Effect of a trainer cow on health, behavior, and performance of newly weaned beef calves.

Abstract

Experiments were conducted to investigate the effects of the presence of a trainer cow on behavior, performance, health, and feeding patterns of newly weaned beef calves. In Exp. 1,252 weaned calves (270+/-18 kg) were allocated to 22 pens (11 to 15 calves per pen). A trainer cow was randomly assigned to each of 11 pens. Calves were weighed prior to feeding on d 0, 3, 7, 14, 21, and 28. Rectal temperatures were taken on each of these days (except d 28) and blood samples were collected on d 0, 3, and 7 and subsequently analyzed for serum haptoglobin and leukotoxin antibody titers. Instantaneous scan observations of calf behavior were made at 10-min intervals between 0730 and 1730 on d 1, 2, 4, 5, and 6. A similar protocol was used in Exp. 2, in which 297 calves (258+/-17 kg) were allocated to 24 pens. Blood analyses included haptoglobin, white blood cell counts (WBC), and neutrophil:lymphocyte (NL) ratios. In Exp. 3, the above protocol was followed and patterns of feed bunk attendance of individual calves were also monitored using radio frequency identification by passive transponder ear tags. Trainer cows did not influence (P > .10) calf rectal temperatures, requirements for antibiotic therapy, WBC, NL ratios, or leukotoxin antibody titers. Pooled across treatments, NL ratios were lower (P < .01) on d 0 (.31) than on d 3 (.36) or d 7 (.39). Although differences in weight gain were detected in some periods within the three experiments, there were no differences (P > .10) overall (d 0 to 28). Trainer cows did not affect (P > .05) frequency or duration of bunk visits by the calves. Averaged across treatments, frequency and duration of bunk visits increased (P < .001) from 9.6 visits/d and 56.7 min/d between d 0 and 3 to 12.3 visits/d and 108.9 min/d between d 15 and 21. The number of calves observed eating during scan sampling observations also increased from 16.4% on d 1 to 25% on d 4 (P < .10) and 29% on d 5 and 6 (P < .05). More (P < .05) calves were observed lying on d 1 (41.7%) and d 2 (45.3%) than on d 4 (37.5%), d 5 (34.8%), or d 6 (36.2%). With a trainer cow present, fewer (36.7% vs 41.5%; P < .001) calves were observed lying and more (11.7% vs 10.2%; P = .08) were observed walking than when no cow was present. Trainer cows did not improve calf health, time spent at the feed bunk, or performance of newly weaned calves.

Electronic identification: Applications in beef production and research

“…In a recent study, we found that 16% of newly arrived cattle did not visit the bunk for a period of 1 d during the first 10 d of introduction to the feedlot. In fact, one animal did not attend the bunk at all during this 10-d period (Gibb et al 2000b). The calf was not visually identifiable as ill, but did lose weight during the 10 d. It remains to be determined if these periods of little or no intake have long term impacts on the animal performance over the entire feeding period.…”

“…A mature cow accustomed to the feedlot pen may, by modelling successful feeding strategies, facilitate newly weaned calves' locating feed and water troughs and may thereby minimize calves' apprehension associated with the novelty of the feedlot environment (Fluharty et al 1995). GrowSafe data revealed, however, that the calves did not start to feed with the trainer cow until after day 8 of the feeding period, suggesting that the cow did little to accustom calves to feeding at the bunk (Gibb et al 2000b). Two additional experiments showed that trainer cows did not influence the growth performance or health status of newly weaned feedlot calves (Gibb et al 2000b).…”

“…GrowSafe data revealed, however, that the calves did not start to feed with the trainer cow until after day 8 of the feeding period, suggesting that the cow did little to accustom calves to feeding at the bunk (Gibb et al 2000b). Two additional experiments showed that trainer cows did not influence the growth performance or health status of newly weaned feedlot calves (Gibb et al 2000b).…”

“…It is well documented that monensin decreases feed intake (Goodrich et al 1984). At the levels presently recommended for finishing diets (26 to 33 ppm), monensin is thought to decrease feed intake by about 1% (Stock et al 1995).…”

“…Previous research on social interactions and herd dynamics has relied primarily on time-consuming visual observations that are seldom conducted throughout the day (Wagnon 1966;Gonyou and Stricklin et al 1981;Bowman and Sowell 1997). The individual animal identification afforded by the GrowSafe system provides even more detailed information about social interactions among cattle housed in groups.…”