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Feed yeast,also named Fodder Yeast,Animal Yeast .

Feed Yeast , used as yeast cell in livestock and poultry feed. Including all single-cell proteins produced by single-cell microorganisms. It is light yellow or brown powder or granule, high in protein and rich in vitamins. Its composition varies with raw materials and bacterial species. The names of various feeds are often prefixed with the names of raw materials to indicate their characteristics, such as sulfite pulp waste liquid yeast, molasses yeast, whey yeast, n-alkane yeast, methanol yeast and so on.

In 1910, German M. Delbrück first used the yeast mud in beer production as supplementary feed, and named it as feed yeast. In 1967, at the first international single-cell protein conference held in the United States, it was decided that all proteins produced by single-cell microorganisms were collectively referred to as single-cell proteins. In addition to yeast, there are bacteria, actinomycetes, algae and filamentous fungi. In 1980, the world's single-cell protein production exceeded 1.4 million tons. China began to produce feed yeast in the early 1960s, but the output is still small.

1. Raw materials and strains:

Commonly used raw materials are wastewater from the production of alcohol and MSG, sulfite pulp waste liquid, wood and agricultural and sideline product waste hydrolyzed sugar liquid (see plant material hydrolysis), molasses, whey and whey product processing waste liquid, methanol, n-alkanes And so on, they all contain carbon sources such as sugars or hydrocarbons and other nutrients necessary for yeast to reproduce.

The strains used in industrial production vary with raw materials. For example, when sugar raw materials, sulfite pulp waste liquid, alcohol and monosodium glutamate waste liquid are used as raw materials, Candida utilis, also known as edible ball Yeast; Candida tropicalis (Candida tropicalis) is used when n-alkane is used as raw material; Hansenula polym-orpha (Hansenula polym-orpha) is used when methanol is used as raw material. The basic characteristics of these single-celled microorganisms are: simple nutritional requirements, can make full use of sugars and organic acids, have strong reproductive power, can reproduce in higher concentrations of reducing substances, have high utilization of reduced substances, and are resistant to high temperatures. It is resistant to acid environment, contains high protein and vitamins, and is free of pathogens and toxicity.

2. Production process:

The liquid fermentation production process includes the steps of culture medium preparation, yeast propagation, yeast separation, concentration and drying. Propagation of yeast requires a suitable medium (such as a certain sugar concentration and nitrogen, phosphorus and other salts) and propagation conditions (such as temperature, pH, oxygen). Within a certain temperature range, the growth rate of yeast increases with the increase in temperature (for example, at 28°C, it is twice as fast as at 13°C). Usually the temperature is 28～38℃, and the pH is 3.5～5.5. Oxygen supply is generally solved by ventilation. The larger the amount of air or the larger the contact surface between the air and the fermentation broth, the more conducive to fermentation, so the sugar concentration of fermentation can be higher. Normally, the bacterial growth is carried out in a continuous fermentation tank, and the yeast is usually separated and concentrated by a high-speed centrifuge, and can also be concentrated by a chemical coagulation method. Drying commonly used drum dryer or spray dryer.

3. Composition and use:

The composition of yeast is related to strains and culture conditions. Generally, it contains 40-65% protein, 1-8% fat, 25-40% carbohydrate, 6-9% ash, and there are about 20 kinds of amino acids. Lysine and tryptophan, which are less in cereals, are more abundant in yeast; especially when methionine is added, the available ammonia is about 30% higher than that of soybeans. Yeast has the same calorific value as beef, and because it is rich in B vitamins, it is usually used as an added feed of protein and vitamins. It is used for raising pigs, cows, chickens, ducks, mink and fish, and can receive good economic effects such as strengthening physical fitness, reducing diseases, fast gaining weight, laying eggs and producing more milk.

4. Nutritional value:

Feed yeast contains 40%-50% protein and has a high digestibility. As a protein feed added to compound feed, it has the same effect as fish meal. Feed yeast protein contains more than 20 kinds of amino acids. Among them, all 8 essential amino acids are contained. The methionine in feed yeast is slightly lower than fish meal, but it is compensated by the choline contained. Choline can regulate fat metabolism in the living body, convert fat into lecithin that can be dissolved in the blood, and then transport it to various tissues in the body. This is extremely beneficial to promote the growth of livestock. Yeast also contains various enzymes and hormones, which can promote the metabolism of animals and improve the disease resistance of young animals and poultry. Adding feed yeast to the compound feed can improve the absorption and utilization rate of the feed. In addition to the well-known pig and chicken feed that can be added with feed yeast, it is more effective to add feed yeast to the compound feed in aquaculture. For example, feed yeast can be added to 3% to 5% in fish bait, and 4% to 5% in prawn bait. Adding feed yeast to various compound feeds can speed up the growth rate, reduce feed consumption, and increase feed returns.

5. Features of fodder Yeast :

⒈High protein utilization rate, the apparent digestibility of YC protein in growing pigs is 89.3%, and that in laying hens is 91.1%.

⒉Improve production performance, can effectively promote growth, increase daily gain, feed remuneration and reproductive performance.

⒊Reduce the cost of feed, which can replace most or all of the fish meal in the diet, and can reduce the cost by 40-100 yuan/ton.

⒋ Good safety, no harmful bacteria such as Salmonella, non-toxic, harmless, non-environmental pollution and cross-contamination to humans, livestock, poultry, fish and shrimps.

⒌Stable performance. It is very stable when added to powders, pellets and premixes. It has good fluidity, no electrostatic adsorption, can withstand gastric acid and granulation high temperature, and has a high rate of viable bacteria.

6. True and false recognition:

Feed yeast is a kind of protein feed made by yeast fermentation using leftovers of agricultural and sideline products or industrial waste. It has high protein content and is easy to absorb, making it an ideal cheap protein feed at present. Chickens are very sensitive to feed yeast. Feeding with high-quality feed yeast has obvious effects, while feeding with fake and inferior feed yeast has no effect or the effect is not obvious, and sometimes even lead to chicken poisoning and death. Therefore, when purchasing feed yeast, the majority of professional farmers must keep their eyes open to identify the true and false, and prevent the purchase of inferior and high-priced counterfeit products.

Look at the feed yeast-generally powdery, mixed with plant feed, especially mixed with cake feed, most of them are fine granules or flakes.

Smell the feed yeast has a peculiar strong scent of yeast element. Put high-quality feed yeast into boiling water and keep it warm for a while. The peculiar smell becomes stronger. The fake and inferior feed yeast generally has a lighter odor, or does not have the unique odor, and it will not change in any odor when it is put into boiling water.

After the feed yeast with good dissolution and fermentation is put into water and stirred evenly, it is easy to suspend, there is a lot of foam, and the foam disappears very slowly. When the fake feed yeast is put into the water, it will either float on the water surface or sink to the bottom quickly, and there is generally no foam, even if there is a little foam, it will disappear quickly.

7. Prospects for feed yeast:

Feed yeast is rich in nutrients, including more than 20 amino acids and multiple vitamins. Among them, the content of B vitamins is extremely rich, far higher than fish meal and meat meal. From a purely nutritional point of view, the rich nutrients and growth factors possessed by yeast additives provide the nutrients needed by the breeding animal body and promote the healthy growth and development of the animals. Feed yeast additives have the efficacy of microecological preparations, which can improve the immunity of animals, regulate the microecological balance of the animal’s gastrointestinal tract, protect the health of young animals, improve the ability of animals to resist stress, and enhance the body’s ability to resist invasion by foreign microorganisms. It provides a more extensive way for the application of yeast additives. Some yeasts contain a variety of enzymes, such as protease, amylase, cellulase, chitinase, ribonuclease and glucanase, etc. These enzymes can supplement animals especially young and under pathological stress. The lack of endogenous enzymes in animals promotes the decomposition of nutrients and improves the digestibility of animals, thereby improving the nutritional value of feed, saving protein resources, and increasing economic benefits.