ABSTRACT We evaluated the effect of reducing free calcium in the cryopreservation medium, using the calcium chelator ethylene diamine tetracetic acid (EDTA) at 0.3% and 0.5% concentrations. Three male mixed breed dogs were subjected to semen collection by digital manipulation (n=16). Each ejaculate was divided in three aliquots, and each one was diluted in TRIS-glucose-egg yolk extender with 6% glycerol and 0.5% Equex STM Paste® (TGE, control); and added with 0.3% EDTA (EDTA 0.3) or 0.5% EDTA (EDTA 0.5). Calcium concentration reduced in EDTA 0.3 and all the calcium ions were chelated in EDTA 0.5. The EDTA addition did not affect sperm morphology or plasma membrane integrity; however, by removing all free calcium (EDTA 0.5), the sperm motility reduced (64.7% in TGE and 45% in EDTA 0.5; p<0.05). Acrosome integrity and sperm binding ability were not improved by calcium chelation. The failure to prevent the premature AR may explain why sperm longevity was not affected by calcium removal. Thus, the partial or complete calcium removal, through EDTA addition, is not able to prevent acrosomal damage or premature acrosomal reaction, and therefore does not improve the dog sperm binding ability.

ABSTRACT The aim of this study was to evaluate the pharmacological semen collection method with urethral catheterization (CT) in captive cougar (Puma concolor) males. The pharmacological method (CT; N= 3) was compared to the electroejaculation technique (EE; N= 4). For CT collection, medetomidine was administrated to induce semen release using a tomcat catheter inserted into the urethra to collect by capillarity. The proposed method was efficacious on all animals used. Through the CT method, semen collected yielded smaller volume (106,7±30,5aµL) and higher concentration (524,1±54,3b x 106sperm/mL) compared to EE (450,0±0,1bµL and 205,0±141,8a x 106 sperm /mL). Evaluations of vigor, motility and sperm pathology demonstrated that CT does not affect semen quality when compared to EE (P> 0.05). Thus, the proposed method consists of a more practical and efficient technique for semen collection with good quality, eliminating the need for eletroejaculation.

ABSTRACT We evaluated the effect of reducing free calcium in the cryopreservation medium, using the calcium chelator ethylene diamine tetracetic acid (EDTA) at 0.3% and 0.5% concentrations. Three male mixed breed dogs were subjected to semen collection by digital manipulation (n=16). Each ejaculate was divided in three aliquots, and each one was diluted in TRIS-glucose-egg yolk extender with 6% glycerol and 0.5% Equex STM Paste® (TGE, control); and added with 0.3% EDTA (EDTA 0.3) or 0.5% EDTA (EDTA 0.5). Calcium concentration reduced in EDTA 0.3 and all the calcium ions were chelated in EDTA 0.5. The EDTA addition did not affect sperm morphology or plasma membrane integrity; however, by removing all free calcium (EDTA 0.5), the sperm motility reduced (64.7% in TGE and 45% in EDTA 0.5; p<0.05). Acrosome integrity and sperm binding ability were not improved by calcium chelation. The failure to prevent the premature AR may explain why sperm longevity was not affected by calcium removal. Thus, the partial or complete calcium removal, through EDTA addition, is not able to prevent acrosomal damage or premature acrosomal reaction, and therefore does not improve the dog sperm binding ability.

ABSTRACT The aim of this study was to evaluate the pharmacological semen collection method with urethral catheterization (CT) in captive cougar (Puma concolor) males. The pharmacological method (CT; N= 3) was compared to the electroejaculation technique (EE; N= 4). For CT collection, medetomidine was administrated to induce semen release using a tomcat catheter inserted into the urethra to collect by capillarity. The proposed method was efficacious on all animals used. Through the CT method, semen collected yielded smaller volume (106,7±30,5aµL) and higher concentration (524,1±54,3b x 106sperm/mL) compared to EE (450,0±0,1bµL and 205,0±141,8a x 106 sperm /mL). Evaluations of vigor, motility and sperm pathology demonstrated that CT does not affect semen quality when compared to EE (P> 0.05). Thus, the proposed method consists of a more practical and efficient technique for semen collection with good quality, eliminating the need for eletroejaculation.