Interaction between bunk management and monensin concentration on finishing performance, feeding behavior, and ruminal metabolism during an acidosis challenge with feedlot cattle1

Abstract

Two commercial feedlot experiments and a metabolism study were conducted to evaluate the effects of monensin concentrations and bunk management strategies on performance, feed intake, and ruminal metabolism. In the feedlot experiments, 1,793 and 1,615 steers were used in Exp. 1 and 2, respectively, in 18 pens for each experiment (six pens/treatment). Three treatments were evaluated: 1) ad libitum bunk management with 28.6 mg/kg monensin and clean bunk management strategies with either 2) 28.6 or 3) 36.3 mg/kg monensin. In both experiments, 54 to 59% of the clean bunk pens were clean at targeted clean time, or 2200, compared with 24 to 28% of the ad libitum pens. However, only 13% of the pens were clean by 2000 in Exp. 1 (summer), whereas 44% of the pens in Exp. 2 (winter) were clean by 2000. In Exp. 1, bunk management and monensin concentration did not affect carcass-adjusted performance. In Exp. 2, steers fed ad libitum had greater DMI (P < 0.01) and carcass-adjusted ADG (P < 0.01) but feed efficiency (P > 0.13) similar to that of clean bunk-fed steers. Monensin concentration had no effect on carcass-adjusted performance (P > 0.20) in either experiment. A metabolism experiment was conducted with eight fistulated steers in a replicated 4 x 4 Latin square acidosis challenge experiment. An acidosis challenge was imposed by feeding 125% of the previous day's DMI, 4 h later than normal. Treatments consisted of monensin concentrations (mg/kg) of 0, 36.7, 48.9, or 36.7 until challenged and switched to 48.9 on the challenge day and 4 d following. Each replicate of the Latin square was managed with separate bunk management strategies (clean bunk or ad libitum). Feeding any concentration of monensin increased number of meals and decreased DMI rate (%/h) (P < 0.12) for the 4 d following the acidosis challenge. Meal size, pH change, and pH variance were lower (P < 0.10) for steers fed monensin with clean bunk management. However, no monensin effect was observed for steers fed ad libitum. Bunk management strategy has the potential to decrease DMI and ADG when steers managed on a clean bunk program are restricted relative to traditional, ad libitum bunk programs. Monensin helps control intake patterns for individuals, but increasing concentration above currently approved levels in this study seemed to have little effect.

Increasing sodium bicarbonate level in high-concentrate diets for heifers. II. Effects on chewing and feeding behaviors

“…Our results for total daily meal-time, meal frequency and eating rate are similar to those reported in a series of experiments working with steers by Putnam and Davis (1963) who fed 24% ground forage (15-min meal criterion), and Chase et al (1976) who fed 28% chopped hay (20-min meal criterion). However, other researchers have reported a much higher daily meal-time, size and length than the present trial when working with steers fed around 10% forage in diets and when using a 20-min meal criterion (Cooper et al, 1999;Erickson et al, 2003). Results are difficult to compare because of different experimental conditions and the selection of the meal criterion may affect the estimation of all these variables (Tolkamp and Kyriazakis, 1999).…”

Performance and bunk attendance of cattle fed steam-rolled or ground corn supplemented with laidlomycin and chlortetracycline or monensin and tylosin

“…However, with G diets, LC reduced (2.1%; P 00.03) the frequency of daily visits (9.3 vs. 9.5), but increased (6%; P B0.001) the duration at the bunk (135.9 vs. 124.0; interaction P B0.001), resulting in increased (12.4%; P B0.001) duration per meal (15.4 vs. 13.7 min). Increased frequency of meals has previously been observed in cattle supplemented with monensin compared with control (Laudert 1995;Erickson et al 2003) or cattle fed salinomycin (Gibb et al 2001). The reduced intakes often observed with feeding monensin are typically associated with more frequent, but smaller meals, resulting in more stable intakes (Chirase et al 1992;Laudert 1995;Gibb et al 2001).…”

“…The second stepwise regression indicated that liver abscesses also increased with increasing frequency of bunk visits (P 00.002; R 2 00.16). Acidosis reduces DMI (Fulton et al 1979;Erickson et al 2003) and contributes to liver abscesses (Galyean and Rivera 2003), both of which can reduce performance (Brink et al 1990). It is possible that the acidosis challenges that resulted in abscessed livers also altered eating patterns, resulting in more frequent visits to the bunk.…”

“…The effect of monensin supplementation on eating behaviour (Chirase et al 1992;Gibb et al 2001) and lactate production (Nagaraja et al Table 3. Effect of medication and grain processing on patterns of bunk attendance 1981) are considered beneficial in minimizing subacute acidosis (Erickson et al 2003). Despite similar (P 00.69) intakes between SR (8.92 kg d…”

Retrospective study of cattle poisonings in California: recognition, diagnosis, and treatment

“…46 A carboxylic polyether ionophore widely used as a feed additive in beef cattle, monensin functions as described above in addition to its use for prevention and control of coccidiosis in cattle. 47 In 2004, the FDA approved use of monensin in total mixed rations for increased milk production efficiency in dairy cattle; the following year, ionophores were widely approved for use in dairy cattle. 48 Intoxications occur as a result of error in the amount of ionophore added to the diet, 49 inaccurate on-farm feeding, 50 administration to the wrong cohort, or exposure of cattle not acclimated to the ionophore-containing ration.…”