The prevalence of mastitis in primiparous heifers in eleven Waikato dairy herds

Abstract

The objective of the study was to determine the prevalence of mastitis among primiparous heifers at calving and at drying off in 11 Waikato dairy herds during the 1993-94 dairy production season. Duplicate quarter milk samples were collected aseptically from 458 heifers within 5 days after calving for bacteriological analysis. Mastitis was diagnosed in at least one quarter in 35.6% of these heifers. Coagulase-negative staphylococci were isolated from 21.8% of the heifers. The prevalence of coagulase-negative staphylococci varied between herds from 4.3% to 44.8%. Environmental streptococci caused mastitis in 12.2% of heifers, ranging from 5.6% to 24.1% between herds. Streptococcus uberus was the pathogen identified most frequently at calving and accounted for more than 90% of the streptococcal isolates. Staphylococcus aureus and coliforms were isolated from less than 1% of samples. Clinical mastitis was observed in 8.1% of heifers at calving; environmental streptococci were isolated from 67.6% of these clinical clinical cases. Only 2.8% of heifers developed clinical mastitis during lactation and environmental streptococci were isolated from 38.5% of these cases. The prevalence of mastitis among 428 of the heifers at drying off was 64.7%; a 1.8 fold increase during lactation. Corynebactetium bovis was isolated from 43% of heifers at drying off even though it was not isolated from any heifers at calving. During the season, the prevalence of Staphylococcus aureus mastitis increased to 2.8% while mastitis caused by environmental streptococci declined to 2.8%. The prevalence of environmental mastitis pathogens decreased during lactation while contagious pathogens increased in each of the 11 herds. Ineffective post-milking teat sanitation probably contributed to the increase in mastitis caused by contagious pathogens. Specific factors were not determined that affected the variation in prevalence between herds.

Application of Streptococcus uberis Multilocus Sequence Typing: Analysis of the Population Structure Detected among Environmental and Bovine Isolates from New Zealand and the United Kingdom

“…An increasing prevalence of S. uberis mastitis has been reported, with approximately 14 to 26% of clinical cases in Canada, the United States, The Netherlands, and the United Kingdom being due to this pathogen (3,9). S. uberis is also highly prevalent in Australia and New Zealand, where the dairy industry is mainly pasture based (13,14). A recent report from New Zealand indicated that over 30% of all clinical mastitis was due to this organism (5).…”

Multiplex-PCR to detect pathogens and analysis of relation of age and stage of lactation of cows to sub-clinical mastitis

“…With respect to the prevalence of environmental streptococcal mastitis, a large proportion of variability in its incidence and, both between geographical locations and within a single herd, can be ascribed to a number of independent variables such as season of the year, stage of lactation, parity, and various management practices (Hogan et al, 1989;Pankey et al, 1996;Hogan & Smith, 2003). Streptococcus agalactiae is one of the obligate pathogen of mammary gland in case of bovines, colonizing the teat canal (Dodd, 1983).…”

Environmental Streptococcal Mastitis: Facts, Fables, and Fallacies

“…Areas under shade trees can produce conditions of high exposure and pastures that are over grazed or grazed during periods of heavy rain may also lead to conditions of exposure similar to housed cattle. The environmental streptococci are the most significant environmental pathogen in New Zealand dairy herds where cows spend virtually 100% of there time on pasture (38,54). Additional research on the association between pasture conditions and teat contamination with environmental pathogens would be beneficial.…”

“…The prevalence of intramammary infections (IMI) and incidence of clinical mastitis have been measured in a host of surveys during the last 25 years. Environmental streptococci have consistently been reported as a leading cause of both subclinical and clinical mastitis throughout the world (11,24,38,51,55). A large proportion of variability in incidence and prevalence of environmental streptococcal mastitis, both between geographical locations and within a single herd, can be ascribed to a number of independent variables identified in these surveys.…”

“…A large proportion of variability in incidence and prevalence of environmental streptococcal mastitis, both between geographical locations and within a single herd, can be ascribed to a number of independent variables identified in these surveys. Among these factors were season of the year, stage of lactation, parity, and various management practices (11,24,38,51).…”