A study aimed at validating a human progesterone enzyme immunoassay kit was carried out on cattle at Bambui, Cameroon. Progesterone ELISA Kits (EH-511) were obtained from Clinpro International. Forty-one cows were selected, of which 19 were pregnant and 22 within 14 days post partum. Blood samples were analysed and progesterone levels were deduced from a curve obtained from standard absorbance values (A450). Results show that 95.5% of postpartum cows had progesterone levels below 1 ng/ ml, with the highest level being 0.75 ng/ml. The mean level was 0.5 +/- 0.26 ng/ml. The cows in the 'pregnant group' had progesterone levels ranging from 3.5 to 17.5 ng/ml. This kit can be used for measuring progesterone levels in cattle. Levels of 1 ng/ml for two consecutive samples or one sample at or above 3 ng/ml are an indication of the presence of corpus luteum, while cows below 1 ng/ml will be in anoestrus.

A study was carried out to evaluate the viability of extended cattle semen, without freezing, under different storage conditions. The semen was collected from Holstein Friesian bulls using artificial vaginas. The semen was extended and stored in a 3-by-4 factorial design (storage system × ice change). The storage media were ice boxes, buckets, and refrigerator. The ice in these media was either replaced daily, on the first and third day, first day only, or no ice at all after the semen collection. Results showed an overwhelming evidence of the effect of storage medium and ice change on sperm viability (P<0.0001). Individual motility before processing was highest in the refrigerator with averages of 44.5%, 39.5% in ice boxes, and 10% in buckets during the 8-day experiment. There was no significant difference (P>0.05) in progressive motility after processing in the refrigerator (34%) and in ice boxes (33%) but significantly higher (P<0.01) to the 10% obtained in buckets. It was shown that spermatozoa in the ice box retained 45% individual motility up to the sixth day after semen was collected on the condition that the ice was changed on the third day. Progressive motility after processing in the ice box was 40% up to the sixth day with the ice changed on the third day while the spermatozoa were well preserved up to the fourth day in the same medium if the ice put on the first day was not changed. This study shows that, if farmers plan to inseminate cows within the first day after semen collection, they can use buckets with ice for the transportation of the extended semen ampoules from the artificial insemination center. Otherwise, the semen needs to be kept in ice boxes and the ice changed on the third day after collection and this semen could be used within a week.