Robotic milking machine's running costs will fall
During 2011 and 2012, the total energy use of the AMS was 106 Watt-hours per litre of milk produced (Wh/l) during its first lactation (range 69-178 Wh/l), and 84Wh/l in its second lactation (range 53-113 Wh/l).
Table 1 (right) gives more information on the performance of the milking systems over two years.
Water heating accounted for the largest portion of energy use (39pc and 30pc in 2011 and 2012, respectively).
The energy consumption of the milk cooling system, air compressor, vacuum pump and robot in 2011 and 2012 are presented in Table 2.
Miscellaneous items such as wash pumps and an office consumed 16Wh/l and 13Wh/l in 2011 and 2012, respectively.
When the relevant tariffs were applied, the average cost of electricity was 1.36 cents per litre of milk (c/l) in 2011 (range 0.84-2.42c/l) and 1.09c/l in 2012 (range 0.68- 1.58c/l).
The average AMS running costs of 1.36c/l (2011) and 1.09c/l (2012) were high compared to an audit of conventional milking systems (0.43c/l) on 21 commercial dairy farms (May-October 2010) by Teagasc, Moorepark.
This may be due to either reduced milk output from the AMS during the start-up years (when milk yield is expected to be reduced by 10-15pc) and/or under-utilisation of the AMS.