29 MAY 2023

The benefits of forage brassicas

Forage brassicas are becoming increasingly popular among farmers as they provide an economical and high-quality feed option for livestock, while also filling seasonal feed gaps. This article explores the benefits of incorporating forage brassicas into a pasture system and how they can add value to a farming business.
man walking through field of forage brassica at sunrise

Forage brassicas have numerous advantages in grazing systems. They are a cost-effective way to accumulate a large amount of feed with a sowing rate of 3 to 5 kg per hectare (ha), and their growth rates are comparable to those of most forage cereals, allowing for rapid biomass accumulation. However, the main strength of brassicas lies in their superior feed quality, which they maintain throughout the season. They have quality parameters of 11 to 12.5 megajoules of metabolisable energy (ME) and 15 to 22 per cent (pc) crude protein, with a low fibre content, making them ideal for lactating dairy cows, finishing lambs, growing steers, or improving the condition of breeding stock.

Brassicas are also highly adaptable to different environments and soil types, from sands to heavy clays. However, they require good levels of nitrogen, phosphorus, and boron and rely on accurate seeding depth (5 to 10 mm) for optimal establishment. With a flexible sowing window from late winter to autumn, they are an excellent option for most systems. There are different types of forage brassicas on the market, including bulbed and leafy turnips, forage rape and hybrids, kale, and radish, each with a unique fit depending on specific requirements.

For farmers looking for quick feed, S&W's Bouncer Forage Brassica is a leafy turnip ready to graze in as little as 5 to 6 weeks, suitable for dairy systems or more intensive beef and sheep enterprises with high soil fertility and rainfall. For bulk feed later in the season, S&W Subzero Forage Brassica is an ideal option, a quick maturity forage rape and kale hybrid, ready to graze early with good regrowth potential, while maintaining quality for a bulkier graze later in the season. Subzero is suitable for large, extensive grazing systems or more intensively managed beef, sheep, and dairy enterprises.

In terms of calculating crop requirements and making it pay, let's take an example. Suppose a farmer has 100 young steers that they want to feed from December to February on a crop of Subzero Forage Brassica and Rebound Millet. In that case, they will need to sow 11.75 hectares to fully feed all steers. The total cost of cultivation, seed, herbicide, and insecticide is estimated at $750 per ha. Assuming that the steers will gain 1 kg per head per day for 100 days, the farmer will make $3,400 per ha, with a stocking rate of 8.5 steers per ha. However, these numbers are only a guide, and farmers should base their calculations on individual costs, target crop yields, and weight gains.

This article was written by Elders supplier S&W Seeds for Seasons magazine.

Please note: this article contains information of a general nature, and does not take into account your personal objectives, situation or needs. Before acting on any information, you should consider the appropriateness of the information provided, and seek advice on whether it is fit for your circumstances.