Abstract
Pregnant dairy cows were allowed to have complete feeds ad libitum. They were divided into two groups, A and B, on the basis of body weight before parturition. Changes in body weight, milk yield, and the lipid component of blood were compared between the two groups at given intervals after parturition.
Group A consisted of six obese cows, which weighed 858 kg on the average before parturition. Group B was composed of 15 non-obese cows, which weighed 728 kg on the average before parturition.
Body weight was measured and blood samples were collected once a week until 10 weeks after parturition. Body weight decreased remarkably in group A. Postpartum recovery was slower in this group than in group B. One week after parturition the glucose level was 45.8mg/dl on the average, showing a tendency to be low, and the level of nonesterified fatty acids (NEFA) tended to be high in group A. Of the keton bodies, β-hydroxybutyric acid presented a significantly high level in group A. Cholesterol and phospholipid showed a tendency to increase in both groups with the lapse of time beginnig with 2 weeks after parturition. The increase in them was slower in group A than in group B.
From the results obtained it was concluded that cows showing a tendency to be obese before parturition were apt to suffer from an insufficient ingestion of energy after parturition. Then, these cows were considered to be readily affected with ketosis as a result of mobilization of lipid in them.
