The transition period of the dairy cow
The transition period is considered critical for the dairy cow and refers to the 3 weeks before calving and 3 weeks after calving. During this period the cow becomes vulnerable as physiological, metabolic and nutritional changes occur. This period can negatively influence the subsequent lactation of the cow, with implications on production and reproduction performance and implicitly on profitability. The manner in which this period is maintained are reflected in the frequency of postpartum disorders (milk fever, abomasum displacement, placental retention).
During the last three weeks of gestation, the cow’s body is under pressure from the rapid growth of the foetus, and from the synthesis of milk components for the subsequent lactation. Plasma insulin concentration decreases during the transition to the foetus and somatotropin increases rapidly between the end of pregnancy and the beginning of lactation.
At the beginning of lactation, the cows mobilize the body reserves (5-8% of the calving weight), the appetite is low and capricious (the ingesta is lower by 45%), the nutritional balance, especially the energy balance, is negative, the lactation curve is in ascension.
The main measures to support the transition period: grouping of cows (ante partum and post partum) in special areas (maternity); feeding balanced diet in terms of ionic (DCAD); maintaining good hygiene of the rest bed; ensuring optimal levels of carbohydrates, which stimulate propionate production; urinary pH monitoring (pH less than 5.8 leads to decreased feed intake and immune imbalances, pH over 7.2 leads to postpartum paraplegia and placenta retention).