Seasonal evaluations of urinary androgen metabolites and semen quality in domestic long tailed chinchilla (Chinchilla lanigera) under natural photoperiod.

DOMINCHIN MF; BIANCONI S; PONZIO M.F.; FIOL DE CUNEO M; RUIZ R.D.; BUSSO J.M.

ANIMAL REPRODUCTION SCIENCE

ELSEVIER SCIENCE BV

Año: 2014 vol. 145 p. 99 - 104

0378-4320

tChinchilla spp. is a South American hystricomorph rodent genus currently consideredalmost extinct in the wild. The high quality of chinchilla fur motivated the harvesting ofchinchillas for the fur market. Reproductive biology advances come from studies on com-mercially exploited animals, especially Chinchilla lanigera. We studied seasonal variation ofurinary androgen metabolites, sperm concentration and sperm functional activity in malesof domestic Chinchilla lanigera under natural photoperiod. In Córdoba city (31◦S?64◦W;Argentina), within the same latitudes as those of the historic Andean distribution (tropicaldeserts; 15◦?34◦S), domestic males (n = 7) were studied in May (autumn), August (winter),November (spring), and February (summer). Urine was seasonally collected (over 24 h; oncefor season, 4 in total) to measure urinary androgen metabolites (RIA), before semen collec-tion by electroejaculation. The results indicated that although testicular volume (relativeto body weight) and values of sperm functional activity did not show seasonal changes, aseasonal variation in androgen excretion was detected, with the highest values occurringduring "short" light/dark cycles (autumn?winter). In addition, viable spermatozoa withintact acrosome mean values during winter?spring were higher than in autumn or sum-mer. This study provides information that might contribute to the assessment of testicularactivity in male chinchilla subjected to genetic selection in the fur industry. In addition,since domestic chinchilla still share some genomic characteristics with their counterpartsin the wild, results presented may alsocontribute to ex situ breeding program of endangeredchinchilla. In conclusion, natural photoperiod cycle affects testicular activity in domesticchinchilla.