LAUSR

The objective was to evaluate seminal plasma supplementation and the relationship between some of its components with frozen-thawed semen quality of donkey ( Equus asinus ). Semen from five Colombian Creole donkeys was collected by the artificial vagina method. From a fraction of each ejaculate the seminal plasma was separated by centrifugation, and vitamin C (VC), vitamin E (VE), total protein (TP) and lipid profile (LP) was evaluated. Semen cryopreservation was performed by conventional freezing in supplemented extender with 20 % of seminal plasma. Motility , structural membrane integrity (SMI), abnormal morphology (AM) and functional membrane integrity (HOS) of sperm, was assessed by SCA ® computerized system, SYBR14 / IP fluorescent assay, eosin-nigrosine staining and hypo osmotic swelling test, respectively. Mixed models were fitted where the fixed effect of the level of each component is included and a Pearson correlation analysis was performed between the plasma components and sperm quality. Means were compared by the Tukey test. It was found that high levels of VC, VE, TP and stearic acid (C18:0) had a deleterious effect on cryopreserved semen quality ( P ≤0.05). While a low level of PT and C18: 0, and a medium level of VE and VC showed higher post-thaw results for motility and membrane integrity ( P ≤0.05). Negative correlation coefficients of VC, VE, TP and C18:0 with different parameters of post-thaw semen quality were found. It is concluded that the composition of seminal plasma supplemented in freezing of donkey semen, influences the post-thaw sperm quality.