In:
Journal of Dairy Research, Cambridge University Press (CUP), Vol. 64, No. 1 ( 1997-02), p. 23-37
Abstract:
Danish organic dairy production is characterized by a low input
of antibiotics for udder treatment and a high input of other mastitis control
procedures. A study was conducted in 14 organic dairy herds with the objectives of
obtaining a comprehensive description of clinical mastitis cases and identifying characteristic patterns in these results. Clinical signs, inflammatory reactions and microbiological identifications were obtained from 367 cases of clinical mastitis occurring
over 18 months. Cow characteristics and preincident values such as milk yield and
somatic cell count were obtained for each cow. Signs of previous udder inflammation
were present in two-thirds of the clinical mastitis cases. Severe local inflammatory reactions were found in 21% of the cases and some indication of generalized
signs such as fever and reduced appetite were found in 35% of the cases. Logistic regression analyses were performed based on the results of an initial (exploratory) multiple correspondence analysis. Coliform mastitis (6% of the cases) was
rarely preceded by pathogen isolation or inflammatory reactions in the same quarter. Coliform mastitis cases usually occurred in one quarter only. Escherichia coli infections were typically (truly) acute cases. Bacteriologically negative
mastitis (20% of the cases) showed strong similarities with clinical coliform mastitis. Staphylococcus aureus cases (18% of the cases) occurred
most frequently in late lactation or around drying-off. Prior isolation of Staph. aureus and slight decreases in milk yield were two factors that interacted but both were strongly and positively
related to clinical Staph. aureus . Staph. aureus mastitis typically had a subclinical
debut, and increasing degrees and duration of inflammation decreased shedding of
this pathogen. Streptococcus dysgalactiae (9% of the cases)
mastitis was typically persistent, virulent and manifest in periods of lower cow resistance.
More patterns of subclinical and clinical Str. uberis mastitis (23% of the
cases) seemed to be present.
Type of Medium:
Online Resource
ISSN:
0022-0299
,
1469-7629
DOI:
10.1017/S002202999600194X
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
1997
detail.hit.zdb_id:
2000010-8
SSG:
22
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