Turning Cows out to Grass - Meeting Energy Requirements in Early Lactation

6 March 2020

Challenging weather has made turning cows out to grass difficult, with some farms only getting cows out for 2-3 hours a day.

Getting adequate dry matter intakes into fresh calved cows to meet energy requirements in early lactation is challenging at best. Therefore, it’s important not to starve early lactation cows whilst housed. Cows can still be turned out with an edge to their appetite by letting feed run out an hour before turnout.


Example dietary scenarios:

1.       Grazing for 2-4 hours per day

  • Maximum 3-4kgDM from grazed grass
  • Ad lib Grass silage – allow silage to run out 1 hour before turnout
  • 26 litres = 8kg concentrate or 30 litres = 10kg concentrate


2.       Grazing for half a day

  • Maximum 7-8kgDM from grazed grass
  • Ad lib grass silage – allow silage to run out 1 hour before turnout
  • 26 litres = 7kg concentrate or 30 litres = 9kg concentrate


3.       Grazing full-time

  • Maximum 12kgDM in March from grazed grass – support maximum M+ 14 litres milk
  • 26 litres = 6kg concentrate or 30 litres = 8kg concentrate


The maximum grass dry matter intakes outlined in the dietary scenarios are only achievable if grass is good quality and weather conditions are favorable. Under conditions of continuous rain grass dry matters intakes can fall by up to 2.5kgDM/head/day. Concentrate supplementation should be increased by up to 3kg in these conditions.

Cows should be built-up to full-time grazing gradually as it takes approximately 3 weeks for the rumen to adapt to the dietary change.


Benefits of meeting energy requirements in early lactation:

  • Maintain body condition
  • Reduces risk of ketosis and fatty liver
  • Earlier resumption of ovarian cyclicity, improving reproductive performance
  • Higher milk yields and persistency of milk yield post peak
  • Higher milk protein content
  • Cows will be more responsive to concentrate supplementation in later lactation


by Claire Beckett, Dairy Technical Support Coordinator