Boosting Calf Immunity with Early-Life Management

Background

The beef industry has (and continues) to rely on the use of vaccines and antibiotics to control BRD and other diseases in cattle production. However, early-life management can play a key role in priming the immune systems of calves to strengthen their ability to withstand BRD. Early vaccination has been proven to be an effective means to boost the immune system of calves. Research around the use of intranasal vaccines on newborn calves is showing that calves vaccinated in early life (and given a booster) have a better chance at fighting off disease after weaning. However, there are still many unanswered questions about the best times to give the initial and booster vaccinations. Calves weaned using low-stress methods, like two-step weaning and fence line weaning  also have improved health and productivity outcomes compared to abruptly weaned calves. This team is looking to fill in the gaps as to the best timing of boosters for intranasal vaccines given at birth (e.g., boosted at pre-weaning or weaning) and the effectiveness of the vaccine program when other management practices like weaning method and co-mingling at the feedlot occur.

Objectives

• Identify optimal vaccination programs that prime effective immunity (antibody and cellular responses, immune memory cells) in calves during pre-weaning and immediately after weaning, and
• Assess the impact of weaning method and viral challenge on immune fitness when calves are managed using an optimized vaccination protocol.

The long-term objective is to design optimal and practical early-life vaccination and weaning programs for beef cattle to improve health, welfare, and productivity and reduce the need for antibiotic treatment.

What they will do

This team will do two related studies to identify optimal pre-weaning, weaning and feedlot vaccination programs with the best long-term effects on health and productivity.

Study 1: 72 beef calves will be allocated to 3 modified live vaccine (MLV) vaccination protocols; (a) intranasal MLV in the first week and an injectable at spring turnout, (b) same, plus a second injectable vaccine two weeks preweaning, or (c) first injectable vaccine at spring turnout and a second at weaning. Immune fitness will be evaluated by measuring immune responses and memory T-cells activation to identify best calf management practices and ADG.

Study 2: 48 calves will all receive the best vaccination program from study 1. Half will be two-stage and half will be abruptly weaned. After 7 hours of transport, they will be challenged with BRSV and PI3, then be monitored for the first 20 days in the feedlot.

In both studies, many samples will be collected and analyzed to measure stress, cell- and antibody mediated immune responses, viral quantification, and memory T-cells.

Implications

Practical beef production and different management practices are important to consider when optimizing vaccination protocols for cow-calf herds. Vaccine efficiency is defined as the ability to improve health outcomes significantly while improving calf growth and economic advantage. Including real-life considerations like the best time to vaccinate and optimal weaning methods gives producers practical insights for what works, and how to improve vaccination protocols to improve animal health, welfare and performance while preserving the effectiveness of antibiotics.