Results and Discussion
Trial 1. Trainer cows in Trial 1 gained 35 lb during the 14-day experimental period when they were housed with newly received calves (Table 2). Trainer cows exhibited a temporary drop in BW during the first week after calf arrival. Calves housed with trainer cows had numerically greater gains during the first 3 weeks than those without trainers but the differences were not significant (P > 0.10). However, overall gains were 10% greater (P < 0.06) and final BW was higher (P < 0.10) for calves with trainer cows than for those without trainers. Trainer cows resulted in a substantial reduction (P < 0.01) in calf morbidity compared with calves housed alone. Daily gains changed (P < 0 .01) over time, but the treatment X week interaction was not significant (P > 0.20). Trainer cows resulted in numerical increases in the percentage of calves eating within 30 minutes post-feeding on d 1, but these differences were not significant (P > 0.20); Table 3). Trends due to the presence of trainer cows disappeared with time post-feeding (P < 0.01) and with days post-arrival at the feedlot.
Trial 2. Cows in Trial 2 gained 159 lb during their 5 weeks in the feedlot and did not exhibit the decrease in gain during the first week of calf arrival as was observed previously (Table 4). Cows in this trial gained over 4.5 lb/day in the feedlot, had a feed intake of approximately 23 lb/day and were very efficient. Unfortunately, trainer cows did not improve performance or health of newly received calves in this trial. Calves with or without trainer cows had gains greater than 2.9 lb/day despite a morbidity incidence of greater than 60%. Point in time assessment of eating behavior was conducted on six separate days in Trial 2 (Table 5). A higher (P < 0.07) percentage of calves were eating 5 minutes post-feeding on days 1, 2, 4 and 8 for calves with trainers versus those without. On days 1 and 8 this difference persisted at 15 minutes post-feeding. By 30 and 60 minutes post-feeding, trainer cows did not affect eating behavior on any of the observation days. It is interesting to note that there was a numerical decrease in percentage of calves eating on day 15 (after the cows were removed) than on day 13 when cows were still present.
Use of cull cows as trainer animals for newly received feedlot calves affected calf eating behavior during the first few days after calf arrival. Calves housed with trainer cows had improved gains and health status in Trial 1, but the response was not consistent in Trial 2. When the presence of trainer animals improved gains, incidence of morbidity was decreased.