Choosing the right kale
Forage quality should be a key consideration when deciding on the kale cultivar that will ultimately determine next winter’s animal performance.
With a wide range of kale cultivars available, it is important to differentiate between short, intermediate and giant types, carefully weighing up the advantages that each can offer to different farming systems. Kale height ultimately impacts on DM yield and other important characteristics including leaf percentage, stem thickness, palatability and feed quality. Short kale types tend to have lower yields but offer higher leaf percentages and stem quality. At the other end of the spectrum, giant types offer the highest yields, but often at the sacrifice of leaf percentages and stem quality.
In a recent study in New Zealand, DM yield, leaf percentage and quality assessments were made between May and September 2016 on four types of kale. Kestrel, a short to medium kale type, was shown to carry higher leaf percentages through the winter and produce high quality stems. This combination of high leaf percentages and soft quality stems means Kestrel can offer a high Metabolisable Energy (ME) feed suitable for chasing live weight gain targets in priority stock classes. Regal, an intermediate type kale, also maintained high leaf percentages while achieving excellent DM yields.
If production of bulk feed for maintenance of live weight is the primary decision driver, a giant type kale should be considered. Traditionally giant type kales have provided high yields while producing plants with significantly lower leaf percentages. However, recent plant breeding efforts have made significant gains in this area. Corsa, a new generation kale, offers significantly higher leaf percentages over traditional giant types while maintaining high DM yields.
For Ian and Jules Luedamann, Kestrel has been the perfect fit in their system since first trying this kale over ten years ago. Together they run a mixed dryland sheep and cropping operation planting around 13 ha of Kestrel each year to provide winter feed for their 1,400 ewes in Anama, Canterbury. Following permanent pasture, sowing Kestrel is the first part of a rotation that is followed by barley before planting back into permanent pasture.
This year’s Kestrel crop was treated and sown at 5 kg/ha on 10 November 2016 yielding an impressive 10,000 kg DM/ha. Average yields in this dryland situation normally range from 9,000-11,000 kg DM/ha, however, Ian’s primary driver for selecting Kestrel is its feed quality and system fit. He has been impressed with Kestrel’s soft stems ensuring palatability, high utilisation and animal performance. High utilisation is important as this means less crop wastage and stem residuals to deal with at the end of the season.
Before the start of grazing, yield assessments are made to ensure accurate crop allocation over the coming winter months. During grazing, utilisation is carefully monitored and Ian is quick to increase break sizes and supplements during adverse weather when utilisation can decline. Kale breaks are always supplemented with cereal silage ensuring ewes have a suitable source of fibre. Cereal silage provides an additional fibre source to ensure ewe Neutral Detergent Fibre (NDF) requirements are met. Brassica crops generally contain insufficient NDF and providing a suitable NDF source such as hay, silage or standing pasture is critical to avoiding nutritional problems such as ruminal acidosis.
Making the right cultivar decision this spring is critical to next winter’s animal performance. Contact your local PGG Wrightson Technical Field Representative for more information.
Article supplied by PGG Wrightson Seeds