What feed additives are used in chicken feed?

According to feed classification, feed additives refer to trace or small amounts of substances added to feed for a specific purpose. These substances are not naturally found in feed, and adding a small amount can improve the quality and function of the feed. Examples include antibacterial growth promoters, mold inhibitors, antioxidants, colorants, and feed additives for preventing caking and binding; these are commonly referred to as non-nutritive additives.

Trace elements, vitamins, and amino acids, commonly known as nutritional additives, do not fall into this category. The additives described in many feed additive manuals and actually used in livestock production and feed industry production belong to the broader category of feed additives, including trace elements, vitamins, and amino acids—so-called nutritional additives.

1. Antibacterial and growth-promoting feed additives

Additives of this type include antibiotics, antibacterial drugs, arsenic preparations, and copper preparations. The main function of these substances is to inhibit the growth of harmful microorganisms in the animal’s digestive tract, enhance the digestive tract’s absorption capacity, improve the utilization of nutrients by farmed animals, and promote growth.

1) Antibiotics

Antibiotics are effective in maintaining animal health and promoting growth, especially in poor breeding environments and with low feeding standards. In egg production, antibiotics are mainly used during the brooding stage to improve chick survival rates; they are prohibited during the laying stage because many antibiotics have adverse effects on egg formation and leave residues in the eggs, affecting their safety as human food.

Many countries have strict regulations on the use of antibiotics in livestock and poultry farming, and my country has also published a list of antibiotics permitted for use in the livestock industry. Relevant regulations should be strictly followed, and animal-specific antibiotics with high safety profiles and not used in human clinical settings should be selected as feed additives. The main antibiotic additives permitted for use in chickens in my country and their dosages are listed below.

2) Other Growth Promoters

• Quinolone has a broad antibacterial spectrum, with antibacterial activity superior to tetracycline and bacitracin zinc, and does not exhibit cross-resistance with tetracycline and penicillin. It is rapidly absorbed and completely excreted in animals, with no accumulation. Chickens and ducks are relatively sensitive to this product, and there are numerous reports of chicken and duck poisoning in China; therefore, its use in poultry is currently prohibited.
• Growth hormone is a protein hormone secreted by the anterior pituitary gland in animals. It promotes protein synthesis and increases weight gain. Chickens already have high levels of growth hormone, so the effects of using growth hormone are not significant.

2.Deworming health supplement

Its main function is to expel internal parasites from livestock and poultry, prevent parasitic infections, promote growth, and improve feed conversion efficiency.

◉Antidotes

These include nematode-specific drugs, tapeworm-specific drugs, and trematode-specific drugs. Only drugs permitted for use in my country should be selected.

◉Anticoccidial Drugs

Because there are many types of coccidia, no single anticoccidial drug is effective against all coccidia to date, and long-term use can lead to drug-resistant strains. Therefore, a rotating drug administration approach should be adopted in production, and anticoccidial drugs should not be used during the laying period of laying hens. Currently approved anticoccidial drugs in my country include maduramycin ammonium, nicarbazin, methylsalicylic acid, fenvalerate hydrobromide, chlorpheniramine hydrochloride, monensin sodium, diclazuril, dinitrothione, lasaloxic acid sodium, and sedulomycin sodium premixes.

3.Feed Preservatives

During feed processing and storage, some feed components often change or become contaminated with mold. Appropriate antioxidants, mold inhibitors, and preservatives can be added during feed formulation. Commonly used antioxidants include ethoxyquinoline, butylated hydroxytoluene, butylated hydroxyanisole, and propyl gallate. There are many types of mold inhibitors; the most commonly used in practice are propionic acid, sodium propionate, and calcium propionate. Adding 0.3% propionate to chicken feed can effectively prevent mold growth; the addition amounts of sodium propionate and calcium propionate are generally 0.1% and 0.2%, respectively.

4.Feed colorants

Primarily used in poultry to enhance the color of egg yolks and broiler skin, thereby improving the commercial quality of the products. These substances are mainly carotenoids and their derivatives. In my country, permitted colorants for addition to chicken feed include β-apo-8′-carotene aldehyde, capsanthin, ethyl β-apo-8′-carotene, astaxanthin, β-carotene-4,4-dione, and lutein.

5.Feed flavorings and spices

Adding these additives to livestock and poultry feed is to enhance and improve feed flavor, increase feed intake, thereby promoting growth and improving productivity. In my country, permitted additives include sodium saccharin, monosodium glutamate, disodium 3,5′-inosinate, and disodium 4,5′-guanylate. Flavorings and spices are less commonly used in laying hen feed.