May 10, 2023

Study shows impact of grazing practices on cattle behaviour and weight gain

Researchers from the USDA's Agricultural Research Service (ARS) are completing a 10-year study to investigate how grazing practices impact cattle behaviour, diet quality, and annual weight gain in extensive rangelands, Phys.org reported.

The team, based at the ARS Rangeland Resources & Systems Research in Colorado state, US, employed advanced technology such as cattle global positioning system (GPS) tracking collars and activity sensors to monitor the animals' grazing activities. These collars provided precise data on daily foraging behaviour, including grazing time, grazing speed, foraging pathways, and meal duration (by how long each animal lowered their head as a sign of eating).

The research findings showcased the potential of this technology in informing livestock managers about the distribution and foraging behaviours of free-ranging cattle. By continuously monitoring foraging behaviour, livestock managers can make more informed decisions regarding the movement of cattle within their operations or determine optimal times for cattle sales.

The study also compared the effects of non-rotational (season-long) grazing systems with multi-paddock rotational systems. Over the course of five years, it was observed that cattle in the rotational system gained, on average, 14% less weight compared to those in the season-long management system.

The researchers attributed this weight difference to the restricted movement of cattle in the rotational system, which limited their ability to selectively graze and resulted in the consumption of lower-quality forages with reduced protein content.

David Augustine, a research ecologist with the ARS Rangeland Resources & Systems Research in Colorado, said cattle in the rotational system exhibited more linear feeding pathways, spent more time on the same patch of grass, and showed less head movement while feeding, indicating less selective foraging behaviour and lower diet quality.

The study's findings, published in Agriculture, Ecosystems, and Environment, highlight the importance of allowing large herds to move freely and access a high-quality diet.

-      Phys.org