Enhanced Honey Bee Colony Strength and Economic Returns from Fall and Winter Feeding with a Complete Pollen-Replacing Feed

Poor nutrition is a known contributing factor to ongoing high rates of honey bee colony mortality. Beekeepers invest significant resources to provide supplemental feeds to their colonies, but currently available diets are nutritionally incomplete. To test whether commercially managed colonies fed a manufactured, nutritionally complete Pollen-Replacing Feed (PRF-1) would exhibit improved colony health outcomes compared to beekeeper-selected Commercial Standard Feeds, we tracked colony health metrics from fall through almond pollination and the subsequent spring in a large-scale, multi-year field trial. By January (in almonds), PRF-1-fed colonies had 1.19 more frames of bees (<i>p</i> < 0.001) and 18.7% more colonies meeting the 8-frame minimum size requirement for high-revenue pollination contracts. After almond pollination (March), PRF-1-fed colonies exhibited a 13.8% increase in survival (<i>p</i> = 0.002), 2.57 more frames of bees (<i>p</i> = 0.006), and 0.79 more frames of brood (<i>p</i> = 0.003). PRF-1-fed colonies also exhibited superior spring build-up, adding 1.22 more frames of bees between January and March (<i>p</i> = 0.03). Economically, a hypothetical 100-colony operation fed PRF-1 garnered an additional $12,065.81 in gross revenue in the first year. Nutritional benefits are projected to compound, leading to exponentially increased revenue over subsequent years. Persistent improvements in colony health demonstrate that providing a nutritionally complete pollen-replacing feed in fall and winter has a long-lasting, positive impact on colony health and commercial viability.