[Guide to feeding of cattle during the grazing period (author's transl].

Grass is high grade roughage. Its energy content (appr. 1650 kcal. NE of dry matter) approximates that of concentrates. As a rule, the protein content of dry matter is much higher than the minimum required for growth or milk production, and this may have an adverse effect on the utilization of Cu and Mg. The structural value of grass is another factor to bear in mind in feeding dairy cows, the more so when concentrates or other non- or less structural products are also fed. Of the mineral constituents the elements Ng, Na, Cu, Co and j require most attention. This is not the case when more than appr. 4 kg of concentrate daily are fed to cows. However, supplying Mg often continues to cause concern. The daily dry matter intake from grass is appr. 2.0-2.5 per cent of body weight, but this varies with the season, climate and indoor or outdoor feeding. Fully grazing cows can produce appr. 25 kg of milk in the spring and appr. 18 kg in the autumn. When the cows are kept indoors at night or kept at zero grazing, the production level is somewhat lower (see Table under 2.3). For cows showing a higher production concentrates are therefore required. To prevent too great an intake of intestinal parasites in young animals (calves), grazing aftermath is the most effective method, though it is not easy to carry out in every case. For stale or dry cows the feed intake from grass usually is too high. This may result in fat cows as well as an increased risk of milk fever.