Effect of Feeding Time, Behavior, and Environmental Factors on the Time of Calving in Dairy Cattle

Abstract

To determine if time of feeding affected time of parturition, 129 Holstein cows and heifers were assigned alternately by expected calving date to either a control or a night-fed group. Animals were transferred at least 2 wk before expected calving to .6-ha wooded lot, which was divided into two equal parts. Animals were fed 20.4 kg (76% dry matter) per day of a total mixed ration. Both groups had feed delivered to the feed bunks at the same time daily. Control animals had access to feed for 24 h each day, but the feed bunk of night-fed animals was covered from 0800 to 2000 h, allowing them to eat from 2000 to 0800 h only. From May to November during 2 yr, 62.5% (40/64) of control animals and 67.6% (44/65) of night-fed animals calved from 0600 to 1800 h. Considering 0500 to 2100 h as herdsman's hours, 82.8% (53/64) of control animals and 84.6% (55/65) of night-fed animals calved during these times. There were significantly more animals calving from 0600 to 1800 h and from 0500 to 2100 h than the one-half and two-thirds expected. Observations for three 24-h periods indicated that control and night-fed groups had significantly different behavioral patterns. Overall, there were no significant effects due to time of feeding on time of calving or for calf or health-related parameters. © 1985, American Dairy Science Association. All rights reserved.