Relationship between feeding strategy, lying behavior patterns, and incidence of intramammary infection in dairy cows

The objectives of this study were to investigate whether feeding strategy influences post-milking standing time in dairy cows and to determine whether this time relates to incidence of intramammary infection (IMI). Fifteen lactating dairy cows (5 most recently fresh, 10 randomly chosen) from each of 6 tie stall dairy farms were enrolled for a total of 90 cows. Quarter samples of milk were taken from each cow once every 3 wk for a total of 3 samplings, and routine bacteriological culture and identification procedures were conducted. National Mastitis Council guidelines were used to define IMI, and occurrence of a new IMI was defined as a positive culture sample following a negative culture sample. Data on lying behavior patterns were collected using data loggers for every cow for 7 d before each milk sampling. For these 7 d, individual milking and feeding times of the cows were also recorded. Our results demonstrated that the provision of feed around milking time (between 30 min before and 60 min after) resulted in the longest post-milking standing times. The shortest post-milking standing times were seen in those cows that were fed >30 min before milking. Feeding cows >60 min after milking resulted in only slightly shorter post-milking standing times than those fed between 30 min before and 60 min after milking. Cows lying down for the first time 40 to 60 min after milking had 1.4 times lower odds of acquiring a new environmental IMI than cows lying down within 40 min after milking. As post-milking standing time increased past 60 min, the odds of acquiring a new environmental IMI increased as well. The cows lying down for the first time 60 to 90, 90 to 120, and >120 min after milking showed 3.2, 5.8, and 7.4 times higher odds, respectively, of acquiring a new environmental IMI compared with cows lying down for the first time within 40 min of milking. Our results suggest that despite being able to manage post-milking standing times by providing fresh feed at different times around milking, the use of such a feeding strategy in tie stall systems is an unrealistic IMI prevention strategy.