Sorghum Hay

Nutritious Forage for Livestock

Sorghum hay is a widely used forage in Australia, especially for feeding cattle, sheep, and other livestock. It’s a versatile and cost-effective feed option, particularly when forage availability is limited. Produced primarily in New South Wales, Queensland, and some areas of Western Australia and Northern Territory, sorghum hay is known for its high energy content and good balance of fibre.

What is Sorghum Hay?

Sorghum hay is made from the forage sorghum variety, which is grown specifically for hay production. Unlike the grain varieties of sorghum, forage sorghum is more vegetative, with greater leaf matter, making it ideal for hay. The leaves provide a good volume of feed, while the stems offer the necessary fibre for healthy digestion in livestock.

Nutritional Value of Sorghum Hay

1. Crude Protein (CP): Typically ranges from 5% to 10%, depending on the growing conditions and maturity at harvest.
2. Neutral Detergent Fibre (NDF): Varies from 55% to 65%, contributing to the hay’s fibre content and aiding digestion.
3. Metabolizable Energy (ME): Sorghum hay generally provides an energy range of 8-10 MJ/kg, making it a good source of energy for cattle and other livestock.

Visual Grading and Quality

The texture and appearance of sorghum hay can vary depending on its maturity at harvest. Forage sorghum hay should be soft and palatable with bright green to olive-green leaves and pale yellow or white stems. A poor-quality hay may have a dull colour, with a musty aroma or excessive dryness. The stem thickness can range from 3-5mm to 8-10mm, with the finer, softer hay being more desirable for livestock consumption.

Prussic Acid and Nitrate Testing

One of the challenges with sorghum hay is the potential buildup of prussic acid and nitrates, particularly when the plant is stressed by environmental conditions. It is recommended to conduct nitrate and prussic acid testing to ensure the hay is safe for feeding to livestock. Testing is particularly important before feeding, as high levels can pose health risks to animals.

Best Maturity for Harvesting

The best time to harvest forage sorghum hay is when the plant is in early flowering, just before or during the vegetative stage. This ensures the highest nutrient retention and digestibility. Sorghum hay harvested later may still contain grain, which can increase nutrient levels but may also make the hay coarser and harder to digest.

Agricultural and Environmental Benefits

Sorghum hay plays a role in sustainable farming practices. It’s often grown as part of a crop rotation and can help with soil stabilization. After harvest, the standing sorghum stubble can provide additional forage for livestock, contributing to a more sustainable farming system. The use of sorghum hay in crop rotations also helps in reducing runoff and promoting soil health.

Frequently Asked Questions about Sorghum Hay

Q. What is a normal level of Neutral Detergent Fibre (NDF) for Forage Sorghum Hay?

A. NDF for forage sorghum hay typically ranges from 55% to 65%, depending on the maturity and growing conditions.

Q. What is the usual range in Crude Protein for Forage Sorghum?

A. Forage sorghum hay generally has a crude protein content between 5% and 10%, with variations depending on growth conditions.

Q. What maturity is ideal to maximize the ME for Forage Sorghum hay?

A. The best maturity for maximising metabolizable energy (ME) in forage sorghum hay is typically just before or during early flowering, when the plants are still in a vegetative state.

Q. Does the colour affect the nutritional value of Forage Sorghum?

A. Yes, bright and clean forage sorghum hay generally has higher feed value than weather-damaged or discoloured hay, which may have reduced nutritional quality.