**1. Introduction**

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The techniques used in assisted reproduction for wildlife or domestic animals are similar, and consist in the collection, evaluation, and cryopreservation of semen; artificial insemination (AI), *in vitro* fertilization (IVF), and embryo transfer (ET).

Considering that the maintenance of genetic diversity is reproduction dependent, reproduction technologies are important tools for the preservation of endangered species, throught the development of methods to increase the fertility in these animals (Howard, 1993).

Several studies show that hormone therapies may induce ovulation and/or superovulation in wild animals (Pope, 2000). The artificial induction of ovulation and superovulation are important components in assisted reproduction techniques, especially in cats, because their ovulation is induced by external stimulations (Hamner et al., 1970).

According to The Word Zoo Conservation Strategy ([IUDZG/CBSG], 1993), some of the many benefits from using assisted reproduction techniques in conservation management programs are:


The reproductive techniques used for domestic animals are gradually being used for zoo animals (Comizzoli et al., 2000; Dresser et al., 1986).

Wildlife Cats Reproductive Biotechnology 371

visualization, demonstrated that this species presents spontaneous ovulation in a higher

The genus Leopardus is polyestral and can cycle all year round (Morais et al., 1996; Moreira et al., 2001); the margay (*Leopardus wiedii*) is the only species in this genus presenting

According to Tebet (1999), the estrous cycle in ocelots is characterized by the presence of serum estradiol peaks associated with relatively low levels of serum progesterone (<2.61 ng/mL). This demonstrates the polyestral characteristic of this species, similar to previously observed for other species such as cats (Shille al., 1979; Tsuitsui & Stabenfeldt, 1996; Verhage

Ocelot females that ovulated and were not fertilized showed a period of increased progesterone serum concentration and estrus inhibition (Tebet, 1999), called pseudopregancy or diestrus, similar to domestic cats (Feldman & Nelson, 1996) and

Under an evolutionary analysis and among other factors, the process of spontaneous or induced ovulation may be related to the sociability of the species. Thus, solitary cats would require a longer estrus period, extended viability of oocytes, and extended time for the

The detection of fecal estrogens and progestins, throught the analyses of fecal metabolites in domestic and wild cats such as the leopard cat (*Felis bengalensis*), cheetah (*Acinonyx jubatus*), clouded leopard (*Neofelis nebulosa*), and snow leopard (*Panthera uncia*) was successfully performed by Brown et al. (1994). Likewise, this methodology has been widely used to monitor ovarian function in Neotropical felines such as the ocelot and margay (Morais et al,

In this context, noninvasive methods such as the quantification of fecal hormonal

The estrus cycle, gestational time, and number of pups observed in different species of

**Estrous Cycle (days)** 

*geoffroyi* 2.50.51 20.05 72-766 1-36

**Gestation (days)** 

18.41.64 70-856 1-46

16.71.34 73-786 1-46

17.61.54 81-846 16

**Pups (nº)** 

**Estrus (days)** 

*pardalis* 4.630.631 16.5 1.52

*tigrinus* 3.0-9.05 15.8 1.52

Margay *Leopardus wiedii* 4.0-10.05 19.5 2.12

frequency compared to what is described for other felines.

et al., 1976), tigers (Seal et al., 1985), and cheetahs (Brown et al., 1996).

ovulation to occur, after the couple meet in the wild (Ewer, 1975).

metabolites are increasingly being used in wildlife animals.

Neotropical wild cats are presented in Table 1.

**Scientific Name** 

*Oncifelis* 

Ocelot *Leopardus* 

Tigrinus *Leopardus* 

spontaneous ovulation (Moreira et al., 2001).

leopards (Schmidt et al., 1988).

1996; Moreira et al., 2001).

**Common Name** 

Geofroy's cat

Artificial insemination has been conducted in different species of carnivores such as cougar (*Felis concolor*), leopard (*Panthera pardus saxicolor*), cheetah (*Acinonyx jubatus*), tiger (*Panthera tigris altaica*), ocelot (*Leopardus pardalis*) tigrina (*Leopardus tigrinus*), and jaguar (*Panthera onca*) (Dresser et al., 1982; Donoghue et al.; 1993, Howard et al., 1992a; Jimenez et al., 1999; Moore et al., 1981; Moraes et al., 1997; Silva et al., 2000; Swanson et al., 1996a).

*In vitro* fertilization (IVF) has also been performed in captive wild cats such as tiger (*Panthera tigris altaica*), jaguar (*Panthera onca*), ocelot (*Leopardus pardalis*) and tigrina (*Leopardus tigrinus*) (Donoghue et al., 1990; Morato et al., 2000; Swanson & Brown, 2004).

The application of artificial reproductive methods in wild animals has not being successful, showing low reproductive rates. Some of the several reasons for these low reproductive rates are lack of knowledgement on the species' physiology, poor sperm or oocytes quality, and difficulties in adapting from the methodologies used in experimental models.

Considering the zoos' limitation to maintain genetically viable populations of threatened species, the establishment of genetic banks containing semen, oocytes, embryos and cells emerge as a strategy to ensure the genetic diversity of populations (Lasley et al., 1994). The potential of assisted reproduction for endangered species should be emphasized by the possibility of semen and embryos cryopreservation, which are genetically valuable for the future populations.

Although there are some records related to the female reproductive physiology (Table 1) and semen characteristics for various Neotropical felids species (Table 2), there is a little knowledge about the fertilization ability using artificial methods (Table 3) in these animals. Studies about the application of assisted reproduction techniques in Neotropical felids showed limitations because of the lack of basic knowledge on the physiology of the species.
