Evening Feeding to Increase Daytime Calving

Kari Lewis, MSU Extension – Glacier County 

Calving is in full swing for many producers!

With calving underway or on the horizon for many ranchers, it’s time to revisit how to increase the proportion of calves born during the daytime.  By using an evening feeding strategy, ranchers can increase the proportion of cows that calve during the day, a time when there’s likely increased observation of the herd and a greater ability to provide assistance if a calving difficulty occurs.  In addition, calves born during the day are born when its warmer and the heat from the sun can reduce cold stress, giving baby calves a better chance for early colostrum consumption and survival. 

This concept of feeding cows in the evening to encourage them to calve during the daytime is well documented scientifically.  For 15 years, one group of cows was fed between 6 a.m. and 8 a.m. in the morning at calving time.  This data resulted in 1,210 observations which showed that there were nearly equal proportions of cows calving during the day and cows calving during the night.  Of the cows fed in the morning, 52% of the cows calved from 6 a.m. to 6 p.m. and 48% of the cows calved from 6 p.m. to 6 a.m.

Another group of cows was fed between 4 p.m. and 6 p.m. which resulted in 537 data observations over five years.  In that group that was fed in the late afternoon, 85% of the cows calved between 6 a.m. and 6 p.m., and only 15% calved during the night. 

Research also shows that it doesn’t matter whether cows were started on the evening feeding program the week before calving started, or two to three weeks prior.  So even if producers have already begun calving, they can still adopt this strategy. 

If cows have free choice access to hay or grass during the day, they can still be impacted by when they calve by varying the time of day when supplement is fed.  An Oklahoma State University study showed that when cows had access to hay around the clock but were fed supplement in the late afternoon or early evening, 72% of the cows calved from 6 AM to 6 PM.  Prior to that, there had been nearly a 50/50 split between cows born in the morning and calves born during the night. 

If it is not feasible to feed the entire herd in the late afternoon or early evening, feeding the first calf heifers at this time is still encouraged.  The first calf heifers are most likely to need calving assistance, so will benefit the most from the increased observation that occurs with daytime calving. 

There are many factors, such as physical activity, variation in hormone secretion, ambient temperature, and day length that can impact what time of day a cow may calve.  However, the research shows that by consistently feeding cows in the evening, cows can be influenced to calve during daylight hours.  For additional information on this topic, please contact Kari Lewis, MSU Extension Agent in Glacier County at 873-2239 or kari.lewis@montana.edu and reference the CowSense Chronicle by Dr. Rachel Endecott, http://animalrangeextension.montana.edu/beef/documents/2-17CowSenseChronicle.pdf where much information for this post came from.