Whilst in Ireland last week, I heard that in the South of Ireland, where summer rations would usually include 2kg compound feed per day, some farmers were feeding 8kg/day to make up for the lack of grass. This is ‘panic buying’, and may be possible in the short-term, but it cannot be the basis for a winter feeding strategy. The dry summer has also no doubt resulted in much reduced winter forage stocks across the UK and Ireland, and raw material prices are on the increase.
To plan in advance is always recommended: Start by accurately calculating how much forage is available, and balance the winter feeding plan around that. It is much more cost effective to buy and transport straight replacement materials than to buy and move silage.
This can be done by finding the volume of the clamp (length x width x height) . As a rough guide, the density of silage DM is approx. 200kg DM/m3, this will vary with DM and clamp height, so this can be further refined.
For example, a clamp of 30m length x 10m width x 3m high contains 900m3 of silage. With density of 200kg/m3, this equates to 180tonnes of dry matter.
On a daily ration which uses 15kg DM silage/hd/day, this will last a 300 cow herd 40 days. On a daily ration of 12kg DM silage/day, this will last 50 days.
A shortage of forage will require replacement of key factors:
A proportion of fibre can be substituted with soya hulls, sugar beet pulp, citrus pulp. The availability of these materials is a concern, and prices can only rise with demand. A small amount of straw can be incorporated into diets – even 0.5kg/day will save 150kg DM per day, or 1T per week (5T of fresh silage)
Quickly degrading protein:
Urea is the most cost effective replacement for quickly-degrading protein found in grass silage. Whilst not usually recommended for grass-based diets, it can be used with care to replace a proportion of the quickly degradable protein found in grass silages. (If the diet already contains urea, care must be taken not to exceed the legal limits of 8800mg/kg DM complete feed when calculated to 12% moisture). Other protein sources are also available of course, including distillers grains, hipro soya, rapeseed meal, but good rationing will make use of cheaper protein sources first.
Often the forgotten nutrient, there are few sources of simple sugars : grass silage surplus foods, such as bakery products, or molasses. Simple sugars are essential in restricted-forage diets as they provide energy to capture the precious, but depleted, supply of grass protein. They are also essential when using urea safely, ensuring a constant supply of energy to the rumen micro-organisms to convert urea into protein. Molasses is a very cost-effective material for replacing energy.
Based on average herd figures and average silage analysis