The main DIFFERENCES BETWEEN PROTEINS used in animal nutrition are:
Animal-based proteins
- Fish meal: High in protein (55–70%) with a favorable amino acid profile.
- Meat and bone meal: Rich in essential amino acids, though its use is restricted in some countries.
Plant-based proteins
- Soybean meal: The most widely used, with 44–48% crude protein and a good amino acid profile.
- Canola meal: Contains 36–40% protein and is more sustainable than soy in some regions.
- Alfalfa meal: Lower in protein but rich in fiber and micronutrients.
Alternative proteins
- Insect meal: Contains 55–76% crude protein, is sustainable, and has a good nutritional profile.
- Microalgae protein: Up to 50% protein in species like Chlorella or Spirulina.
- Single-cell protein: Highly digestible, derived from microorganisms.
Amino acid profile
- Fish meal has the best profile of essential amino acids.
- Plant proteins are often deficient in certain amino acids like methionine.
- Insect protein offers a valuable and balanced amino acid profile.
Digestibility
- Animal proteins generally have higher digestibility.
- Concentrated soybean protein has high digestibility, comparable to fish meal.
- Pea protein has lower digestibility, especially for monogastric animals.
Antinutritional factors
- Plant proteins like soy contain antinutritional factors that may affect digestion.
- Insect and single-cell proteins lack these factors.
Sustainability
- Insect and microalgae proteins are considered more sustainable.
- Fish meal production can have negative environmental impacts.
Cost and availability
- Soybean meal is generally more affordable and widely available.
- Alternative proteins such as insect meal are still more expensive but are gaining traction.
The choice of protein source depends on the animal species, growth stage, costs, local availability, and environmental considerations. The current trend is toward diversifying protein sources and increasing the use of sustainable alternatives.