This article is a summary of the 2022 Nebraska Beef Cattle Report “Comparison of Partially Confined and Traditional Cow-Calf Systems”. Zac E Carlson, Levi J. McPhillips, Galen E. Erickson, Mary E. Drewnoski, and Jim C. MacDonald were collaborators on this research study and report.  The report is summarized by Aaron Berger, Nebraska Extension Beef Educator.

Crop Residue Availability in Comparison to Perennial Pasture

Perennial grass pasture and rangeland in many parts of Nebraska as well as the northern plains region has been converted into cropland for corn and soybean production.  This has resulted in limited pasture availability in these areas. Research conducted by the University of Nebraska has demonstrated that grazing cattle on corn residue can be an excellent way to utilize this feed resource without having any detrimental impact to subsequent crop production. This corn residue is often significantly less expensive as a feed resource than grass pasture that is grazed in the spring and summer. 

Greater Availability of Annual Forages (Cover Crops) for Grazing

Another development that has occurred is the significant increase in the amount of annual forages or cover crops that are planted in the late summer and fall to provide soil health benefits and weed control.  These forages are often of high quality and can be utilized as a feed resource for livestock grazing during the late fall, winter and early spring. Grazing of cover crops can provide production benefits to livestock owners as well as both economic and agronomic benefits to crop producers.

Comparing the Two Production Systems

The combination of these conditions prompted a research study to evaluate a late summer/fall calving system (August-September) that utilized the grazing of cover crops (oats) and cornstalk residue during the fall and winter.  This system also employed dry lot feeding of cows utilizing a limit fed ration consisting of modified distillers grains, wheat straw and supplement during the spring and summer months.  Cows in the alternative system calved in dry lot pens from mid-July through mid to late September during the two years of the experiment. Pairs remained in the pens until late October, at which time they were placed on summer planted oat pasture for grazing until early to mid-January.   

This alternative system was compared to a more traditional spring calving system (April to early June) where cow-calf pairs are grazed on perennial pasture from May through October and then grazed on corn residue from mid-November through mid-March.  Hay was fed to the traditional cows from March through early May. Cow and calf performance data was collected from both groups and compared to one another. This included cow performance, pre-weaning calf growth, post-weaning calf growth as well as performance in the finishing phase and carcass data. The study was conducted over two years with 80 cows being assigned to each of the two production systems.  Within each system, cows were broken further into groups of 20 to have four replicates of each production system.

There were no statistical differences in conception rates, calving rates and weaning rates when comparing the alternative system to the traditional system. Cows in the alternative system tended to have lower body condition scores, averaging near 5 at the time of breeding, while cows from the traditional system had an average body condition score of 6 or higher at breeding. A body condition score of 5 for mature cows is considered adequate at the time of breeding to achieve acceptable conception rates.  This difference in body condition score did not significantly impact conception rates, which was reflected in both groups of cows averaging just over 94% in a 60-65 day breeding period for both years of the experiment.

There was a significant difference between the two systems in calf performance through weaning and finishing. Although both groups of calves were weaned on average at the same days of age (168), the calves from the traditional spring calving production system were 99 pounds heavier than the late summer/fall born calves. Post weaning, during the backgrounding/growing phase, calves from the alterative system had greater average daily gain and a better feed to gain ratio than calves from the traditional system.  In the finishing phase, the advantage was once again with the traditional calves as they had higher average daily gains and better feed conversion, being on feed for 27 less days.  It should be noted that the time frames in which these calves were fed differed, so weather conditions may have played a significant role in the variations in performance, with weather stress likely having a greater impact on the calves fed from the alternative system, especially in the finishing phase.

Summary and Potential Application of Principles

A late summer calving production system that utilizes seasonal limit feeding of cows as an alternative to grazing summer pasture, may be a viable option for regions that have an abundance of inexpensive crop residue that can be directly grazed as well as harvested and fed.  Total feed costs and the cost of delivering harvested feed will need to be scrutinized. Management practices focused on ensuring calf health, especially if calving occurs in a dry lot, is important. In order to have acceptable pregnancy rates, fall calving cows will need to have access to high quality forage or be supplemented significantly with protein and energy when grazing crop residue prior to and through the breeding season. Calves from this production system will likely weigh less at weaning than calves from a traditional spring calving system and may need to be fed longer to reach the same weight at harvest. However, these calves fit a different marketing window than traditional spring born calves which may provide a price advantage when selling.     

Spring calving cow herds can complement a late summer/fall calving production system in being a source of replacements.  Young cows that do not become pregnant in the spring calving herd could be rebred for use in a late summer/fall calving herd. Use of a terminal breeding program where replacement heifers are not retained may be an option that fits a late summer/fall calving model where crop residue and seasonal dry lot feeding are utilized. 

For more information on management considerations when dry lotting and confining cows, please see the Dry Lotting and Confinement Cow Series. 

Interviews with the authors of BeefWatch newsletter articles become available throughout the month of publication and are accessible at https://go.unl.edu/podcast.