title: Comparison of ketosis, clinical mastitis, somatic cell count, and reproductive performance between free stall and tie stall barns in Norwegian dairy herds with automatic feeding.
abstract: Differences in ketosis and clinical mastitis rates, mean somatic cell counts (SCC) and reproductive performance scores (fertility status index = FS-index) between herds housed in free stall (n = 533) and tie stall (n = 59) barns were measured in relation to management and environmental factors in a retrospective cohort study of Norwegian dairy farms with automatic grain feeding systems. Herds with tie stalls were found to have a higher clinical mastitis rate, (61.6 cases per 100 cow-years versus 46.4 cases per 100 cow-years (p < 0.01)); a significantly higher proportion of herds with ketosis, (relative risk = 1.59, (p < 0.01)); and a lower mean fertility status index, (67.3 versus 82.8 (p < 0.01)). No significant difference in mean SCC was found between the 2 groups of dairies (p = 0.32). Large herds had higher Loge geometric mean SCC than small herds (p < 0.01) and herds with high SCC had lower milk production than herds with low SCC (p < 0.01). Herds that scored "very good" on cow cleanliness had significantly lower adjusted mean SCC than herds with scores of "average" or "good" (p < 0.05). Herds in barns with a concrete floor had an adjusted mean number of cases of clinical mastitis of 51.4 per 100 cow-years, 14 per cent higher than herds in barns with rubber mats, litter bed or wood (45.2 cases per 100 cow-years) (p < 0.05). Herds with high milk production level had higher FS-index than herds with low milk production (p < 0.01). Lower disease rates and the higher fertility status measured in the present study favor free stall herds over tie stall herds.
authors.affiliation: Department of Medicine and Epidemiology, University of California, Davis, USA. jpvalde@online.no
authors.forename: J P
authors.initials: JP
authors.lastname: Valde
authors.forename: D W
authors.initials: DW
authors.lastname: Hird
authors.forename: M C
authors.initials: MC
authors.lastname: Thurmond
authors.forename: O
authors.initials: O
authors.lastname: Osterås
mesh_terms: D000822:Animal Husbandry / Q000592:standards*; D000818:Animals; D002417:Cattle; D002452:Cell Count / Q000662:veterinary; D015331:Cohort Studies; D015986:Confounding Factors, Epidemiologic; D003612:Dairying / Q000295:instrumentation / Q000379:methods*; D004435:Eating / Q000502:physiology*; D005260:Female; D015994:Incidence; D007662:Ketosis / Q000453:epidemiology / Q000503:physiopathology / Q000662:veterinary*; D016014:Linear Models; D008414:Mastitis, Bovine / Q000453:epidemiology* / Q000473:pathology / Q000503:physiopathology; D008892:Milk / Q000166:cytology* / Q000378:metabolism; D008954:Models, Biological; D009664:Norway / Q000453:epidemiology; D012098:Reproduction / Q000502:physiology*; D012189:Retrospective Studies; D011795:Surveys and Questionnaires