Influence of Dry Period Bacterial Intramammary Infection on Clinical Mastitis in Dairy Cows

Abstract

Milk samples were taken from 1920 quarters (480 cows, six herds) on four occasions to examine the relationship between quarter level intramammary infection (IMI) during the dry period and clinical mastitis in the next lactation. All quarters were sampled at drying off and within 1 wk of calving, and two quarters from each cow were sampled both 0 to 7 and 8 to 14 d before calving. Milk samples were collected from all cases of clinical mastitis during the following lactation. Logistic regression models were developed to investigate the associations between IMI present during the sampling period and clinical mastitis. The probability of a quarter succumbing to clinical mastitis increased when Streptococcus dysgalactiae, Streptococcus faecalis, Escherichia coli, or Enterobacter spp. were cultured at drying off and when Escherichia coli, coagulase-positive staphylococcus, Serratia spp., or Streptococcus faecalis were cultured in two out of three late dry and post-calving samples. Quarters from which Corynebacterium spp. were isolated at drying off were at an increased risk of clinical mastitis, whereas the presence of Corynebacterium spp. in the late dry and post-calving samples was associated with a reduction in the risk of clinical mastitis. The risk of mastitis for specific pathogens increased if the same species of bacteria that had caused mastitis was isolated at least twice in the late dry and post-calving samples. Kaplan-Meier survival plots indicated that clinical mastitis associated with dry period infections was more likely to occur earlier in lactation than clinical mastitis not associated with dry period infections. There was evidence of quarter susceptibility to IMI or the possibility that infection with one organism led to clinical mastitis with another.

Incidence of intramammary infections during the dry period without or with antibiotic treatment in dairy cows – a quantitative analysis of published data

“…Indeed, reportedly, 50% of the IMI occurring during the dry period persist until the following lactation, and, among these persisting IMI, 50% become clinical during the following lactation [50]. Furthermore, bacteria present during the dry period could have a deleterious effect on the subsequent lactation [28,54]. Thus, the number of clinical cases in early lactation due to new IMI occurring during the dry period could be slightly different between selective DCT and blanket DCT [11].…”

Evaluation of minor pathogen intramammary infection, susceptibility parameters, and somatic cell counts on the development of new intramammary infections with major mastitis pathogens

“…IMI with an increased risk of major pathogen NIMI (7 significantly), and 2 found no effect. Green et al (2002) found the timing of Corynebacterium spp. infection to be relevant-quarters infected at dry-off showed a trend for increased occurrence of clinical mastitis, whereas quarters infected 1 wk precalving or postcalving had decreased likelihood of clinical mastitis occurrence.…”

“…It may be that the effect of Corynebacterium spp. on NIMI is complicated and depends on several factors (Green et al, 2002).…”

“…Few of these accounted for within-herd, within-cow, or within-quarter factors, which undoubtedly play a role in the response to mastitis pathogens. Green et al (2002) identified several issues relating to quarter susceptibility: anatomical features, immunological characteristics, previous infections, and other alterations in the environment. All of these factors may affect the defense of a quarter, and even of a cow, to pathogen challenge.…”

Phenotypic and functional analysis of bovine peripheral blood dendritic cells before parturition by a novel purification method

“…However, the function for maintaining the tolerance during the pregnancy has not been clearly described in DCs in bovine blood. Previous works showed that in late gestation, the cows had a heightened susceptibility to persistent infections caused by mastitis and abortion‐causing pathogens (Green, Green, Medley, Schukken, & Bradley, 2002; Williams et al., 2000). Therefore, we studied cattle which were 1 month before parturition.…”