Dry period management and new high somatic cell count during the dry period in Dutch dairy herds under selective dry cow therapy

Abstract

The aim of this study was to describe the current management practices that could influence udder health during the dry period and to investigate the associations between management and new high SCC during the dry period. In 2008 the Netherlands started to improve transparency and decrease the use of antimicrobials in animal husbandry. Prevention of new high SCC during the dry period via antimicrobial dry cow treatment (DCT) was no longer allowed in animals with a low SCC before the dry period. An increase of new high SCC during the dry period was expected in dairy cows without antimicrobial protection, but was not observed. In 2018 an online questionnaire was conducted among 1,942 Dutch dairy farms using 12 different veterinary clinics. The questionnaire asked about the management of dry cows at the start of and during the dry period, and around calving, considerations in the use of DCT, and knowledge of the 2012 guidelines for selective DCT. A total of 690 farmers (36%) responded to the questionnaire. Data on new high SCC during the dry period, use of antimicrobials for intramammary DCT and mastitis treatment, herd size, and milking system were available from other sources. Descriptive statistics were used to evaluate the associations between the different variables. For analysis of new high SCC on herd level, explanatory variables were analyzed using a generalized linear mixed model. Respondents indicated that the most important management factor to reduce the risk of new high SCC was reduction of milk yield before dry-off. The variables associated with a lower proportion of new high SCC on herd level during the dry period were the use of dip or spray after drying off, a higher animal-defined daily dose of intramammary antimicrobials for DCT, the use of DCT in low-SCC cows based on SCC or mastitis history, correct knowledge of the guideline, and awareness of importance of low infection rate and good hygiene during dry-off. The variables associated with a higher proportion of new high SCC on herd level were dry cow housing other than cubicles and a higher animal-defined daily dose for intramammary antimicrobials for mastitis. This research clearly indicates that farmers can balance limited use of antimicrobials at dry-off with management measures to maintain good udder health during the dry period.

Antibiotic Use in Alpine Dairy Farms and Its Relation to Biosecurity and Animal Welfare

“…However, no correlation between AMU and SCC was found in the present study. A previous study demonstrated that it is possible to reduce antibiotics in dry-off without increasing somatic cells count (SCC) in the following lactation by implementing management measures to maintain good udder health [ 38 ]. For example, some risk factors for E. coli mastitis at the herd level include the bedding material and the design of cubicles [ 39 ].…”

Integrierte Tierärztliche Bestandsbetreuung und Selektives Trockenstellen in Deutschland

“…Die als kritisch gesehenen Punkte des ST, wie die Notwendig keit eines gewissenhaften Managements und entsprechender Hy giene auf einem Betrieb, haben einen wesentlichen Einfluss auf eine mögliche Antibiotikareduktion [38,39]. Der zusätzliche Arbeits aufwand durch die Anwendung der Auswahlkriterien für die Be handlung zum Trockenstellen, die Dokumentation, die Analyse von intramammären Infektionen (IMI) sowie des Antibiotikaeinsatzes und die Durchführung einer Erfolgskontrolle ermöglicht eine ob jektive Bewertung des Trockenstellmanagements.…”

Selective dry cow therapy effect on milk yield and somatic cell count: A retrospective cohort study

“…In addition to the Nordic countries, selective DCT has recently become a national approach in the Netherlands, guided by Dutch national legislation. The reported SCC thresholds of the Dutch guidelines on the use of aDCT are slightly lower than the current Finnish recommendations, and the proportions of treated cows appear to be higher (Scherpenzeel et al, 2016;Vanhoudt et al, 2018;Krattley-Roodenburg et al, 2021). The results of a recent experimental field trial showed that when cow selection was based on microbiological culture, the proportion of selectively aDCT-treated quarters ranged in herds from 32% to 62%, and when selection was based on SCC and mastitis history, the proportion ranged from 19% to 68% (Rowe et al, 2020a).…”

“…The selective treatment practice later expanded outside the Nordic countries. In 2012, the Netherlands banned prophylactic use of antibiotics in livestock, and, as a result, Dutch dairy farmers switched to the selective DCT approach ( Vanhoudt et al, 2018;Krattley-Roodenburg et al, 2021).…”

“…According to the Vilar et al (2018) survey, 35% of Finnish herds were using ITS at dry-off in 2017, and this use was more common on larger farms with a parlor or AMS milking system. Practically all Finnish farms use a gradual milk cessation method, and the daily milk yield at dry-off is typically less than 15 kg (Vilar et al, 2018), which also seems to be the management practice in Dutch farms with a selective DCT approach (Krattley-Roodenburg et al, 2021). Gradual milk cessation accelerates the involution process and improves immunological defenses in the udder (Bushe and Oliver, 1987;Vilar and Rajala-Schultz, 2020), and may thus be a practice that positively supports the selective DCT approach.…”