北海道根室管内の217乳牛群における死廃・病傷事故と乳量水準および飼養形態との関連

Abstract

Effects of milk yield and feeding system on death and disease incidence and average calving numbers were examined in 217 dairy herds in the Nemuro district of Hokkaido. High-yielding herds tended to demonstrate a lower calving rate, higher culling rates, lower milk somatic-cell counts, and fewer non-pregnant days. There was little difference in death and disease incidence related to milk yield and feeding systems. Disease rateswere higher in high-yielding herds. Disease rates were higher among cattle kept tied in barn stalls than in those free in their stalls. Incidences of mastitis, displaced abomasum, gastroenteric disorder, and ketosis were higher in high-yielding herds. Incidences of mastitis, teat injury, and ovarian disorder were higher in herds tied in barn stalls, whereas occurrences of displaced abomasum and milk fever were more numerous in herds housed free in barn stalls. These results indicate a close association between disease prevalence and feedingsystem management.