EFFECT OF TWO CONFINEMENT SYSTEMS ON ESTROUS AND DIESTROUS BEHAVIOR IN DAIRY COWS

Four groups of dairy cows ranging in age from 3 to 9 yr were observed continuously for 80 days after calving by closed circuit television and videorecorder over a period of 1.5 yr. Groups 1 and 2, each consisting of 16 cows were housed in a windowless free-stall area while groups 3 and 4, each consisting of 12 cows were housed in a conventional tie-stall area. Eating, drinking, resting and standing activities and number of changes between lying and standing positions were recorded daily. There was no difference between the two housing systems in their effect on ovarian function. There were marked differences in the monitored activities of cows in the two confinement systems. During estrus the increase in standing was more noticeable in the free-stall animals. The tie-stall animals stood normally for longer periods and had a greater number of changes in position each day with a sharp decrease at estrus. An interaction between age of cow and housing system was found. The older cows in the free-stalls rested approximately 4.5 h/day more than the comparable age group in the tie-stalls. The younger tie-stall cows had a significantly greater number of changes in position per day than any other group while the younger free-stall animals had the least.