The evaluation of body condition assesses the fat cover on a cow according to a five-point scale. The BCS indicates the cow’s stored energy reserves, which change depending on the stage of lactation and quality of nutrition. Good health, milk production and reproductive fitness depend on a good BCS. Cows which have been dried off at a BCS of 3,5 to 4 and calve at the same score should not lose more than 1 point in the first 60 days in milk.
Those calving with a low BCS use up their energy reserves, delaying conception and affecting milk production. BCS at calving influences the loss of condition between calving and mating and is positively associated with conception to first service after calving. It is best to calve a cow in good condition with adequate reserves. For about the first 60 days of lactation, she is in a negative energy balance because of the demands made for peak milk production.
On the other side of the chart, overcondition at calving may cause dystocia, retained placenta, milk fever, ketosis and other metabolic problems. The drop in condition from calving to the lowest BCS should not be more than 1 to 1,5 points.
Malcolm Stewart-Burger founded the Society of Master Dairymen and designed the Maxi Milk System. He is currently a part-time consultant to Nutex Feeds and De Heus. Contact Malcolm at [email protected]. Please state ‘Milking for profit’ in the subject line of your email.