Silage preservation: Turning grass into high-energy forage

With advances in grass technology and on-farm grass management practices, it is now well accepted that grazed grass can be economically turned into milk and meat outputs.

While there is rightly an increased focus on grazed grass, grass silage accounts for 20-25% of total annual feed on dairy farms and up to 30% of total annual feed on beef farms.

As a standalone feed, grass silage is expensive to produce and when a land charge is factored in, first-cut silage is now costing in the region of €300/acre to grow and ensile.

According to Agritech sales director, John Kenny, it is therefore most important that the desired level of silage quality is achieved as often as possible.

“With lengthy dry periods no longer in existence, quality silage is an essential requirement for the freshly-calved cow as it will help support early lactation milk yield and allow the cow to return to cyclicity as quickly as possible.

“For beef cattle, a daily liveweight gain of 0.6kg is considered the optimum for winter performance where the animals are returning to grass in the spring. Again, quality silage will play a key role in achieving this growth level,” John explained.

Silage samples analysed recently show significant variations in quality, with many Irish beef farms estimating an average of just 66% dry matter digestibility (DMD).

The difference between good and bad silage quality has a significant impact on animal performance. In the winter of 2012, Teagasc in conjunction with the Irish Cattle Breeding Federation (ICBF), conducted a study on weanling performance on 18 farms when housed.

The results indicated a significant shortfall in liveweight performance, despite all farms feeding 1-2.5kg of silage/head/day.

Only four of the 18 farms had a daily liveweight gain in excess of 0.51kg and seven of the farms had an average daily liveweight gain of just 0.25kg.

According to John, “silage of 75% DMD in quality must be a target for farms going forward”. Quality silage starts with quality grass cut at the correct growth stage.

Every silage field which contains a high proportion of perennial ryegrass will have a sward of 80% DMD at approximately the middle of May.

Once grass-silage fields go past the middle of May, they lose an average of 3% DMD units per week, with this loss increasing to 6% DMD units in poor weather or lodged crops.

“A very important part of securing as much of the quality in the winter forage as possible is through the application of a proven silage additive at ensiling.

A good quality silage additive speeds up the preservation process and retains more of the feed value within the pit, in addition to retaining more actual silage in the pit. In fact, the extra retained silage alone will cover the cost of the additive,” says John.

Agritech’s GrasZyme SugarBoost Forage Additive has long proven itself as an effective silage preservation aid and is formulated with accelerated fermentation and animal performance as the primary focus.

Having undergone numerous trials on dairy and beef research institutes throughout Ireland and the UK, GrasZyme Sugarboost has shown daily milk yield increases of 1L, a 0.09% increase in milk protein and 110g extra daily liveweight gain.