The influence of concentrated barley grain-based pellets in an automated milking system with free traffic on the production performance of dairy cows

This article examines various combinations of concentrated feeds in the form of concentrated barley grain-based pellets to determine whether the composition of concentrated pellets fed into an automated milking system (AMS) affects on the frequency of visits to the milking box, the milking frequency, and the milk yield and milk components. This study included three experiments with a 30-day period (the first 15 days are the adaptation period, the last 15 days are the period of data collection), in which cows received different compositions of PMR and concentrated pellets (Pellets 1, Pellets 2 and Pellets 3). Cows fed Pellets 2 and Pellets 3 had higher frequency of AMS visits (4.4 vs. 4 per cow per day; P = 0.28), milking frequency (3.4-3.5 vs. 3.3 per cow per day, P = 0.22) and a higher frequency of milking refusals (1.1-1.0 vs. 0.6 per cow per day; P = 0.10) than cows receiving Pellets 1. Despite changes in AMS attendance, there were no significant differences in the consumption of concentrated pellets between treatments (P = 0.34), the percentage of fat in milk (P = 0.82) and percentage of protein content in milk (P = 0.80). Cows receiving the Pellets 3 had higher milk yield (38.2 kg per cow per day; P = 0.08), ESM yield (41.4 kg per cow per day; P = 0.07) and had lower costs concentrated pellets per kg of milk (149.9 g; P = 0.04). These changes indicate that the composition of concentrated pellets may influence on the performance of cows in AMS.