Sickness behavior in dairy cows during Escherichia coli mastitis

Abstract

The consequences of mastitis in terms of dairy cow behavior are relatively unknown. Future assessment of dairy cow welfare during mastitis will be facilitated by knowledge about the potential of mastitis to induce sickness behavior. Our aim was to examine behavior of dairy cows in the period from 2 d before (d -2 and -1) to 3 d (d 0, 1, and 2) after experimental intramammary challenge with Escherichia coli. Effects of experimentally induced mastitis on behavior were examined in 20 primiparous Danish Holstein-Friesian cows, all 3 to 6 wk after calving and kept in tie stalls. After evening milking on d 0, each cow received an intramammary infusion with 20 to 40 cfu of E. coli in 1 healthy front quarter. Paraclinical and bacteriological examinations were conducted to confirm infection. Half of the cows were subjected to liver and udder biopsies twice during the trial. Behavior was video-recorded on 5 consecutive days, d -2 to +2 after challenge when the cows were not disturbed by humans. The behavior of the animals was compared among all days. Infection with E. coli altered the behavior of the dairy cows. Time spent feeding was lower in the initial 24 h after infection compared with that on the other days (16.6±1.1, 16.5±1.0, 13.2±1.2, 18.1±1.1, and 16.0±0.8% of time for d -2, -1, 0, 1, and 2, respectively). The duration of standing idle increased on d 0 compared with that on the control days and d 1 and 2 (29.4±2.6, 28.0±2.3, 39.1±2.6, 31.4±3.8, and 25.9±2.6% of time for d -2, -1, 0, 1 and 2, respectively). The frequency of self-grooming behavior per hour decreased in the initial 24h compared with that on d -2, -1, and 2 (4.1±0.8, 5.4±1.9, 3.2±0.6, 3.6±0.6, and 4.8±1.0 for d -2, -1, 0, 1, and 2, respectively). Likewise, duration of rumination and frequency of turning the head against the udder decreased in the first days after infection (rumination: 32.2±1.6, 34.8±1.8, 27.9±1.7, 30.0±2.6, and 34.8±1.7% of time; and frequency of turning head: 0.6±0.1, 0.6±0.1, 0.3±0.1, 0.3±0.1, and 0.6±0.1 per hour for d -2, -1, 0, 1 and 2, respectively). The cows subjected to biopsies showed an overall decreased lying time during the entire observation period (36.3±1.5 vs. 46.1±2.2% of time) but not directly related to the period after the biopsies. Dairy cows show classic signs of illness behavior in the hours after intramammary challenge with E. coli. This knowledge can be useful for the development of welfare assessment protocols, early disease detection, and for future work aimed at understanding the behavioral needs of dairy cows suffering from mastitis.