Document Type : Research Paper
Ph. D. Student, Department of Animal Science, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran
Assistant Professor, Department of Animal Science, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran
Assistant Professor, Department of Animal Science, Sari Agricultural & Natural Resources University
The objective of this study was to consider economic consequence of delayed conception of milking cows in large dairy farms in Iran. Optimum open days and milk production at peak were assumed to be 110 days and 45 kg respectively. Price of milk, feed, semen and hormones were calculated based on average prices of autumn, 2013. Results of this study showed that increasing days in milk (DIM) from 110 to 170 has doubled costs of sperm and veterinary hormones. Delaying of each day of conception in cows with 45 kg of milk production at peak, during first; second, third and fourth estrous cycle beyond the optimum days open (110 d) cause economic losses of 308503, 572818, 812689 and 1013331 Rials, respectively. Feed costs compromise 54.7 to 56.6 percent of the loss, and any one percent change in feed price will directly cause 0.55 percent changes of the loss.
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