Forage brassicas such as Maris Kestrel Kale and Redstart Hybrid Brassica were sown on many farms this year as a means to overcome the looming winter feed shortfall as a result of the drought experienced throughout the summer.
John O’Dwyer who milks 140 cows along with his father John Paul in Ballytarsna, Cashel, Co. Tipperary began growing Maris Kestrel in 2012. Incorporating Maris Kestrel into their farming system helps stretch winter feed, while also ensuring heifers continue to reach their target weights.
This year’s crop was sown in mid–June which is later than usual for the O’Dwyers. Despite the late sowing date John is very pleased with how the crop is looking. “The crop didn’t green until the end of August but the mild weather we are experiencing at the moment has meant we have been afforded the time for the crop to really get going and reach its full potential,” John explains.
The O’Dwyer’s usually begin grazing kale on October 1st, however for this year, it is likely to be mid–November before the 30+ heifers will be introduced to the crop. As John also feeds silage for roughage, he anticipates his 6 acre crop will be utilised until early February.
Heifers will be introduced to kale at about 220kgs with an expectation that they will reach a target weight of 330kgs by May 1st; in time for Spring breeding.
One of the big benefits in going from kale and then straight to grass is that animals suffer no setbacks and begin to thrive immediately, compared to those turned out to grass from sheds over the winter, where often they will have a setback initially, until they adjust to the different diet. John stated, “moving from Maris Kestrel kale to grass has always been an easy and quick transition for us.”
The O’Dwyers average 10t DM/ha of kale on dry land and John feels that Maris Kestrel is a high quality crop giving excellent animal performance. “Despite the ground conditions even in difficult winters, the appetite was still there, and the crop remains palatable” says John.
Maris Kestrel has outstanding whole plant digestibility, meaning that all of the plant, including the stem, is utilised. Once grazed kale will leave a clean seed bed, making Maris Kestrel the perfect crop prior to reseeding upon which John will sow Top 5 Extend.
Management advice for grazing brassicas:
- Introduce stock slowly, allow 1–2 hours access and build up to full time access after 7–10 days
- Brassicas should form no more than 70% of the diet, with 30% coming from a fibre source such as silage, hay or straw
- Ensure animals have access to fresh water
- Brassicas are low in certain minerals especially selenium, iodine, coper and cobalt. Animals should be given a bolus to ensure adequate minerals are provided. Speak to your vet for more advice
- Use long and narrow strips to maximise utilisation and minimise wastage
- Monitor utilisation to ensure animals are being offered adequate feed, you don’t want them to run out of feed too early in the day but neither do you want feed left behind
- All brassica crops should be consumed by mid–February as they can mature and flower, producing toxins which can affect animal health