Temporal patterns of lost milk-production following clinical mastitis in a large Michigan Holstein herd

Cows with three hundred and sixteen cases of clinical mastitis were sampled by microbiologic culture during a 6-mo period on a 1700-cow Michigan Holstein dairy farm. Daily milk weights were obtained on all cows before clinical onset and for 60 d after onset. Predicted postmastitis production, projected on the basis of premastitis production and the lactation curves of contemporary nonmastitic herdmates, was compared with actual daily milk production during the 60 d following clinical onset. Cows experiencing clinical mastitis produced approximately 341 kg less salable milk during the 60 d after clinical onset compared with projected production. This milk loss included both decreased production and milk withheld from market following antibiotic treatment. Pluriparous cows lost 2.06 times as much milk as first lactation cows, and cows with mastitis occurring before 150 d in lactation lost 1.40 times as much milk when compared with other cows. Cows with mastitis occurring in the winter showed a milk loss 1.37 times greater than cows with mastitis in summer. The identity of the mastitis agent isolated from the clinical case was not strongly associated with the drop in milk production in the 60 d following clinical onset.PT: J; CR: 1987, LABORATORY FIELD HDB 1990, STATISTICAL ANAL SYS BARLETT PC, 1990, J DAIRY SCI, V73, P2794 BLOSSER TH, 1979, J DAIRY SCI, V62, P119 BUNCH KJ, 1984, LIVEST PROD SCI, V11, P91 DOHOO IR, 1984, PREV VET MED, V2, P671 DOHOO IR, 1984, PREV VET MED, V2, P755 ERB HN, 1985, J DAIRY SCI, V68, P3337 FELL LR, 1964, DAIRY SCI ABSTR, V26, P551 FETROW J, 1987, COMP FOOD ANIMAL, V9, F103 JAZEN JJ, 1970, J DAIRY SCI, V53, P1151 KENNEDY BW, 1982, J DAIRY SCI, V65, P843 KIRK JH, 1988, AGRIPRACTICE, V9, P3 LUCEY S, 1984, ANIM PROD, V39, P165 LUPS P, 1966, DAIRY SCI ABSTR, V28, P1288 MARTINEZ J, 1984, THERIOGENOLOGY, V21, P569 ODONOVAN J, 1960, J DAIRY RES, V27, P115 RAUBERTAS RF, 1982, J DAIRY SCI, V65, P419 WIGGANS GR, 1980, USDA DHI LETT, V56, P1 WILTON JW, 1974, J DAIRY SCI, V55, P183; NR: 20; TC: 37; J9: J DAIRY SCI; PG: 12; GA: FP207Source type: Electronic(1