Sheep conference: The importance of good-quality silage

Opening the Teagasc National Sheep Conference earlier this week, Prof. Gerry Boyle outlined that, while it is not possible to control what goes on outside the farm gate, every effort should be made to increase efficiencies on individual farms.

Speaking at the conference – which was held in the Tullamore Court Hotel, Teagasc’s Tim Keady gave a detailed presentation on SheepNet and its objectives.

During his presentation, he touched on the importance of feeding top-quality silage; the majority of sheep that are housed between mid and late pregnancy in this country are offered grass silage.

He said: “Dry matter digestibility (DMD) is the most important factor that effects silage feed value. A series of studies undertaken at Athenry over the last 15 years can be summarised that, each 5% unit increase in silage digestibility increases ewe weight by 6.5kg and lamb birth weight by 0.25kg.”

Grass silage feed value on concentrate requirements during late pregnancy:
  • DMD is the main factor affecting silage feed value;
  • Silage chop length affects silage intake by sheep;
  • Each 5% unit increase in silage digestibility increases ewe weight post lambing by 6.5kg and lamb birth weight by ≥0.25kg;
  • Enables optimum use of concentrate supplementation, thus reducing costs;
  • Silage feed value must be determined (laboratory analysis) to develop a feed plan.

Continuing, Tim said: “The energy requirements of ewes increase in late pregnancy. Consequently, the quality of silage that you have to feed to your ewes will impact on the amount of concentrate that is required to supplement in late pregnancy.

“For example, as you decrease digestibility, concentrate requirement increases dramatically. In extreme cases, with high-digestibility silage precision chopped and low-digestibility – either large baled or single chopped – the amount of concentrate increases by 350%.

Effects of silage quality on total concentrate requirements (kg/ewe) of twin bearing ewes during late pregnancy. Data source: Teagasc

How to produce high-quality silage

Tim highlighted the importance of silage testing.

“The average digestibility of silage produced in Ireland – based on 15,000 samples analysed in one laboratory – is 69% DMD.

“You hear people talking about excellent silage at 70% DMD; however, that’s only average. To have a good-quality silage, your target should be 75% DMD.

“To produce this, you need to ensile leafy herbage, targeting a wilt of approximately 25% dry matter (DM) if you’re putting it into a clamp or 30% DM if it’s going into large bales.

“The important thing is if you are wilting silage, you need a rapid wilt. Do not leave it on the ground more than 36 hours because digestibility starts to decline after approximately 24 hours. Ensile rapidly to get a rapid fermentation and get the pH down fast,” he concluded.