Outwintering dairy heifers does not affect milk yields, says study

Outwintering dairy heifers has no negative effect on future milk production or fertility, new research has found.

As part of a trial, carried out by AHDB Dairy and Harper Adams University, 48 heifers were split into three groups:

  • Group one was outwintered on fodder beet and grass silage
  • Group two was outwintered on deferred grazing and grass silage
  • Group three was housed and fed grass silage and concentrates.

See also: The full in-depth article on outwintering How to save £150 a head by outwintering dairy heifers

Daily liveweight gains were measured frequently. All heifers were housed six weeks before calving and their performance was monitored for the first 12 weeks of their lactation.

While daily liveweight gains were lower on the grass system, subsequent milk yields were not affected by the different feeding options.

Furthermore, fertility was actually better in heifers kept outdoors:

  • 50% of heifers that were outwintered on grass were confirmed pregnant after their first service in comparison with 36% of those fed fodder beet and 31% of those housed
  • Those outwintered had a lower calving interval and improved days to conception.