Finishing Time and Weights of Grass-fed Beef Animals

November 1, 2016

For more than 20 years, Jane Jewett has owned WillowSedge Farm near Palisade, Minneosta. She and her family raise and direct-market pork, poultry, lamb, and grass-fed beef on 113 acres. An increasing interest in grass-fed beef operations led Jewett to make the transition to grass-fed beef in 2008.

Her interest in applying for an NCR-SARE grant was sparked after reading the scientific journal article titled: “Comparative Life Cycle Environmental Impacts of Three Beef Production Strategies in the Upper Midwestern United States” (2010)*.

Jewett was curious about a passage that assumed 1100 lbs. live weight and 22 months of age at slaughter for grass-fed beef; compared to 1,400 lbs. and 17 months for feedlot beef. Jewett was somewhat surprised by these findings because she knew she could produce 1,100 lb. live weight in a lesser amount of time solely on forage.

She hypothesized that the long finishing time of grass-fed beef cattle in the study could be due to producers raising heritage breeds of cattle, which tend to grow more slowly and may be smaller-framed animals than modern breeds; or to using an inadequate quality of forage.

Jewett felt that modern breeds raised on well-managed grass and forage were not properly represented in the study and wanted to compare the productivity of grass-finished systems with a feedlot beef system in a situation where cattle breeds and level of management of the system were similar.

In 2012, Jewett applied for an NCR-SARE Farmer Rancher Grant and received $19,829 to study the finishing time and weights of grass-fed beef animals. The funds provided Jewett the opportunity to collaborate with three other grass-fed beef operations in Minnesota: Edgar Brown from Willow River,  Jake and Lindsay Grass of Grass Meadows Farm from Pine City, and Bill and Bonnie McMillin from Kellogg.

Jewett found that it was possible to produce an 1,100 lb. live weight (600 lb. carcass weight) in a 15-to-18 month time frame, depending on genetics and feed. 

She noted that with quality forage and good genetics, grass-fed results could exceed feedlot results–Bill McMillin achieved a 1,387 lb. live weight (749 lb. carcass weight) in 14 months.

“If we can capture the environmental benefits of pushing more acres into perennial forage while sacrificing very little of the beef productivity potential of a feedlot, I think that would be ideal–and I also think that is achievable,” said Jewett.

* Nathan Pelletier, Rich Pirog, and Rebecca Rasmussen. 2010. Comparative life cycle environmental impacts of three beef production strategies in the Upper Midwestern United States. Agricultural Systems. 103(6):380-389.*

View Jane's presentation on this project, from the 2016 Farmers Forum, through NCR-SARE's YouTube playlist. Visit for this and other videos.

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Topics: Bovine, Feed/Forage, Livestock, Livestock Products, Meat
Related Locations: North Central