Patterns of clinical mastitis manifestations in Danish organic dairy herds

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.

Monitoring udder health and milk quality using somatic cell counts

“…It also includes low incidence of clinical mastitis, minimize potential hazards for human health such as prevention of residues in milk, potential transfer of antibiotic resistance to human pathogens, and transfer of pathogens through dairy products. Addressing consumer demands with regard to product safety, transmission of infectious diseases, welfare and eco-system health [56] becomes a constraint on the dairy production systems. It is therefore inevitable that more complete udder health programs and monitoring systems have been developed and implemented.…”

Effect of mastitis and related-germ on milk yield and composition during naturally-occurring udder infections in dairy cows

“…Nevertheless, the response time to infection may vary according to the pathogenic variability of the strains and their resistance to antibiotics, as well as to the animals' own resistance. That variability was especially revealed with Streptococcus uberis [22,26,37].…”

Dynamics of mammary infections in organic dairy farms in Northern Spain

“…The difference between considering one (23.2%) or two controls (21.2%) is small and would include both incorrectly diagnosed udder quarters and short duration mastitis. In spite of the difficulties to compare data, particularly for gram-negative microorganisms, most studies, both in conventional and organic farms, have shown lower mastitis rates than in our organic farms (Hovi & Roderick, 1998;Vaarst, 2001;Lopez-Villalobos et al, 2003;Sato et al, 2005;Piepers et al, 2007;Ruegg, 2009).…”