“Ionophore and Direct-Fed Microbial Use in the Commercial Cattle Feeding Industry”
by Justin W. Waggoner, beef systems specialist
A number of different non-nutritional feed additives are currently used in the cattle feeding industry. Ionophores (lasalocid, monensin, and laidlomycin proprionate) are among the most common feed additives used. These compounds selectively inhibit specific types of ruminal bacteria which results in improved feed efficiency, average daily gain, and reduced risk of acidosis during the feeding period. A recent survey of consulting nutritionists conducted by Samuelson et al., (2016), which summarized responses from 24 consulting nutritionists (servicing more than 14 million head annually) reported that 92.3% of their clients use some type of ionophore in the receiving diet and 97.3% used an ionophore in the finishing diet. The most commonly used ionophore in receiving diets was monensin (77.3%) followed by lasalocid (22.7%).
All of the nutritionist surveyed used monensin in the finishing diet if an ionophore was used. Approximately 55% of the nutritionist surveyed used the same ionophore in both receiving and finishing diets, while the remaining 45% used different ionophores based on cattle type and diet. The majority of nutritionists surveyed also reported that direct-fed microbials (probiotics) were used by their clients in receiving (62.5%) and finishing rations (59.6%).