Browsing by Author "Finnholm, Jenny"

Subacute ruminal acidosis (SARA) and ketosis are metabolic diseases that occur in milking cows and affect milk production and feed efficiency. The aim of this thesis was to investigate how milk production and composition of diet and silage affected the occurrence of ruminal acidosis and ketosis in milking cows. Data was provided from six dairy farms with milking robots. From the farms, data was collected from milking test-day results, rumination and performance reports from robot. The farms took samples from silage regularly and feeding plans were updated continuously. Three farms with Gea and three farms with Lely milking robots participated in the study. Data from these farms were collected and sorted in separate Excel-files and analysed with logistic regression analysis to obtain the odds ratios for ruminal acidosis and ketosis and to compare the farms with each other. The odds ratio for ruminal acidosis increased with increasing milk production and concentrate allowance for both Lely- and Gea farms. When dietary and silage crude protein concentration increased the odds ratio for ruminal acidosis decreased in Gea farms but not in Lely farms. An increase in dietary concentrate proportion increased and increase of dietary fibre decreased the odds ratio for acidosis in both farm groups, while an increase of dietary starch and silage fibre increased the odds ratio only in Gea farms. The odds ratio for ketosis decreased when milk production increased in Lely farms. The odds ratio for ketosis increased in Gea farms but decreased in Lely farms when concentrate allowance increased. An increase of dietary starch decreased the odds ratio for Gea-farms but not for Lely-farms. The odds ratio for ketosis decreased for both groups when rumination time increased. There were differences in the odds ratio for ruminal acidosis and ketosis between the farm groups for milk production, rumination time and for various descriptive variables regarding the composition of feeding diet and silage. This suggests that in addition to production level and feeding composition there are other factors influencing the risk of ruminal acidosis and ketosis in farms.