Bovine respiratory disease (BRD) or pneumonia causes inflammation of the lung tissue and airways. Often, its damage is irreversible and you often cannot prevent pneumonia from having an effect later in life. Even mild cases of pneumonia can have an impact on daily live weight gain (DLWG) and feed conversion efficiency (FCE), increasing the cost of production.
Pneumonia in young calves has been shown to have a negative effect on growth rates. DLWG targeting 0.8kg can fall to as little as 0.4kg and never recover completely (Andrews A.H 2000.)
The damage from pneumonia includes impacting the age of first insemination as heifers become less likely to meet their target weight. Research demonstrates body weight of heifers which had pneumonia was estimated to be reduced by 10kg (range 1 -18kg) at 3 months and 29kg (range 22-3kg) at 14 months. (Van der Klerx, 2002). Recent research also highlights, heifers calving in the age group between 21 and 26 months have an increased first lactation milk yield and lifetime milk production (Krezel-Czopek,2018); it is critical we, as farmers, do everything we can to hit these target FFweights.
Following on from this, a 2012 study by Alex Bach demonstrated that for every 100g of increased average daily gain during the first 2 months of life an additional 225kg of milk could be expected during the first lactation.
Beef Cattle
Targeting finish weight is imperative for beef systems to remain sustainable and have a positive impact on net zero targets in years to come. A study by Littledike et al., (1996) showed that animals with lung damage were on average 21kg lighter than animals with healthy lungs. Cattle with lung damage have the potential to reduce live weight gain by up to 6kg per month (Laura,2007). Finishing time can be delayed 33-59 days for cattle displaying clinical and subclinical signs of pneumonia (Barielle, N et al.2008) increasing the cost of production and overall sustainability on your farm.
Subclinical Pneumonia
Further to this, once the affected animals were slaughtered, another study looked at lung damage at slaughter and the relationship between total weight at slaughter. Results show 70% of cattle had lung damage at slaughter despite only 35% being treated for pneumonia showing that those with clinical disease are only the tip of the iceberg. Littledike et al .1996. Having attended a talk recently by Alex Bach, he suggested that if pneumonia is prevalent vets should ultrasound all calves to detect subclinical cases of pneumonia. Although pneumonia can sometimes show signs such as increased respiratory rates, nasal discharge, and elevated temperature, subclinical pneumonia has no outward showing symptoms. It is important that farmers are aware that although no clinical signs of pneumonia can be seen by the naked eye, the likelihood of subclinical cases within your herd is most likely high.
T.E., Woollen N.E., Perino, L.J. Littledyke, E.T. (1996) Relationships among treatment for respiratory tract disease, pulmonary lesions evident at slaughter and rate of weight gain in feedlot cattle. Journal of the American Veterinary Medical Association 209
Andrews A.H. (2000) Calf pneumonia costs. Cattle Practice Vol 8 Part 2, 109-114
Barielle, S et al (2008). Impact of respiratory disorders in young bulls on performance and profitability. Rencontres Recherches Ruminants 15: 77-80
Van Der Fels-Klerx HJ, Saatkamp HW, Verhoeff J and Dijkhuizen AA (2002). Effects of bovine respiratory disease on the productivity of dairy heifers quantified by experts, Livestock Production Science 75(2): 157-166
Williams, P. and Green, Laura E. (2007) Associations between lung lesions and grade and estimated daily live weight gain in bull beef at slaughter. In: 3rd Flagship Congress British-Cattle-Veterinary-Association, Glasgow, Scotland, 2007. Published in: Cattle Practice, Vol.15 (No.3). pp. 244-249
Sawa A., Siatka K., Krezel- Czopek S. 2018. Effect age at first calving on first lactation milk yield, lifetime milk production and longevity of cows., Annals of animal Science.
