Planning Winter Feed Requirements
With summer nearing a close and housing just around the corner, it is worth spending some time planning ahead how much forage and purchased feeds you will require. Not only is this useful to ensure adequate forage stocks but it will also help with forward budgeting of feed costs.
A good starting point is to sample the forages you have on farm. Once you know the dry matter of the forages, you can work out the volume of dry matter contained in the clamps (volume = length x breadth x height in m). Then multiply this by the estimated density of the forage from the following table. Remember to factor in a percentage for waste and any extra in case turnout is delayed:
Guide to silage density depending on DM and height of silage in clamp (density in kg/m3)
|Silage DM%||Height of silage in clamp (m)|
These silage density figures can also be used to estimate wholecrop and maize silage stocks (Source: ADHB)
With the help of your nutritionist, you can then work out the total dry matter requirement of forages for the milking herd, dry cows and youngstock to see you through the winter-feeding period. This will require winter rations for all classes of stock to be drawn up to assess forage requirements and look at what feeds will need to be purchased.
If supplies look tight, it is best to secure additional forage supplies early (make sure you get an analysis on any purchased forage) or see what forage replacers are available. Distillery/moist by-products can extend forage supplies and also save on protein concentrates, depending on their specification. With protein costs still relatively expensive, now is the time to look around to see what deals are out there. Getting winter prices now may save you money on concentrate feeding, as well as help to spin out forage stocks. If so, secure the required tonnage now and remember to factor in any extra loads to cover you over the Christmas/New Year shutdown period.
The decision of the concentrate/forage replacer required on farm may also depend on forage dry matter. For example, if silage is wet (less than 25% DM) with a low pH and high PAL (potential acid loading value over 900Meq/kg DM), then nutritionally improved straw (NIS), soya hulls or sugar beet pulp are ideal to provide highly digestible fibre for rumen health. If silage is of high dry matter, then moist distillery byproducts or potatoes (or other vegetable waste) can help moisten the ration and improve intakes.
A core sample is useful to assess the dry matter and calculation of forage stocks but once clamps are open for feeding, take a representative sample from the silage face (once past the ramp) to check quality and repeat as necessary throughout the winter. As a minimum, resample every couple of months to rebalance rations and see where savings can be made. This is more important for grass silage as opposed to wholecrop forages which tend to be more consistent in quality throughout the clamp.
While it is important to maximise the use of forage in the diet from a cost and rumen health perspective, forage inclusion will be determined by its quality and the expected/desired milk output to ensure that sufficient concentrates are fed to maintain cow condition and protect fertility.
While considering forage stocks and what will be fed to what, a mineral analysis on different forages will also be of benefit for ratioing dry cows. Dry cows require lower quality forage than the milking herd to minimise weight gain during the dry period but take note of whether the forage intended for dry cows contains a high level of potassium (and DCAB value), which could increase the milk fever risk depending on your feeding strategy and mineral supplementation. This is where the advice of a trusted nutritionist is vital to optimise performance of dry cows and minimise health issues at calving.
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