sheep being fed© Tim Scrivener

Sheep farmers are being urged to measure grass covers pre-turnout to avoid a shortfall in feed this spring.

Liz Genever, Eblex beef and sheep scientist, said the cold and relatively dry weather had had a negative impact on grass growth.

“Ewes in good condition, with twin lambs [with grass] at 4cm should get what they need.”

But if grass was below 4cm in height at turnout it would be necessary to supplement lactating ewes at grass, she told Farmers Weekly at an Eblex workshop held in association with Campaign For the Farm Environment in Warnham, West Sussex.

She said a 60-70kg ewe rearing twins requires 33MJ of energy a day. If ewes don’t receive this, Dr Genever said they will be at risk of losing body condition.

“If grazing is restricted you probably want to be using supplements to compensate for that lack of grass.

She also advised farmers to monitor sward heights throughout the grazing season to ensure they aren’t faced with feed deficits later on in the year.

“Grass might be 4cm when sheep go out, but in the first week what happens to it? Monitor sward heights,” she stressed.

By monitoring grass covers Dr Genever said farmers could start feeding early if they do predict a shortfall and this would prevent big changes in the diet.

She said another benefit of supplementary feeding early on in the grazing season is it will take the pressure off grass.

“By feeding them at grass they won’t be eating so much grass will stay ahead of them and it will give it a chance to get going.”

Dr Genever said farmers should prioritise thin ewes or those rearing triplets over singles.

 

How to calculate the energy gap – an example

ME requirement (MJ/day)

18.3

ME from forage

10.7

Ewe weight (kg) x (DMI/100) x ME in grass

70 x (1.4/100) x 10.7 = 11.68

Deficit

18.3-11.68 = 6.62MJ

Source: Eblex 

 

 Energy requirements for early lactating ewes to maintain weight

 

Milk yield (kg/ewe/day)

No. of lambs

1

2

3

Ewe weight

ME (MJ)

ME (MJ)

ME (MJ)

50kg

13.6

21.9

 

60kg

15.6

23.7

32.2

70kg

15.8

23.8

32

Source: Eblex