Alternatives in Donkey semen cryopreservation: Mare vs. Jenny Colostrum.

The aim of this study was to test and compare two new components in extenders for freezing donkey semen: mare colostrum and jenny colostrum. Colostrum was obtained from four mares and four jennies right after the foal's birth. Ejaculates were collected from five fertile donkeys. Sperm samples were pooled, diluted and cryopreserved in three different experimental extender groups: lactose supplemented with egg yolk extender (20%) as the control group, lactose supplemented with jenny colostrum extender (20%), and lactose supplemented with mare colostrum extender (20%). After thawing, we evaluated the sperm motility by means of computer-assisted analysis, viability by SYBR-14 and propidium iodide (PI), membrane functional by HOS test and acrosome integrity by isothiocyanate conjugated with peanut agglutinin (FITC-PNA) and PI. The results demonstrated that lactose-jenny colostrum extender displayed significantly higher values (p < .05) in nearly all parameters evaluated - Total Motility, Viability, HOS test, VCL, VSL, VAP, LIN, STR and WOB -, compared with mare colostrum and egg yolk extenders after thawing. In conclusion, the extender containing jenny colostrum used for donkey semen cryopreservation improved the donkey sperm quality after the freezing-thawing process.

Effect of Mare Colostrum in Extenders for Freezing Stallion Semen.

This study aimed to evaluate the addition of mare colostrum in stallion freezing extenders to improve sperm quality. First, colostrum samples were collected from four mares after the foal's birth and their composition was determined. Ejaculates were collected from nine fertile stallions. Sperm samples were pooled, diluted, and cryopreserved into three experimental extender groups: Lactose-based extender supplemented with mare colostrum (20%), lactose-based extender supplemented with egg yolk (20%), and BotuCrio. The quality of the post-thaw semen samples were evaluated assessing sperm motility by means of computer-assisted analysis, viability by SYBR-14 and propidium iodine (PI) stain, acrosome integrity by fluorescein isothiocyanate and peanut agglutinine (FITC-PNA) and PI stain, plasma membrane functionality by hypo-osmotic swelling (HOS) test, and DNA denaturation by acridine orange (AO) test. There were no significant differences in the percentages of total motility, acrosome integrity, and DNA fragmentation among the extenders after thawing. Kinematics parameters showed significantly higher values in BotuCrio than in lactose extenders (P < .05). BotuCrio and lactose colostrum extender yielded significantly better rates for HOS-test, linearity, straightness, and wobble than egg-yolk extender (P < .05). However, in relation to sperm viability, lactose egg yolk extender showed significantly better results in comparison to the others seminal experimental media (P < .05). In conclusion, the incorporation of mare colostrum into cryopreservation media protected the sperm against cold-shock; therefore, it may be a good cryoprotectant agent alternative in extenders for freezing stallion semen.

A preliminary study on the use of jenny colostrum to improve quality in extenders for freezing donkey semen.

Sperm quality in donkeys (Equus asinus) after freezing thawing is still considered lower than that from other animals, including horses. The aim of this study was to test a new freezing extender supplemented with jenny colostrum on donkey sperm. After thawing, we evaluated sperm motility by means of computer-assisted analysis, viability by SYBR-14 and propidium iodide (PI), membrane functional integrity by HOS-test and acrosome integrity by isothiocyanate conjugated with peanut agglutinin (FITC-PNA) and PI. Ejaculates were collected from five fertile Donkeys. Sperm samples were pooled, diluted and cryopreserved into three experimental extender groups: BotuCrio®, lactose-extender supplemented with egg yolk (20%) and lactose-extender supplemented with jenny colostrum (20%). The results demonstrated that lactose-jenny colostrum samples displayed significantly higher values in almost all parameters evaluated (p < 0.05) compared with the other two extenders after thawing (BotuCrio® and lactose-egg yolk based extender, respectively) -Total Motility, Viability, HOS test, VCL, VSL and VAP. Acrosome status, LIN, STR and WOB despite showing lower values, none of them were statistically significant (p > 0.05). In conclusion, the extender containing jenny colostrum can be successfully used for donkey semen crypreservation and could effectively improve donkey sperm qualities after freezing -thawing.