Straw is a by-product of cereal production. It's the dry stalks of cereal plants after the grains and chaff have been removed. It makes up half of the yield of cereal crops such as barley, oats, wheat and rye. It is usually gathered and stored in a straw bale, which is basically a bundle of straw tightly bound with wire. Bales can be in the shape of square, rectangle or round.
Straw is very high in fibre and low in nutrients. Hence, it is not suitable for inclusion at high levels in the diets for high producing animals. It's main benefit is the provision of fibre to help improve good rumen function. Barley and oat straw offer the best nutritional value and they play an important role as a feed for young calves and lambs. They may be bulky but they are a consistent source of fibre for growing heifers and cattle.
Maize and legume straws have higher nutritional value as compared to barley or oat straw. Legumes contain high level of protein, magnesium and calcium. With that being said, they are sometimes difficult to dry and could be prone to mould due to their think stems.
Wheat straw has the lowest nutritional value as compared to the other types of straws.
Method of Preservation
The crops harvested for grain will usually be approximately 80-85% dry matter. Therefore, the straw will require little drying when harvested. It can be picked up and baled for storage immediately after harvesting.
Usually, the fungal problems will occur in the leaf. Hence, straw will be less susceptible to spoilage than hay. With that being said, the quality of the straw will still be dependent on weather condition from harvest up to the time straw is being baled and removed for storage.
Advantages of Straw
Can be stored for an extended period of time without much nutrient loss
Great source of long fibre
Easy to handle during feed-out
Does not require special storage equipment
Can be sold for bedding
Disadvantages of Straw
Low in nutrient value
Needs to be stored in dry conditions
Can be dusty
Limited intake because of high dry matter and low digestibility
Can be mouldy if harvested in wet weathers