Is there a relationship between extended grazing and calf immunity?
- Project No: 2024F2259R
- Lead Researcher(s): Nilusha Malmuthuge (Agriculture and Agri-Food Canada)
- Collaborators: Tim McAllister, Trevor Alexander, Aklilu Alemu (Agriculture and Agri-Food Canada); Glesie da Silva (University of Alberta); Katie Wood, Mike Steele (University of Guelph); Danny Le Roy (University of Lethbridge); Christine Bassett (Coaldale Veterinary Clinic)
- Year Started: 2025
Background
Extended grazing, such as swathgrazing, bale grazing, or utilizing stockpiled forages have proven to be economically beneficial approaches to winter feeding on the prairies. However, these systems can suffer from reduced feed quality, which means that pregnant cows may not be meeting all their nutritional requirements when wintered in this fashion. Similarly, dam nutrient restrictions can have lasting impacts on calf health and performance through fetal programming.
Objective
Evaluate the impact of cows wintering in extended grazing systems with or without protein supplementation on:
- Priming of calf immune responses prior to weaning
- Activation of immune system “memory” programming
- Calf vigour at birth, pre-weaning growth
- Cow body condition score, body fat and weight, time to rebreeding, and colostrum quality
- Activation of stress responses in dams and calves
- Economic costs and benefits
Implications of the research
This project will provide more information on how maternal nutrition impacts calf health and performance, specifically under extended grazing systems. Examining supplementation strategies for use in extended grazing situations may result in an approach to optimize calf immune fitness and approach without sacrificing the cost savings of extended grazing.
This project is also supported by RDAR and the Beef Cattle Research Council