TY - JOUR ID - 1774 TI - Accuracy of oestrus detection in cows and its economic impact on Shiraz dairy farms JO - Iranian Journal of Veterinary Research JA - IJVR LA - en SN - 1728-1997 AU - Kafi, M. AU - Zibaei, M. AU - Rahbari, A. AD - Department of Clinical Sciences, School of Veterinary Medicine, University of Shiraz, Shiraz, Iran AD - Faculty of Agricultural Economics, School of Agriculture; University of Shiraz, Shiraz, Iran AD - Department of Clinical Sciences, School of Veterinary Medicine, University of Shiraz, Shiraz, Ir Y1 - 2007 PY - 2007 VL - 8 IS - 2 SP - 131 EP - 137 KW - accuracy KW - Oestrus detection KW - Dairy cows KW - Economics KW - Iran DO - 10.22099/ijvr.2007.1774 N2 - No report has been published on the economical losses associated with errors in oestrus detection in cows under Iranian intensive dairy management. The following study was carried out to determine the accuracy of oestrus detection by farmers using artificial insemination in Shiraz dairy farms. Milk samples were collected from 179 Holstein milking cows at the time of artificial insemination. Milk progesterone concentration was determined using a commercial radio-immunoassay kit. It was assumed that a milk progesterone concentration greater than or equal to 3 ng/ml indicated the presence of active luteal tissue and that all animals in oestrus had a concentration less than 1 ng/ml. Results of the present study showed that error in oestrus detection was higher in dairy herds with more than 85 milking cows compared to that of the smaller size herds (14.4 vs 7.3%; χ2  = 2.59; P = 0.1). Five out of 11 herds (45%) had an oestrus detection error higher than 10 percent while in the remaining six herds the oestrus detection error varied from 0 to 7.1%. Based on the assumptions and calculations made in the present study, the net cost of one day delay in conception for a cow producing 25 litres milk in peak lactation was calculated at 40591.98 Rials (4.51 $US) when conception is delayed from 85 to 100 days post-calving, increasing to 60120.89 Rials (6.68 $US) per day if conception occurred at 146 to 175 days post-calving.   UR - https://ijvr.shirazu.ac.ir/article_1774.html L1 - https://ijvr.shirazu.ac.ir/article_1774_f3a2afb7349a302e78d9dbf23d0910b9.pdf ER -