Implications of weaning on lung health of beef calves

Author – Dr Stephanie Sammes


Ultrasound is an accurate diagnostic tool used to assess lung lesion scores of calves during weaning in response to different nutritional and health management strategies.

  • A trial was conducted in Northern Australia using weaners housed in yards (day 0-7) and then paddocks (day 8-35).
  • Two diets: Diet 1 (D1) loose lick with NaturSafe (Diamond V);Diet 2 (D2) loose lick (control).
  • Two vaccine groups/diet: (a) no BRD vaccine, (b) BRD vaccine(n=50 weaners/diet).

Lung score significantly (P < 0.0001) increased from day 0-35 (Fig. 1).


At yard entry, 90% of weaners had a lung score of 0, 10% had score of 1.

At yard exit, 23% had a lung score of 0, 77% had score ≥1.

At paddock exit, 3% had a lung score of 0 and 97% had score ≥1.


No TRT differences (P ≥ 0.10) in magnitude for change in lung score. Overall, mean DMI and DMI as % of LW was greater (P ≤ 0.04) for D1a/b versus D2a/b, no differences for mean ADG (P ≥ 0.14).


Fig. 1. Number of weaners per lung score category at yard entry (day 0), yard exit (day 7) and paddock exit (day 35). Lung score 0 (normal/healthy), 1 (pleural thickening), 2 (lobular lesion), 3 (lobar lesion).

Enhancing calves feed intake is an important strategy to help boost calf health and performance. Results showed NaturSafe increased feed intake, suggesting a possible intake stimulatory effect.


The large increases in lung score up to 36-days post-weaning, highlights the importance of implementing both health and nutritional management strategies to support lung health and improve performance of beef calves during weaning.