Optimizing stallion semen dilution based on hydrogen ion index

All-Russian Research Institute for Horse Breeding, Ryazan region, Rybnovsky district, Divovo, 391105, Russia

^* Corresponding author: naumenkova.00@mail.ru

Abstract

The dependence of the results on the individual qualities of stallion semen is very high, which is an obstacle to the wider use of the cryopreservation method in practice. It has been shown in this work that semen from successive samples from the same stallion has different hydrogen ion concentrations (pH) and different buffer capacities. When Lactose-chelate-citrate-yalk environment (LCHCY) is diluted, the pH of semen varies depending on its initial value. But in 30-40% of cases, the hydrogen ion concentration (pH) shifts more or less from the expected value. In order to establish the maximum possible survival time of refrigerated and cryopreserved semen, the optimum pH acidity value after dilution was determined. The maximum survival time depended on the initial sperm concentration. It was possible to adjust the acidic pH value after dilution by dropwise addition of buffer solutions of the initial medium to the acidic or alkaline side. An individual approach to the semen dilution procedure by adjusting the pH value after dilution makes it possible to increase the number of stallions for artificial insemination with semen resistant to refrigeration and cryopreservation.