Dairylink: Silage Quality

21st April 2015


Bad silage means costs will rise on winter milk farms so Dairylink adviser Conail Keown advises to plan now for 2015.

Silage quality has been a major limiting factor on the Dairylink farms during 2014. All the herds in the project have suffered as a result of the low energy and dry matter forage being used on-farm as a consequence of the poor weather conditions that were symptomatic of spring 2014 and an inability to capitalise on the rare good days.

The consequences of feeding poor-quality forage are clear – increased concentrate usage and the associated costs incurred in an attempt to maintain herd performance. This solution is fine when concentrate feed is relatively cheap and milk price is relatively high, but as we know too well, this is currently not the case in Ireland.

Failure to get the most from home-produced forage last season had a major impact on the bottom line for two Dairylink project farms. Both Nigel Corbett and Bill Brown required additional concentrate feeding to make up the shortfall in forage quality.

In Nigel’s case, his relatively low silage quality, with an ME of 10.2MJ/kg DM, meant he needed an additional 4kg/cow/day of concentrate to maintain his herd’s nutrient requirements throughout the winter. For a 100-cow herd, this is £12,000 effectively eroded from profit.

Bill was in a similar situation on his farm. However, with a larger herd, the associated total cost of additional concentrate was even greater.

Nigel and Bill are perfect illustrations of the research that has shown that for every week’s delay in silage cutting date, an additional 2kg of concentrate/cow/day will be required to supplement this forage.

Getting silage quality right this year is a priority for the Dairylink group, particularly for the autumn-calving herds when feed demand is at its highest during the winter months.

Growing higher-quality grass silage can reduce the amount of bought-in concentrate significantly, which will help profit margins in what will undoubtedly be a challenging winter.

Fertilizer requirements

A review of the nitrates action programme in Northern Ireland has resulted in changes which have affected on fertilizer recommendations for grass.

An additional phosphorus (P) index of 2- has been included and the availability of P in manures for soils of index 0 and 1 has been reduced from 100% to 50%.

This will allow farmers to use livestock manure more accurately to maintain soil P indices at optimum levels.

Table 1 highlights the P and K requirements for first-cut silage for soils at various fertility levels.

It also illustrates the difference between the Morgan soil phosphorus test and subsequent phosphorus requirements more commonly used in ROI, and the Olsen soil test and requirements used in NI.

All farmers in the Dairylink project have followed the relevant recommendations, based on their individual soil analyses carried out under the project earlier this year.

Typical recommendations

On the Dairylink project farms, 35% of the total silage area analysed presented with a P index of 2+ and a K index of 2+.

The typical nutrient recommendations for such ground are highlighted in Table 2.

The table illustrates the N, P and K requirements for first-cut silage where slurry has been applied with a splash plate.

The project farmers were also advised to split their chemical fertilizer application if spreading during a period of potential wet weather to limit losses to N as a result of heavy rain.

This tactic had the additional benefit of allowing some of the silage area to be grazed, if growth slowed.

Weekly update

Good growth conditions in the past week have radically improved the grass situation on all the Dairylink project farms.

Both farmers in Tyrone moved into double-digit growth for the first time this year, with a combined average growth of 25kg DM/ha.

While most of the farmers are just finishing the first rotation on their farms, the second round regrowth is promising good-quality grass.

For example, paddock covers measured last week on Bill Brown’s farm showed 1,100kg DM/ha available (2,600kg DM/ha total cover) in paddocks soon to be grazed in his second rotation.

Meal feeding levels

Meal feeding levels on all the project farms were reduced last week in an attempt to increase grass utilisation and the protein content of meal will fall to 16% to 18% for most project farmers.

When deciding to close paddocks for silage, the Dairylink farmers are giving consideration to the most recent average farm grass cover recorded and their total herd feed demand.

However, it is worth noting that cows will struggle to graze individual paddocks with cover in excess of 1,600kg DM/ha available (3,100kg DM/ha total), and perhaps these paddocks would be better closed for silage.

This article has been reproduced with the kind permission of the Irish Farmers Journal. Please click on the below Irish Farmers Journal logo to be brought to additional dairy articles

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