Effects of Heated Drinking Water on the Growth Performance and Rumen Functionality of Fattening Charolaise Beef Cattle in Winter

SIMPLE SUMMARY: Efficiency has been a major metric for measuring the production performances and profitability of zootechny, especially in beef cattle farming, even in terms of environmental sustainability. More efficient beef cattle farming should include a decrease in total feed consumption, equal or greater production performance and lower methane emissions and manure excretion. In fact, the rumen is the keystone of cattle efficiency. Strategies to maintain the rumen’s stability while enhancing its functionality can be drivers of better overall efficiency. Besides the feeds used and nutritional management, drinking water—specifically, its temperature—can alter and modulate the ruminal environment, due to the high sensitivity of the ruminal microbiota. Drinking heated water kept at a constant temperature can lead to enhanced production efficiency, due to better rumen stability and increased viability of ruminal bacteria. ABSTRACT: The effects of heated drinking water on growth performance and rumen functionality in fattening beef cattle during winter were evaluated. Newly received Charolaise bulls (n = 224) were allocated to two experimental groups: (i) water at room temperature (RTW) (weight 408 ± 34 kg); (ii) constantly heated water (25 °C) (HW) (weight 405 ± 38 kg). Growth performances, feed intake, feed conversion rate, water intake and carcass characteristics were evaluated. Internal reticuloruminal wireless boluses were used to collect rumen pH and temperature values every 10 min. Bodyweight was not affected by the water temperature, but the overall average daily gain (ADG) was significantly higher in the HW group (1.486 vs. 1.438 kg/head/day in the RTW; p = 0.047). Dry matter intake was significantly higher in the HW group (p = 0.001), even though the final feed conversion rate (FCR) was not influenced. There was also a tendency for better cold carcass weight (CCW) and carcass yield (CY) in the HW group. Drinking heated water reduced the time (min/day) during which the ruminal pH was below pH 5.8 or 5.5, and the time during which the temperature was lower than 37 or 39 °C (p < 0.001). The use of heated drinking water is a plausible a strategy for enhancing ruminal stability and the overall production efficiency in fattening beef cattle, which will lead to both better growth performance and higher ruminal stability.