Efficacy of laidlomycin propionate for increasing rate and efficiency of gain by feedlot cattle.

Abstract

One thousand twenty steers and heifers were used in six feeding trials to examine the influence of laidlomycin propionate on feedlot performance and to determine the most efficacious dietary concentrations of that ionophore. Cattle were fed diets ranging in energy content from 1.08 to 1.49 Mcal NEg/kg of DM. Laidlomycin propionate improved rate of gain and feed conversion in both steers and heifers. Improvements in performance were not evident when laidlomycin propionate was fed at only 3 mg/kg. However, both average daily gain and feed conversion were improved by laidlomycin propionate within the range of 6 to 12 mg/kg of DM (P less than .001). Feed consumption was not substantially affected by inclusion of laidlomycin propionate in the diet. Improvements in ADG and feed conversion were greater on lower-energy diets than on higher-energy diets, but both these performance characteristics were improved regardless of the type of diet fed. Average daily gain was maximized with laidlomycin propionate at 6 mg/kg, whereas improvements in feed conversion were sustained through 12 mg/kg. Carcasses of cattle fed diets containing 6 to 12 mg/kg of laidlomycin propionate weighed 7.3 kg more (P less than .001) than carcasses of cattle fed the control diets. Yield grade and quality grade were not affected by laidlomycin propionate (P greater than .05).

Influence of Ionophore Supplementation on Growth Performance, Dietary Energetics and Carcass Characteristics in Finishing Cattle during Period of Heat Stress

“…This change may be explained partially by increases in diet energy density. In a six-trial summary, Spires et al (1990) also found a negative association (R 2 = −0.53) between diet NE and feed conversion response to the ionophore laidlomycin propionate. Based on their regression equation, expected feed conversion response to ionophore supplementation is negligible when dietary NE g is greater than 1.55 Mcal/kg.…”

Effect of salinomycin or monensin on performance and feeding behavior of cattle fed wheat- or barley-based diets

“…As ruminal starch digestion increases, as occurs with high-wheat diets, relative to barley or corn (McAllister et al 1990), microbial profiles and biochemical pathways shift to direct carbon and hydrogen away from methanogenesis and toward propionate production (Schelling 1984). Reducing methane production is also one of the primary means by which ionophores improve energetic efficiency (Bergen and Bates 1984), thus the potential for M and S to improve ruminal fermentation would decline as ruminal starch digestion increases (Spires et al 1990). On the other hand, the moderating effect of M and S on ruminal pH (Nagaraja et al 1985), and, therefore, on acidosis, may be most beneficial on a rapidly fermented diet.…”

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

“…Feeding LC resulted in increased (P 00.01) fat cover resulting in lower (P 00.01) meat yield compared with carcasses from cattle fed MT. Feeding laidlomycin has increased thickness of backfat in feedlot cattle in previous research (Spires et al 1990). …”

“…0.80) due to antibiotic supplementation. Although both laidlomycin (Spires et al 1990) and monensin (Goodrich et al 1984) improve feed efficiency over control diets, response was similar when they were compared with each other (Galyean et al 1992). Both tylosin (Brown et al 1975;Vogel and Laudert 1994) and Table 2.…”

“…Reduced intake is commonly reported when monensin is fed to feedlot cattle, especially immediately following introduction (Spires et al 1990;Galyean et al 1992). In the six trials reported by Spires et al (1990), in which laidlomycin was included at 3 to 12 mg kg (1 , DMI was not significantly affected compared with control diets, but a linear decline in DMI with increasing levels was noted. Laidlomycin fed at 6 or 12 mg kg…”