The prophylactic effect of a dry-cow antibiotic againstStreptococcus uberis

Williamson, J.; Woolford, M. W.; Day, A.M.

doi:10.1080/00480169.1995.35898

Cited by 102 publications

(104 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In a meta-analysis of 5 studies, blanket DCT was compared with selective DCT and showed no significant difference in protection against new IMI in 3 studies when cow-level selection was practiced for drying off with antibiotics. This indicates no preventive effect of DCT in this approach (Rindsig et al, 1978;Browning et al, 1994;Williamson et al, 1995). However, these studies are hard to compare with our study because they were carried out over 20 yr ago in herds with different housing systems and with different production levels.…”

Section: Discussionmentioning

confidence: 42%

Evaluation of the use of dry cow antibiotics in low somatic cell count cows

Scherpenzeel

Uijl

Schaik

et al. 2014

Journal of Dairy Science

104

125

View full text Add to dashboard Cite

The goal of dry cow therapy (DCT) is to reduce the prevalence of intramammary infections (IMI) by eliminating existing IMI at drying off and preventing new IMI from occurring during the dry period. Due to public health concerns, however, preventive use of antibiotics has become questionable. This study evaluated selective DCT in 1,657 cows with low somatic cell count (SCC) at the last milk recording before drying off in 97 Dutch dairy herds. Low SCC was defined as <150,000 cells/mL for primiparous and <250,000 cells/ mL for multiparous cows. A split-udder design was used in which 2 quarters of each cow were treated with dry cow antibiotics and the other 2 quarters remained as untreated controls. The effect of DCT on clinical mastitis (CM), bacteriological status, SCC, and antibiotic use were determined at the quarter level using logistic regression and chi-squared tests. The incidence rate of CM was found to be 1.7 times (95% confidence interval = 1.4-2.1) higher in quarters dried off without antibiotics as compared with quarters dried off with antibiotics. Streptococcus uberis was the predominant organism causing CM in both groups. Somatic cell count at calving and 14 d in milk was significantly higher in quarters dried off without antibiotics (772,000 and 46,000 cells/mL, respectively) as compared with the quarters dried off with antibiotics (578,000 and 30,000 cells/mL, respectively). Quarters with an elevated SCC at drying off and quarters with a positive culture for major pathogens at drying off had a higher risk for an SCC above 200,000 cells/mL at 14 d in milk as compared with quarters with a low SCC at drying off and quarters with a negative culture for major pathogens at drying off. For quarters that were culture-positive for major pathogens at drying off, a trend for a higher risk on CM was also found. Selective DCT, not using DCT in cows that had a low SCC at the last milk recording before drying off, significantly increased the incidence rate of CM and SCC. The decrease in antibiotic use by drying off quarters without DCT was not compensated by an increase in antibiotic use for treating CM. Total antibiotic use related to mastitis was reduced by 85% in these quarters.

show abstract

Section: Discussionmentioning

confidence: 42%

Evaluation of the use of dry cow antibiotics in low somatic cell count cows

Scherpenzeel

Uijl

Schaik

et al. 2014

Journal of Dairy Science

104

125

View full text Add to dashboard Cite

show abstract

“…However, most other studies described lower rates of between 4 % and 14 % 4,30,36,47,52,58 . The expected rate of new IMIs during the dry period in bacteria-negative quarters that were untreated was reported by Eberhart 14 to vary between 8 % and 12 % while Berry 4 reported new infection rates of 34.4 % in untreated cows compared with 10.3 % in treated cows.…”

Section: New Imismentioning

confidence: 89%

“…A large variation in intramammary overall cure rate was reported by various authors 17,20,35,42,46,52,54,58 of between 21.2 % and 80 %. Rainard 43 estimated that between 70 % and 90 % of infections present at drying off can be eliminated with dry cow therapy and the cure rate of IMI during the dry period was found to vary significantly between major and minor pathogens 14,46 .…”

Section: Cure Ratementioning

confidence: 99%

“…It is well known that the beginning and end of the dry period are the highest risk periods for new IMIs 7,8,19,41,42 . A 2nd period of increased susceptibility occurs prior to parturition during the period of colostrogenesis and lactogenesis, while the fully involuted udder is quite resistant to coliform infections, but susceptible to SUB and SAG 15,50,58 . Although the infected mammary gland of the lactating cow is the main source and reservoir of STA, it may also be present on the teat skin and external orifices and lesions of cows, bedding, insects and the water supply 42 .…”

Section: New Imismentioning

confidence: 99%

See 1 more Smart Citation

Intramammary infection rate during the dry period in cows that received blanket dry cow therapy : efficacy of 6 different dry-cow intra-mammary antimicrobial products

Petzer¹,

Lourens²,

Schans³

et al. 2009

J. S. Afr. Vet. Assoc.

View full text Add to dashboard Cite

The objectives of this study were to compare the efficacy of 6 different dry-cow intramammary antimicrobial products for the treatment and prevention of mastitis during the dry period in a well-managed high producing Friesland dairy herd, and the influence of treatment on the somatic cell count (SCC) of cows during early lactation. One of 6 dry-cow intramammary antimicrobial products was randomly allocated to 162 cows due for drying off over a period of 14 months. All cows were sampled twice prior to drying off, and twice after calving for the determination of SCC and presence of microorganisms. The quarter prevalence of pathogens at drying off and post-calving, the overall quarter cure rate and the rate of new intramammary infections occurring during the dry period were determined. The overall quarter prevalence of intramammary infections (IMIs) at drying off was 29.78 % and after calving 22.22 %.There was a statistically significant difference (P < 0.05) between the prevalence of major and minor pathogens at drying off (7.87 % and 21.91 %) and at calving (4.47 % and 17.75 %). The most prevalent pathogens isolated at drying off (21.14 %) and at calving (16.98 %) were coagulase-negative staphylococci (CNS). The quarter cure rate during the dry period was 83.94 %. The cure rate for the major pathogens (98%) was significantly better (P < 0.05) than that for minor pathogens (78.9 %).The overall quarter cure rate varied from 72.3 % to 93.9 % for the various products. The rate of new quarter infections during the dry period was 17.44 % with a significant difference (P<0.05), between the prevalence of new quarter infections with major (4.32 %) and minor pathogens (13.12 %). CNS was the most prevalent pathogen causing new quarter infections (12.34 %) and the rate o f new quarter infections varied from 13.4 % to 24.1 % for the various products.It is concluded that there is a difference in efficacy between antimicrobial intramammary dry-cow products in their ability to cure and prevent new IMIs during the dry period. Dry-cow products are mainly formulated for efficacy against Gram-positive cocci, while providing no or little protection against Gram-negative bacteria. Therapeutic levels may persist for only 14 to 28 days into the dry period and fail to protect the udder during the last trimester. Dry-cow therapy should, however, always form part of a holistic approach to the dry period which also considers cow factors, dry-cow management, microorganisms and the environment of the dry cow.

show abstract

“…Several authors have suggested that minor pathogens break down teat defenses or interfere with the keratin plug, allowing major pathogens to penetrate and initiate infection (Hogan et al, 1988;Williamson et al, 1995;Zadoks et al, 2001b;Berry and Hillerton, 2002a,b). It has also been shown that the presence of subclinical mastitis aids in the growth of major pathogens in the udder by the release of nutrients necessary for their survival (Mattila et al, 1984;Mattila and Sandholm, 1986;Kitt and Leigh, 1997).…”

Section: Meta-regressionsmentioning

confidence: 99%

Examining the effect of intramammary infections with minor mastitis pathogens on the acquisition of new intramammary infections with major mastitis pathogens—A systematic review and meta-analysis

Reyher

Haine

Dohoo

et al. 2012

Journal of Dairy Science

View full text Add to dashboard Cite

Major mastitis pathogens such as Staphylococcus aureus, Streptococcus agalactiae, Streptococcus uberis, Streptococcus dysgalactiae, and the coliforms are usually considered more virulent and damaging to the udder than minor mastitis pathogens such as Corynebacterium bovis and coagulase-negative staphylococci (CNS). The current literature contains several studies detailing analyses with conflicting results as to whether intramammary infection (IMI) with the minor pathogens decreases, increases, or has no effect on the risk of a quarter acquiring a new intramammary infection (NIMI) with a major pathogen. To investigate the available scientific evidence regarding the effect of IMI with minor pathogens on the acquisition of NIMI with major pathogens, a systematic review and meta-analysis were conducted. The total extant English-and Frenchlanguage literature in electronic databases was searched and all publications cited by relevant papers were investigated. Results from 68 studies were extracted from 38 relevant papers. Random-effects models were used to investigate the effects of CNS and C. bovis on acquisition of new IMI with any of the major pathogens, as well as individually for the minor pathogens and Staph. aureus. Significant heterogeneity among studies exists, some of which could be accounted for by using meta-regression. Overall, observational studies showed no effect, whereas challenge studies showed strong and significant protective effects, specifically when major pathogens were introduced into the mammary gland via methods bypassing the teat end. Underlying risk can account for several unmeasured factors, and studies with higher underlying risk found more protective effects of minor pathogens. Larger doses of challenge organisms reduced the protective effect of minor pathogens, and studies with more stringent diagnostic criteria for pathogen IMI identified less protection. Smaller studies (those utilizing fewer than 40 cows) also showed a greater protective effect than larger studies.

show abstract

The prophylactic effect of a dry-cow antibiotic againstStreptococcus uberis

Cited by 102 publications

References 6 publications

Evaluation of the use of dry cow antibiotics in low somatic cell count cows

Evaluation of the use of dry cow antibiotics in low somatic cell count cows

Intramammary infection rate during the dry period in cows that received blanket dry cow therapy : efficacy of 6 different dry-cow intra-mammary antimicrobial products

Examining the effect of intramammary infections with minor mastitis pathogens on the acquisition of new intramammary infections with major mastitis pathogens—A systematic review and meta-analysis

Contact Info

Product

Resources

About