Do Pen Design, Feedbunk Space and Stocking Density Affect Digestive Health?

Project Title

Stocking Density and Feed Bunk Space as a Risk Factor for Liver Abscesses


Dr. Diego Moya, Western College of Veterinary Medicine

Dr. Greg Penner and Kathy Larson, University of Saskatchewan

Status Project Code
In progress. Results expected in March, 2024 ANH.23.19


Most research aimed at optimizing rumen health has looked at things like forage inclusion rate, grain processing, bunk and feeding management and antimicrobials. However, pen design, bunk space and stocking density could affect animal health and welfare, particularly on high grain finishing diets. When there isn’t enough bunk space for all animals to eat at the same time, animals that are lower in the pecking order will have less time to eat (and will potentially consume more fine feed particles). This could increase the risk of acidosis and abscesses in those less dominant animals.

Industry recommendationsregarding feedlot pen design, bunk space per head and pen stocking density were developed many years ago. Fewer feeder cattle are horned now, but enter and leave the feedlot at much larger sizes. Roller compacted concrete is becoming a popular choice among some cattle feeders. This improves drainage, pen conditions and animal cleanliness, but also allows higher animal densities. Animals will interact more frequently in more densely stocked pens. This could affect feeding behavior, as well as overall stress levels, which may impact animal performance and health.


  • assess the consequences of increased competition for space on animal temperament and stress
  • determine the role of feed bunk space and pen stocking density on the development of rumen acidosis and liver abscesses
  • analyze the costs associated with the different space allowances tested.

What they will do

Portable fencing will be used to modify the shape of pens in a research feedlot. The researchers will compare three stocking rates (industry standard 15m2 per head, vs. 30 or 7.5 m2), each with two different feed bunk allowances (1 vs 2 feet per head). A total of 900 head of steers will be fed for 116 days in each of three years (50 head per pen). Cattle will be fed twice daily, using slick bunk management.

Animals will be weighed every 28d, and intake will be measured on a pen basis. Six head per pen will be fitted with rumen pH monitors as well as accelerometers to track animal activity. Animal standing, lying, feeding, drinking, and interactive behavior will be monitored by video. Animal temperament will be evaluated using chute behavior score and exit speed on weigh days. Hair cortisol will be measured as an indicator of stress. Carcass grade, bruising, liver abscesses, gut tissue and digesta samples will be collected at slaughter.


Significant changes in housing conditions have been imposed on the poultry and swine industries due to animal welfare concerns. The cattle feeding hasn’t faced the same level of scrutiny yet, but when we do we’ll need to have answers and options available.