Meta-analysis of dry cow management for dairy cattle. Part 1. Protection against new intramammary infections

Abstract

The objective of this study was to estimate the preventive effect of various dry cow management measures against quarter new intramammary infections (IMI) during the dry period up to 21 d postcalving. Moreover, the potential publication bias was assessed in the studies selected for this analysis. The intervention measures were blanket dry cow therapy (BDCT), selective dry cow therapy (SDCT), cloxacillin compared with other dry cow therapy products, and teat sealant. A meta-analysis relative risk (RR) was calculated per intervention and pathogen group when enough studies were available from the 33 selected studies. Results of the meta-analyses were examined using publication bias tests. Blanket dry cow therapy showed significant protection against new IMI caused by Streptococcus spp. [the pooled RR was 0.39 (0.30 to 0.51)] but no protection was observed against coliform new IMI [the pooled RR was 0.95 (0.81 to 1.10)]. After correction for publication bias, it became doubtful whether DCT is protective against new Staphylococcus spp. IMI. Cloxacillin showed similar protection against new quarter IMI compared with other DCT products [the pooled RR was 1.09 (0.94 to 1.25)]. Selective dry cow therapy showed higher protection against new IMI compared with no DCT [the pooled RR was 0.51 (0.30 to 0.86)]. However, BDCT showed more protection when compared with SDCT [the pooled RR was 0.55 (0.37 to 0.80)], but the inference about whether BDCT is superior to SDCT was dependent on whether the selection criteria for SDCT was at the cow or quarter level. Internal teat sealants showed significant protection against new IMI during the dry period [the pooled RR was 0.39 (0.18 to 0.82)]. Publication bias should be taken into account when attempts are made to review literature in a meta-analysis.

Treatment of Mastitis in Cattle

“…One meta-analysis of 22 studies published before 2003 on the effectiveness of ADCT estimated the cure risk for treated quarters was 78%, compared with a spontaneous cure risk of only 46%. 41 Evidence-based decision making should be applied when selecting an appropriate ADCT formulation. As with products for lactating cows, most IMM ADCT products were introduced when contagious mastitis caused by S aureus and S agalactiae was a major concern for the dairy industry.…”

Behavior and welfare of dairy cows submitted to drying: Review

“…Nessa época as vacas estão mais susceptíveis a infecções na glândula mamária, embora possa ocorrer em qualquer outro período da lactação. Vários estudos têm sido desenvolvidos para prevenção e tratamento dessas infecções, causadas por uma variedade de patógenos contagiosos e ambientais (Halasa et al, 2009).…”

Escherichia coli J5: imunização de fêmeas bovinas leiteiras contra mastites causadas por Escherichia coli

“…Assume-se que essa terapia não apresenta alta efi cácia contra coliformes, uma vez que a maioria dos antibióticos disponíveis não tem ação contra bactérias gram-negativas e, portanto, não possuem grande efi cácia contra novas IIM que se iniciam no período pré-parto (HALASA et al, 2009).…”