Maize Silage Deficiencies
Maize silage has many valuable benefits as a supplement for pasture-fed dairy cows – it is relatively low in crude protein and high in starch, complementing pasture’s typically high protein and low soluble sugar content through spring and autumn. The relatively high yield potential of maize and its long storage life as silage makes it one of the most popular supplementary feeds in New Zealand dairy systems.
Maize silage is useful in early spring when pasture availability limits dry matter intake (DMI); later it helps to boost peak milk production levels by balancing the protein and starch content of the pasture to better meet the cow’s requirements. Through autumn and winter, feeding maize silage helps to lift cow condition scores and to extend milk production through the late lactation phase. During this time, a diet of pasture alone is likely to limit what can be achieved in terms of milk production and cow condition.
When you’re feeding maize silage to cows, it’s important to look at the nutritional requirements of your stock, and see how that is being met by the composition of the feed – the silage, the pasture and any other feeds being offered. The table below shows the typical analysis of maize silage and autumn grass, and the requirements of lactating dairy cows.
Maize silage has relatively low levels of several minerals – most notably calcium, magnesium and sodium. Low dietary intake of these key minerals can cause stock health issues (mainly in spring), but they can also reduce the productivity of the cows.
If your goal of providing supplementary feed in autumn is to help extend lactation, then you want to make sure that the feed supports productivity. When it comes to maize, there’s an easy way to achieve this, simply use a mineral additive, which can be added to the maize silage prior to feeding out. This will boost the levels of calcium, magnesium and sodium so that the cow receives the dose of minerals that she requires for health and productivity.