13 August 1999

Eclipse opportunity for grazing pattern research

DAYLIGHT is thought to be crucial to cow grazing patterns, so how have they reacted to the eclipse?

As FW went to press (Tue), an Institute of Grassland and Environmental Research study using cows at the Duchy College, Redruth, Cornwall, aimed to discover whether cow feeding patterns altered because of darkness. Wednesdays total eclipse is due to last two minutes and two seconds at the site.

IGER researcher Mark Rutter explains that the eclipse will occur at a time of day when cows would normally take a large meal.

Cows at Duchy College were fitted with behaviour recorders on Aug 2. These monitor animals biting, chewing, eating and ruminating periods. After a few days acclimatisation, monitoring began five days before the eclipse and will continue for a further five days after it.

Dr Rutter wants to find out whether or not cows take their scheduled meal when its darker than normal at that time of day.

"Cows usually eat three or four meals a day with the longest meal lasting three to four hours and finishing around sunset. This pattern stays the same regardless of the time of year, suggesting daylight is critical to cow eating patterns.

"If we can understand cows meal patterns better, we can tailor grazing management to suit them best and improve performance."

A previous MDC-funded study of cow grazing behaviour showed that its better to offer cows fresh grass in the afternoon. "When only moving them to new pasture once a day, doing so in the afternoon increased milk yield by 5% for no extra effort," says Dr Rutter. He believes this is because grass is higher in sugar and cows which graze longer in the evening can fill up on longer grass more easily. &#42