Dr. Atul P. Dhok and Dr. Nitin. V. Kurkure
Maharashtra Animal and Fishery Sciences University,
Near Futala Lake, Nagpur, 440001
Ph. 9921310135, email: nitinkurkure@mafsu.in
India is the world’s fifth-largest producer of chicken meat and the third-largest producer of eggs, having 851.81 million poultry in the country with a 16.8% increase from the previous census, produces 129.60 billion eggs with an annual growth rate of 6.19% and 4.78 million tonnes of poultry meat with a 6.86% annual growth rate. The main input in poultry production is feed, and advances in feed technology have made it much easier to use the genetic potential of birds. About 70–75% of the total cost of producing chicken meat and eggs in poultry farming is made up solely of feed costs. Poultry feeding aims to transform low-quality feed resources, such as cereal grains, oil cakes, and other waste products from farming and industry, into high-quality food, such as meat and eggs. Corn and soybean meal, which frequently combined make up 70–80% of the overall component of poultry feed. Soya DOC is the most expensive item among the frequently used feed ingredients.
Nutritionists have been forced to look for alternate sources of feed components due to the rising expense of conventional feed ingredients in most developing nations. In emerging nations, there is a greater need for alternative ingredients, which has a significant impact on the need for feed and raw materials. The cost of producing feed has increased as a result of the ever-increasing demand and decreasing supply of raw feed ingredients. There are two ways to lower the cost of production: one is to reduce feed costs, which appears challenging given the rising costs of feed ingredients, and the other is to investigate new feed ingredients that are less expensive, locally accessible, and comparable in terms of their nutrient contents to currently used feed ingredients. Due to its high protein content and easy digestion, soya bean meal is the primary source of protein for chicken feed in India, however, the use of other protein sources could lower the price of the protein supply. Earlier attempts have been made to replace soya partially with rapeseed meal, sunflower seed meal, guar meal, cotton seed meal, sesame meal, rice and maize gluten meal, and other potential byproducts including animal protein sources were employed in the production of chicken, yet soya DOC is not completely substituted. Currently, efforts have been made to explore the potential utilization of energy and proteins from several grain by-products, which are cheaper with high nutritive values. Distillers Dried Grains with Solubles (DDGS) can play a vital role in formulating inexpensive diets for poultry.
Production of DDGS
DDGS is a co-product of ethanol production plants that use corn for manufacturing. During the yeast fermentation in ethanol plants, corn is ground, mixed with water, cooked, and the liquefied starch from this process is hydrolyzed and fermented to produce ethanol and CO2. As a result, the non-fermentable components of this process which are rich in essential nutrients such as protein, fat, fiber, vitamins and minerals are recovered in a highly concentrated form as Distillers Dried Grains with Solubles. Although distillers dried grains was used by the poultry industry for some time, DDGS took its place more recently. This is due to the rapid development in production and the improved quality when derived from the new-generation ethanol plants. In light of the large-scale production of corn DDGS entering the world market, the nutritional value of corn DDGS for poultry may be a key concern for the poultry industry.
Further, modern rice byproducts that can be used by rice processing businesses are accessible in significant quantity and at lower prices, such as rice-based distillers’ dried grains with solubles (rDDGS). It is a fairly recent feed ingredient with a brownish colour and a coarse, powdery texture. DDGS is produced by drying mash over an extended period after multiple stages of concentration. These products are made up of initial raw material components that are resistant to fermentation (such as non-starchy carbohydrates, protein, fat, and ash), as well as yeast biomass. Protein, exogenous amino acids, B-group vitamins, biotin, and mineral components, including phosphorus, are all abundant in the dried grains of cereal distillers.
Nutritional composition of DDGS
DDGS contains all the nutrients in corn grain except most of the starch, which has been fermented to ethanol and carbon dioxide. By removing only the starch, the nutrients in corn grain are concentrated about three times in conventionally processed DDGS, which then typically contains about 27% crude protein, 10% oil, and 0.8% phosphorus. The high protein DDGS, resulting from the corn grain’s pre-fermentation fractionation, contains approximately 40% crude protein. The overall survey conducted in the country and after analyzing several samples of DDGS from various sources and different locations, it was revealed that the average protein and fat content of rice DDGS is (45.88 and 4.36) and for corn DDGS (28.50 and 7.36). The recent study conducted at MAFSU reported the composition of protein and fat of rice DDGS as (50.06, 4.95) and soya DOC as (45.77, 1.40), respectively. The DDGS has got relatively high protein content; high-energy content; high concentration of bypass protein (55 percent of crude protein); contains dried yeast cells that provide vitamins, improve palatability, increase fiber digestion and microbial protein synthesis; high methionine content, relatively high concentration (0.7 to 0.9 percent) of a readily available and inexpensive source of phosphorus; contains no anti-nutritional factors. The nutritional composition of DDGS is affected by grain and their composition, how many solubles are being added, use of processing technologies, enzymatic milling processes, type of fermentation, drying temperature and duration etc.
Feeding of DDGS in poultry
Many researchers have used various types of DDGS in broilers up to 15 percent on various occasions. The development of broilers and the characteristics of the carcass were unaffected by the addition of rice DDGS up to 12% level. Broiler can safely integrate DDGS at a 10% inclusion level. Rice DDGS can be safely added to layer diets up to 10% inclusion level without having an impact on egg production or egg quality features. The use of protease and other fibrolytic enzymes in broiler diets containing DDGS increases the broiler chickens’ performance. Some researchers have used higher levels of corn DDGS in broilers without compromising performance. However, when formulating diets containing corn DDGS, digestible amino acid values should be used especially for lysine. For layers, corn DDGS is a promising candidate for partial replacement of corn, soybean meal and inorganic phosphate and supports excellent layer performance and egg quality. The DDGS could be added to laying hen diets at levels of 10 to 20%, accounting for about 30% of the total dietary protein, without synthetic lysine supplementation, and did not affect egg production.
At Maharashtra Animal and Fishery Sciences University, Nagpur, India, various types of DDGS have been explored during the last ten years. The Jowar DDGS was successfully included up to 10 percent in the broiler diet. Also, corn DDGS has been included in broiler diets up to 10 percent. The rice DDGS have been included successfully in broiler diet up to 10 percent using fiber degrading enzyme. It has also replaced soya DOC at 5 and 10 percent in layer diet. Rice DDGS with 50 percent protein was incorporated up to 20 percent inclusion level in broiler diet with and without protease supplementation and the inclusion of rice DDGS at 15 percent level with the supplementation of protease enzyme could be economical. It was observed that 20 percent rice DDGS was economical when it was incorporated during the starter and finisher phases in broilers.
Future Scope of DDGS
The Ethanol for Petrol (EBP) program is an ambitious initiative of GOI aimed at achieving 20 % ethanol blending with petrol by 2025-26 and currently, 12 % ethanol is being blended, which offers maximum availability of DDGS in the country. It is expected to produce 2.45 MMT of DDGS by 2025-26 in the country and the feed sector is also expected to grow up to 54.6 MMT by 2025-26. However, while using DDGS you need to consider variations in product quality, mycotoxin content, and ensure all tests are done before use. Also, there is a need to build acceptability of DDGS in the animal feed sector in a staged manner; need support from feed manufacturer associations, distilleries associations, and poultry associations to build consistency in product quality; BIS to get standards in place for ingredients /packing, etc.; need to conduct an outreach program with nutritionists and feed millers on the benefits of biofuel co-products.