Sweet molasses feed key to understanding grazing behavior in cattle

(Press-News.org) Researchers tempted grazing cattle with sweet molasses feed to discover whether cows would roam far and wide to graze or stick close to the herd, water supplies and feed stations.

The findings by animal scientists at the University of California, Davis, and published in the journal Scientific Reports, offer a low-cost way for ranchers and others to identify the best cows for their landscapes to optimize grazing while meeting the nutritional needs of cattle. 

This is the third in a series of papers about research seeking to better understand the grazing personalities of cattle. The first studies established that the cows weren’t mindless wanderers or followers but had personalities that differentiated how far and wide they would graze, said Kristina Horback, the senior author on the paper and an associate professor in the Department of Animal Science.

 “This final study is trying to figure out, ‘Can we have any early indicators so that we don't have to put GPS collars on all cows, but just do a quick practical test?’” Horback said.  

Water quality, soil health and habitats can be degraded by cattle grazing unevenly or concentrated in specific areas. A herd with animals that wander around a landscape to graze can benefit the landscape by distributing grazing areas and defecation sites while also reducing fuel loads for wildfires.

Routine checks yield grazing personality The research took place from June to August over two years at the UC Sierra Foothill Research and Extension Center in Browns Valley. Horback and others tracked 50 pregnant Angus and Hereford beef cows wearing GPS collars across the 625-acre site, which is a mix of grassland and treed areas. The elevation ranged from 600 to 2,028 feet.

Researchers were able to predict cows’ likely grazing personalities by analyzing behavior in situations such as pregnancy checks or vaccinations, which require the cows to walk through chutes or narrow passageways. 

At the end of the chutes, the cows had two choices: go one direction to join the herd or another direction to pursue sweet molasses feed placed at different distances. The animals that moved slowly through the chutes and would go out of the way for the feed were consistently the grazing wanderers. 

“They were the ones on range that would go far and wide, that would also not really be that motivated to be closely, tightly packed with the rest of the herd,” Horback said. 

The homebodies consistently sought out the herd.

“They would not choose that sweet molasses,” Horback said. “They would go right back to the herd as quickly as they could, and then on range, they would just stay together. They have their social group there.”

Future generations  Next up in the research is to see if grazing personalities pass down to later generations. Horback is looking at the female calves of the studied cows to see if they pick up on the same patterns as their moms. 

“If there are any calves who are fostered off to another cow, do they pick up the grazing patterns of their birth mom or their adopted mom?” Horback said. “There’s no guarantee that genetics alone will determine the grazing behavior of a cow, but it could increase the likelihood that a cow is a hill-climber or a bottom-dweller.”

She is also working with colleagues in New Zealand and New Mexico to analyze blood samples from the cows that were tracked as part of related studies to see if genetic testing can provide some insight into behavior. 

UC Davis emeritus professor Juan Medrano published research a decade ago about genetic markers in cows that could indicate either hill-climbers or bottom-dwellers. 

“I hope to build on that knowledge with a larger, international dataset to understand whether grazing personalities are heritable,” Horback said.

Maggie Creamer, who earned her Ph.D. in animal behavior at UC Davis, contributed to the research, which was supported by the Russell L. Rustici Rangeland and Cattle Research Endowment.

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