# Chicken Feed Options: Types, Nutrition, and Feeding Strategies ## Key Takeaways - Commercial complete feeds are formulated by nutritionists to provide balanced protein (18-24% for starters, 14-16% for growers, 16-18% for layers), energy, vitamins, and minerals, crucial for preventing deficiencies like amino acid imbalances (methionine, lysine) and ensuring optimal growth and production. - Nutritional requirements vary significantly by life stage: chicks (0-8 weeks) need high protein (18-22%) and moderate calcium (1%), while laying hens (18+ weeks) require higher calcium (3.5-4.5%) for eggshell formation. - Homegrown grains (corn, wheat) provide energy but are deficient in essential amino acids and must be supplemented with protein sources (soybean meal, insect meal) and vitamin/mineral premixes to avoid deficiencies and mycotoxin contamination. - Supplements like oyster shell provide essential calcium for eggshell quality, while insoluble grit aids digestion in the gizzard, particularly for birds consuming whole grains or forage. - Feed contamination, including mycotoxins from moldy grain and heavy metals, poses significant health risks, leading to reduced feed intake, immunosuppression, and potential toxicity in poultry and humans consuming their products. - Accurate record-keeping of feed intake, feed conversion ratio (FCR), body weight, and egg production is critical for evaluating feed efficiency, identifying nutritional deficiencies (e.g., thin shells from calcium deficiency), and preventing common failures like feed waste or refusal. --- Poultry farmers and backyard keepers face a central decision: which feed type and feeding strategy best supports flock health, egg or meat production, and cost efficiency. This article compares commercial feeds, homegrown options, and supplements, with guidance on feeding by life stage. It covers nutritional requirements, practical implementation, record-keeping, common failures, and welfare considerations. The goal is to help you make informed, evidence-based feed management decisions. ## At a Glance: Chicken Feed Types and Their Primary Uses | Feed Type | Primary Use | Key Nutritional Profile | Typical Form | Best For | |-----------|-------------|------------------------|--------------|----------| | Commercial complete feed (starter, grower, layer, broiler) | All life stages | Balanced protein, energy, vitamins, minerals, species-specific formulations | Crumbles, pellets, mash | Consistent nutrition, high production, disease prevention | | Homegrown grains (corn, wheat, barley, oats) | Energy source, supplement | High energy, moderate protein, lacks complete amino acid profile | Whole or cracked grain | Reducing feed cost, free-range supplementation | | Protein supplements (soybean meal, fish meal, insect meal) | Protein boost | High protein (40-60%), essential amino acids | Meal, pellets | Meeting protein requirements, especially for growers and layers | | Sprouted seeds (barley, wheat, legumes) | Fresh forage, vitamin source | Moderate protein, high moisture, vitamins A, E, B complex | Sprouted greens | Improving gut health, reducing feed cost, winter forage | | Grown mealworms | Live protein supplement | High protein (50%), fat, calcium | Live or dried larvae | Treats, protein boost for layers, reducing commercial feed use | | Pumpkin seeds | Parasite control supplement | High protein, fiber, cucurbitacin | Whole or ground seeds | Natural deworming, supplement for layers | | [Grit and oyster shell](/knowledge/animal-farming/poultry/grit-oyster-shell-supplements-chicken-digestion-eggs) | Digestion and calcium | Calcium carbonate, insoluble grit | Crushed shell, granite grit | Digestive health, eggshell quality | | Vitamin/mineral premix | Balancing homemade rations | Complete micronutrient profile | Powder, liquid | Preventing deficiencies in non-commercial feeds | ## Nutritional Requirements by Life Stage Chickens have distinct nutritional needs that change with age, production phase, and purpose. Meeting these requirements directly affects growth rate, egg production, feed efficiency, and flock health. The Food and Agriculture Organization of the United Nations provides foundational guidance on [poultry nutrition](/knowledge/animal-farming/poultry/poultry-nutrition-essentials-balancing-feed-for-optimal-health-and-growth) and feed management through its poultry production resources [1]. ### Starter Phase (0-8 Weeks) Chicks require a high-protein diet (typically 18-22% crude protein) to support rapid muscle and skeletal development. Commercial starter feeds are formulated with balanced amino acids, vitamins, and minerals. Key considerations include: - **Protein quality**: Essential amino acids like methionine and lysine must be present in correct ratios. Homegrown grain-only diets are deficient in these. - **Calcium level**: Starter feeds contain moderate calcium (around 1%) to avoid kidney damage. Do not feed layer feed or oyster shell to chicks. - **Feed form**: Crumbles or fine mash are easier for young chicks to consume. Whole grains are not suitable. - **Water access**: Clean water must be available at all times. Dehydration reduces feed intake and growth. ### Grower Phase (8-18 Weeks) As chickens approach maturity, protein requirements decrease to about 14-16% crude protein. Grower feeds support continued growth without excessive fat deposition. Key points: - **Energy density**: Adjust feed energy based on breed and activity level. Meat-type birds need higher energy than layers. - **Calcium**: Maintain moderate calcium (1-1.5%) to prepare for egg production without causing metabolic issues. - **Feed form**: Pellets or crumbles are efficient. Whole grains can be introduced gradually as scratch feed. ### Layer Phase (18+ Weeks) Laying hens require a diet with higher calcium (3.5-4.5%) for eggshell formation, along with 16-18% crude protein. Commercial layer feeds are formulated to meet these needs. Important factors: - **Calcium source**: Oyster shell or limestone can be offered separately to allow hens to self-regulate intake. - **Phosphorus**: Available phosphorus must be balanced with calcium. Ratios of 2:1 to 3:1 calcium to available phosphorus are typical. - **Amino acids**: Methionine and lysine remain critical for egg production and feathering. - **Feed intake**: Layers eat about 100-120 grams of feed per day, depending on breed, temperature, and production level. ### Broiler Phase (0-8 Weeks) Meat-type chickens have high protein and energy requirements for rapid growth. Commercial broiler feeds are typically 20-24% crude protein in starter, decreasing to 18-20% in finisher. Key considerations: - **Growth rate**: Fast growth requires precise nutrition. Deficiencies lead to leg problems, poor feed conversion, and mortality. - **Feed form**: Pellets improve feed intake and reduce waste compared to mash. - **Feed restriction**: Controlled feeding may be used to prevent metabolic disorders. The Merck Veterinary Manual provides guidance on poultry health and nutrition management [3]. ## Commercial Feed Options Commercial feeds are the most reliable way to provide complete, balanced nutrition. They are formulated by animal nutritionists and manufactured under quality control standards. ### Complete Feeds Complete feeds contain all necessary nutrients in correct proportions. They are available as: - **Mash**: Ground ingredients, less processed. Can be dusty, and birds may selectively eat certain particles. - **Crumbles**: Mash that is compressed and broken into small pieces. Reduces waste and selective feeding. - **Pellets**: Compressed feed that is easy to handle, reduces dust, and prevents ingredient separation. ### Medicated Feeds Some commercial feeds contain approved medications (e.g., coccidiostats) to prevent diseases like coccidiosis. These are typically used for starter and grower phases. Withdrawal periods must be observed before slaughter or egg collection for human consumption. The USDA Animal and Plant Health Inspection Service provides information on poultry disease management and biosecurity [2]. ### Organic and Non-GMO Feeds Organic feeds are produced without synthetic pesticides, fertilizers, or genetically modified ingredients. They must meet certification standards. Non-GMO feeds avoid genetically modified crops. These options are more expensive and may have variable nutrient profiles. ## Homegrown Feed Options Growing your own feed can reduce costs and provide fresh, high-quality ingredients. However, homegrown feeds rarely provide complete nutrition and must be supplemented. ### Grains Corn, wheat, barley, and oats are common energy sources. They are low in protein and deficient in essential amino acids. Key management points: - **Storage**: Grains must be stored in dry, rodent-proof containers. Moldy grain can contain mycotoxins, which are harmful to poultry. Mycotoxins in poultry feed and feed ingredients from sub-Saharan Africa and their impact on the production of broiler and layer chickens have been reviewed, highlighting the risks of contaminated feed [14]. - **Processing**: Whole grains are harder to digest. Cracked or rolled grains improve digestibility. - **Supplementation**: Grains must be balanced with protein sources, vitamins, and minerals. ### Protein Sources Homegrown protein options include: - **Soybeans**: Must be heat-treated to inactivate trypsin inhibitors. Raw soybeans are toxic. - **Sunflower seeds**: Good protein and fat source. Can be fed whole or ground. - **Fish meal**: High-quality protein but expensive and may cause fishy flavor in eggs if overfed. - **Insect meal**: Growing interest as a sustainable protein source. Mealworms and black soldier fly larvae are options. ### Sprouted Seeds Sprouting seeds (barley, wheat, legumes) increases vitamin content and digestibility. Sprouted seeds for chickens provide fresh forage, especially in winter. Key points: - **Nutrition**: Sprouting increases vitamins A, E, and B complex. Protein content remains similar but becomes more digestible. - **Management**: Seeds are soaked for 12-24 hours, then drained and rinsed twice daily until sprouts appear (3-7 days). - **Feeding**: Offer as a supplement, not a complete feed. Sprouts are high in moisture and low in energy. ### Grown Mealworms Growing mealworms for chickens is a sustainable protein supplement. Mealworms are high in protein (about 50%) and fat. Key management: - **Setup**: Mealworms are raised in bins with bran or oats as bedding, and vegetable scraps for moisture. - **Harvest**: Larvae are harvested after 8-10 weeks. They can be fed live or dried. - **Feeding**: Offer as treats or protein boost for layers. Do not exceed 10% of total diet. ### Pumpkin Seeds Pumpkin seeds for chickens are often used as a natural deworming supplement. They contain cucurbitacin, which may help expel [intestinal parasites](/knowledge/parasites/pet-parasites/intestinal-parasites-dogs-cats-identification-treatment). Key points: - **Preparation**: Seeds can be fed whole or ground. Ground seeds are more effective. - **Feeding**: Offer as a supplement, not a replacement for commercial feed. - **Limitations**: Evidence for efficacy is limited. Do not rely solely on pumpkin seeds for parasite control. ## Supplements and Additives Supplements are used to correct deficiencies, improve health, or enhance production. They must be used carefully to avoid imbalances. ### Vitamin and Mineral Premixes These are essential when feeding homegrown or incomplete rations. Premixes provide trace minerals (zinc, copper, selenium) and vitamins (A, D, E, B12). Key points: - **Selection**: Choose a premix formulated for poultry. Livestock premixes may have different ratios. - **Mixing**: Follow manufacturer instructions. Over-supplementation can be toxic. - **Storage**: Keep in cool, dry place. Vitamins degrade over time. ### Grit and Oyster Shell - **Insoluble grit**: Granite or flint grit helps birds grind feed in the gizzard. Essential for birds on whole grains or forage. - **Oyster shell**: Provides calcium for eggshell formation. Offer free-choice to laying hens. ### Probiotics and Prebiotics These support gut health and may improve feed efficiency. They are available as powders or liquids added to feed or water. Evidence for specific benefits varies. ### Alpha-Lipoic Acid Alpha-lipoic acid has been studied as a feed supplement for poultry nutrition, with potential antioxidant effects [8]. However, it is not a standard component of commercial feeds and should be used only under veterinary guidance. ## Feeding Strategies by Production System The feeding approach depends on whether birds are confined, free-range, or pastured. ### Confined Systems Birds have no access to forage. Complete commercial feed is the primary diet. Key management: - **Feed form**: Pellets or crumbles reduce waste. - **Feeder management**: Use appropriate feeders to minimize spillage and contamination. - **Water**: Clean water must be available at all times. ### Free-Range Systems Birds have outdoor access and can consume grass, insects, and seeds. This reduces feed costs but does not eliminate the need for balanced feed. Key points: - **Supplementation**: Provide complete feed as the base diet. Forage contributes to nutrition but is insufficient alone. - **Seasonal variation**: Forage quality and quantity vary. Increase feed allowance in winter or drought. - **Biosecurity**: Outdoor access increases exposure to wildlife and pathogens. The USDA National Agricultural Library provides resources on animal health and welfare, including biosecurity practices [5]. ### Pastured Systems Birds are moved to fresh pasture regularly. This system maximizes forage intake and reduces feed costs. Key management: - **Forage quality**: High-quality pasture provides protein, vitamins, and minerals. Legumes like clover are especially nutritious. - **Supplementation**: Provide complete feed at 50-70% of ad libitum intake, depending on forage availability. - **Rotation**: Move birds frequently to prevent overgrazing and parasite buildup. ## Practical Implementation Steps Implementing a feeding program requires planning, observation, and record-keeping. ### Step 1: Assess Flock Needs Determine the age, breed, production stage, and purpose of your flock. Use this information to select the appropriate feed type and formulation. ### Step 2: Choose Feed Type Decide between commercial complete feed, homegrown ingredients, or a combination. Consider cost, availability, labor, and nutritional completeness. ### Step 3: Calculate Feed Requirements Estimate daily feed intake based on bird weight, production level, and environmental temperature. Use feed conversion ratios (FCR) for meat birds and feed intake per dozen eggs for layers. ### Step 4: Source Feed Purchase commercial feed from reputable suppliers. For homegrown ingredients, ensure proper storage and quality control. ### Step 5: Implement Feeding Schedule Provide feed at consistent times. For confined birds, use ad libitum feeding. For free-range or pastured birds, adjust based on forage availability. ### Step 6: Monitor and Adjust Observe bird behavior, body condition, egg production, and feed intake. Adjust feed type or amount as needed. ## Records and Measurements Keeping accurate records helps evaluate feed efficiency and flock health. ### Feed Intake Records - **Daily feed consumption**: Weigh feed offered and subtract leftovers. Record per bird or per group. - **[Feed conversion ratio](/knowledge/animal-farming/poultry/feed-conversion-ratio-measuring-improving-poultry-efficiency) (FCR)**: For meat birds, calculate FCR = feed consumed (kg) / weight gain (kg). Lower FCR indicates better efficiency. - **Feed cost per dozen eggs**: For layers, calculate feed cost per dozen eggs to assess profitability. ### Body Weight and Condition - **Weekly weights**: Weigh a sample of birds to track growth. Compare to breed standards. - **[Body condition scoring](/knowledge/animal-farming/farm-management/body-condition-scoring-a-tool-for-feed-management)**: Assess breast muscle and fat cover. Adjust feed if birds are too thin or too fat. ### Egg Production Records - **Hen-day production**: Number of eggs laid per hen per day. Target 80-90% for commercial layers. - **Egg weight**: Weigh eggs regularly. Small eggs may indicate protein deficiency. - **Eggshell quality**: Check for cracks, thin shells, or rough texture. Calcium deficiency is a common cause. ### Health Observations - **Feed refusal**: Sudden decrease in feed intake may indicate disease or feed palatability issues. - **Water intake**: Monitor water consumption. Decreased intake can precede disease. - **Fecal consistency**: Loose droppings may indicate digestive upset or feed change. ## Common Failure Patterns Recognizing and addressing common feed-related problems can prevent production losses. ### Nutritional Deficiencies - **Protein deficiency**: Poor growth, reduced egg production, feather pecking. - **Calcium deficiency**: Thin-shelled eggs, egg breakage, osteoporosis in layers. - **Vitamin deficiency**: Leg weakness, poor feathering, reduced hatchability. - **Amino acid imbalance**: Reduced feed efficiency, poor egg quality. ### Feed Contamination - **Mycotoxins**: Moldy feed can cause reduced feed intake, liver damage, immunosuppression. Mycotoxins in poultry feed and feed ingredients from sub-Saharan Africa have been reviewed for their impact on broiler and layer production [14]. - **Heavy metals**: Toxic metals in chicken feed and eggs have been quantified, highlighting the importance of feed quality monitoring [11]. Chromium propagation from poultry feeds to chicken tissues and eggs has also been studied [12]. - **Pesticides**: Contaminated grains can cause toxicity. Use certified feed ingredients. ### Feed Waste - **Spillage**: Improper feeder design or placement leads to waste. Use feeders with lip edges. - **Selective feeding**: Birds may eat only preferred ingredients in mash feeds. Use pellets or crumbles. - **Rodent and bird consumption**: Secure feed storage to prevent wildlife access. Interspecific variation in wildlife responses to cattle, swine, and chicken feed in forests surrounding poultry farms has been documented [7]. ### Feed Refusal - **Palatability**: Sudden feed changes can cause refusal. Transition gradually over 5-7 days. - **Spoilage**: Wet or moldy feed is rejected. Clean feeders regularly. - **Temperature**: Hot weather reduces feed intake. Adjust feeding times to cooler parts of the day. ## Welfare and Safety Context Proper feeding is central to poultry welfare. Malnutrition, starvation, or contaminated feed cause suffering and production losses. ### Welfare Indicators - **Body condition**: Birds should have adequate muscle and fat cover. Emaciation or obesity indicates feeding problems. - **Feather condition**: Poor feathering may indicate protein or amino acid deficiency. - **Behavior**: Normal feeding behavior includes regular visits to feeders. Lethargy or aggression at feeders may indicate competition or hunger. - **Mortality**: Increased death loss may be linked to feed quality or nutritional imbalances. ### Biosecurity - **Feed storage**: Store feed in rodent-proof containers. Clean up spills promptly. - **Feed delivery**: Use dedicated equipment for feed handling. Avoid cross-contamination with manure or dead birds. - **Wildlife exclusion**: Prevent wild birds and rodents from accessing feed. They can introduce diseases. ### [Food Safety](/knowledge/bacteria/livestock-bacteria/cooking-chicken-bacteria-prevention) - **Withdrawal periods**: Observe withdrawal times for medicated feeds before slaughter or egg collection. - **Egg quality**: Feed ingredients can affect egg flavor and safety. Avoid fish meal or strong-flavored ingredients before egg collection. - **Heavy metals**: Monitor feed sources for toxic elements. Assessment of potentially toxic element contents in chickens and poultry feeds from Bangladesh markets has implications for human health risk [13]. ### Professional Escalation Criteria Consult a poultry veterinarian or animal nutritionist if you observe: - **Unexplained mortality**: More than 1-2% death loss per week. - **Severe production drop**: Egg production falls by more than 20% in one week. - **Persistent feed refusal**: Birds refuse feed for more than 24 hours. - **Suspected toxicity**: Signs of poisoning (tremors, paralysis, sudden death). - **Mycotoxin contamination**: Visible mold on feed or confirmed mycotoxin analysis. - **Nutritional deficiency signs**: Severe feather loss, leg deformities, poor growth. ## Limitations and Trade-offs Every feeding strategy has limitations. Understanding these helps you make informed decisions. ### Commercial Feed Limitations - **Cost**: Complete feeds are expensive, especially organic or non-GMO options. - **Availability**: Some regions lack reliable supply of quality feeds. - **Ingredient variability**: Nutrient content can vary between batches. ### Homegrown Feed Limitations - **Nutritional incompleteness**: Homegrown grains and forages rarely meet all requirements. - **Labor**: Growing, harvesting, processing, and storing feed requires significant time and equipment. - **Quality control**: Homegrown feeds are more susceptible to mold, pests, and nutrient variability. ### Supplement Limitations - **Over-supplementation**: Excess vitamins or minerals can be toxic. - **Cost**: Some supplements are expensive and may not provide proportional benefits. - **Evidence gaps**: Many supplements lack robust scientific evidence for efficacy. ## Frequently Asked Questions ### What is the best feed for laying hens? Commercial layer feed (16-18% protein, 3.5-4.5% calcium) is the most reliable option. It provides balanced nutrition for egg production and shell quality. Supplement with oyster shell free-choice. Homegrown options require careful balancing with protein sources and vitamin/mineral premixes. ### Can I feed chickens only grains? No. Grains are high in energy but low in protein, essential amino acids, vitamins, and minerals. Feeding only grains leads to nutritional deficiencies, poor growth, reduced egg production, and health problems. Grains must be supplemented with protein sources, vitamins, and minerals. ### How do I grow mealworms for chickens? Mealworms are raised in bins with bran or oats as bedding. Add vegetable scraps for moisture. Maintain temperature around 25-30°C. Harvest larvae after 8-10 weeks. Feed live or dried as a protein supplement. Do not exceed 10% of total diet. ### Are pumpkin seeds effective for deworming chickens? Pumpkin seeds contain cucurbitacin, which may help expel intestinal parasites. However, scientific evidence for efficacy is limited. They can be used as a supplement but should not replace veterinary deworming protocols. Consult a veterinarian for parasite management. ### How do I sprout seeds for chickens? Soak seeds (barley, wheat, legumes) in water for 12-24 hours. Drain and rinse twice daily. Sprouts appear in 3-7 days. Feed as a fresh forage supplement. Sprouts are high in moisture and vitamins but low in energy. Do not replace complete feed. ### What is the difference between mash, crumbles, and pellets? Mash is ground feed that can be dusty and allows selective feeding. Crumbles are mash compressed and broken into small pieces, reducing waste. Pellets are compressed feed that is easy to handle, reduces dust, and prevents ingredient separation. Pellets are preferred for most commercial operations. ### How much feed does a chicken eat per day? A laying hen eats about 100-120 grams of feed per day. Broilers eat more relative to body weight. Feed intake varies with breed, temperature, production level, and feed quality. Monitor feed consumption and adjust as needed. ### Can I mix my own chicken feed? Yes, but it requires careful formulation to meet nutritional requirements. Use a vitamin/mineral premix to balance homemade rations. Consult an animal nutritionist or use validated feed formulation software. Improper mixing can lead to deficiencies or toxicities. ## Related Farming Guides - [Mycoplasma Management In Commercial Poultry](/knowledge/animal-farming/poultry/mycoplasma-management-in-commercial-poultry) - [Layer Chicken Farming Pullet Development Egg Production Nutrition And Flock Health](/knowledge/animal-farming/poultry/layer-chicken-farming-pullet-development-egg-production-nutrition-and-flock-health) - [Poultry Brooding Management For The First Two Weeks](/knowledge/animal-farming/poultry/poultry-brooding-management-for-the-first-two-weeks) - [Carp Farming Pond Production Feeding And Harvest Management](/knowledge/animal-farming/aquaculture/carp-farming-pond-production-feeding-and-harvest-management) - [Broiler Chicken Farming Flock Management From Placement To Processing](/knowledge/animal-farming/poultry/broiler-chicken-farming-flock-management-from-placement-to-processing) ## Related Clinical & Scientific Guides * [Poultry Farm Fencing: Materials, Design, and Predator Exclusion](/knowledge/animal-farming/poultry/poultry-farm-fencing-materials-design-predator-exclusion) * [Broiler House Wind Speed and Airflow Measurement](/knowledge/animal-farming/poultry/broiler-house-wind-speed-airflow-measurement) * [Broiler House Heating Systems: Types and Efficiency](/knowledge/animal-farming/poultry/broiler-house-heating-systems-types-efficiency) ## References and Further Reading - [www.fao.org](https://www.fao.org/poultry-production-products/en) - [www.aphis.usda.gov](https://www.aphis.usda.gov/livestock-poultry-disease/avian) - [www.merckvetmanual.com](https://www.merckvetmanual.com/poultry) - [FAO Animal Production and Health](https://www.fao.org/animal-production/en). Food and Agriculture Organization of the United Nations. - [Animal Health and Welfare](https://www.nal.usda.gov/animal-health-and-welfare). USDA National Agricultural Library. - [Chicken genome editing for investigating poultry pathogens.](https://pubmed.ncbi.nlm.nih.gov/36278430). Avian pathology : journal of the W.V.P.A, 2023. - [Interspecific variation in wildlife responses to cattle, swine and chicken feed in the forests surrounding poultry farms.](https://pubmed.ncbi.nlm.nih.gov/35314571). The Journal of veterinary medical science, 2022. - [Alpha-lipoic acid: An inimitable feed supplement for poultry nutrition.](https://pubmed.ncbi.nlm.nih.gov/28447384). Journal of animal physiology and animal nutrition, 2018. - [OMICs approaches and technologies for understanding low-high feed efficiency traits in chicken: implication to breeding.](https://pubmed.ncbi.nlm.nih.gov/36927292). Animal biotechnology, 2023. - [Effects of genotype, sex, and feed restriction on the biochemical composition of chicken preen gland secretions and their implications for commercial poultry production.](https://pubmed.ncbi.nlm.nih.gov/36547363). Journal of animal science, 2023. - [Quantification of toxic metals in chicken egg and chicken feed via SOM-artificial neural network.](https://pubmed.ncbi.nlm.nih.gov/38265542). Environmental monitoring and assessment, 2024. - [Using X-ray fluorescence technique propagation of chromium (Cr) from poultry feeds to different parts of chicken including her Eggs](https://doi.org/10.1088/1742-6596/1718/1/012015). Journal of Physics Conference Series, 2021. - [Assessment of potentially toxic element contents in chickens and poultry feeds from Bangladesh markets: Implications for human health risk](https://doi.org/10.1016/j.toxrep.2024.101706). Toxicology Reports, 2024. - [Mycotoxins in poultry feed and feed ingredients from sub-saharan africa and their impact on the production of broiler and layer chickens: A review](https://doi.org/10.3390/toxins13090633). Toxins, 2021. > This article is educational and is not a substitute for veterinary diagnosis, treatment, public-health guidance, or regulatory reporting.