Cryoprotective effect of the egg yolk of different species on the sperm quality of rams under conditions of the Peruvian Altiplano

Abstract

The objective was to evaluate the cryoprotective effect of the egg yolk of different domestic birds on sperm quality of rams in conditions of the Peruvian Altiplano. The semen was collected by using an artificial vagina form 6 Corriedale rams and 63 sheep were used for insemination. The semen volume was conserved with Tris diluent + 15% egg yolk according to treatment [quail (TI), creole hen (TII), farm hen (TIII) and pigeon (IV)] csp 100 mL, the collection was diluted 1:1 with fraction A (Tris+yolk) and cooled to 5°C where fraction B (Tris+yolk+glycerol) was added; adjusting the sperm concentration to 300x106 (0.25 mL straw), subjecting to equilibrium for 1.5 h (5ºC), then frozen at a rate of -20ºC/min until reaching -120oC and stored; cervical artificial insemination was performed in 25 ewes in heat and 38 to synchronized heat. The semen evaluation was carried out at the collection, equilibration and thawing phase, determining total motility (MT), progressive motility (MP), membrane functionality (Host), and membrane integrity (VIT). The thawing results were for treatments I, II, III and IV the percentages of MT of 54.30, 51.86, 57.87 and 44.21 (p> 0.05); MP of 50.03, 51.36, 50.72 and 45.98 (p> 0.05); Host of 59.44, 55.86, 60.50 and 49.3 (p 0.05) respectively. The gestation was evaluated at 45 days post insemination resulting in 48% (12/25) and 21.05% (8/38) for natural and synchronized heat respectively (p=0.0245). In conclusion the membrane functionality was greater with quail, creole hen farm egg yolks; as well as a higher gestation rate in sheep inseminated in natural heat.

Keywords

• criopreservation
• egg yolk
• semen
• ram