The industry standard for feeding kale to dairy cattle during the winter risks cows being underfed, Lincoln University researcher Innocent Rugoho has found.
Standing kale is a main quality feed source for cows wintered off the dairy platform. Cows graze the kale leaf and stalk behind electric fences.
Mr Rugoho, who came to New Zealand in 2004 from his native Zimbabwe after completing an undergraduate science degree, found that the lower nutrient status of the kale stalk has not been taken into account in previous calculations, risking underfeeding.
For his research project he compared three groups of cows, one was fed a high kale allowance, another a lower kale allowance and a control group was fed on grass alone.
He found the quantity and higher nutritional status of the higher allowance of 14 kilograms of dry matter a cow a day resulted in a significant increase in cow body condition score over the more typically fed 11kg DM/ cow/day.
«Cows need to be fed well throughout the whole year, and providing adequate feed in winter is very important to farmers who want to ensure that their cows regain condition and are prepared well for the next calving and lactation.»
He said that until now there has been little experimental data on the utilisation and forage behaviour of cows grazing kale in response to changing the level of their allowance.
Eleven kilograms of kale a day was the industry standard. «Farmers will struggle to put condition on their cows at that level,» he said.
The reason the usual feed calculations put the cows at risk of being underfed was because the low nutrient status of the kale stems had not been compensated for.
Mr Rugoho said cows that did not gain the required condition would take longer to come on heat and would have less chance of conceiving.
He also found there was no improvement in utilisation or body condition score if cows were fed kale more than once a day.
Mr Rugoho’s initial exposure to the New Zealand outdoor dairying system was an eye opener as most dairy farming in Zimbabwe is indoors.
Starting with Synlait Farms, he said he did «everything on farm» for the three years he was with the company on its Ngamarua Dairies farm near Rakaia.
In the Synlait Farms setup his endeavours to further his academic career were supported by Ngamarua managers Stuart and Debbie Bland, and he was given a stack of farming books by Synlait Milk chief executive John Penno.
A certificate from Synlait Farms reads: «In recognition of outstanding accomplishments and contributions 2004 to 2006.»
At Lincoln University he completed a post-graduate diploma in agriculture before starting on his doctorate in 2008.
He has completed the doctorate, but has yet to graduate. Mr Rugoho is hoping to continue dairy research at Lincoln.
Source: Stuff
