Silage crops for cattle’s optimum health: Part Three …correct growing and processing


THE small grains used to make silage include oats, wheat, rye, and triticale. 

Triticale, a cross between durum wheat and rye, produces very good silage and is similar in quality to common wheat.  

Oats are probably the most popular small grain used for silage.  

Oats and wheat produce comparable yields and both make very palatable silage if correctly handled. 

Rye grows at lower temperatures than oats or wheat and may produce more forage than oats or wheat. 

However, because rye has more stems and fewer leaves than oats or wheat, rye is often less acceptable to cattle. 

Planting and fertilising small-grain varieties recommended for grain production can also be used for silage. 

Planting dates and management of small-grain varieties should be the same as for other grain production. 

Small-grain crops should be planted during the early part of the planting season.

Early-maturing varieties of wheat should be planted in the later portion of a planting period. Mid-season or late varieties should be planted in the first half of the planting period. 

Plant about 45kg/acre of seed on a clean, tilled seedbed, where all the required fertiliser except nitrogen (N), has been incorporated prior to planting.  

Apply 18-22kg/acre of nitrogen prior to planting with the complete fertiliser then top-dress with an additional 26-36kg/acre of nitrogen.

Small grains can also serve as dual-purpose crops. 

These crops can be grazed during the fall and winter and then cattle can be removed in early spring to allow growth for silage production.  

To successfully do this, the crop must be planted about one month earlier and an additional 23kg/acre of nitrogen top-dressing made, with the nitrogen going on in two top-dressing applications.

All of the small grains, except rye, can be harvested for silage.  

Dry matter yields will increase, and crude protein percentage will decrease as the plants mature. The moisture concentration will range from 80–85 percent at late-boot to about 70 percent at early-dough stage. 

When small grains reach the dough stage, the moisture content is satisfactory for direct chopping and ensiling.  

The optimum dough stage for ensiling may last for only four to six days. 

Once the plant turns yellow, quality drops rapidly and the material becomes low in moisture and difficult to pack in the silo.

Harvest rye at the late-boot to early-head stage. 

If rye goes beyond this stage of maturity, quality decreases rapidly. Although yield is lower than with material cut at the dough stage, digestible dry matter and protein concentrations are higher. 

Harvesting at this earlier stage of growth and higher moisture content requires additional equipment because the crop must be cut, conditioned, wind rowed, and wilted to at least 70 percent moisture content before being picked up, chopped and packed in the silo in its semi-dry state.

Improved hay and pasture grasses can be successfully ensiled. 

Due to weather and storage problems often associated with hay production, higher yields and better-quality forage may be obtained when grasses are harvested as silage, rather than as hay.

With good management, it is possible to harvest  eight to 10 tons of dry matter per acre per year from improved forage grasses. 

An early-spring application of nitrogen (N), phosphorus (P), and potassium (K2O) recommended from soil-test results will get the grass off to a good start. 

A supplementary application of 36kg/acre of nitrogen plus 18kg/acre of K2O will be needed after each harvest on mineral soils because large amounts of plant nutrients are removed from fields when hay or silage is harvested. 

The nutrient status of the soil should be monitored closely by taking soil samples each fall after the last harvest or when regrowth has slowed due to cool weather.

The first harvest can be taken when 35-40cm of growth accumulates in the spring, with subsequent harvests about every four weeks. 

Good-quality silage can be made by cutting at four weeks and wilting to 60–70 percentage moisture. 

If the grass is cut directly without wilting, use a silage additive to enhance fermentation.

Alfalfa, red clover, and other hay-type, cool-season legumes  either alone or in combination with grass, have some potential as silage crops. 

When harvested at the optimum stage of growth, these crops are high in protein and buffering capacity but low in sugar. 

These crops need to be wilted to 60 percent moisture to concentrate the sugars.

In addition, a silage aid that improves lactic-acid formation such as ground corn, molasses or a lactic-acid bacteria inoculant should be added.

Perennial peanut, annual peanut, cowpea, pigeon pea and forage soybean can also be ensiled. 

These forages should be wilted to 60 percent moisture and stored after application of a silage aid that improves lactic-acid formation, such as ground corn, molasses or a lactic-acid bacteria inoculant.

To determine the moisture content of a silage crop in order to know whether the crop is ready to be harvested and stored as silage the ‘squeeze test’ for moisture may be used as a crude field test to determine when to start analysing the moisture content of forages destined for silage production. 

After the grass has been in the swath for two to four hours under good drying conditions, run a small amount through the chopper. 

If a squeezed fistful forces free juice into your hand with the ball holding its shape when pressure is first released, the forage is too wet.

When the forage reaches 60–70 percent moisture, the ball will momentarily hold its shape after squeezing and then gradually expand. 

There should be no free juice on your hand. 

This is the right moisture for chopping into silage. 

When the forage gets too dry, the ball will spring open and quickly fall apart when released.

The squeeze test is a crude guide for determining the optimal maturity for harvesting. 

This field test should be followed by more precise methods. 

Zimbabwean farmers ought to be well trained to make their own  cattle silage, particularly in these unpredictable climate change eras, we live in.

Dr. Tony Monda holds a PhD. in Art Theory and Philosophy and a DBA (Doctorate in Business Administration) and Post-Colonial Heritage Studies.   He is a writer, lecturer and a specialist Post-Colonial Scholar, Zimbabwean Socio-Economic analyst and researcher. E-mail:


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