Relationship Between Allogrooming and Disease in Feedlot Steers: Social Interactions May Provide Information about Individual Animal Health

Social interactions within a group of cattle may provide information about an individual animal’s health status. To determine whether social licking (e.g., allogrooming) can be used as an indicator of animal health, Bos indicus cross steers (n = 36) were housed in drylots (8-10 steer/pen), individually identified, and video recorded prior to (d -2, -1) and after (d1, 2, 4, 8) inoculation (d0). Half of the cattle within each pen were inoculated with Mannheimia haemolytica (MH) and the other half were inoculated with a phosphate buffer solution (PBS). We hypothesized that MH cattle would receive more allogrooming post-inoculation. Cattle were fed 2x/d and video recordings on d -2 and d4 were decoded 2h before and 2h after each feeding for the duration of time (sec) each steer gave or received allogrooming. The total amount of time on d-2 and d4 spent giving and receiving allogrooming was used to develop four behavioral phenotypes: 1) GIVE (n = 4): gave >1 sec, received 0, 2) RECEIVE (n = 8): gave 0, received >1, 3) BOTH (n = 23): gave >1 and received >1, and 4) NEUTRAL (n = 1): gave 0 and received 0. GIVE steers (130.3 ± 104.3) spent less time (sec) allogrooming than BOTH steers (149.4 ± 42.5). RECEIVE steers (55.3 ± 18.0) spent less time (sec) receiving allogrooming than BOTH steers (150.0 ± 26.9). A Generalized Linear Mixed Model (PROC MIXED) evaluated the impact of day and treatment on the duration of time spent giving or receiving allogrooming. Neither treatment nor day influenced the duration of time spent giving allogrooming. Treatment (P=0.13) slightly influenced the duration of time spent receiving allogrooming. MH steers (138.3 ± 32.3) spent more time (sec) receiving allogrooming than PBS steers (77.9 ± 21.3). Transition matrices identified that 27% of MH and 16.7% of PBS steers that were classified as BOTH on d -2 remained BOTH on d4. Steers classified as GIVE on d -2 were classified as RECEIVE on d4 for 11.1% of PBS and 0% of MH steers. Of the MH inoculated BOTH steers, on d-2, 27.8% were re-classified as RECIEVE on d4, while no PBS steers made this transition. Allogrooming is a comfort behavior associated with social dominance and partnership, yet some steers were observed to never give or receive allogrooming. The duration of time individuals receive allogrooming may be a useful metric for identifying sick animals and warrants further investigation.