14 Dairy cow – ketosis Daily milk yield: The cow is dried off 6–8 weeks before the expected calving date. She is no longer milked and does not produce any milk during this period. After calving, lactation begins; milk yield rises rapidly and peaks around the 10th week of lactation. Energy requirements: The energy requirements depend heavily on the daily milk yield, as energy is needed for milk production. During the dry period, energy requirements are very low, as the cow only needs to meet the needs of her own body and that of the growing calf. As soon as lactation begins, the cow’s energy requirements rise sharply. The higher the milk production, the higher the energy requirements. Quantity of available energy: With calving and the onset of lactation, energy requirements rise sharply. The animals’ feed intake usually does not increase quickly enough, leading to an energy deficit that can persist until the 10th week of lactation. There can be many reasons for insufficient feed intake. Every high-yielding cow has an energy deficit; the decisive factor is the size of this deficit. The quicker the cow gets back into full production after calving – i.e. the smaller the dip outlined in red in the graph – the lower the risk of ketosis. 6–8 weeks before calving Calving Up to 10 weeks after calving Ketosis Development and causes Factors relevant to the development of ketosis include: • the 6–8 weeks prior to calving (dry period) • the 10 weeks following calving • milk yield • the energy requirement • the quantity of energy actually available. Background information Ketosis (acetonemia) is a disorder of carbohydrate metabolism. It usually occurs in the first few weeks after calving and is caused by an energy deficit. The high energy requirements resulting from the onset of lactation after calving cannot be met by the gradual increase in feed intake. As a result of this energy deficiency, the animals break down body fat and the level of ketone bodies in the blood rises characteristically. Preventive measures • Optimisation of dry cow feeding and management (no overcrowding, ample feeding space, etc.) • Optimisation of transit feeding and management (no overcrowding, ample feeding space, etc.) • Feeding or drenching with glucoplastic substances (e.g. propylene glycol, propionate, etc.) • Monitor hoof health (a prerequisite for high feed intake) Risk factors • Poor dry-off management • Inappropriate feed rations • High milk yield • Stress & illness (reduced feed intake) Daily milk intake Amount of energy required Amount of available energy Time
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