MILK-YIELD, INTAKE, AND BLOOD TRAITS OF LACTATING COWS FED GRASS-SILAGE CONSERVED UNDER DIFFERENT HARVESTING METHODS

Thirty-two Holstein cows (8 primiparous) were assigned to negative con trol or to one of three treatments to assess three forage harvesting a nd conservation techniques. Forage was harvested as low moisture silag e by either a cylinder-type forage harvester, a self-loading forage ha rvester, or a round baler. Treatment diets were fed from wk 4 to 15 of lactation and consisted of silages harvested by the respective method s supplemented with concentrate at 1.1% of BW. Unsupplemented silage h arvested by a cylinder-type forage harvester was used as a control. Da ily DMI was higher for cows fed supplemented heap silage cut with eith er a cylinder-type forage harvester (23.7 kg) or a self-loading forage harvester (22.6 kg) than for cows fed the control (20.0 kg) or supple mented round bale silage (20.1 kg). Milk yield was highest for cows fe d supplemented heap silage cut with a cylinder-type forage harvester ( 26.6 kg/d) and lower for those fed supplemented heap silage cut with a self-loading forage harvester (22.7 kg/d) or the control (20.8 kg/d). Milk composition and digestibilities of DM, N, ADF, and energy were s imilar among treatments. Postfeeding NEFA concentration decreased more for control cows than for those fed supplemented silage, which was re lated to greater BW loss. The high milk yield for cows fed supplemente d heap silage cut with a cylinder-type forage harvester could be relat ed to a high DMI and low BW gain.