Behavioral changes in dairy cows with mastitis.

Mastitis is a frequent and painful disease in dairy cows. However, pain detection and alleviation in mastitic cows has been overlooked. The objectives of this study were to measure behavioral changes in dairy cows with clinical mastitis and to investigate the effect of intramammary infusion of an antibiotic on lying behavior and behavior during milking. In experiment 1, 42 lactating cows were used: 14 mastitic cows and 28 control cows. Mastitic and control cows were subjected to an evaluation of pain responses on d 1 (mastitis detection day), and 2, 3, and 7d after the last antibiotic treatment (d 10+). The antibiotic treatment was administered to mastitic cows twice a day, starting on d 1, for at least 3 consecutive days. Behavioral changes were evaluated by measuring lying behavior, reactivity during milking (stepping, lifting, and kicking), weight distribution, and hock-to-hock distance. Overall, mastitic cows spent less time lying down on d 2 compared with control cows. The percentage of time lying on the mastitic quarter side did not differ significantly between mastitic and control cows. No differences were observed between control and mastitic cows on the number of steps per 24h on each day. Restless behavior during milking did not differ between treatments. Restless behaviors differed significantly within mastitic cows between days. Frequency of kicks per minute was higher on d 1 compared with d 2, frequency of lifts was higher on d 1 and 2 compared with d 10+, and frequency of steps was higher on d 2 compared with d 10+. The variability of weight that mastitic cows applied to the leg on the mastitic quarter side was higher on d 1 than on d 10+. For control cows, the variability in weight applied to the homologous leg of the mastitic quarter side leg was higher on d 1 compared with d 2 and 3. The hock-to-hock distance did not differ between treatments. Mild clinical mastitis might not cause sufficient pain to observe marked changes in behaviors. However, cows showed differences in lying time and reactivity during milking and slight differences in the laterality of lying. To further develop methodologies for assessing pain in mastitic cows, it is worth applying the methodologies used in this study to cows with moderate to severe mastitis, followed by their validation using analgesic treatment, to ensure that any change is a pain-specific behavior rather than a simple reflex. In experiment 2, no effect of intramammary infusion of the antibiotic was observed on lying behavior or behavior during milking. Cows with mild clinical mastitis present behavioral changes in lying behavior and at milking time, which could be associated with discomfort.

Associations of dairy cow behavior, barn hygiene, cow hygiene, and risk of elevated somatic cell count.

Poor dairy cow hygiene has been consistently associated with elevated somatic cell count (SCC) and the risk of subclinical mastitis. The objective of this study was to determine the associations between dairy cow standing and lying behavior, barn hygiene, cow hygiene, and the risk of experiencing elevated SCC. Lactating Holstein dairy cows (n=69; 86 ± 51 DIM; parity: 2.0 ± 1.2; means ± SD), kept in 1 of 2 groups, were monitored over a 4-mo period. Each group contained 61 ± 1 (mean ± SD) cows over the study period; complete data were obtained from 37 and 32 animals within each respective group. Cows were housed in a sand-bedded, freestall barn with 2 symmetrical pens, each with a free cow traffic automatic milking system. To vary barn hygiene, in 4 consecutive 28-d periods, alley manure scrapers in each of the 2 pens were randomly assigned to frequencies of operation of 3, 6, 12, and 24 times per day. During the last 7 d of each period, cow hygiene (upper leg/flank, lower legs, and udder; scale of 1 = very clean to 4 = very dirty) and stall hygiene (number of 0.15×0.15-m squares contaminated with manure in a 1.20×1.65-m grid) were recorded. Standing and lying behavior of the cows were collected during those days using data loggers. Individual-cow SCC was recorded at the beginning and end of each 28-d period. Elevated SCC was used as an indicator of subclinical mastitis; incidence of elevated SCC was defined as having a SCC >200,000 cells/mL at the end of each 28-d period, when SCC was <100,000 cells/mL at the beginning of the period. Less frequent scraping of the barn alleys was associated with cows having poorer hygiene. Poor udder hygiene was associated with poor stall hygiene. Longer lying duration was associated with poor hygiene of the upper legs/flank and udder. Greater premilking standing duration was associated with poor udder hygiene and decreased frequency of lying bouts was associated with poor hygiene of the lower legs. Higher milk yield was associated with poor hygiene of the udder and lower legs; multiparous cows had poorer hygiene of the upper legs/flank and udder. Over the study period, 24 new cases of elevated SCC were detected. No associations existed for the risk of experiencing an elevated SCC with alley scraping frequency or cow behavior patterns. However, increased odds of occurrence of elevated SCC were noted for cows of lower milk yield as well as for multiparous cows. In summary, these results show that cow hygiene is affected by the standing and lying behavior of cows and by the cleanliness of the cow's environment. These findings emphasize the need for cows to be provided clean standing and lying environments. The results also show that frequent cleaning of barn alley floors will help improve cow hygiene.

Short communication: The effects of experimentally induced Escherichia coli clinical mastitis on lying behavior of dairy cows.

Clinical mastitis is a commonly occurring and economically important problem in the dairy industry. Researchers have suggested that changes in lying behavior could be useful as early indicators of cow discomfort and poor welfare. The objective of this study was to determine the associations between the onset of illness resulting from experimentally induced clinical mastitis and measures of lying behavior. Clinical mastitis was induced in 21 lactating dairy cows (parity=2.0±1.0, range=1 to 4; days in milk=61±18) by intramammary infusion of 25 or 100 µg of Escherichia coli lipopolysaccharide (LPS) into 1 uninfected mammary quarter. Lying behavior was monitored from 2 d before through 3 d after the LPS challenge by fitting each cow with a data logger. Calculated outcome measures were total lying time, lying time on the side of the intramammary infusion, number of lying bouts, and average lying bout duration. Cows spent less time lying down on the day of the challenge compared with the 2 d before (633.3 vs. 707.0 min/d; SE=29.6), particularly during the 4 to 7h following LPS infusion. However, no significant relationship was found between the mammary quarter challenged and cow preference for lying side throughout the episode of induced clinical mastitis. Given that lying is a high-priority behavior in dairy cows and that increased lying time is an adaptive sickness behavior to facilitate recovery, we infer that this reduction in lying time may present a concern for cows with clinical mastitis. Although additional studies with larger numbers of animals are needed, automated monitoring of lying behavior could be an important component of the on-farm early detection of health problems, such as mastitis, in the future.

Sickness behavior in dairy cows during Escherichia coli mastitis.

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.