Lack of correlation between the electrical conductivity of milk and the blood progesterone levels in cows.

A study was conducted to investigate the possibility of measuring the electrical conductivity (EC) of cow's milk as a practical and cost-effective means of determining oestrus in cows. Prostaglandin injections were used to synchronise the oestrous cycle of 15 cows. From the onset of oestrus, milk and blood samples were collected from each cow every 2nd day over a period of 22 days. A portable, commercially available instrument was used to measure the EC of the milk. The blood progesterone levels were determined by means of an enzyme immuno-assay method. No correlation was found between the EC of milk and the blood progesterone levels of the cows tested. Electrical conductivity measurements of milk are of no value in determining the onset of oestrus in cows.

Micro-spoon technique in estimation of sperm concentration in rat epididymis.

Several technical procedures were described for estimation of epididymal sperm concentration until today. In all of the described techniques, epididymal material was drawn into a micro-pipette before counting procedure. We aimed to proceed this stage without using any pipette because of the difficulty in aspirating very viscous epididymal material into a micro-pipette. For measuring epididymal material we used a 2 microl reservoir which we named as a micro-spoon. It was filled with the epididymal material and layered in a tube with Ringer's solution of 2 ml containing sodium hyaluronate. Then, it was mixed in order to obtain 1/1000 diluted suspension. Sperm cells in this suspension were counted on a Makler chamber under a light microscope. The procedure was easy and time saving, compared to the other techniques.