Pastures are harvested at certain stages of their growth for conservation and subsequent utilization during periods of feed scarcity. Pasture harvesting is necessary for a better supply of high-quality feed because forage dry matter progressively decreased with advancing maturity.

The quality of conserved forage depends on the harvesting method and the moisture content at the time of harvest and storage. Different types of machinery are used in harvesting pasture species in Nigeria, due to their high efficiency compared to manual methods such as using cutlasses, etc.

1. Growth Stages of Cutting Pasture

There are three growth stages of cutting pasture species:

Pre-Flowering Stage: This is a stage in pasture growth in which the pasture specie has more vegetative growth before setting flowers for seed production. This period starts from the early stage of growth (3 weeks after planting), up to 8 or 9 weeks post planting period in grass species.

However, in legume species, the period depends on the specie and management practices applied. During this stage, there are more leaves in the shoot and the stems are not hard (lignified).

The moisture content of forage at this stage is usually high with little dry matter content. Therefore, more material needs to be harvested before conserving it for future use.

Flowering Stage: At this stage, the pasture specie produces flowers for seed production. Fertilized ova result in immature seeds, which can be grazed by livestock or even defoliated for conservation.

This stage is known as the bloom stage. The amount of dry matter at this stage supersedes the moisture content, and therefore farmers normally harvest their pastures at this stage depending on the type of enterprise.

Post-Flowering Stage: During this stage, seeds are set by the pasture specie. However, the moisture content of the seeds is still high compared to dry seeds. This stage is sometimes known as the dough stage in maize plants for silage.

The forage at this stage contains a high level of fiber for structural support. Livestock feeds very little quantity of the forage material at this stage, even though the moisture content is very low.

2. Moisture Reduction Techniques in Pastures

Forages are made up of water and dry matter components. The amount of these components depends on the stage of growth of the forage. However, moisture remains the most important factor to be considered before using or storing any material for future use.

Therefore, moisture content can be reduced from the forage by wilting the material for a few days after cutting. Thereafter, the wilted forage can be further sliced into fine, smaller cuts to facilitate moisture loss.

Also, there has to be frequent turning of the forage material while in the field depending on the dimension, density, and structure of the swath.

3. Preservation Methods in Pastures

Pasture Harvesting and Processing Methods — Hay

Pastures can be preserved in many forms based on the interest of the farmer. These preservation techniques include the followings:

Hay – This refers to conserved forage that is in the dried stage. Spreading the forage in the sun or inside the barn can do the drying process either. However, sun-cured hay is cheaper to make than barn-cured hay, but barn-cured hay is more qualitative than sun-cured hay.

This is because of fewer leaf losses in the barn compared to the field. Hays are stored as rectangular or round bales, cubical bales, or stacks. The quality of hay depends on the stage of cutting the forage and climatic conditions.

Silage – Silage is conserved forage that has undergone complete anaerobic fermentation for a period of 3 weeks. Fresh forage material is harvested at the appropriate stage of pasture growth.

The material may be allowed to wilt or used directly to make silage while the moisture content is still high. The forage has to be cut into smaller pieces before transporting into the silo.

A silo is a structure for making silage. After uploading the forage in the silo, it has to be well consolidated. Some additives are added to the material to facilitate intake.

Finally, a polythene material is used to cover the silo completely for a period of three weeks. Silage is more acceptable to livestock than hay because of its quality. However, it is more expensive to make than hay.

Pellets: Pastures can also be preserved in form of pellets. This is possible by using the pelletized machine after drying the forage into hay.

This will facilitate packaging, easy handling, and transportation of the forage from one place to the other. Also, its acceptability to livestock is higher compared to hay.

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