Influence of feeding time and diet on time of parturition in multiparous ewes

Three hundred three pregnant ewes were randomly allotted to treatments in a 2 (diet) X 2 (feeding time) factorial arrangement 10 d before the first lambs were due in two lambing seasons to study the effect of time of feeding and diet on time of lambing. Behavioral activities were observed to determine if there was a relationship to time of parturition. All ewes were fed .5 kg ground whole corn per day plus either: alfalfa hay fed at 2200 each day, alfalfa hay fed at 1000 each day, alfalfa haylage fed at 2200 each day or alfalfa haylage fed at 1000 each day. Lambing data from 1983 and 1984 were combined across years because no treatment X year interactions (P greater than .05) were detected. Average time of day for lambing did not differ (P greater than .05) among treatments. In general, no differences due to treatments were observed in lambing time or behavioral activities studied. When data were pooled across treatments, two peak lambing times were observed. These peak times for lambing were from 0300 to 0700 (22.1%) and from 1500 to 1900 (22.5%). During these two 4-h periods (8 h total) 44.6% of the ewes gave birth.