The Use of Monosaccharides, Disaccharides, and Trisaccharides in Synthetic Diluents for the Storage of Ram Spermatozoa At 37°C and 5°C

Abstract

Using synthetic semen diluents based on 20 mM phosphate buffer, 31 Mm N aCl, 0·8 % non.dialysable skim milk solids, plus antibiotics, and 185 mM of the sugars ribose, arabinose, xylose, glucose, mannose, fructose, galactose, rhamnose, maltose, lactose, sucrose, or raffinose, it was found that ram spermatozoa survive best at 37°C in diluents containing glucose, mannose, fructose, or sucrose; however, at 5°C ribose, arabinose, xylose, and galactose were the sugars of choice. Increasing replacement of fructose in the diluent with up to 185 mM of these sugars resulted in increased survival at the respective temperatures. Part replacement of 185 mM fructose in the range 7·75-62 mM with the sugars most favourable at 5°C was of little benefit. No effect of changes in osmotic pressure was noted using varying concentrations of the sugars to give tonicities of 0·9, 1· 0, and 1 ·1 relative to 154 mM NaCI or 308 mM sugar. Increased motility scores and percentages of motile sperma· tozoa were observed when 17 mM fructose was added to ribose and arabinose diluents at 5°C, but not when added to diluents containing xylose, the hexoses, galactose, fructose, and glucose; nor for any sugar· containing diluent at 37°C.