Associations of cow-level factors, frequency of feed delivery, and standing and lying behaviour of dairy cows milked in an automatic system

Abstract

The objectives of this observational study were to quantify the standing and lying behaviour of dairy cows milked in an automatic milking system (AMS) and determine associations of this behaviour with cow-level factors (parity, stage of lactation, production, lameness) and feeding management (frequency of feed delivery). Ninety lactating Holstein cows (178±83 d in milk (DIM); parity: 2.1±1.9), kept in a free-stall barn in one of two pens, each with a free-traffic AMS, were monitored for a period of 70 d. To vary feeding management, in two consecutive 35-d periods, cows in each pen were delivered a total mixed ration (TMR), in a random order, once daily (at 0730) or twice daily (at 0730 and 1730). During the last 7 d of each period, standing and lying behaviour were recorded with data loggers, while milking information was recorded by the AMS. Cows were lameness (gait) scored twice each period. Cows lay down for 10.9±2.0 h d-1, produced an average of 34.7±8.7 kg d-1 of milk, and milked 2.6±0.6 times per day. Cows spent more time standing after milking (P=0.04) when fed once daily compared with twice daily. Lying duration tended to increase (P=0.06) when feed was delivered twice daily. Milk yield (P<0.001) and lying bout frequency (P=0.05) were negatively associated with DIM, while lying bout length (P=0.005) and total duration of lying (P=0.01) were positively associated with DIM. Cows with higher gait scores milked less frequently (P=0.04), and spent more time lying per day (P=0.008) and tended to have more lying bouts per day (P=0.06). Overall, the results of this observational study suggest that the standing and lying behaviour of AMS-milked cows may be influenced by feed delivery frequency, but are more consistently associated with stage of lactation and lameness.