With increasing demand and competition in the poultry sector, quail farming is making an impressive debut among the poultry farmers. A remarkable increase in the population of quails has been noticed in India according to livestock census (2012). Further research regarding the cost-effective ways of quail feeding and rearing is the need of the hour to explore this unexplored area of Indian poultry farming. India accounts for 5.68% of the global fish production. Indian Aquaculture is extremely promising and has grown over around seven fold in the last two decades with freshwater aquaculture contributing over 95% of the total aquaculture production. It is estimated that only 40% of the raw material is utilized for human consumption. The remaining 60% of the raw material is considered processing waste and can be utilized for low-valued products. Fish silage is a liquid product produced from the whole fish or parts of it, to which acids, enzymes or, lactic acid producing bacteria are added, with the liquefaction of the mass provoked by the action of enzymes from the fish. After collection and processing of fish wastes, fermented fish silage (FFS) is prepared by adding jaggery to the paste. The decrease in pH below 4.5 during fermentation is responsible for preservation of the product. The dry matter, crude protein, crude fat and total ash percentage of fermented fish silage estimated are 40.55±0.52%, 15.56±0.53%, 33±2.26%, 4±0.34% and 25.39+0.29 %, 38.97+1.46 %, 38.75+1.06 %, 4.56 ± 0.23% respectively. The various studies regarding the use of fish silage based diet in poultry concludes that the supplementation of fermented fish silage is adequate enough to meet the normal protein requirements of different poultry birds and the body weight, body weight gain, feed conversion ratio and percentage of carcass yield did not show any significant difference by the dietary inclusion of fish silage compared to control diet in most of the commercial poultry birds. The balanced protein, fat and mineral content of the fish silage could be made use of in preparation of poultry, fish and livestock feed as well as fertilizer. Therefore supplementation of fish silage in the poultry ration would not only increase the revenue without compromising the nutritional status, feed efficiency, growth, serum biochemistry and overall performance of birds but this practice would also help the fish industry to increase their income and provide a safe methodology to mitigate the pollution generated from fish waste.
The poultry industry; an integral and dynamic part of India’s livestock sector plays many dimensional roles in improving the socioeconomic condition of the poor farmers along with providing them a source of sustainable livelihood. Poultry is the quickest source of meat and eggs and its production involves the least hazardous process in relation to other livestock enterprises. At present, poultry is one of the fastest growing segments of the agricultural sector in India. India has emerged as the world’s fifth largest poultry meat producer with annual production of 2.2 million tonnes (BAHS-2012, Department of Animal Husbandry, Dairying & Fisheries, M/O Agriculture).
With increasing demand and competition in the poultry sector, quail farming is making an impressive debut among the poultry farmers. To meet the ever increasing demand for fast food as well as to compete with the broiler and layer industries, another alternative and evenly competitive farming has become vital for the existence of the farmers. Quail being the smallest among various poultry species is farmed worldwide for its quality meat and egg production (Baumgartner, 1994). Quail meat and eggs are considered to be a good alternative source of cheaper animal protein in terms of very low fat and cholesterol content which makes it the choice of people suffering from high blood pressure (Rogerio, 2009). The eggs and meat produced from quail are considered to be nutritious which makes it a vital species in agricultural sector (Kayang et al., 2004). The nutritional value of quail eggs is three to four times greater than chicken eggs and is rich sources of antioxidants, minerals, vitamins, and gives us a lot of nutrition than do other foods (Lalwani, 2011). It helps in alleviating anaemia by increasing the level of haemoglobin in the body while removing toxins and heavy metals.
Quail is popularly known as Bater. Japanese quail (Coturnix coturnix japonica) belongs to class Aves, order Galliformes and family Phasianidae. They are sexually dimorphic birds, exhibiting both monogamous and polygamous relationships. Efficient growth rate results in rapid and early maturity at the age of six weeks (Wilson et al., 1961) leading to its suitability for commercial rearing under intensive management (Egbeyale et al., 2013). It is also known as coturnix quail. Due to similarity to chicken in several aspects, quails have been used as pilot animal for pathological, nutritional and physiological studies (Singh et al., 2015). Quail farming has been accepted by farmers as a potential alternative to chicken farming because of its small size, delicacy, cardiac friendly, nutritious meat and egg production potentiality, short incubation period, less floor space requirement, rapid growth, short generation interval, less susceptibility to disease and low feed intake (Amrutkar et al., 2013). Countries like Japan, India, China, Italy, Russia, and the United States have established commercial Japanese quail farming industries (Hubrecht and Kirkwood, 2010). This bird provides developing countries with a stable source of animal proteins and developed countries with a suitable alternative to chicken.
Feed cost accounts around 70% of the total cost of production which is a growing challenge for the poultry sector. Lack of quality protein sources with a good amino acid profile due to reduced availability and relative high cost is another eye catching problem. There are many non conventional feeds and by-products which if effectively utilized could improve the supply of poultry feeds. Fish by-products are the most important by-products available at reasonable prices and have the potential to be used as a high protein supplement in poultry feeding. Fish wastes can be advantageously upgraded into fish feed by fermentation with lactic acid bacteria. This procedure is safe, economically reasonable and environment eco-friendly. The pH value of the fish silage decreases below 4.5 during ensiling and this pH decrease is partially responsible for preservation (Soltan et al., 2008).
India is the 2nd largest producer of fish in the world with a share of 5.68% of the global total, as per FAO statistics. It is also world number two in aquaculture production as well as in inland capture fisheries. The total fish production in India during 2013-14 (provisional) is registered 9579 metric tonnes, with a contribution of 6136 metric tonnes from inland sector and 3443 metric tonnes from marine sector and in Odisha is 413.79 metric tonnes (Handbook on fisheries statistics, 2014). The average growth in fish production during 2013-14 stands at 5.96%, which has been mainly due to 7.29% growth in inland aquaculture and the remaining 3.67% growth from marine sectors (Handbook on fisheries statistics, 2014).
The processing of fish mainly generates waste products such as scales, fins, viscera and the bones which is about 60% of total weight of fish (Gildberg, 1993), which produces a total of more than two million tonnes of waste per year which is a major cause of environmental pollution (Kjos et al., 2000, Barroga et al., 2001). Among the total waste, the waste from the viscera only accounts to be about 30,000 tonnes, causing environmental pollution. The fish wastes can be converted to fish-meal, which can be a solution to the problem but again high cost involved in fish-meal preparation and its periodic scarcity have encouraged the people to go for preparation of some alternative protein feedstuffs from fish wastes (Fagbenro and Jauncey, 1998). Fish silage has been recommended as an alternative source for utilization of fish waste, or fish industry by-products providing with a high quality protein source for feeding of animals (Zynudheen et al., 2008). Fish ensiling requires less advanced technology than fishmeal production, and is more convenient in areas where fish waste is neither available in the quantities nor on a regular basis as required for profitable fishmeal production. In regions, where by-catch surplus or fish wastes are available, fish silage represents a possible alternative to fishmeal as a source of animal protein.
Primarily the fish silage concept derived from Sweden in the year 1930 followed by Denmark producing the first commercial fish silage in 1940. Fish silage is basically a liquid product made from either whole fish or parts of fish that are liquefied by action of enzymes in the fish in the presence of added acids, enzymes or, lactic acid producing bacteria. This is an excellent protein product of high biological value and can be used as a feed supplement for fish, livestock and poultry or also as a fertilizer. During silage processing, enzymes found in muscles hydrolyze proteins and nitrogen becomes more soluble. Proteins are hydrolyzed to free amino acids, thus making silage the most available amino acid source for protein biosynthesis (Espe et al., 1992). The process of acidification is aided by the lactic acid bacteria leading to the activation of digestive endogenous proteases, which help in the liquefaction. Hydrolysis of protein takes place which improves the digestibility due to production of peptides and highly soluble free amino acids Proteins from fermented silages are more digestible than those from acid addition (Vidotti et al., 2003).
Fish or, its waste contains only small amount of free sugar. Therefore fermented fish silage can be prepared by addition of fermentable carbohydrate sources like molasses, lactose, dextrose, and corn or tapioca flour etc. as a source of carbon for growth of different micro organisms. Different workers have used molasses at 10-15% level. Molasses was preferred as it was relatively cheaper. In biological ensiling the acidifying flora may be naturally present in fish waste or, carbohydrate source or, added as a pure starter culture like Lactobacillus plantarum, Pedioccocus acidilacticiand Lactobacillus acidophilus. Lactobacillus plantarum, which is homofermentative, has been shown to be very effective starter culture. These bacteria produce large amount of lactic acid which decreases the pH and renders the medium unsuitable for growth of other microbes (Raa and Gidberg, 1982). Some lactic acid bacteria produce antibiotics which contribute to the preservation of the product. The fermentation of biological silage in presence of lactic acid bacteria (LAB) can provide the revival of different bio-molecules and also prevents the process of rancidification (Rai et al., 2010). In presence of some LAB, the enzymes like amino oxidases help in degradation of various biogenic amines. Fermentation adds flavour to fish silage which hides the fish odour of the product and may prevent rancidification and other chemical reaction which cause quality reduction. The biological silage produced by lactic acid fermentation is cheaper with higher nutritional value than the product preserved by chemicals. The recovery of several value-added compounds from aquatic sources, such as proteins, lipids, minerals and chitin can be made possible by the use of this process (Cira et al., 2002; Plascencia et al., 2002).
Procedure for Preparation of Fermented Fish Silage (FFS)
After collection of dressed waste (intestine and gills) of marine or fresh water fishes, these wastes are generally washed in portable water, chopped and ground using meat grinder into paste for silage preparation. Fermented Fish Silage (FFS) can be prepared by adding jaggery to the paste. 200g (20%) jaggery is mixed with 1 kg fish silage. Addition of 200ml water is done to make it more liquid. 200ppm Butylated Hydroxytoluene (BHT) also added to prevent auto oxidation & 0.1% potassium sorbate can be added as mould inhibitor. 0.2 g BHT and 1 g potassium sorbate are mixed with 1 kg fish silage. Ensilation process is aided by incubating the materials in air tight plastic containers at room temperature (28-30o C). The silage is stirred twice daily to ensure the uniform distribution of jaggery. The fermentation process normally takes about a week. The pH value of the fish silage decreases below 4.5 during ensiling which is an indicator of successful lactic acid fermentation and this pH decrease is partially responsible for preservation of silage. The odour of the silage is generally agreeable and the colour of FFS is dark brown. The silage appears as thick solid mass for the first 24 hours but gradually becomes semisolid as the liquefaction proceeds and finally is converted to thick liquid.
Determination of Proximate Composition of Fermented Fish Silage (FFS)
The processing of fresh water fishes results in considerable quantities of processing; discards of which visceral waste is the major one. Ensilation using different fermentable carbohydrate sources could be the viable alternative to convert these waste into useful by products. The dry matter, crude protein, crude fat and total ash content of the FFS is generally estimated using the AOAC (1995) procedure. In short, the dry matter content is determined by drying the homogenate in a hot air oven at 1050C until a constant weight is obtained. The crude protein content can be calculated by converting the total nitrogen concentration (6.25 x N) determined with the Kjeldahl procedure. Crude fat (ether extract) is determined using the Soxhlet extraction system. Ash content is measured by dry ashing in a muffle furnace at 5500C for 6 h. The dry matter, crude protein, crude fat and total ash percentage of fermented fish silage estimated are 40.55±0.52%, 15.56±0.53%, 33±2.26%, 4±0.34% and 25.39+0.29 %, 38.97+1.46 %, 38.75+1.06 %, 4.56 ± 0.23% respectively. The low fat content of silage might be due to the fact that oil is efficiently trapped in the microbial silage because of the high binding capacity of the supplementary polysaccharide and the slow autolysis of the fish proteins (Raa and Gildberg, 1982). The proximate composition of fermented fish silage (FFS) has been presented in Table 1.
Table 1: Proximate composition of fermented fish silage prepared from fresh water fish visceral waste
Effect on Growth, Feed Consumption and Feed Conversion Efficiency
The study regarding the utilization of fish by-products as fish silage in the nutrition of poultry where two levels of fish silage (2.5 and 5.0%) were used as an alternative source of protein showed that feeds containing fish silage gave significantly higher feed utilization (Balios, 2003). In another experiment, Ganegoda et al., 1982 studied the effect of dried fish silage as a protein source for poultry. Formic acid ensiled silver belly fish silage was compared with silver belly fish meal in a seven-week feeding experiment with 288 broiler chickens. It was reported that food intake, weight gain and food conversion efficiency were less on the fish silage diets than on the fish meal diets. In contrast to this, Krogdhal, 1985 investigated the effect of acid added fish silage (formic and propionic acid) as protein source in diets of broiler chicks and meat-type ducks. The silage was used in replacement for herring meal as well as soybean meal protein and comprised up to 40% of dietary crude protein. The parameters like broiler performance; weight gain, utilization of metabolizable energy and nitrogen were not influenced negatively by the viscera silage. The ducks fed viscera showed comparatively better performance. Fish viscera silage has the potential of becoming a protein source for poultry. During the evaluation of nutritional quality of two types of fish silage for broiler chickens, no significant effects related to performance of birds were observed Johnson et al., 1985. Ensilation of the fish waste was done either by adding formic acid or by fermentation with a bacterial starter culture and molasses. The production of acid silage meal (ASM) and fermented silage meal (FSM) was done thereafter by adding wheat bran (85:15 w/w liquid: bran) to the resultant liquid and dried up to 70ºC. The wheat-based diets were incorporated with 25, 50 and 100 g kg−1 of ASM and FSM at the expense of soya bean meal. Two control diets were prepared containing soya-bean meal as the predominant protein supplement in one diet and addition of fish meal (50 g kg−1) was done at the expense of some of the soya-bean meal in the other control diet. The six replicate groups each containing five birds were fed starter diets (13.25 MJ ME kg−1, 12 g kg−1 lysine) from 1-day-old to 21-days-old and finisher diets (13.25 MJ ME kg−1, 9.5 g kg−1 lysine) from 22 to 42-days-old age. No significant effects were observed due to the dietary inclusion of either ASM or FSM on the feed consumption and live weight of broiler chickens compare to those fed on control diets. Regarding the food conversion ratio of chicks incorporated with fish silage based diets; Machin et al., 1990 conducted a feeding trial on performance of broiler chicks fed on low and high oil fish silages. The diets containing the silages dried on to cassava meal, or fish meal produced from the same batch of fish were fed to the chicks. The weight gains of chicks fed on balanced diets containing 4.7 or 9.4% crude protein from high oil fish (HOF) silage (9.8 and 19.6% of the dietary dry matter) and 5.2 or 10.4% crude protein from low oil fish (LOF) silage (6.8 and 13.5% of the dietary dry matter) were 99, 85 and 98 and 91%, respectively, of the gains achieved with corresponding fish meals. Food conversion ratios for the above dietary treatments were respectively, 97, 103, 101 and 99% of those of chicks fed on fish meals. In another 28-day growth trial in broiler chicks the nutritional qualities of fermented fish waste, fermented whole herring, and herring fish meal were evaluated by incorporating each ingredient at 5% or 10% level into balanced diets. During the study, Nwokola and Sim, 1990 found that the three fish products sustained significantly different (P<0.05) average feed: gain ratios in broiler chicks. The highest such ratio was associated with the chicks fed fermented herring. In contrast to this, another study was undertaken on the effect of concentrated fish silage and additional fish fat on growth performance by allocating 600 day-old male and female chicks with an initial weight of 36.3 g ± 0.6 SD to five treatment groups (8 replicates, each containing 15 birds) and fed with control diet, two test diets with 50 g kg–1 fish silage and different levels of fish fat (6 or 8 g kg–1), and two diets with 100 g kg–1 fish silage and different levels of fish fat (8 or 10 g kg–1), Kjos et al., 2000 found that chicks fed diets with fish silage had a greater weight gain (P<0.001), a greater feed intake (P<0.05) and a lower feed-to-gain (MJ ME kg–1) (P<0.001) than those fed the control diet.
There are a few evidences regarding the use of fish silage when it comes to the dietary quality of feed due to addition of fish silage. Espe et al., 1992 studied the substitution of fish silage protein and a free amino acid mixture for fish meal protein in a white Leghorn chicken diet. A basal diet containing about 550 g kg−1 of the protein from fish meal were fed to the White Leghorn chickens. The parts of the dietary fish meal protein (150 and 300 g kg−1 fish meal protein) were substituted with graded amounts of fish silage protein or an amino acid mixture simulating fish meal protein. Better growth and feed efficiency were observed in fish silage protein. The replacement of dietary fish meal with fish silage did not diminish the dietary quality of the feed for young growing chickens. Another experiment was conducted by Hammoumi et al., 1998 on characterization of fermented fish waste used in feeding trials with broilers by taking chopped pilchard waste mixed with 15% molasses and inoculated with Lactobacillus plantarum for a fermentation period of 15 days. The fermented product was incorporated with bran and barley to make 3 formulas, which were then fed to broilers in 4 trials using 5 broilers each. The weight gain was recorded for 20 days. Total nitrogen content of silage decreased while non protein nitrogen and total volatile nitrogen content increased. The study indicated that there is a considerable potential for the use of fish silage as a nitrogen source and as a probiotic ingredient for poultry feeding.
Regarding the experimentation on the growth of broiler chicks fed with fermented fish viscera silage where isonitrogenous (21% protein) and isocaloric (ME=2900K Cal/kg) diets for broiler chicks were formulated replacing 25% and 50% fish meal by fish viscera silage along with fish meal at 8% (w/w) was kept as control. Consumption of diets containing silage was 7.3% lower, resulting into about 5% reduction in growth compared to control. During the experiment, Javeed et al., 1996 found that the cumulative feed conversion ratio was in the range of 2.20 to 2.29 and was not influenced by diets. It was suggested that fish meal up to 50% can be replaced by fish viscera silage in broiler diets without significantly affecting growth. In contrast to the above findings, Rathina et al., 1996 observed a comparatively higher feed consumption in broiler chickens due to addition of fish silage. During the study on the effect of feeding extruded diets containing fermented fish and poultry offals on growth of broiler chickens where fish meal at 5% (w/w) in the diet was treated as control and 50% of fish meal was replaced either by fermented fish viscera silage (FVS) or by poultry intestine silage (PIS) in two experimental diets, Rathina et al., 1996 observed the consumption of silage diets was more by 19.4% in FVS and 16.7% in PIS compared to control. Feed conversion efficiency of silage diet was also better (FCR = 2.12 for FVS, 2.27 for PIS and 2.62 for fish meal diets) resulting in better growth in birds fed with silages. Another study conducted by Widjastuti et al., 2011 on the effect of Tuna (Thunnus atlanticus) fish silage in ration on the performance of broiler by allocating 100 broiler day old chicken into 4 treatment groups (5 replicates, each containing 5birds) and fed fish silage at 0, 4, 6 and 8% levels concluded that waste of Tuna fish silage up to 4 percent level in ration had optimal response on the final body weight (1755.03g, 1844.87g, 1654.84g, 1439.53g, respectively).
Kaur et al., 2005 conducted a 30 week experiment to evaluate the effect of dietary protein quality on laying Japanese quails. One hundred and four, 5 week old quails divided into 2 groups with 26 replicates each containing 2 birds were given soybean meal (D1) or, fish meal replacing 5% of soybean meal (D2). It was observed that feed intake and feed utilization did not differ due to protein quality. The gain in body weight continued up to 14th week of age. It was concluded that fish meal supplementation was not required if the diet of laying quails was adequately balanced with the critical amino acids, calcium and available phosphorous. On the other hand a further 8 week trial was conducted by Collazos and Guio, 2007 to evaluate the effects of biological fish silage supplementation in laying Japanese quails. A total of 120, 60 day old laying Japanese quails were distributed into 4 treatments (controls, 2, 4 and 6% of biological fish silage), with 5 replicates and 6 birds per replicate. Feed consumption was measured weekly. It was observed that feed intake, feed efficiency, body weight variation were not affected (P>0.05). Biological fish silage can be included in laying diets of Japanese quails up to 6% without adverse effects on performance. Another different study on the effect of replacing unsalted dried fish with fish waste silage on nutrient utilization and growth of broiler chicken by allocating day old (Vencob) broiler chicks (180) into three groups (5 replicates, each containing 12 birds) and offering isonitrogenous and isocaloric rations in which protein of unsalted dried fish was replaced by fish waste silage at 0, 50 or 100% levels indicated that the cumulative feed intake & feed conversion ratio of birds in the 3 different dietary treatments did not differ significantly (P>0.05). Smitha et al., 2005 in this study concluded that fish waste silage could be added replacing unsalted dried fish in the broiler ration without any harmful effects. Coming to the research regarding the ducks, two experiments were conducted by Sakthivel et al., 2005 to evaluate the effect of supplementing dried cuttle fish waste silage in the diets of White Pekin broiler ducks. Replacement of dried fish by dried cuttle fish waste silage was done at 0 and 100 percent levels in isocaloric and isonitrogenous starter and finisher diets under experiment 1 while the replacement was done at 0, 50 and 100 percent levels in experiment 2. No significant difference was observed in Body weight, feed efficiency, average daily gain and feed intake due to dietary inclusion of dried cuttle fish waste silage up to six weeks of age in both the experiments. Body weight gain was significantly lower (P<0.01) in cuttle fish waste silage fed group at eighth week of the first experiment, but there was no difference between the groups in the second experiment. Basing on these experimental conclusions, another investigation was performed to evaluate the effect of dietary supplementation of fermented fish silage on performance of Japanese quail. The birds were divided at a random basis into three different groups consisting of 48 quails in each group. The experiment was conducted for a period of 28 days. During the experiment, Zynudheen et al., 2008 observed no significant difference in the body weight gain in birds supplemented with fermented fish silage as compared to that of dried fish waste and unsalted dried fish supplemented groups of birds. In agreement to this experimental finding, Boitai, 2015 studied the effect of feeding acid treated fish silage on the performance of broiler chickens during 0 to 6 weeks of age. A total of 180 day old Vencobb broiler chicks were randomly distributed into three dietary groups with three replicates in each group with 20 chicks in each pen. The birds were offered three different diets such as control (without fish silage), 5% AFS and 10%AFS during the period of study. All the diets were isocaloric and iso-nitrogenous. The body weight, body weight gain, feed conversion ratio and mortality did not show any significant difference by the dietary inclusion of acid treated fish silage compared to control diet in commercial broiler chicken. Significantly lower feed consumption was noted in 10% fish silage group compared to 5%fish silage and the birds with control diet. The researcher concluded that AFS can be included up to 10% in the diet of broiler chickens.
An 8 week feeding trial was conducted to know the effect of replacing fish waste meal with shrimp waste meal at five levels (0, 25, 50 75 and 100%) on broiler chicken performance by distributing 204 day old chicks of Anak breed into 6 groups of 5treatments and one control of 34birds each, subdivided into 2replicates of 17 birds each and offered iso-nitrogenous and iso-caloric diets. No significant difference was observed in average weekly feed intake (P<0.05). Best weight gain (212.20 g ±9.73 and 520-439±28.61 for the starter and finisher phases respectively) was resulted at a replacement level of 0% while the 100% replacement level had the least (P<0.05) weight gain in both phases. FCR was best (P<0.05) at the 0% level (1.67±0.12) for the combined phase while the lowest value was recorded for the 100% level in the combined phase. The replacement of fish waste meal with shrimp waste meal was directly proportional to the rate of feed consumption and FCR but indirectly proportional to weight gain. The experimental findings recommend that the 0%, control and 25% level of replacement of fish waste meal with shrimp waste meal were optimum for the performance of broiler chicken (Ingweye et al., 2008). In contrast to the above mentioned results, further investigation was done by Darsana et al., 2009 on the effect of complete replacement of fish meal with processed fish wastes; viz, fish waste acid silage (fish waste mixed in 3% formic acid and dried) and surimi waste powder (fish waste cooked in 20% water and dried) on the body weight, feed efficiency and haematology of broiler chicken. Two experimental diets were formulated by replacing 100 per cent of fish meal in the control diet with fish waste silage and with surimi waste powder. These diets were allotted to the groups G-II and G-III, respectively. While the group G-I was fed with standard broiler finisher ration of BIS specification, which formed the control diet. The rations of G-I, G-II and G-III were made isocaloric and isonitrogenous. It was concluded that there was no significant difference in the body weight & feed consumption between any of the experimental groups. The feed efficiency was also similar in all the groups. There are also some remarkable findings in relation to the performance and carcass characters of different groups of poultry species. AI-Marzooqi et al., 2010 evaluated the effect of feeding fish silage on performance and meat quality characteristics of broiler chickens raised under closed and open-sided housing systems by allocating 240 day old vencob broiler chickens in 48wire cages(24 cages in each, a closed and open sided) into 4 treatment groups(6 replicates- each 5 birds) for every 120 birds. 85% fish silage was mixed with 15% crushed corn and dried. Four diets containing various levels of fish silage-crushed corn mixture (0, 10, 20 and 30%) were evaluated. It was observed that the type of housing had significant effects on feed intake and body weight gain (P<0.01). The feed consumption was 4.7% lower in case of birds in the open-sided house and they gained 10.6% less than their counterparts in a closed house. Birds in both houses fed diets containing 10 and 20% fish silage performed better as compared to the birds fed 30% fish silage. It was concluded from the current study that fish silage can replace up to 20% of soybean meal in broiler diets without affecting growth performance of broiler chickens. In agreement to the above experimental findings, Ramirez et al., 2013 studied the effect of biological fish silage on the performance of quails (Coturnix coturnix japonica). A total number of 160, 21 day old quails were distributed into 4 treatment groups and each treatment with four replicates. An oven-dried mixture of fish silage and soybean meal (1:1 w/w) was used to prepare the diets with different levels of inclusion (0, 10, 20 and 30%). The study showed that the inclusion level did not affect the growth and feed conversion ratio.
One of the major requirements for maximum production from poultry sector includes good feeding. Hence nutrition plays a vital role on the performance; health and welfare of the animal and quality of feed as well as efficiency in feeding are the key factors for successful production. Regarding the dietary assessment of fish silage, Magana et al., 1999 experimented on the preparation of tuna fish wastes silage and its nutritional evaluation in broilers. 70% fish silage was mixed with 30% sorghum. Four starter diets for 9-day-old broiler chicks were prepared at different levels from the final dried silage (5, 10 and 15%). The control diet (0%) contained soybean meal as the predominant protein supplement. There was no significant difference in the feed intake, weight gain and feed conversion on the final dried product (P<0.05). It was reported that 15% of this product can be included without adverse effects on broilers. In addition to this, another study was conducted by Babu et al., 2005 on biochemical and microbiological quality of Formic acid silage and Lactobacillus fermented silage. Formic acid @ 2%, 2.5%, 3%(v/w) added to silver belly(Leiognathus sp.) mince to produce acid silages(AS) where as Lactobacillus plantarum culture @5%(v/w) along with molasses @ 10% and 12%(v/w) mixed with fish mince to prepare fermented silage(FS). Addition of sodium benzoate @0.5 %( w/w) done to FS to inhibit mould growth. Microbiological quality of AS and FS was found to be good as indicated by the absence of total coliforms, faecal coliforms, E. coli, Salmonella, Vibrio cholerae, coagulase +ve, Staphylococci and H2S producing bacteria. AS had relatively higher fungal count than FS along with total yeast mould count was highest in AS (1600/g). Delgado et al., 2007 conducted a different experiment on the preparation of silage from whole Spanish mackerel & its evaluation in broiler diets. The liquid silage obtained was mixed with sorghum (1:2 w/w). This silage-sorghum flour was used to prepare five diets with different silage-sorghum mix inclusions, (0,110, 220, 330 and 440g/kg of diet) and evaluated in a 21 d feeding trial with broilers. In the feeding trial, there were no differences between the weight gain and feed conversion of the control diet and the four diets prepared with increasing amounts of silage-sorghum mix (P<0.05). It was concluded that silage-sorghum mix is a good alternative to use as fish wastes or undesirable marine species in poultry feeding. A further comparative evaluation was done by Ozyurt et al., 2015 on the composition of fatty acid and biogenic amines in acidified and fermented fish silage. Production of fish silage was done by using Klunzinger’s pony fish through the process of acidification (3% formic acid or, 1.5% formic acid and 1.5% sulphuric acid) and fermentation (Lactobacillus plantarum and Streptococcus thermophilus). The different nutritional, microbiological and chemical properties were estimated during a storage period of 60 days at ambient temperature. A slight increase in saturated fatty acid and a slight decrease in polyunsaturated fatty acid were observed in all silages as compared to the raw material. The acidified or fermented fish silage should be considered as potential feed component for animals not only because of its high nutritional value but also due to its appropriate microbiological and chemical quality.
Effect on Carcass Characteristics
An investigation regarding the use of concentrated fish viscera silage, preserved by acid (formic and propionic acid) as protein source in diets for broiler chicks and meat-type ducks was carried out by Krogdhal, 1985. The silage was used in replacement for herring meal as well as soybean meal protein and comprised up to 40% of dietary crude protein. The parameters like broiler performance; weight gain, utilization of metabolizable energy and nitrogen were not influenced negatively by the viscera silage. The ducks fed viscera showed comparatively better performance. On the other hand, during the study on the growth and meat quality of broiler chicks fed with fermented fish viscera silage where isonitrogenous (21% protein) and isocaloric (ME=2900 kcal/kg) diets for broiler chicks were formulated replacing 25% and 50% fish meal by fish viscera silage, Javeed et al., 1996 found that silage had no marked effect on dressing yields (68.2-68.4%). It was suggested that fish meal up to 50% can be replaced by fish viscera silage in broiler diets without significantly affecting the meat quality. Another evaluation was done on the effect of feeding extruded diets containing fermented fish and poultry offals on meat quality of broiler chickens by Rathina et al., 1996. Fish meal at 5% (w/w) in the diet was treated as control and 50% of fish meal was replaced either by fermented fish viscera silage (FVS) or by poultry intestine silage (PIS) in two experimental diets. Yield of carcass was 69.2 – 70.2%. Fishy taint was observed in cooked muscles from birds fed with FVS and fish meal.
Ingweye et al., 2008 conducted an 8 week feeding trial to know the effect of replacing fish waste meal with shrimp waste meal at five levels (0, 25, 50, 75 and 100%) on broiler chicken performance by distributing 204 day old chicks of Anak breed into 6 groups of 5treatments and one control of 34birds each, subdivided into 2 replicates of 17 birds each and offered iso-nitrogenous and iso-caloric diets. The percent liver, gizzard, abdominal fat, drumsticks, and breast were significantly (P<0.05) affected by treatment application. In agreement to the above finding, another study was conducted on the effect of dietary amino acids profile with or without fish meal on meat production in Japanese quail for a period of 5 weeks by Kaur et al., 2009. 928 day-old Japanese quails were divided into 24 groups. Eight diets with four levels of EAA (90, 100, 110 and 120%) ; each with or without fish meal were formulated and each diet was offered to 3 replicated groups. 10 quails from each treatment were sacrificed at the end of the experiment to study the carcass traits and meat composition. The blood loss and feather loss did not differ significantly (P> 0.05). The eviscerated carcass yield was lowest at 90% EAA level with or without fish meal. The relative weight of gizzard and giblet was lower at 110 and 120% EAA level as compared to 90% EAA level where as Widjastuti et al., 2011 experimented regarding the effect and optimal of adding waste product of Tuna (Thunnus atlanticus) fish silage in ration on the performance of broiler by allocating 100 broiler day old chicken into 4 treatment groups (5 replicates, each containing 5birds) and fed fish silage at 0, 4, 6 and 8% levels. It was concluded that waste Tuna fish silage up to 4 percent level in ration had optimal response on carcass percentage (69.20%, 72.63%, 67.85%, and 65.90% respectively). In contrast to this, Ramirez et al., 2013 studied the effect of biological fish silage on the performance of quails (Coturnix coturnix japonica). A total number of 160, twenty one day old quails were distributed to 4 treatment groups. Four replications per treatment (experimental diets) were carried out. An oven-dried mixture of fish silage and soybean meal (1:1 w/w) was used to prepare the diets with different levels of inclusion (0, 10, 20 and 30%).The study showed that the carcass yield (70.3%) were not significantly different among the treatments (P>0.05).
Effect on Serum-Biochemical Parameters
Serum biochemical profile elicits nutritional and physiological status of an individual. An evaluation of biotransformation of fish waste into a stable feed ingredient was done by Faid et al., 1997 in which chopped pilchard wastes, viscera, head and tails were mixed with 25% molasses and inoculated with Saccharomyces sp. and Lactobacillus plantarum for a fermentation period of 15 days. pH along with Coliform and Clostridium counts decreased considerably. Total nitrogen decreased while the non protein nitrogen and total volatile nitrogen increased significantly. The occurrence of mixed fermentation by pure cultures of yeast and lactic acid bacteria strains could be involved in preservation, transformation and the improvement of the organoleptic quality of the obtained product.
Another experiment was conducted by Ozcelik et al., 2004 on the effect of high environmental temperature on the blood parameters of Japanese quails with different body weights. Two temperature groups consisting of control (18-240C) and experiment (350C) and two weight groups such as heavy group (live weight >27 g) and light group (live weight < 27 g) were constituted. The effect of high temperature on the parameters like total protein, albumin, phosphorous, triglyceride and total cholesterol varied significantly where as the effect on AST, ALT and calcium were found non significant at the end of the research. In contrast to the above findings, Darsana et al., 2012 conducted an experiment on forty five broiler chickens at 4 weeks of age, for a period of three weeks, to assess the effect of complete replacement of fish meal with processed fish wastes (fish waste acid silage and surimi waste powder) on the blood protein, lipid and antioxidant status in broiler chicken. At three weeks of age, they were randomly divided into three groups viz., GI, GII and GIII of 15 birds each. Two experimental diets (D2 and D3) were prepared by replacing 100 percent of dried unsalted fish (animal protein) in the finisher ration of the control diet (D1) by processed fish waste acid silage (D2) and surimi waste powder (D3). All diets were made isocaloric and isonitrogenous. GI, GII and GIII were fed with D1, D2 and D3 diets, respectively from the 4th to the 7th week of age. The result showed that the serum total protein, albumin and globulin, triglycerides, total cholesterol were similar in all the groups and the major elements (Na, K, Ca and Mg) and iron were similar in all the groups and were within the normal levels; however similar results were obtained during the study of the effect of dietary inclusion of 0, 5 and 10% AFS on serum biochemical parameters of broiler chickens at 6 weeks of age (Boitai, 2015). The total protein, albumin, globulin, A/G ratio, calcium and triglycerides concentration in the serum did not vary significantly due to dietary inclusion of 10% AFS in the diet of broiler chickens. However, significantly (P<0.05) higher concentration of total cholesterol in the serum was observed due to 10% AFS compared to that of control (0%AFS).
Economics of Quail Production with Fermented Fish Silage Supplementation
Sakthivel et al., 2005 conducted two experiments to evaluate the effect of supplementing dried cuttle fish waste silage in the diets of White Pekin broiler ducks. Dried fish was replaced by dried cuttle fish waste silage at 0 and 100 per cent levels in isocaloric and isonitrogenous starter and finisher diets in experiment 1, whereas in experiment II, dried cuttle fish waste silage replaced dried fish at 0, 50 and 100 per cent levels. The treatment groups showed lower feed cost per kg gain as compared to that of the control in both the experiments. The cuttle fish waste silage can be used economically to substitute dried fish on protein basis in the diet of ducks without affecting growth rate or feed efficiency. In another trial, Smitha et al., 2005 studied the effect of replacing unsalted dried fish with fish waste silage on nutrient utilization and growth of broiler chicken by allocating Day-old (Vencob) broiler chicks (180) into three groups (5 replicates, each containing 12 birds) and offered isonitrogenous and isocaloric rations in which protein of unsalted dried fish was replaced by fish waste silage at 0, 50 or 100% levels. The cost of feed per kg gain of birds in the three dietary treatments was Rs. 20.15, 19.83 and 19.73, respectively. It was concluded that 9.7% fish waste silage could be added replacing unsalted dried fish in the ration of broilers with economic benefits.
Darsana et al., 2009 investigated the effect of complete replacement of fish meal with processed fish wastes; viz, fish waste acid silage (fish waste mixed in 3% formic acid & dried) and surimi waste powder (fish waste cooked in 20% water and dried) on the body weight, feed efficiency and haematology of broiler chicken. Two experimental diets were formulated by replacing 100 per cent of fish meal in the control diet with fish waste silage and with surimi waste powder. These diets were allotted to the groups G-II and G-III, respectively. While the group G-I was fed with standard broiler finisher ration of BIS specification, which formed the control diet. The rations of G-I, G-II and G-III were made isocaloric and isonitrogenous. It was showed that the complete replacement of animal protein (fish meal) in the finisher ration of broiler chicken with processed fish waste would reduce feed cost without comprising the nutritional status, feed efficiency and overall performance. Similar to the above experimental findings, Boitai, 2015 studied the economics of production of broiler chicken due to incorporation of 0 (control), 10 and 15% of AFS up to 10% in the diet of broiler chickens during 0 to 6 weeks of age. Considering the composition of three rations the cost per kg feed was Rs 28.24(control), Rs 27.45(T1) and Rs 26.07 (T2) fed during 0-3 weeks of age. Thus an approximately Rs 0.79 per kg feed and Rs 2.17 per kg of feed would be saved by supplementing 5% and 10% of the fish silage, respectively on air dry basis in broiler starter compared to control. The cost of feed consumed per chick was significantly higher (P<0.05) in T1 (Rs 22.17) than T2 (Rs 19.00) but the differences between control and T1 and control and T2 were found to be non significant. The cost of feed per kg live weight gain was significantly lowest (P<0.05) in T2, 10% fish silage group (Rs 44.21) than control, control diet (Rs 49.75) and T1, 5% fish silage group (Rs 51.78). Considering the composition of three rations the cost per kg feed was Rs 27.24(control), Rs 26.36(T1) and Rs 25.33 (T2) fed during 4-6 weeks of age. Thus an approximately Rs 0.88 per kg feed and Rs 1.91 per kg of feed would be saved by supplementing 5% and 10% of the fish silage, respectively on air dry basis in broiler finisher compared to control. During 4-6 weeks period the cumulative feed intake/ chick was highest in T1 (2265.52 g) than T2 (2103.16 g) but the differences between control and T1 as well as control and T2 were found to be non significant. The cost of feed consumed per chick was significantly lower in T2 (Rs 53.27) than control (Rs 61.42) but the differences between T1 and T2 as well as control and T1 were found to be non significant. The feed cost per kg live weight gain was significantly lowest in T2 (Rs 43.85) than control (Rs 48.78) and T1 (Rs 46.94) but the differences between control and T1 was found to be non significant. In agreement to the above mentioned findings, an 8week experimental trial was conducted to assess the effects of biological fish silage supplementation in laying Japanese quails (Collazos and Guio, 2007). A total of 120, 60 day old laying Japanese quails were distributed into 4 treatments (control, 2, 4, 6% of biological fish silage) containing 5 replicate groups and 6 birds per replicate group. Experimental diets were formulated according to the NRC recommendations. It was observed that the fish silage is capable enough to be utilized economically in various agricultural species.
Taking into consideration several advantages and drawbacks, it is concluded from the above study that fermented fish silage (FFS) can be included in the diet of broiler Japanese quails up to 5% level without affecting the performance and cost of production. The various studies regarding the use of fish silage based diet in poultry concludes that the supplementation of fish silage is adequate enough to meet the normal protein requirements of different poultry birds and the body weight, body weight gain, feed conversion ratio and percentage of carcass yield did not show any significant difference by the dietary inclusion of fish silage compared to control diet in most of the commercial poultry birds. The balanced protein, fat and mineral content of the fish silage could be made use of in preparation of poultry, fish and livestock feed. Therefore supplementation of fish silage in the poultry ration would not only increase the revenue without compromising the nutritional status, feed efficiency, growth, serum biochemistry and overall performance of birds but this practice would also help the fish industry to increase their income and provide a safe methodology to mitigate the pollution generated from fish waste.