Kale proves a big attraction
KALE, ensiled in big bales or mixed with whole-crop cereals in clamps, was the main attraction at the SAC conference and open day.
John Vipond, SAC kale expert, said the crop had considerable potential, although growers were still on a steep learning curve and there was limited data on feed values.
"Potentially it has a high feeding value but, for the moment, we recommend inclusion at no higher than 30% of forage intake and animals should be allowed time to adapt to the diet. It is not pleasant to handle but cows find it very palatable," said Dr Vipond.
He said total costs of big bale kale were about £360/ha (£146/ acre) or £10 a big bale where fertiliser needs were assumed to be met from slurry and the yield was 28t/ha (11t/acre). Each bale weighed 800kg and at 22% DM yielded 176kg. The cost a tonne of DM fed was, therefore, £56.70 compared with £60 for silage.
"Assuming an ME of 11.5 and crude protein of 23%, the relative value compared with barley at £120 and soya at £220 is £33/t of fresh material. Good grass silage with an ME of 11.5 and protein of 15% is worth £28/t on the same basis," said Dr Vipond.
John Bax from the college said there was a big potential for kale and whole-crop wheat to be grown together.
"I have seen it in alternative strips and mixed throughout a field," he said. "But it would be better to grow the crops in blocks and then harvest across both blocks with a forage harvester to mix the two." *