Abstract

Maximising milk harvested per robot is an important goal of pasture-based automatic milking systems (AMS). Results are presented from an analysis of 2937 cow milkings in a year-round milking system during January 2003 at the Dexcel Automatic farm (average herd size = 75 cows). Each cow milking was classified as OK (yield > 80% of expected yield, EY), Yield Carry Over (YCO, 20% < yield < 80% EY), or Failed (F, yield < 20% EY). The time and duration (from entry to exit from crate) of each cow milking was determined, as well as milk yield, and from these milk harvesting rate was calculated. There were an average of 95.8 cow milkings/day, average milking frequency was 1.13 milkings/cow/day (range 0.9 – 1.9 milkings/cow/day). Eighty-four percent of milkings were classified as OK, 8.9% as YCO and 7.1% as F (after which the cow was returned to the yard for another attempt). Milking times ± SD (F = 3.76 ± 2.57, YCO = 7.63 ± 3.31, OK = 10.07 ± 4.09 minutes/event) and milk harvesting rate (F = 0.09, YCO = 0.76 and OK = 1.37 kg/minute) suggest that failed milkings were costly in terms of time. The data show potential for improving the 24 h milk harvest per AMS through cow selection, a more consistent flow of cows through the AMS and technological improvements. KEYWORDS: milk harvesting efficiency; automatic milking systems; grazing; dairy cows.

KL, Davis, JG Jago, R Wieliczko, PJA Copeman, K Bright, and MW Woolford

Proceedings of the New Zealand Society of Animal Production, Volume 65, Christchurch, 271-275, 2005