish waste silage can be used economically to substitute dried fish on protein basis in the diet of birds without affecting growth or feed efficiency.

Table 4: Cumulative body weight gain and cost of feed per kg live weight gain of broiler chickens

Means with different superscripts in a row differ significantly (P<0.05)

In the present study, there was a saving of Rs 5.06 per kg live weight gain when 10% fish silage was incorporated on air dry basis compared to control diet. The present finding is in agreement with the work of Smitha et al. (2005) who observed economic benefits by dietary addition of 9.7% fish waste silage in broiler chickens. Darsan et al. (2009) also reported that complete replacement of animal protein (fish meal) in the finisher ration of broiler chicken with processed fish waste would reduce feed cost without compromising the nutritional status, feed efficiency and overall performance.

Conclusion

From the findings of the present study, it is concluded that dietary incorporation of acid treated fish silage up to 10% in broiler diet was not only economized the cost of production but also satisfied the nutritional requirements of broilers and this practice would also help the fish industry to increase their income and provide a safe methodology to mitigate pollution from fish waste.

Acknowledgments

The authors acknowledge the fund and infrastructural facilities provided by Director, ICAR-Central Institute for Women in Agriculture, Bhubaneswar. The authors are very much grateful to all the staffs of ICAR-CIWA for their unconditional support and guidance. We are equally thankful to Dean, College of Veterinary Science & Animal Husbandry, Orissa University of Agriculture and Technology, Bhubaneswar.

References

1.    Al-Marzooqi W,  Al-Farsi MA, Kadim IT, Mahgoub O and Goddard JS. 2010. The Effect of Feeding Different Levels of Sardine Fish Silage on Broiler Performance, Meat Quality and Sensory Characteristics under Closed and Open-sided Housing Systems. Asian Australian Journal of Animal Science. 23:1614-1625.

2. Barroga AJ, Pradhan R and Tobioka H. 2001. Evaluation of fish silage-sweet potato mixed diet with Italian ryegrass silage as basal ration on nitrogen utilization and energy balance in growing lambs. Journal of Animal Sci 72: 189-197.
3. Darsan MG, Sreekumar KP and Jalaludeen A. 2009. Effect of feeding processed fish wastes on the growth and haematology of broilers. Indian Journal of Poultry Science. 44: 213-217.
4. Duncan DB 1955. Multiple range and F-tests. 11: 1-42.
5. Espe M, Haaland H and Njaa LR. 1992. Substitution of fish silage protein and a free amino acid mixture for fish meal protein in a chicken diet. Journal of Science Food and Agriculture. 58: 315-319.

6.    Gildberg A. 1993. Enzymatic processing of marine raw materials. Process Biochemistry. 28: 1-15.

7. Johnson RJ, Brown N, Eason P and Sumner J. 1985. The nutritional quality of two types of fish silages for broiler chickens. Journal of Science Food and Agriculture. 36:1051-1056.
8. Kjos NP, Herstad O, Overland M and Skrede A. 2000. Effects of dietary fish silage and fish fat on growth performance and meat quality of broiler chicks. Canadian Journal of Animal Science. 80:625-632.
9. Magana L, Avila E and Sotelo A. 1999. Silage preparation from tuna fish wastes and its nutritional evaluation in broilers. Journal of Science Food and Agriculture. 79:1915–1922.
10. Sakthivel PC, Mercy AD and Viswanathan TV. 2005. Feeding value of dried cuttle fish waste silage on the growth performance of broiler ducks. Tamilnadu Journal of Veterinary Animal Science. 1: 15-21.
11. Smitha NF, Mercy AD, Viswanathan TV and Mercy KA. 2006. Effect of replacing fish meal with fish waste silage on the performance of’ broilers, Indian Journal of Animal Nutrition. 23: 125-127.
12. Snedecor GW and Cochran WG. 1989. Statistical methods. 8^th Oxford and IBH Publishing Company, New Delhi.
13. Tanuja S, Mohanty PK, Kumar A, Moharana, A and Nayak SK. 2014. Shelf Life Study of Acid Added Silage Produced from Fresh Water Fish Dressing Waste with and without the Addition of Antioxidants. International Journal of Agriculture and Food Science Technology. 5:91-98.
14. Vedhanayakam K, Jaganafhan, V and Venkatakrishnan R. 1976. Use of fish silage in chick rations, Cheiron. 5: 122-125.