Global consumption of fish and derived fish products has increased enormously in the last decades. The change in consumer trend can be due to a number of different factors. The most important of these is the increasing knowledge that fish constitute an important and healthy part of the human diet due to the presence of omega 3 polyunsaturated fatty acids (PUFA), which play an important role in human health. And these are due to the biological value of fish that contains high vitamins, minerals and proteins. As a result, it is a well-known fact that fish are a high quality food source.
Demand for fish is also increasing due to the increasing world population, higher living standards and the general good image of fish among consumers. Fish as a whole has a lot of food potential and can therefore be expected to provide relief from malnutrition, especially in developing countries. Superior quality protein and well-balanced essential amino acid profile from meat, milk and eggs provide essential minerals and fatty acids. In addition to the fact that fish meat is delicious and highly digested; It also minimizes the risk of heart disease and increases life expectancy.
Aquaculture is one of the fastest growing growth sectors in the world, and Asia currently contributes about 90% to global production. Protein-rich diets and use as a source of income are especially for people who are economically weak. However, the continued increase in fish meal prices and disease outbreaks restrict aquaculture production and therefore affect both the economic development of the country and the socio-economic situation of the local population in many countries of Asia. However, the use of probiotics is one of such methods that gains importance in the control of potential pathogens.
Fruit processing waste and vegetable waste are potential energy sources that should be used as an ingredient in fish feed in urban areas. In India, 35 million tons of fruit and vegetables are processed annually, resulting in approximately 10 million tons of waste. This waste from fruit processing operation creates a great unused energy and protein source. Most of this waste is just dumped on the fields, which causes pollution. Possible uses of these wastes in animal feed preparation have been suggested by some workers. The use of these large wastes often goes unnoticed by animal nutritionists, especially in the case of fish feed. Fish consumption is associated with health benefits due to its rich content in high nutritional proteins, minerals, vitamins and distinctive lipids.
Very little attention has been paid to the use of vegetable and fruit processing wastes that are very cheap, easily available and high in fiber. In view of the above, this study was carried out on Labeo rohita’s fingers. This study aims to formulate fish feeds composed of by-products and nutritious food industry waste-based materials using a quality assessment with probiotics and to evaluate the effects on fish treated with this new type of feed.
Fish Food Formulation and Preparation
Waste was collected from various food processing industries, approximately 2 kg of orange and potato peel wastes were collected and dried continuously for 1 week. One week after oven drying these were pulverized. The powder was used as a medium to grow probiotics. Pure probiotic culture was inoculated into the filtrate used as medium under sterile conditions and incubated at 37 ° C for 24 hours and growth was observed after 24 hours. Calcium carbonate was used to immobilize the probiotic spores grown in the medium. The experimental diet contained 4% potato peel powder or 4% orange peel powder, 4% probiotic blended calcium carbonate and 2% starch as binder. The ingredients are the same for both feeds, except for the orange peel meal (OPF) with orange peel and potato peel used in the potato peel meal (PPF).
The experiment was carried out over a period of 60 days and the fingers of Labeo carp (Ham) were obtained from Lake Futala, Nagpur, Maharashtra. Labeo rohitafingers are preferred due to their high nutritional value and easy availability. The Experiment was created in three separate experimental groups in 09 uniform sized glass aquariums (each 20 L capacity). Each of the aquariums was stocked with 10 fingers. The initial length and weight were recorded in the experimental aquarium before the nails were loaded.
All tubs were ventilated for 24 hours with a 2 HP air blower. Before being fed experimental diets, fish were conditioned overnight to empty their gut and increase their appetite and intake for new diets. The fish were fed twice a day (5% body weight) at 10.00 and 20.00 hours. As the water turned cloudy, the water was changed every two days to maintain good water quality / dissolved oxygen content.
The test tubs were manually flushed with fecal matter and all water flushed, and excess feed was left daily. The siphoned water was replaced with an equal volume of fresh chlorine-free tap water. Water quality was monitored using the standard method for temperature, pH, alkalinity, dissolved oxygen, total hardness, calcium hardness, and magnesium hardness. After 60 days of experiment, the fish were removed from the aquarium and the final length and weight noted.
It was then dissected to remove muscle tissue and liver that were nutritious and edible. Tissues such as muscle and liver are separated from the bones and cleaned by rubbing on filter paper to remove excess water. The tissues thus obtained were weighed and processed for protein content.
• Nutritional indexes: The growth response of fish fed different diets was monitored by recording the average increase in weight and length.
• Average weight gain: Gives the weight gain of the animals during the test period. It was calculated using the formula.
• Average gain in weight. (g) = Average Final weight. (g) – Average Start wt. (g)
• Average gain in length: This gives the increase in standard length over the experimental time. It was calculated using the formula below.
• Average gain in length (cm) = Average Final length (cm) – Average Initial length (cm)
Protein Prediction Using the Lowry Method. This assay has been introduced by Lowry et al. It is highly sensitive and can detect protein levels as low as 5 g / ml. This is the most common method for protein predictions.
The experiment was designed in a completely random block design with three replications for each procedure. Upon the end of the experiment, all surviving fish were collected and the length and weight recorded separately. All statistical analyzes were performed using IBM SPSS Statistics version 20.
This study described above was conducted over a period of 60 days. The orange peels and potato peels were characterized, followed by the orange peel feed (OPF) and potato peel feed (PPF) formulation. Market common fish feed (CFF) was taken as control. The three test diets are designated CFF, OPF and PPF. Feeding was done once a day and water quality parameters such as dissolved oxygen, water temperature pH, total alkalinity, total hardness; The calcium hardness and magnesium hardness as well as the growth response were monitored every two weeks.
The quality of the water was maintained with periodic partial replenishment throughout the working period. Upon conclusion of the trial, higher growth response was noted with PPF treatment, as well as initial and final weight and length of fish. Results show that significant growth in PPF and OPF showed brighter body scales than the other two feeds. During the study period, the fish were very healthy and normal, which did not show any negative impact on their health. No infection was noted during the 60-day experimental period.
As a result; all food processing industries generate significant amounts of waste of varying nature. Managing these wastes in a way that minimizes the impact on the environment is a major concern. The concept of waste has changed a lot recently, with a focus on using waste materials as input for the production of new or reusable products. Vegetable and fruit waste is produced in significant quantities and can be easily obtained with minimal charging. The comparative use of these wastes as a dietary ingredient was evaluated using Labeo rohita fingerlings as a test type.
Author: Ozlem Guvenc Agaoglu