Shifting Calving Time

beef cow and calf on dormant pastureWith the new year just upon us, it might seem a bit early to be thinking about calving if you are a beef farmer.  However, if you are an early calving farm starting the calving season in February, now may be the time to adjust your feeding schedule to get more of your calves born during the day.  This may be an important adjustment to make, especially if you have a large heifer herd due to calve, as heifers are often the animals that need the most assistance giving birth.

Over the years there have been several research studies investigating how the timing of feeding affects the number of nighttime calving situations.  One of the initial studies was completed to “ground-truth” anecdotal observation that more calves were born during the day when the herd was fed in the evening.  Gus Konefal was the Canadian farmer that made the initial observation known in the 1970s.

The Konefal method fed the herd twice daily, a late morning feeding at 11 am and a night feeding at about 9:30 pm.  These feeding times were started a month prior to calving, continuing through the whole calving season.  Konefal reported that approximately 80 percent of the herd calved between 7 am and 7 pm with this feeding schedule.

A small Canadian study with around 100 animals compared an 8 am and 3 pm feeding schedule to an 11 am and 9 pm feeding schedule for timing of calving.  Forty percent of the cows on the 8 am/3 pm feeding schedule calved during the day while 80 percent of the 11 am/9 pm group calved during the day.

There also was a large study done with once a day feeding at dusk.  About 1300 cows and heifers were used in this trial completed across 15 farms in Iowa.  Using this method, 85 percent of calves were born between 6 am and 6 pm.  In this trial, night feeding was started either the week before calving or about three weeks before calving.  There was no apparent difference in calving timing between the two groups.

For folks that have their cows and heifers on a pasture and 24 hour access bale-feeding system, a similar effect can be achieved by feeding supplement at night.  Oklahoma State University switched from a daytime supplement feeding to a late afternoon/early evening feeding and saw 72% of cows calving between 6 am and 6 pm.

While the mechanism behind this feeding effect is unknown, there may be hormonal involvement.  What is known is that rumen contractions fall a few hours before calving.  During the last two weeks of gestation, intraruminal pressure declines, with the most rapid fall just prior to calving.  While we don’t know exactly what is going on, there is a thought that feeding at night causes intraruminal pressure to rise during the night and fall during the day.

Whether you choose to do twice a day feeding or once a day feeding, nighttime feeding may help you reduce the number of nighttime calvings.  Remember to transition animals to any new feeding time.  Once you have selected your feeding time(s), stick to them as close as possible as deviating from the schedule could negatively influence your results.  Be sure to continue doing night herd checks as there will still be some night calvings.

The University of Wisconsin-Extension provides research-based information to help citizens of Wisconsin make informed decisions based on science.  UW-Extension extends the boundaries of the university to the boundaries of the state, helping the people of Wisconsin and beyond access university resources and engage in learning, wherever they live or work.


Note: This article originally was published in the Marquette County Tribune, Waushara Argus, and/or the Berlin Journal.  This article was written by Lyssa Seefeldt, UW-Extension Agriculture Agent for Marquette County unless otherwise noted.