Evaluation of Systems for Feeding Supplemental Concentrate to Cows in Groups

A herd of 211 Holstein cows plus heifers calving subsequently was stratified into equal performance groups that were assigned randomly to three feeding system subherds fed for 68 wk: 1) bunk-fed silage mixture plus concentrate individually via transponder control; 2) onegroup total mixed ration; and 3) a twogroup total mixed ration system with respective ratios of forage:concentrate: 1) 48:52, 2) 56:44, and 3) 55:45 with 42:58 for the first 24 wk of lactation and 72:28 for the remainder.Respective average dry matter intakes (kg/cow per day) for the three feeding systems were forage 8.6, 10.3, and 10.1 and concentrate 9.3, 8.0, and 8.3.Cows fed concentrate via transponder control produced significantly more milk than cows in the one-or two-group total mixed ration systems, 2.7 and 3.8 kg/cow per day.Calculated intakes of net energy lactation (Mcal/cow per day) were 29.0, 28.8, and 29.1 for the three subherds, but relative to milk energy output, corresponding efficiencies were 61.0, 54.4, and 51.0%.Cows averaged 14 daily visits to the feeders with a range of 2 to 32.There were low correlations between concentrate allocation and number of feeder visits and concentrate allocation and total time spent in feeder.