Inclusion of DDGS (Dried Distillers Grains with Solubles) 
in Poultry Feed

Inclusion of DDGS (Dried Distillers Grains with Solubles) 
in Poultry Feed

DDGS is a by-product of the ethanol production process and has high nutrient feed valued, suitable for the livestock industry. When ethanol plants produce ethanol, they use starch only from input grains like rice, corn, millets or wheat.After starch extraction, the byproduct contains – protein, fibre, oil and essential amino acids suitable for livestock feed called Dried Distillers Grains with Solubles.

The poultry sector among accounts for about 1 per cent of the national GDP and about 14 % of the livestock GDP. The total poultry population is 851.8 million, whereas commercial poultry population is 534.74 million (DADH, 2019). The growth rate of commercial broiler market is around 8-10 % per annum. The current demand for commercial poultry feed in India is approximately around 36 million tons and that of plant protein source is nearly 10 million tons. The poultry industry is in a state of crisis because of fluctuation in the price of maize and soyabean which are the common ingredients used to formulate the ration. There is a need for significant research to be carried out for an alternative protein source mainly to decrease the feed cost. Recently, crisis in supply of soyabean meal increased the feed cost and feed manufacturers were constantly in search for an alternative protein source to decrease cost of production, and had to import soyabean from other countries. Distillers dried grains with solubes is co product of ethanol industry produced by dry milling. Corn, wheat, sorghum, barley, rice can be used for ethanol production (Dinani et al., 2018), which can be used as an alternative plant protein source.

Ethanol production steps

Ethanol (C2H6O) is a simple liquid alcohol that is formed from the fermentation of sugars in their natural occurrences or being derived from starchrich grains or lignocellulosic feedstocks. There are commonly three groups of materials that can be used for manufacturing ethanol, which are: (a) feedstocks which contain substantial amounts of readily fermentable sugars. Sugars are readily fermentable by the yeast S. cerevisiae to produce ethanol. During the fermentation process, the yeast produces the enzyme invertase and uses it to convert sucrose to glucose and fructose Ethanol production by S. cerevisiae is carried out via the glycolytic pathway (also known as the Embden-Meyerhof-Parnas or EMP pathway), (b) starches and fructans Corn is used almost exclusively for ethanol production where ethanol is produced from corn by either the wet-milling or dry-grind process., and (c) cellulosic materials Lignocellulosic feedstocks are also referred to as lignocellulosic biomass or simply biomass. (Hoang et al., 2021) Ethanol production from starch-bearing cereal grains will be produced from wet milling or dry grinding.

https://www.deshbandhucollege.ac.in/pdf/resources/1587398881_BT(H)-VI-Industrial_and_Environmetal_Microbiology-1.pdf

Dry grinding

Dry grind ethanol process is grouped into the ‘frontend’ processes convert the starch-rich cereal grain into ethanol as efficiently as possible. The ethanolrich beer that is produced in the front-end operations is recovered in the ‘back-end’ distillation process and dehydrated to produce fuel ethanol. The residual suspension, called whole stillage, rich in nonfermentable dissolved and suspended solids, is processed in back-end dry house operations, usually producing distillers’ dried grains with solubles (DDGS) and thin stillage. (Monvceaux and Kuehner, 2009) In the dry-grind process, after grinding, water and a thermostable α-amylase are added to the ground corn. In the next step, which is called preliquefaction, the slurry then is brought up to 60–70◦C (warm cook) or 80–90 ◦C (hot cook). The slurry, is held at these temperatures for about 30–45 min. The swelling and hydration of the starch granules cause increase of the slurry viscosity and loss of crystallinity of the granule structures. The next step is called liquefaction, where the mash is maintained at 85–95◦ C for a period or forced through a continuous jet cooker at 140–150 ◦C. At the end of the liquefaction, starch is hydrolyzed to short chain dextrin’s (two to four glucose units). The temperature of the mash is lowered to 32o C and the pH adjusted to approximately 4.5. The mash then is placed in a fermentor. Glucoamylase and the yeast culture from the yeast propagation tank are also added. The process combining enzymatic hydrolysis and fermentation is called simultaneous saccharification and fermentation (SSF) (Hoang and Ngheim, 2021). The starch is converted into ethanol and carbon dioxide. The rest of the grain constituents (protein, lipids, fiber, minerals, and vitamins) are unchanged chemically, but concentrated. These residual components all end up in a coproduct known as distillers dried grains with solubles (DDGS). During coproduct recovery, the nonvolatile components following the distillation step, known as whole stillage, are usually centrifuged to produce a liquid fraction (thin stillage) and a solid fraction (distiller’s wet grains, or DWG). A significant portion (15% or more) of the thin stillage is recycled as backset to be used as processing water to slurry the ground grain. The remaining thin stillage is concentrated through evaporation into condensed distiller solubles (CDS), which are mixed with DWG to become distiller’s wet grains with solubles (DWGS) and then dried into DDGS (Liu, 2011).

Chemical Composition

The major obstacle to the use of DDGS in diets for animals is the wide variation in the nutritional content of DDGS produced in different distilleries due to differences in ethanol processing methods (Liu, 2009). The color is a strong indicator of the nutritional value of DDGS, particularly of corn DDGS. An incorrect processing method (i.e., higher drying temperatures) results in darker DDGS which have lower nutritional value conditioning their use in animal feeds (Fastinger et al., 2006). DDGS is very low in starch but higher in non-starch polysaccharides (NSP) content as compared to their parent grains used. DDGS is higher in gross energy than parent grain. DDGS contain all the nutrients from grain in a concentrated form and majority of starch has been utilised in fermentation process during ethanol production . This will concentrate all nutrients about three-fold present in the cereal since two third to three fourth portion of cereal content is starch (Swiatkiewicz and Koreleski, 2008). The nutrient composition of Rice DDGS (RDDGS) varies depending on the source of grain and the methods of RDDGS production. Generally, RDDGS contains approximately 44% crude protein, 5% fat, 6% crude fiber. The chemical composition of RDDGS analyzed by different authors is given in Table 1 Gupta et al., (2016), Kumar et al., (2017), Dinani et al., (2018), and Talsani et al., (2021) who reported a crude protein content between 44 % to 45 % in RDDGS. A high crude protein content of 61.41 % in RDDGS was reported by Ranjan et al., (2017), and a low crude protein content 28.55 % in RDDGS was observed by Xue et al., (2012). The range of crude fiber 1.23 to 5.33 % and ether extract content was 3.19 to 7.67 %. A crude fiber content (4.89 to 10.85 %) and ether extract (2.24 to 8.90 %) was also observed by the above reported authors. The variation in the crude fiber and ether extract content of RDDGS may be due to variation in the nutrient content of the DDGS produced from different sources of grains and due to differences in ethanol processing methods and drying methods of DDGS (Pedersena et al., 2014). Moisture content of the samples ranged from as analyzed by different authors were ranged between 7 to 11 %, crude protein percent was as high as 61 %. Based on the analysis of 8 samples obtained from different parts of Telangana and Tamil Nadu by Kaninde (2022) and observed that the moisture content varied between 14 to 19 % and crude protein was 39 % to 47 %, gross energy ranged between 3980 to 4227 K cal / kg. Crude fiber content ranged from (1.23 – 5.33 %) and variation was high. The coefficient of variation in the crude fiber (53 %) and ether extract (30 %) was high.

Amino acid composition of RDDGS

RDDGS contain all the nutrients from grain in a concentrated form and majority of starch has been utilized in fermentation process during ethanol production (Babcock et al., 2008). This will concentrate all nutrients about three-fold present in the cereal since two third to three fourth portion of cereal content is starch (Swiatkiewicz and Koreleski, 2008). The amino acid profile of RDDGS showed lower lysine (0.64 – 1.23 %) content than soya bean meal (2.99 – 3.22 %) and the other amino acids were well within the range. Luu et al., (2000); Xue et al., (2012); Gupta et al., (2016); Kurcheriya et al., (2019); Yang et al., (2019), who observed that the lysine content was lesser than soyabean meal. This phenomenon may possibly be due to variation in amino acid composition of the parent grains used for ethanol production, compared with soya protein amino acid profile (Lim et al., 2008). The variation in the nutrient content is related to drying process, uneven mixing of CDS and DWG during drying process which will result in change in nutrient variability in DDGS, and due to high temperature, which may reduce the protein quality. (Liu, 2011.

An Excellent Ingredient for use in Animal Feeds –

Record high feed ingredient prices around the world are causing animal nutritionists to search for lower cost alternative feed ingredients to minimize the cost of food animal production.

The high energy, mid-protein, and high digestible phosphorus content of DDGS make it a very attractive, partial replacement for some of the more expensive feed sources :

• Traditional energy (Corn)
• Protein (Soybean Meal)
• Phosphorus (mono- or dicalcium phosphate) used in animal feeds.

When DDGS is added to properly formulated feeds, it results in

1. Excellent animal health
2. Performance
3. Food product quality.
4. Lower ration cost.

These attributes have made DDGS one of the most popular feed ingredients for use in animal feeds around the world.

Application

DDGS (Dried Distillers Grain in Soluble) is a protein rich diet that has replaced majority of the protein diets in market that includes soybean, Mustard, GNE and similar items. Proteins, fiber and minerals present in DDGS Feed makes them a smart choice for cattle that gives them higher energy. DDGS Fish Feed makes the fish immune to infections and diseases. DDGS is coming up as most desired livestock feed.

DDGS in feed
DDGS has low amylase content and is thus easy to digest. DDGS has high amount of amino acids and proteins and is ideal for livestock. The moisture content in DDGS is at the max 10% and has a long shelf life.

Applications

DDGS Feed for Livestock 
DDGS is basically sticky in nature. It has very low amylase content and high protein content. It is relatively easy to digest and has high nutritional value. The moisture content in DDGS at the maximum is 10%. It has higher biological value than other gluten. It has an above average amino acid profile and has great health benefits for your livestock. As renowned DDGS manufacturer in North India, we ensure DDGS is hygienically packed and there is no contamination of the feed. Because of its long shelf life and low cost, it is widely popular among farmers as an ideal feed ingredient.

DDGS Usage Guide

Color the Only or Best Indicator of DDGS Quality? – Currently, there are no grading

systems that define and regulate the quality standards for DDGS like those existing for corn, soya and other grains. Color of feed ingredients is used as a subjective indicator of the amount of heat damage which consequently affects the amino acid digestibility.

As a result, color has become a quality assessment factor for some DDGS. Although a darker colored DDGS sample may indicate reduced amino acid digestibility for poultry and swine, it is not always the case. Many factors influence the color of DDGS, and other measurements of quality should be used in order to obtain an accurate assessment of DDGS quality.

Mycotoxins in DDGS

Many players in the market are selling DDGS which may contain high amounts of mycotoxins that can negatively affect animal performance. Mold growth can be due to production process, improper storage conditions.

Mycotoxins can be present in DDGS if the material is adulterated or the grains used were impure. Thus DDGS should be purchased from only reliable vendors to eliminate the presence and concentration of mycotoxins in DDGS.

USAGE

Use of DDGS in Dairy Cattle Diets – Rice DDGS can be included in dairy cow diets up to 20 percent of the diet without decreasing dry matter intake, milk production, and percentage milk fat and protein. Adding 20 to 30 percent DDGS to a lactating cow diet also results in milk production being equal to, or greater than when diets containing no DDGS are fed. Milk fat percentage varies among various studies, but was not significantly changed by the inclusion of distiller’s grains in the diet. Milk protein percentage is decreased when more than 30 percent DDGS is added to the diet. When formulating diets containing DDGS for lactating dairy cows,consideration should be given to type of forage, forage to concentrate ratio, crude fat content of DDGS, and the need for supplemental crystalline lysine to achieve optimal performance. Rice DDGS can be effectively used in a total mixed ration by lactating dairy cows under heat stressed climatic conditions making it a valuable feed ingredient for use in dairy rations in subtropical and tropical regions of the world. Although there has been limited research to evaluate feeding DDGS to growing dairy heifers, diets containing up to 40 percent DDGS have been used to achieve excellent growth rate and feed conversion in growing beef cattle rations.

Use of DDGS in Poultry Diets – Rice DDGS is an excellent feed ingredient for use in layer,broiler, duck, and turkey diets and contains approximately 85 percent of the energy value of corn for poultry. Conservatively, DDGS can be added at 5 to 8 percent of starter diets for broilers and turkeys, and 12 to 15 percent of diets for layers and growing-finishing diets for broilers, ducks, and turkeys when diets are not formulated on a digestible amino acid basis, and achieve excellent performance and egg and meat quality. Recent research studies have shown that DDGS can be added to poultry diets at even higher dietary inclusion rates (25 percent for layers and broilers) to achieve excellent performance and egg and meat quality provided that accurate nutrient profiles specific to the DDGS source are used, and diets are formulated on a digestible amino acid basis.

Use of DDGS in Swine Diets – Rice DDGS is an excellent for use in swine diets in all phases of production. Maximum recommended dietary DDGS inclusion rates to support excellent performance are up to 30 percent for nursery pigs weighing more than 7 kg, growing finishing pigs, and lactating sows, and levels of up to 50 percent of the diet for gestating sows. These recommendations are based on the assumption that diets are formulated on a digestible amino acid basis. Feeding diets containing more than 20 percent DDGS causes pork fat to become less firm. Therefore, depending on pork fat quality standards in a given country, some markets may require feeding no more than 20 percent DDGS throughout the grower-finisher phase, or withdrawing it from the diet 3 to 4 weeks before harvest to achieve desired pork fat quality.

Benefits of DDGS in poultry diets

With growing demand for food and scarce resources, the animal livestock industry doesn’t have the luxury of letting anything go to waste. Corn by-products (DDGS) from the ethanol industry are considered to be waste, but can still have a use as a feed ingredient. Because it is considered a waste product it is a very cheap source of crude protein, crude fibre, available phosphorous, unsaturated fatty acids and essential amino acids. Besides that it is an effective replacer of soya and corn in the poultry diet with the added benefit that it reduces feed costs by replacing soya in the diet as the price of soya is very high and often fluctuates. Replacing soya by DDGS is worth while, because it is a resource that will stay around for some time.

Enormous availability

Ethanol production is continually increasing and so the availability of DDGS will be enormous throughout the season.

In the poultry diet there are many advantages. Poultry fed with DDGS have a better feed intake, feed conversion ratio, body weight and body weight gain. And DDGS improves meat and egg quality by enriching it with omega-3 fatty acids (Linoleic acid) which is good for heart patients. Also, improved phosphorous bioavailability and therefore less phosphorous excretion prevents environmental pollution. Because of high phosphorous bioavailability, less exogenous phosphorous is supplemented and again it reduces the feed cost.

Feeding DDGS to chicken layers

The use of high quality corn DDGS in layer diets is an excellent partial replacement for corn, soybean meal and inorganic phosphate and supports excellent layer performance and egg quality. DDGS could be added to the diet of laying hens at levels of 10 to 20%, accounting for about 30% of the total dietary protein, without synthetic lysine supplementation, and has no effect on egg production or egg weight. Also an improvement in interior egg quality (Haugh units) was seen. Because of high xanthophylls in DDGS, egg yolk colour is improved. The oleic acid content decreased, and linoleic acid increased in egg yolk as increasing levels of DDGS were added to the diet, but the amount of saturated fatty acids in the yolk was not affected by DDGS supplementation. So feeding layer diets containing up to 15% DDGS did not affect production.

Feeding DDGS to broilers

Positive performance and better meat quality are the result when DDGS is added to broiler diets. The weight gain of 
broilers increased when small quantities of DDGS (2.5 and 5%) were added to the diet. DDGS can be added to broiler diets at levels up to 25% to achieve good performance if dietary energy level is held constant. High quality DDGS is an acceptable ingredient in broiler diets and a 6% maximum dietary inclusion rate in the starter period and 12 to 15% DDGS in grower and finisher phases of broiler production is recommended.

Potential constraints

Due to the use of sulphuric acid in the process, ethanol by-products may be high in sulphate which increases the risk of sulphur toxicity, when fed large amounts of distillers’ grain. A high concentration of H2S inhibits the oxidative processes in nerve tissue and results in central nervous system disorders. Besides that mycotoxins are a risk factor. Maize is susceptible to fungal infections producing mycotoxins. Due to the concentration that non-starch components undergo during the distillery process, mycotoxin concentrations are about three-fold in corn distillers’ grain compared to the original grain. It is thus of utmost importance that maize intended for bio-ethanol production is free of mycotoxins before processing. There are also ways to alleviate mycotoxin problems, such as removing damaged grains before they enter the process. Chemical treatments (NaOH, NH4OH, H2O2, NaCl, CH2OH) have to be performed to detoxify mycotoxins in stillage.

Copper

Certain traditional whisky distilleries use copper rather than stainless steel for stills and pipes, and their by-products tend to contain high levels of copper, which is toxic. Maize distillers’ dark grain, for instance, may contain between 15 and 120 mg/kg of copper. While copper content and biological copper availability are highly variable in whisky by-products, it is essential to check copper levels before buying such products. Copper is not an issue in industrial ethanol production.

Inclusion 15% or higher

At present, the recommended maximum dietary inclusion levels for corn DDGS are 15% for broilers, turkeys, layers, and ducks, but higher levels of corn DDGS can be used successfully with appropriate diet formulation adjustments for energy and amino acids. When formulating diets containing corn DDGS, digestible amino acid values should be used especially for lysine, methionine, cystine, and threonine. Diets should also be formulated by setting minimum acceptable levels for tryptophan and arginine due to the second limiting nature of these amino acids in corn DDGS protein.

The ever present mycotoxin problem can be mitigated by thorough examination before processing the corn. Copper and sulphur contamination is unavoidable in our processing technology and so the level of inclusion should be less in some areas. So in the future, the challenge is to prevent industrial contamination for safe usage of DDGS in poultry breeder rations.

DDGS: Alternative grain resource in poultry feed industries

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