Opportunities to enhance performance and efficiency through nutrient synchrony in forage-fed ruminants.

Increasingly, the need for optimized nutrient utilization to address increasing production costs and environmental considerations will necessitate opportunities to improve nutrient synchrony. Historically, attempts at synchronizing nutrient supply in ruminants, particularly in cattle consuming high-forage diets, have met with variable results. The success of nutrient synchrony has been measured primarily in ruminants by increases in microbial yield, microbial efficiency, nutrient utilization, and to a lesser extent, animal performance. Successful synchrony of nutrient supply to cattle consuming forage-based diets faces several challenges. From a feed supply aspect, the challenges to nutrient synchrony include accurately measuring forage intake and consumed forage chemical composition. The issue of forage intake and chemical composition is perhaps the most daunting for producers grazing cattle. Indeed, for forage-fed cattle, the availability of forage protein and carbohydrate can be the most asynchronous aspect of the diet. In most grazed forages, digestion rates of the carbohydrate fractions are much slower than that of the corresponding protein fractions. Additionally, the forage-supplement interaction exerts a large impact on the synchrony of nutrients. The supplemental feedstuffs compose the component of the nutrient synchrony scenario that is most often manipulated to influence synchrony. The supplement type (e.g., starch vs. fiber, dry vs. liquid), nutrient profile, and degradation rates are often prime considerations associated with nutrient synchrony on high forage diets. Other considerations that warrant attention include temporal intake patterns of the forage and supplement, increased use and types of coproduct supplements, and an assessment of the success of nutrient synchrony. Synchronization of nutrient utilization by forage-fed ruminants has and will continue to encounter challenges for successful outcomes. Ultimately it is the improvement in animal performance and optimization of nutrient utilization efficiency that dictates whether nutrient synchrony is a successful strategy.