Milk Yield, Milk Composition, and Behavior of Holstein Cows in Response to Jet Aircraft Noise Before Milking

Abstract

The objectives were to evaluate effects of jet aircraft noise before milking on milk yield and composition, amount of residual milk, and behavior of dairy cows. Thirty-six Holstein cows (79 to 155 DIM) were assigned to a partially balanced incomplete block design with three treatments. Cows received two of the three treatments during consecutive 21-d periods, each preceded by 5- to 7-d adjustment periods. Treatments were control (ambient noise) and ambient noise plus one of two recorded jet aircraft noises. Cows were exposed to jet noise up to four times daily on 10 to 12 d per period. Yields of milk, 3.5% FCM, residual milk, and components and component percentages were not affected significantly by exposure to recorded jet noise. Differences detected were due to time of milking, period, advancing stage of lactation, and management. Objective and subjective evaluations detected no evidence of behavioral responses, such as vocalization or aversive behaviors (startle, freeze, or retreat) at time of noise or more aggressive or agitated behavior during subsequent milking or postmilking. The lack of behavioral response was not caused by habituation of cows to noise during the 21-d periods.