FACTORS AFFECTING THE PERFORMANCE OF SIMULATED LARGE HERRINGBONE AND PARALLEL MILKING PARLORS

A simulation model of double-16 and double-20 herringbone and parallel milking parlors and double-32 and double-40 parallel milking parlors was used to examine the effects of size, design, operating characteris tics of the milking system, management strategies, and milk yield on p arlor performance. Analysis of factorial experiments indicated that sm aller parlors were more efficient. Turns per hour and milk per stall p er hour for double-16, -20, -32, and -40 parallel parlors were 5.87, 5 .91, 5.21, and 5.00 turns/h and 56.19, 56.46, 49.66, and 47.94 kg/h, r espectively. A wider pulsation ratio (60:40 to 70:30) increased perfor mance measures about 4%, and increased vacuum pressure (46.6 to 50.8 k Pa) increased performance measures >6%. Parallel parlors outperformed herringbones by nearly 8%. Abbreviated milking procedures resulted in a >6% increase in performance measures over standard milking procedure s. Performance response was significantly diminished when the amount o f milking labor exceeded deficit amounts (20 to 32 units per milker) f or abbreviated milking procedures or standard amounts (13.3 to 16 unit s per milker) for standard milking procedures. When milk yield increas ed, turns per hour decreased, but milk per stall per stall per hour in creased.