Module 2: Overview of Feed Resources

Animal feeds according to encyclopeadia are classified as follow:

1. concentrates, high in energy value, including fat, cereal grains and their by-products (barley, corn, oats, rye, wheat), high-protein oil meals or cakes (soybean, canola, cottonseed, peanut [groundnut]), and by-products from processing of sugar beets, sugarcane, animals, and fish, and

2. roughages, including pasture grasses, hays, silage, root crops, straw, and stover (cornstalks)

How does the Food and Agriculture Organization (FAO) categorize feed

IAFFD classification of feed

Types/origins of forages and roughages

• Grass forage

• Legumes forage

• Forage crops / Fodder (cultivated plants like corn cut and used as forage)

• Browse (leaves and small branches of trees/shrubs, and other non-herbaceous vegetation)

Forms of forages and roughages

• Pasture

• Fresh cut (green chop) (80-90% moisture)

• Hay (dried to less than 12-15% moisture)

• Silage (50-80% moisture)

• Haylage (Partly dried to 20-50% moisture and ensiled); halfway between hay and silage

• Compressed (cubed), dehydrated (less than 10% moisture)

Forage legumes description

Plants of the legume family are noted for their high content in protein due to their symbiotic nitrogen-fixing bacterial colonizing their root

Forage legumes examples

• Alfalfa, also called Lucerne, (Medicago sativa) is Canada's most valuable forage.

• Red clover (Trifolium pratense) is more suited to imperfect soil drainage than alfalfa.

• Alsike clover (T. hybridum) and white clover (T. repens) are also widely cultivated.

Grass forages

• Timothy (Phleum pratense) is the dominant forage grass in eastern Canada.

• Crested wheatgrass (Agropyron cristatum) is a dominant forage grass in western Canada.

• Orchard grass (Dactylis glomerata) and Russian wild ryegrass (Elymus junceus) are dominant forage grasses in British Columbia.

• Bromegrass (Bromus inermis) is grown in eastern Canada and on the Prairies.

• Kentucky bluegrass (Poa pratensis) is commonly grown in many areas.

Examples of forage grain/crop

• Corn

• Barley

• Oat

• Wheat

Factors affecting forage quality

Six major factors affecting forage quality (not yield):

1. Maturity

2. Crop species

3. Harvest and storage

4. Environment,

5. Soil fertility

6. Variety (genetic)

What happens as forage matures

• As forage grasses and legumes approach reproductive maturity, yield and dry matter (DM) accumulation increases

However, forage quality decreases:

• Less leaves (higher protein, lower fibre part)

• More stems (more fibrous part)

• Lower crude protein

• Higher levels of fibres that are difficult to ferment (ADF = Acid detergent fibres

Ensiling/silaging and how it’s done

• Ensiling forages is a practice where wilted or fresh cut grass is packed into an anaerobic environment.

• The ensiling process relies on lactic acid bacteria utilizing the water- soluble sugars within the plant to produce organic acids which lower the pH from 6.0 to 3.8-5.0, depending on the forage species.

• The low pH and anaerobic conditions limit bacterial growth and degradation of the quality of the silage

Good ensiling practices include

Good ensiling practices involves preserving forage, excluding oxygen, and reducing the pH quickly through bacterial fermentation.

Silage quality

• Lactic acid should be the primary acid in good silage. This acid is stronger than the other acids (acetic, propionic, and butyric) in silage and therefore is usually responsible for greater decrease in silage pH.

• Fermentations that produce lactic acid result in the lowest losses of DM and energy from the crop during storage compared to fermentation conditions promoting the production of other organic acids.

• In general, silages with high levels of acetic acid and butyric acids can result in reduced feed intakes by ruminants.