Associations between energy metabolism, LH pulsatility and first ovulation in early lactating cows.

This study was designed to elucidate associations between energy metabolism and LH pulsatility characteristics in early lactation, and days to first ovulation, in order to explain the relationship between energy balance and fertility observed in epidemiological studies. To this end, 10 multiparous HF cows were monitored during lactation, after the application of two different feeding strategies during the dry period. Days to first ovulation was assessed using blood progesterone measurements and LH pulsatility was measured in 8-h windows in the third week postpartum. The association between depth of negative energy balance and days to ovulation was confirmed. However, this study does not support the idea that LH pulsatility characteristics in early lactation are predictive for the interval between parturition and first ovulation.

The lipid composition of serum lipoproteins in the harbour seal, Phoca vitulina.

The density profile of serum lipoproteins and their lipid composition was studied in 12 adult, female harbour seals. The animals were sampled after an approximate 20 hr fast. The density profile of lipoproteins showed that the harbour seals displayed a distinct VLDL (density less than 1.006 g/ml) and HDL band (density about 1.125 g/ml), but no clear LDL band. There was a rather diffuse population of lipoproteins in the density range of 1.019-1.100 g/ml. Mean serum total cholesterol concentration was 5.7 mmol/l; about 60% of this cholesterol was located in the HDL fraction (density greater than 1.063 g/ml). The fasted seals were found to carry 4% of serum total lipids in chylomicrons. These lipoproteins consisted of 51% of triaclyglycerols (on the basis of total chylomicron lipids). The LDL (defined as heparin-manganese precipitable lipoproteins in VLDL and chylomicron-deficient serum) contained 49% of cholesterol and 43% of phospholipids (on the basis of total LDL lipids). The HDL (defined as heparin-manganese soluble lipoproteins in VLDL and chylomicron-deficient serum) contained 36% of cholesterol and 58% of phospholipids (on the basis of total HDL lipids).

[Polyarthritis in calves (author's transl)]. / Polyarthritis bij kalveren

The development of polyarthritis was studied in thirty-six calves. Thirty patients were from two to eleven days of age; six animals were older than eleven days. Besides clinical studies, the synovial fluid was examined both biochemically and bacteriologically in addition, a blood culture was made. When the synovial fluids of twenty-six calves were studied bacteriologically, P. multocida was isolated in ten cases, P. haemolytica in two cases, E. coli in ten cases, streptococci in three cases and D. pneumoniae in one case; bacteriological examination of the synovial fluid was negative in ten cases. Blood cultures were positive in twenty animals (P. multocida in five cases, P. haemolytica in two cases, E. coli in eleven cases, S. subacidus in one case and D. pneumoniae in one case). Twenty-five calves were treated by intra-articular as well as intramuscular injection of kanamycin (sulphate); six animals were treated with similar injections of ampicillin. Treatment with ampicillin was initially instituted in five calves; after some time, however, kanamycine (sulphate) was substituted for this medication. Twenty-seven calves recovered completely.