Clinical findings in post partum dairy cows

The clinical findings in 183 post partum periods of dairy cows from an experimental herd are reported. Sixty-nine, 30, 46, and 38 post partum periods of the Swedish Red and White Breed, the Swedish Friesian Breed, crosses between these two breeds, and the Swedish Jersey Breed, respectively, were followed by clinical examination at 10-day intervals until first service. Heat detection was done three times daily and plasma progesterone assay at 10-day intervals. The highest occurrence of big follicles (12-15 mm) was between 21-30 days, coinciding with the time of first ovulation. Fifty percent of the cows had the 1st, 2nd and 3rd ovulation at 17, 36 and 56 days post partum, respectively, and the first, second and third ovulations came at 21.2, 39.1 and 58.3 days on average, with significant differences between parities and breeds. The first two oestrous cycles lasted 17.5 +/- 5.6 and 20.8 +/- 2.1 days without differences due to parity and breeds. The data indicate a complete uterine involution between 41 and 50 days post partum.