Milking Efficiency in AMS Using Quarter Level Milking Can be Improved By Applying a High Take Off Level

At the udder level, increasing the milk flow rate at which milking is terminated, shortens milking time and increases milking efficiency in automatic milking systems (AMS). It is hypothesized that this can be improved upon by setting the milk flow rate at the udder quarter level, regardless of feed availability. The objective of this study was to investigate the effect of udder quarter level milk flow rates (0.06, 0.3, or 0.48 kg/min) applied with or without teaser feed on milking time, milk yield, SCC and the degree of udder emptying, of cows in a FeedFirst™ AMS system. Thirty cows were assigned to six groups, balanced by parity (2.9±1.5), days in milk (142±25 d), and production (34.0±11.7 kg/d). All cows had SCC < 115.000 cells/ml when enrolled. Cows were exposed to treatments for 7d using a 3×2 factorial arrangement within a 6×6 Latin square. Data on milk yield, milking time and interval were automatically collected by the AMS. Milk samples for SCC were collected at the udder level during the last 2d of each period. Udder-level residual milk yield was sampled on the last milking during periods 1, 3, and 5. For harvesting residual milk, cows received an intramuscular injection of oxytocin (70 I.U., Partoxin™ vet) and milking was initiated again 3 min after the injection using a bucket milking machine. The data were analysed by ANOVA in a linear mixed-effects model using repeated measures in SAS (v9.4). Teaser feed was found non-significant for all response variables. Milking interval for the study was below 8 hours for all treatments and was not affected by take-off level or teaser feed (P > 0.05). Milking time was shortest for 0.48 (6.7±0.5 min) and increased with lower take-off levels (P < 0.05): 7.2±0.5 min for 0.3 and 7.6±0.5 min for 0.06. Milking time was not affected by teaser feed or the interaction of take-off level × feed. No treatment effect or interaction was evident for milk yield, residual milk yield, residual milk yield as % of total milk, or SCC (P > 0.05). In conclusion, milking efficiency in AMS can be improved by applying a take-off level of 0.48 kg/min on udder quarter level without losing milk yield or increase SCC. An effect of teaser feed on udder emptying could not be demonstrated in this study, indicating that teaser feed is less important when cows are directed through the feeding area before milking.