Effects of a sorbitol-containing additive fed to dairy cows for 30 days postpartum.

The objective of this study was to determine the effects of early postpartum supplementation with Rally, a sorbitol-containing feed additive (RAL), on lactation performance and automatic milking system (AMS) metrics on a commercial dairy farm. Multiparous (MT) and primiparous (PP) Holstein cows were randomly assigned to either the RAL supplementation (570 g/d RAL; RAL-MT, n = 75, RAL-PP, n = 34) or control group (CTL-MT, n = 72; CTL-PP, n = 38). The RAL cows were supplemented from 1 to 30 DIM via an automated feed dispenser in the AMS. Milk production and other metrics were recorded for 1 to 90 DIM. Outcomes were analyzed with a linear mixed effect model with repeated measures. Analyses were conducted separately for the 2 periods: supplementation (1-30 DIM) and postsupplementation (31-90 DIM). Multiparous cows fed RAL produced (± SE) 3.52 ± 1.29 kg more ECM per day than CTL cows during the supplementation period. Multiparous cows fed RAL had 0.66 fewer refusal visits per day to the AMS (visits when it was not time for cows to be milked) during the supplementation period than CTL cows. Daily milk yield and ECM yield and number of refusal visits per day were similar for primiparous cows fed RAL and CTL during the supplementation period. Multiparous cows fed RAL continued to produce 2.17 ± 1.11 kg more ECM per day than CTL cows during the postsupplementation period. Multiparous cows fed RAL had 0.59 fewer refusal visits per day during the postsupplementation period than CTL cows. Daily milk yield and ECM yield, rumination time, and number of refusal visits per day during the postsupplementation period were similar between primiparous cows fed RAL and CTL cows. The results from this study indicate that RAL supplementation during the first 30 DIM increased milk yields when fed to multiparous cows.