Comparing steam-flaked and pelleted barley grain in a feed-first guided-flow automated milking system for Holstein cows

摘要

Provision of a palatable feed in automated milking systems (AMS) is considered an essential motivating factor to encourage voluntary visits to the milking stall. Although the quantity and composition of AMS concentrates have been previously investigated, the form of the concentrate has not been extensively evaluated. The objective of this study was to evaluate the effects of feeding pelleted (PB; 132.9 +/- 56 DIM, 47.4 +/- 9.51 kg/d milk yield) versus steam-flaked barley (SFB; 133.0 +/- 63 DIM, 40.5 +/- 8.23 kg/d milk yield) in an AMS on dry matter intake, AMS visits, milk and milk component yield, and partial mixed ration (PMR) feeding behavior. Twenty-nine Holstein cows of varying parities were enrolled in this study. Cows were housed in freestall housing with a feed-first guided-flow barn design; 7 cows were housed in a separate freestall pen to enable individual PMR intake and feeding behavior monitoring. This study was conducted as a 2-way crossover, with two 21-d periods in which each cow received the same basal PMR but was offered 2 kg/d (dry matter basis) of PB or SFB in the AMS. Cows receiving the SFB had fewer voluntary AMS visits (2.71 vs. 2.90 +/- 0.051, no./d), tended to have a longer interval between milkings (541.7 vs. 505.8 +/- 21.02 min), spent more time in the holding pen before entering the AMS (139.9 vs. 81.2 +/- 11.68 min/d), and had lower total box time (19.7 vs. 21.4 +/- 0.35 min/d) than cows fed PB. Despite changes in AMS attendance, there were no differences for average milk (44.0 kg/d), fat (1.62 kg/d), and protein (1.47 kg/d) yields or AMS concentrate intake (2.02 kg/d). These behavioral changes indicate that offering SFB as an alternative to PB may reduce motivation for cows to voluntarily enter the AMS.