Some observations on the behavior of grazing lactating cows.

Summary The grazing habits and related activities of eight lactating Holstein cows have been recorded for two periods of 240 consecutive hours each. The first trial was conducted during the last part of July and the second during the first part of September. The following results were obtained. 1.The average standing time per cow was 900 minutes; lying down time, 540 minutes; and loafing time, 358 minutes per 24 hours. 2.The cows grazed an average of 542 minutes and ruminated 518 minutes per 24 hours. 3.On the average, defecations occurred 15.0 times, urinations 9.4 times, and drinking 3.9 times in 24 hours. 4.On the average, grazing time was divided approximately equally between the a.m.-p.m. and p.m.-a.m. milkings; however, high environmental temperatures were observed to increase night grazing. 5.The animals averaged 58 bites per minute while grazing and 64 jaw movements per minute while ruminating. 6.The feeding of a limited amount of grain decreased grazing time approximately 7½%. 7.The results have been discussed from the standpoint of pasture management. The contribution of such studies to the over-all problem of pasture herbage evaluation has been mentioned.