Digestibility and intake of hay from extensively and intensively managed grassland

Botanical composition of grass managed without fertiliser and herbicides for 10 years evolved to a considerable diversity of species, mainly woolly soft grass, meadow crowfoot and rough stalked meadow-grass. Grass hay from this extensive management (EH) was compared with intensively managed perennial grass hay (IH) of low quality in a digestibility trial with wethers and an intake trial with heifers. Ten Holstein-Friesian (HF) and 10 Belgian Blue (BB) double-muscled heifers were involved in a cross-over experiment to investigate intake during a 4-week period. Hays were fed ad lib and supplemented with 1 kg concentrate daily to correct for a different protein content. The mean live weight of the heifers was 280 kg and 269 kg for the respective breeds. Crude protein content from the digestibility trial and the intake trial was higher for IH than for EH (108 vs. 70 g/kg DM (dry matter)), but crude fibre content was similar: 334 and 328 g, respectively. Digestibility of organic matter, crude protein and crude fibre were higher for IH than for EH. Mean daily DM intake of IH and EH amounted to 4.26 and 4.43 kg in HF heifers and 3.28 and 3.69 kg in BB heifers. Daily live-weight gain averaged 0.83 and 0.92 kg, respectively for IH and EH in HF heifers and 0.45 and 0.59 kg in BB heifers, respectively. It is concluded that the intake of EH was higher (P = 0.007) than for low quality IH, although the energy value tended to be lower.