Field friendly method for wild feline semen cryopreservation

Gediendson Ribeiro De Araujo,Ronaldo Gonçalves Morato,Letícia Coelho Ferreira Bergo,Gustavo Guerino Macedo,Thyara De Deco-Souza,Leanes Cruz Da Silva,Tarcízio Antônio Rego De Paula,Pedro Nacib Jorge-Neto,Maitê Cardoso Coelho Da Silva

doi:10.11609/jott.5744.12.5.15557-15564

Abstract

The aim of this study was to develop a field-friendly method for free-living jaguar and cougar semen cryopreservation. Six captive Jaguars Panthera onca and three captive Cougars Puma concolor were chemically restrained with a combination of medetomidine (0.08–0.1 mg/kg) and ketamine (5 mg/kg). Semen was collected through a tomcat urinary catheter with an open end, diluted for a final concentration of 50 x 106 sperm/mL in a TRIS-egg yolk extender and packaged into 0.25 mL straws. We compared two cooling methods: CoolA - in which straws were placed in a glass tube that was placed in a glass bottle containing water (600mL at 38°C) and transferred to a polystyrene container (12L) containing an 11cm column of ice and water at room temperature; CoolB – where the glass bottle – straws kit was transferred to a 4.26L cooler containing nine blocks (81cm3) of Ice Foam recyclable ice, previously frozen in liquid nitrogen. The sperm volume varied from 2 to 720 µl for the jaguars and from 80 to 140 µl for the cougars. Sperm concentration varied from 224 to 5,115 x106 sperm/mL for the jaguars and from 485.7 to 562.5 x 106 sperm/mL for the cougars. Concerning the cooling treatments, there was no difference in frozen-thawed sperm quality between the methods, in both species. Thereby, the cooling method using recyclable ice frozen in liquid nitrogen can be used for semen cryopreservation in wild felines, eliminating the need for electric energy.

Highlights

MATERIALS AND METHODSThe Jaguar Panthera onca and the Cougar Puma concolor are apex predators and play a crucial role in the prey population control, both are considered keystone species for the ecosystems conservation (Crawshaw Jr. 1991)
They need electricity to freeze the ice for 12h before being used. These devices are not feasible for use in free-living felines, since capture sites are often difficult to access and without electricity. This difficulty is clearly demonstrated when we evaluate the articles published in scientific journals, in which only two papers describe the characteristics of fresh sperm in free-living Jaguars, but they did not cryopreserve the samples (Morato et al 2001; Araujo et al 2018)
Semen collection by urethral catheterization was effective in all animals, with good volume and concentration (Table 1), one Jaguar and one Cougar only ejaculated seminal fluid and were not considered for statistical analysis in frozen-thawed semen

Summary

Introduction

The Jaguar Panthera onca and the Cougar Puma concolor are apex predators and play a crucial role in the prey population control, both are considered keystone species for the ecosystems conservation (Crawshaw Jr. 1991). Threats such as deforestation and human activity are resulting in a reduced Jaguar and Cougar population in Brazil, and both species are classified as Vulnerable by the Brazilian Red Book of Threatened with Extinction Fauna (ICMBio 2018a). Semen cryopreservation allows translocation of genetic material among populations, dispensing the transport of individuals, which reduces the stress caused by the translocation and the risks of transmission of infectious diseases (Wildt 1990)

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Conclusion