Mastitis incidence and milk quality in organic dairy farms which use suckling systems in calf rearing

In order to identify important factors influencing animal health and general disease resistance, detailed qualitative and quantitative farm data were collected from 99 organic dairy farms in the Netherlands. Mastitis incidence and milk quality were focal points of the data collection. In this paper the results of a group of farms which rear dairy calves in suckling systems (n=11) are presented. It was found that compared to other farms in the study (n=88), suckling systems in calf rearing had no clear adverse effects on mastitis incidence and milk quality. In 2006 average clinical mastitis incidence on suckling farms was 14%, on other farms 20%. The percentage of cows with a somatic cell count less than 250,000 at drying-off was lower (60 vs. 66%) at suckling farms. Also immediately after calving the percentage of cows with a somatic cell count less than 250,000 was lower (65 vs. 75%) on suckling farms. Between other farms and suckling farms, but also within suckling farms, distinctively different attitudes to disease management prevailed. Most suckling farms recently introduced suckling systems in calf rearing. Only 1 or 2 generations of suckled heifers had been introduced into the herds up to now. In order to judge whether suckling systems have a potential to improve udder health in future dairy herds, evaluation should be carried out again once suckled heifers constitute the majority of the herd.