Nutritional Requirements of Pigs

July 18, 2025

Nutritional Requirements of Pigs How to Choose the Best Pig Feed for Different Growth Stages

Pig farming is one of the most important sectors in animal agriculture worldwide. It contributes significantly to the global food supply by providing high-quality protein, essential nutrients, and economic livelihoods for millions of people. To maintain a successful pig farming operation, one of the most critical factors is nutrition. Proper feeding not only supports the health and well-being of pigs but also directly impacts their growth rates, feed efficiency, reproductive performance, and ultimately, the profitability of the farm.

Pigs have different nutritional needs throughout their lifecycle, and feeding strategies must adapt accordingly. What a piglet requires for optimal growth immediately after weaning is different from the diet a finisher pig needs to maximize lean muscle gain or what a sow needs during gestation to maintain her body condition. Selecting the best pig feed for each growth stage ensures that animals receive the nutrients they need without wastage or nutritional gaps that can stunt growth or cause disease.

In this comprehensive guide, we will explore how to choose the best pig feed for every phase of development — from newborn piglets to finishing pigs and breeding stock. You will learn about the unique nutritional requirements of each stage, the types of feed available, key ingredients, and practical feeding management tips. Whether you are a commercial producer aiming for high-efficiency production or a smallholder focused on sustainable and cost-effective feeding, this guide will provide the knowledge you need to optimize your pig feeding program.

1. Understanding Pig Growth Stages

Pigs grow and develop rapidly from birth to market weight, which generally takes between 5 to 6 months depending on genetics, environment, and feeding management. During this time, their nutritional needs change significantly as they transition through several distinct growth phases. Each phase requires feed formulations tailored to meet their specific energy, protein, vitamin, and mineral needs.

1.1 Starter Piglets (0-8 Weeks)

The starter phase encompasses newborn piglets up to around 8 weeks of age. This stage is crucial because piglets are vulnerable to diseases and nutritional stress after birth and during weaning.

Key Characteristics:

Piglets are born with limited energy reserves.
They rely initially on sow’s milk, which provides critical antibodies and nutrients.
From about 2-3 weeks, they start to nibble on solid feed to develop their digestive system.
The feed must be highly digestible, nutrient-dense, and palatable.
Protein quality is very important, with emphasis on essential amino acids like lysine and methionine.
Vitamins such as A, D, E, and B-complex are vital for immune development.
Energy comes mainly from carbohydrates and fats.

Feeding Focus:
The goal is to support rapid growth, strengthen immunity, and ease the transition from milk to solid feed. Many producers use specially formulated creep feeds that are low in fiber and contain animal proteins like fishmeal for digestibility.

1.2 Weaners (8-12 Weeks)

Weaning usually occurs between 3-4 weeks of age, though it can vary depending on management systems. The weaner stage covers the period immediately after weaning, typically 8 to 12 weeks of age.

Key Characteristics:

Weaning is a stressful period — piglets lose access to sow’s milk and face new social and environmental challenges.
Digestive system is still developing; hence feed must be easy to digest and highly palatable.
Nutritional demands increase to support compensatory growth after weaning stress.
Feed must contain adequate energy, highly digestible protein, and balanced minerals.
Feeds often contain feed additives like probiotics and enzymes to support gut health.

Feeding Focus:
Minimize growth setbacks by providing a gradual transition diet, rich in essential nutrients and easily digestible ingredients. Water must be clean and abundant.

1.3 Growers (12-16 Weeks)

The grower phase follows the weaner stage, typically covering pigs aged 12 to 16 weeks. At this stage, pigs experience accelerated growth and muscle development.

Key Characteristics:

The digestive system is more mature, allowing for more complex diets.
Energy and protein are the primary nutritional focuses.
Amino acid requirements are still high but gradually decrease compared to starter phase.
Fiber can be increased moderately to support gut health and reduce feed costs.
Vitamins and minerals continue to be important for healthy development.

Feeding Focus:
Provide a balanced diet that supports rapid growth while optimizing feed efficiency. Cost-effective ingredients like corn and soybean meal are commonly used.

1.4 Finishers (16 Weeks to Market Weight)

Finishers are pigs in the final growth phase before slaughter, generally from 16 weeks of age until they reach market weight (around 100-120 kg).

Key Characteristics:

Growth rate slows compared to earlier phases.
Feed focuses on maximizing lean meat production and feed conversion efficiency.
Protein levels are reduced slightly compared to growers.
Energy density is adjusted to avoid excessive fat deposition.
Feed intake increases significantly as pigs approach market weight.

Feeding Focus:
Use cost-effective diets that promote lean growth and efficient weight gain without overfeeding energy, which can lead to excessive fat and reduced carcass quality.

1.5 Breeding Stock (Sows and Boars)

Breeding pigs have very different nutritional requirements based on physiological status — maintenance, gestation, lactation, or recovery.

Key Characteristics:

Maintenance diet needs are lower but must provide balanced vitamins and minerals.
Gestating sows require energy and minerals to support fetal development.
Lactating sows have high energy and protein demands to support milk production.
Boars require maintenance diets with good nutrient balance to maintain fertility.

Feeding Focus:
Adjust feed based on reproductive stage to maintain body condition, maximize reproductive performance, and support piglet growth.

2. Nutritional Requirements at Different Growth Stages

Each growth stage has specific nutritional demands for energy, protein, amino acids, vitamins, and minerals. Understanding these requirements is key to selecting or formulating the best feed.

2.1 Energy Needs

Energy is required for maintenance, growth, reproduction, and activity. It is mainly provided by carbohydrates and fats in feed.

Starter piglets require high energy density feeds due to small stomach capacity.
Growers and finishers have increasing feed intake but lower energy density.
Breeding sows need energy adjusted to physiological state.

2.2 Protein and Amino Acids

Protein supports muscle and tissue development. The quality of protein, determined by amino acid composition, is critical.

Lysine is the first limiting amino acid in pig diets.
Starter and weaner pigs require high protein levels with balanced amino acids.
Growers and finishers have moderate protein needs.
Breeding stock require amino acids for reproductive performance.

2.3 Vitamins and Minerals

Essential for metabolism, bone development, immune function, and reproduction.

Starter and weaner pigs need vitamins A, D, E, and B-complex in adequate amounts.
Minerals like calcium, phosphorus, zinc, and selenium are critical throughout all stages.
Mineral supplementation prevents deficiencies and supports growth.

2.4 Fiber and Other Nutrients

Fiber plays a role in gut health and feed intake regulation.

Starter pigs require low fiber feeds for digestibility.
Growers and finishers can tolerate moderate fiber levels.
Fiber sources can reduce feed cost and improve gut motility.

2.5 Water Requirements

Although often overlooked, water is the most critical nutrient for pigs. Proper hydration affects feed intake, digestion, metabolism, and temperature regulation.

Piglets need clean, fresh water from an early age, even during the starter phase.
Water intake generally increases with age and feed consumption.
Insufficient water leads to reduced feed intake, slower growth, and health issues.
Water quality, including absence of contaminants and appropriate temperature, is important for optimal intake.

2.6 Energy and Protein Ratios

The balance between energy and protein is crucial for efficient growth.

High protein without sufficient energy leads to inefficient nitrogen utilization and increased feed costs.
Excess energy without enough protein causes fat deposition instead of lean tissue.
Feed formulation must optimize this balance according to pig growth stage and desired production outcomes.

3. Types of Pig Feed

Selecting the appropriate type of feed depends on pig growth stage, available resources, and farm management. There are several common types of pig feed, each with unique advantages and considerations.

3.1 Commercial Pelleted Feeds

Description:
Pelleted feed is processed into uniform pellets, which are easy for pigs to consume and digest.

Advantages:

Consistent nutrient content.
Reduced feed wastage.
Easier to handle and store.
Often contains additives for health and growth promotion.

Considerations:

More expensive than mash or homemade feeds.
Requires access to reliable suppliers.
Pelleting process can increase feed digestibility.

Best Stage Use:
Widely used for starter, weaner, and grower pigs for their palatability and nutrient density.

3.2 Mash Feeds

Description:
Mash feed is a loose mixture of ingredients without pelleting.

Advantages:

Generally cheaper to produce or buy.
Easier to customize formulations.
Can be made on-farm.

Considerations:

Less uniform feeding.
Higher risk of feed segregation or wastage.
Can be dusty, affecting pig respiratory health.

Best Stage Use:
Often used for growers and finishers or in smallholder farms where feed cost is a priority.

3.3 Homemade Feed Mixes

Description:
Farmers mix locally available ingredients such as maize, soybean, fishmeal, and supplements.

Advantages:

Cost-effective if ingredients are locally sourced.
Flexibility to adapt to ingredient availability.
Useful for small-scale or resource-poor farmers.

Considerations:

Requires knowledge of nutrition to avoid imbalances.
Variability in ingredient quality.
Potential for contamination if not handled properly.

Best Stage Use:
Common in smallholder and backyard pig production systems, suitable across all growth stages if formulated well.

3.4 Forage and Alternative Feedstuffs

Description:
Incorporates fresh or preserved forages, agricultural by-products (like cassava peels, brewer’s grains), and alternative protein sources.

Advantages:

Low-cost or free feed resource.
Provides fiber for gut health.
Can reduce dependency on commercial feeds.

Considerations:

Often low in energy and protein.
Must be supplemented with concentrates.
Variable nutritional content and digestibility.

Best Stage Use:
Primarily used in growers, finishers, and breeding stock diets as part of a balanced feeding strategy.

4. How to Choose Pig Feed by Growth Stage

Matching the right feed to each growth phase is essential for maximizing pig performance. The key is understanding the nutritional profile needed and the feed types suitable at each stage.

4.1 Starter Piglet Feeds

Starter feeds should be highly digestible, nutrient-dense, and palatable to encourage early feed intake.

Characteristics:

High protein (18-22%)
Balanced amino acids, especially lysine, methionine, and threonine
Easily digestible carbohydrates and fats
Low fiber content to reduce gut stress
Inclusion of milk by-products or animal proteins like fishmeal
Added vitamins, minerals, and health-promoting additives (probiotics, enzymes)

Tips:

Use pelleted feeds for easy consumption.
Introduce creep feeding at 1-2 weeks to ease weaning.
Ensure constant availability of clean water.

4.2 Weaner Feeds

Weaner feeds must support the transition from milk to solid feed, promote gut health, and maintain growth.

Characteristics:

High protein (18%)
Moderate energy density
Use highly digestible ingredients such as soybean meal, fishmeal
Addition of feed additives for gut health (probiotics, organic acids)
Balanced minerals and vitamins

Tips:

Provide small, frequent meals.
Use palatable formulations to stimulate intake.
Gradually transition to grower feeds by 8-10 weeks.

4.3 Grower Feeds

Grower feeds focus on rapid muscle gain and efficient feed conversion.

Characteristics:

Moderate protein (14-16%)
Balanced amino acids
Increased fiber content to improve gut motility
Cost-effective ingredients like corn and soybean meal
Adequate vitamins and minerals

Tips:

Feed 2-3 times daily.
Monitor growth and adjust feed accordingly.
Maintain water availability.

4.4 Finisher Feeds

Finisher feeds emphasize energy efficiency and lean growth.

Characteristics:

Lower protein (12-14%)
Balanced energy levels to avoid fat deposition
Amino acid profiles that support muscle retention
Inclusion of fats or oils to increase energy density if needed

Tips:

Avoid excessive energy to prevent fat.
Monitor body condition regularly.
Adjust feeding as pigs approach market weight.

4.5 Breeding Stock Feeds

Feeding breeding pigs varies depending on stage.

Gestation Diets:

Moderate energy
Balanced protein (12-14%)
Adequate calcium, phosphorus, and trace minerals

Lactation Diets:

High energy and protein to support milk production
Increased vitamins and minerals
Palatable and nutrient-dense

Boar Diets:

Maintenance level feeding
Balanced nutrition to maintain fertility

Tips:

Avoid overfeeding during gestation to prevent obesity.
Provide adequate nutrition to maintain sow body condition through lactation.
Monitor boar condition regularly.

5. Common Ingredients in Pig Feed and Their Functions

Selecting the right feed also involves understanding the nutritional role of common feed ingredients.

5.1 Energy Sources

Energy fuels all biological activities.

Corn (Maize): Primary carbohydrate source; high in starch, low fiber.
Wheat: Similar to corn but slightly more protein.
Barley: Moderate energy with higher fiber content.
Sorghum: Alternative grain with variable digestibility.
Fats and Oils: Concentrated energy sources that improve feed density and palatability.

5.2 Protein Sources

Protein supplies essential amino acids.

Soybean Meal: High-quality plant protein, rich in lysine.
Fishmeal: Animal protein, highly digestible.
Meat and Bone Meal: Protein and minerals.
Canola, Sunflower, Pea Meals: Alternative plant proteins.

5.3 Vitamins and Minerals

Support metabolic functions, growth, and reproduction.

Calcium and Phosphorus: For bone development.
Trace minerals: Zinc, copper, selenium.
Vitamins: A, D, E, K, B-complex.

5.4 Feed Additives

Enhance digestion, health, and feed efficiency.

Enzymes: Improve fiber digestibility.
Probiotics: Support gut microflora.
Mycotoxin binders: Prevent toxin absorption.

6. Feed Formulation Techniques and Tools

Formulating the right feed involves balancing nutrient requirements with ingredient availability and cost.

6.1 Nutrient Balancing

Meet the pig’s requirements for energy, protein, amino acids, vitamins, and minerals.
Avoid deficiencies and excesses.
Consider digestibility and ingredient interactions.

6.2 Least-Cost Formulation

Use software or manual calculations to minimize feed cost while meeting nutrition.
Adjust formulation as ingredient prices fluctuate.

6.3 Quality Control

Regularly test ingredients for nutrient content and contaminants.
Monitor feed storage conditions.

7. Feeding Management Practices

Feed at consistent times and in appropriate amounts.
Provide unlimited access to clean water.
Maintain hygiene in feeding areas.
Monitor pig health and growth regularly.
Train farm staff on feeding protocols.
Adapt Feeding Programs Based on Seasonal Changes
Seasonal temperature fluctuations impact pig appetite and metabolism. During hot weather, pigs eat less but need more water and diets adjusted for energy density to maintain growth. In colder months, feed intake usually increases, and rations may require higher energy content to support body heat production. Monitoring feed intake and body condition regularly during seasonal transitions ensures pigs remain healthy year-round.

8. Challenges and Solutions in Pig Feeding

Nutrient deficiencies — prevent through balanced diets.
Digestive upset — manage weaning stress and feed transitions carefully.
Feed cost management — use local ingredients and optimize feed efficiency.
Environmental stress — adjust diets for heat or cold.

9. Case Studies and Practical Tips

Smallholder farms can improve piglet growth with creep feeding and locally sourced feed.
Commercial farms benefit from pelleted feeds, feed additives, and computerized formulation.
Always monitor and adapt feeding programs based on pig performance and changing conditions.
Case Studies and Practical Tips
Effective pig feeding strategies vary depending on the scale of the operation, available resources, and management knowledge. Below are examples and practical tips based on real-world practices from both smallholder and commercial pig farms:
Smallholder Farm Example – Creep Feeding and Local Feed Use
In many rural areas, small-scale pig farmers have successfully improved piglet health and growth through the introduction of creep feeding. For instance, a farmer in northern Kenya began creep feeding piglets at just 10 days old using a homemade mix made from roasted maize, fishmeal, and sweet potato vines. Despite limited access to commercial feeds, this approach reduced piglet mortality, improved early weight gain, and shortened the weaning period. Smallholders can also benefit from using locally available feed ingredients like rice bran, cassava, broken maize, and banana stems. By formulating balanced rations with what's on hand and observing pig behavior and body condition regularly, farmers can optimize feed efficiency even on a tight budget.
Commercial Farm Example – Pelleted Feed and Digital Monitoring
A commercial piggery in the Philippines reported measurable improvements in feed efficiency and growth rates after switching from mash to pelleted feeds. Pelleted feed reduced wastage and prevented pigs from selecting only certain components of the ration. The farm also incorporated additives such as probiotics and enzymes, which improved digestion and gut health. To further enhance efficiency, they used computerized feed formulation software and automated systems to monitor feed intake, weight gain, and performance across different pig groups. This allowed for timely adjustments to feeding programs based on real data.
Practical Tip:
Whatever the farm size, consistently monitor pig performance metrics like feed intake and growth rate. Be prepared to adjust feeding practices based on seasonal changes, market prices, and pig health conditions. Record-keeping and observation are key to long-term success in pig feeding.
Conclusion

Understanding pig nutrition is the cornerstone of proper feed selection. Pigs are monogastric animals, meaning they rely on a single-chambered stomach to digest food, much like humans. As such, their feed must be carefully balanced to deliver essential nutrients such as proteins, carbohydrates, fats, vitamins, minerals, and water in digestible forms. Each stage of development — starter, weaner, grower, finisher, and breeding — presents unique physiological challenges and opportunities. Providing precise nutrition during these stages supports tissue development, boosts immunity, enhances feed efficiency, and prepares animals for either market or reproduction.

For instance, in the early stages, piglets must receive high-quality, highly digestible proteins and energy sources to develop a strong immune system and adapt to life outside the sow. Any delay or deficiency during this phase can have long-term effects, resulting in stunted growth or susceptibility to disease. Creep feeding and the use of additives such as probiotics or prebiotics can help ease the transition from milk to solid feed and ensure the gut is prepared for the more complex nutrients that follow.

As pigs enter the grower and finisher stages, the nutritional emphasis shifts to promoting lean muscle development and efficient feed conversion. This is where the economics of feeding begin to play a larger role. Feed represents the largest single cost in pig production — often up to 70% of total production costs. Therefore, choosing cost-effective ingredients while still maintaining nutritional adequacy is essential. This is why least-cost feed formulation, supported by either software or expert consultation, becomes vital in commercial operations.

At the same time, nutritional precision must not compromise animal welfare. Imbalanced rations can result in nutritional disorders such as rickets, anemia, or metabolic diseases. Underfeeding protein, for example, can lead to poor growth rates, while overfeeding energy may cause excess fat deposition and reduce carcass quality. Moreover, excessive nutrient excretion — a common issue with imbalanced diets — can contribute to environmental pollution, particularly in the form of nitrogen and phosphorus runoff. Thus, sound nutrition is also a pillar of sustainable farming.

Breeding stock, including sows and boars, have very different nutritional demands, tied closely to reproductive cycles. Gestating sows require sufficient energy and minerals to support fetal growth without becoming obese, while lactating sows need high-protein, high-energy diets to maintain milk production and body condition. If a sow’s nutritional needs are not met, her litter’s growth and survival can be compromised. Similarly, boars must be fed maintenance diets that support fertility and prevent health problems associated with excess weight.

Another critical dimension to pig feeding is the choice between commercial feeds and home-based formulations. Commercial pelleted feeds offer convenience, consistency, and superior digestibility but are often more expensive. On the other hand, homemade mixes, when designed correctly, can be more affordable and adaptable to local conditions. However, they require a solid understanding of pig nutrition and access to clean, quality ingredients. Both strategies can be effective depending on the scale of production, available resources, and knowledge level of the farmer.

Feed form also plays a role. Pelleted feeds are preferred in many commercial operations due to their uniformity and reduced waste. Mash feeds, while cheaper, can be dusty and may lead to selective eating. In smallholder systems, integrating locally available agricultural by-products, forage, and alternative feedstuffs can provide a sustainable supplement to conventional feeds — but only when their nutritional value is well understood and balanced accordingly.

Equally important to feed type and composition is feeding management. Timing, frequency, cleanliness, and water availability all impact how efficiently pigs utilize their feed. Even the best-formulated feed can be rendered ineffective if animals are fed irregularly, if troughs are contaminated, or if water supply is inadequate. Water, often underestimated, is essential for digestion, nutrient absorption, thermoregulation, and metabolic function. A shortage of clean water can rapidly decrease feed intake and lead to poor performance or even death.

Additionally, the use of feed additives such as enzymes, probiotics, organic acids, and toxin binders has become increasingly common. These components, while optional, often improve nutrient digestibility, enhance gut health, and protect pigs from feed-borne pathogens or mycotoxins. For example, in environments where grains may be exposed to mold, the use of a mycotoxin binder can prevent the negative health effects and growth reduction associated with contaminated feed.

The future of pig feeding lies in precision nutrition — tailoring diets not just to the species or life stage, but to the genetic potential and specific conditions of each pig population. With the integration of digital technologies, sensors, and data analytics, farmers can monitor feed intake, body weight, and even individual pig behavior in real time. This allows for more accurate ration adjustments and minimizes waste, while also identifying health issues early. Genetic advances in breeding are also influencing feed needs, as newer pig lines may require different nutrient profiles than traditional breeds.

On a global level, pig feed practices are evolving in response to rising demand for sustainable agriculture, tighter environmental regulations, and concerns over antibiotic resistance. Producers are expected to reduce the environmental footprint of their operations, which includes optimizing feed efficiency, minimizing nutrient losses, and sourcing ingredients responsibly. Feeding strategies that support these goals not only protect the environment but also appeal to increasingly informed consumers and policy makers.

In conclusion, feeding pigs properly at every growth stage is not simply a technical task — it is a strategic investment that determines the success of the entire pig production enterprise. By understanding the nutritional needs of pigs, selecting appropriate feed types, using quality ingredients, and applying best practices in feeding management, producers can ensure optimal growth, health, and profitability. Whether you operate a small backyard system or a large commercial facility, the principles remain the same: nutrition is the engine that drives performance.

Well-fed pigs grow faster, stay healthier, reproduce efficiently, and produce higher-quality meat. More importantly, strategic feeding ensures a sustainable future for pig production — one where economic success goes hand-in-hand with animal welfare and environmental responsibility.