More Milk from Grass 3 High Yield and Quality Forage from Grassland Grass Intake Depends on Quality Dairy cows are able to eat huge amounts of grass or grass and clover mixtures and consequently produce a lot of milk. A daily intake per cow of 19 kg dry matter in fresh grass or 16 kg silage dry matter is possible, but the amount of milk produced depends mainly on the quality of the feed. As the rumen of the cow can only contain a certain amount of feed, the concentration of energy in the available diet must be high and the content of nondigestible fibres must be low. When the forage quality is improved, the daily milk production increases because the fermentation of carbohydrates in the cow speeds up and the flow of forage through the rumen accelerates. As a consequence, forage intake increases. Clover in combination with grass increases feed intake, because clover has a lower content of fibre than grass. Inclusion of up to 50% white clover in the diet increases forage intake by 10–20%. This is a healthy cycle. The high forage intake also affects the health of the cow in a positive way. What is good quality? The content inside the plant cells is close to 100% digestible, whereas the cell walls degrade slowly or are even totally indigestible to the ruminant. See figure 1 and 2. The digestibility of organic matter, including cell walls, decreases as the grass or clover plant gets older, and at the same time yield of dry matter increases. The challenge is to determine the optimal time of harvest with the best compromise between yield and quality. Figure 1. Plant dry matter composition changes as the grass grows.
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