0106 Evaluating preweaned calf housing and its impact on calf respiratory parameters on New York dairy farms

Abstract

The objectives of this project were to (1) evaluate environmental and air quality parameters across different types of calf housing facilities; (2) evaluate rates of respiratory illness in preweaned calves; and (3) determine the impact of environmental factors, air quality, and housing type on calf health. This was an observational study in which calf facilities were evaluated on a single visit during June 2015. Housing included hutches (n = 9), individual pens in a barn (n = 11), and group pens in a barn (n = 9). Facility and calf pen evaluations included wind speed, temperature, relative humidity, heat stress index, bedding type, bedding composite sample for bacteria counts, nesting score of calf pens, calf health scoring, and airborne bacteria. Data were analyzed using SAS 9.3 to determine the impact of housing type, environmental, and air quality variables on calf respiratory score. A total of 29 facilities and 437 preweaned calves were evaluated. Calf facility temperature averaged 24.2°C (range 15.5 to 30.6°C) with a relative humidity of 21.5% (range 10 to 78%) and a heat index of 21.5°C (range 6 to 30.9°C). Temperature and airborne bacterial counts were greater in hutches as compared with individual and group pens (P < 0.01). Humidity was similar for hutches and group pens, but greater than individual pens. Gram negative airborne bacterial counts were lowest in individual pens. No difference in heat index was observed across housing type. Mean calf respiratory scores was 2.5 (range of 0 to 9) on a 12 point scale; 13.33% of calves evaluated scored greater than 5, indicating a respiratory challenge. Prevalence of respiratory illness in preweaned calves ranged from 0 to 50% of calves on a per farm basis (mean = 11.05% of calves/farm), with 44.82% of farms having no respiratory illness and 10.32% of farms having 30 to 50% of evaluated calves exhibiting signs of respiratory illness. There was a negative correlation between respiratory score and pen temperature (R2 = 0.90). There was no influence on respiratory score by housing system, bedding type, ventilation system, relative humidity, airflow, or airborne bacterial counts. Data collected from this study suggests that respiratory illness continues to be a challenge, even when weather is temperate. Additional research is needed to evaluate rates of respiratory illness during cold stress and transitional weather, as well as to evaluate management factors that increase the risk of infection.