Epidemiology of Mastitis in Pasture-Grazed Peripartum Dairy Heifers and Its Effects on Productivity

Abstract

An observational field study was conducted on 708 heifers in 30 spring-calving dairy herds in the Waikato region of New Zealand. The aim of the study was to describe patterns and effects of intramammary infection (IMI) and clinical mastitis (CM) in the peripartum period. Mammary secretion samples for bacteriological testing were taken from all quarters approximately 3 wk before the planned start of the calving period and within 5 d following calving, in addition to quarters diagnosed with CM within 14 d of calving. Precalving IMI was diagnosed in 18.5% of quarters, and of these, coagulase-negative staphylococci were the predominant isolate (13.5% of quarters). Streptococcus uberis prevalence increased 4-fold to 10.0% of quarters on the day of calving compared with the precalving period. Prevalence of all pathogens decreased rapidly following calving. Clinical mastitis cases were predominantly associated with Strep. uberis (64%). The daily hazard of diagnosis was higher in heifers than in cows (0.06 vs. 0.02/d on d 1 postcalving, respectively), but was not different by d 5 (0.005 vs. 0.002, respectively) of lactation. Intramammary infection with a major pathogen was associated with an increased risk of removal from the herd (15 vs. 10% for infected and noninfected heifers, respectively) and somatic cell count >200,000 cells/mL at subsequent herd tests (15 vs. 8%), but neither CM nor IMI were associated with reduced milk yield or milk solids production. Results suggest that bacterial species involved and the pattern of IMI prevalence in pasture-grazed peripartum heifers differ from those in other production systems. Further, mastitis control programs need to target major environmental pathogens causing precalving IMI, because new infections are likely before the onset of lactation, whereas existing detection and control measures are generally implemented after calving. Novel control programs that reduce new infections due to Strep. uberis immediately before calving are required to reduce the incidence of CM in pasture-grazed dairy heifers.

Effect of mastitis during the first lactation on production and reproduction performance of Holstein cows

“…The effects of mastitis on production yields are more severe when the mastitis developed in early lactation before the peak yield (Le Maréchal et al 2011). In contrast to our results, Compton et al (2007) did not find an association between the presence of clinical mastitis in the first 14 days of lactation and future milk production. It is possible that the pathogen causing the infection has an important impact on milk production and this may be responsible for the different results in the literature.…”

Melhoramento genético visando à resistência a mastite em bovinos leiteiros

“…As bactérias podem escapar dos mecanismos de defesa naturais por inoculação direta na cisterna do teto através de infusão intramamária, pela multiplicação de colônias de bactérias ao longo do canal (especialmente após a ordenha), ou por propulsão pela flutuação do vácuo no final do teto durante a ordenha (Compton et al, 2007). Uma vez passada a barreira física do canal, patógenos invasores são confrontados com o sistema imunológico.…”

Alternativas en el manejo de la mastitis en novillas

“…Los SCN son considerados como la principal causa de las IIM en novillas no servidas y en novillas preñadas, tanto en hatos en confinamiento (23, 37, 39) como en hatos en pastoreo continuo (45). Algunos de los SCN son parte de la flora normal de la piel de los bovinos e incluyen las especies Staphylococcus simulans, Staphylococcus hyicus y Staphylococcus epidermis; otros se encuentran en el ambiente como las especies resistentes a la novobiocina.…”

“…En estudios epidemiológicos en diferentes lecherías usualmente se reportan pocos cuartos infectados con Gram negativos. Por ejemplo en hatos confinados Pankey et al (25) reportaron 2.2% de los cuartos con IIM y Compton et al (45) reportaron menos del 1 % de los cuartos en hatos en pastoreo. Las IIM causadas por este tipo de patógenos usualmente se observan desde 2 semanas antes del parto y no son perdurables (27).…”

“…Corynebacterium bovis es prevalente en condiciones medioambientales de humedad y calor (54) y su presencia en novillas preparto es muy baja tanto en hatos confinados (22,55) como en hatos en pastoreo (45). A. pyogenes se ha reportado afectando a las novillas desde dos semanas antes del parto (27), pero su prevalencia es baja tanto en hatos confinados como en pastoreo.…”