Health, physiology and behavior of dairy calves reared on 4 different substrates

The objective of this study was to investigate the effect of four different rearing substrates on the health, physiology and behavior of group housed dairy calves. At 1 wk of age, 80 calves were moved into one of 20 experimental pens (n = 4 calves/pen) where they remained until 6 wk of age. Pens had floors covered with pea metal (PM), rubber chip (RC), sand (SA) or sawdust (SW; n = 5 pens / rearing substrate). Body weight, cleanliness, health, and skin surface and vaginal temperature were recorded at 1, 3 and 6 wk of age. Escherichia coli numbers were assessed on the skin surface of the shoulder and in the feces of calves at 3 and 6 wk of age. Blood samples were taken at 1, 3 and 6 wk of age to measure hematological values and cortisol, immunoglobulin-G and lactate concentrations. Behaviors (lying, running and self-grooming) were recorded in the home pen at 1, 3 and 6 wk of age using video recorders and accelerometer data loggers. At 6 wk of age, calves were tested individually in an arena test and behavior was recorded continuously for 20 min. Body weight did not differ among calves reared on PM, RC, SA or SW, regardless of age. All calves were clean and no calves displayed any clinical signs of disease, lameness, leg lesions or injuries at wk 1, 3 or 6, regardless of substrate type. The number of E. coli recovered from a surface area of 100 cm2 on the shoulder of each calf was affected by rearing substrate, with more E. coli recovered from calves reared on SW than PM, RC or SA at 3 and 6 wk of age. Fecal E. coli counts were not affected by rearing substrate at 3 or 6 wk of age. Over the entire study period, calves reared on PM and SA had lower skin temperatures than calves reared on RC or SW, but skin temperature was similar between calves reared on PM and SA. However, vaginal temperature did not differ among calves reared on different substrates at 1, 3 or 6 wk of age. Hematology values and cortisol, immunoglobulin-G and lactate concentrations of calves were similar among rearing substrates over the 6 wk study period. In the home pen, rearing substrate did not influence time spent lying, however, calves reared on SW performed more lying bouts than calves reared on PM or SA. In addition, rearing substrate did not influence the time calves spent running, however, calves reared on SW spent more time self-grooming than calves reared on PM, RC and SA. During a 20 min arena test, running (frequency and duration) and the frequency of bucks, jumps and kicks performed by calves was not affected by rearing substrate. In conclusion, the physiology and behavior of calves reared on PM, RC and SA was similar to SW, which is considered the preferred rearing substrate to use when rearing calves. Therefore, PM, RC and SA may be acceptable alternative rearing substrates for rearing group housed dairy calves. Referred to by: M.A. Sutherland, G.M. Worth, C. Cameron, C.M. Ross, D. Rapp. Corrigendum to “Health, physiology, and behavior of dairy calves reared on 4 different substrates” (J. Dairy Sci. 100:2148–2156) Journal of Dairy Science, Volume 100, Issue 5, May 2017, Page 4194. doi:10.3168/jds.2017-100-5-4194