73 Artificial incubation of resplendent quetzal (Pharomachrus mocinno mocinno) eggs

The scientific literature lacks information regarding the incubation conditions and hatching success of the resplendent quetzal (Pharomachrus mocinno mocinno). Jesús Estudillo López, founder of the El Nido aviary, was the first to succeed with quetzal reproduction in captivity. Quetzals do not typically reproduce in captivity and the aim of this study was to increase fecundity through artificial incubation. Over a 3-year period (Yr1, Yr2, and Yr3), data about quetzal eggs, artificial incubation, and diet were recorded for 3 quetzal pairs (ranging from ~4-12 years old, with females ~4-8 years old). Eggs were manually collected from artificial nests and egg substitution was utilised. Quetzals can continue laying eggs up to 8 times with egg substitution. Eggs were weighed and placed into an 80W incubator (INCA 200®, DMP Engineering, Tel Aviv, Israel) with an automatic egg turner. The eggs were incubated for 17 to 18 days at 37.2 to 37.6°C with a relative humidity of 20 to 40%. Fisher’s exact test (2-tailed, α=0.05) was used for statistical analyses comparing the numbers of eggs hatched, infertile eggs, and eggs experiencing embryonic death for the study period. Eggs were candled on Day 3 to determine fertility by the presence of a darker area with vasculogenesis. Hatchability (%) was determined by dividing the total number of offspring hatched by the total number of eggs deemed fertile after candling. All of the eggs that did not hatch were opened at the end of the incubation period to detect early embryo death. A total of 27 quetzal eggs [mean weight (g)=17.3, s.d.=1.2] were incubated over 3 years, of which 10 (~37%) hatched, with 3 (30%) fledging and surviving to adulthood. Six of the eggs (~22%) suffered embryonic mortality during incubation, whereas 11 eggs were infertile (~41%). Hatchability over the study period was 62.5% (10/16). During Yr1 and Yr2 two eggs hatched each year, and compared with the 6 eggs that hatched in Yr3, a noteworthy but not significant difference was observed (Yr1v. Yr2, P=1; Yr1v. Yr3, P=0.188; Yr2v. Yr3, P=0.170). Embryonic death of the eggs was also not significantly different between the years (Yr1v. Yr2, P=1; Yr1v. Yr3, P=0.314; Yr2v. Yr3, P=0.303). However, the number of infertile eggs was significantly different between Yr1v. Yr3 (P=0.007) and Yr2v. Yr3 (P=0.003), but not Yr1v. Yr2 (P=1). During Yr1 and Yr2 the diet consisted of fruit (aguacatillo, banana, and papaya) and a mouse pup once a week. In Yr3 the diet was modified to include blueberry and a commercial food for Tucans (Mazuri®; https://www.mazuri.com/) and a new quetzal pair was added. The modified diet will continue to be used given that there were fewer infertile eggs. However, future research will need to be conducted to elucidate which variables specifically contribute to better hatching results. The results of this study demonstrate an assisted reproductive technique for quetzals that can benefit conservation efforts for this species.

130 In Vitro Production of Hybrid Desert Bighorn×Domestic Sheep Embryos Using Frozen–Thawed Epididymal Semen from a Hunter-Harvested Ram

Although considered a species of least concern by the International Union for Conservation of Nature red list, the Desert Bighorn sheep (Ovis canadensis nelsoni) is listed in Appendix II of CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) in Mexico, due to population size and the lack of protected areas. Postmortem epididymal sperm collected from a hunter-harvested Desert Bighorn sheep ram in Mexico, with an unofficial Safari Club International score of 197 2/8 and an estimated 5.5 years old, were used to evaluate the in vitro production (IVP) of embryos using postmortem-collected ram sperm. Testicles with epididymides were placed in the refrigerator ~45 min after harvest. Sperm were extracted from each epididymis and assessed separately for total motility (TM), progressive motility (PM), and membrane integrity using a phase contrast microscope. The sperm suspension was obtained from the distal end of both epididymides and cryopreserved 12 h postmortem using triladyl with egg yolk. Membrane integrity and morphology were evaluated using Eosin-Nigrosin stain. Sperm DNA fragmentation was analysed using the Halomax kit (Halosperm SL, Madrid, Spain) with fluorescence microscopy. Centrifugation with density gradient PureSperm (Nidacon International, Mölndal, Sweden) was used to remove dead sperm and debris before IVF. Ovaries were collected from Domestic sheep (Ovis aries) at a local slaughterhouse. The maturation medium was TCM-199 with Earle’s salts and a modified Tris-buffered medium was used for fertilization. Frozen straws of sperm from the Desert Bighorn ram were thawed for 45 s at 37°C. Sperm were diluted with modified Tween medium B with milk powder (mTBM) to a final concentration of 5 × 106 cells mL−1. The gametes were co-incubated for 18 h under previously described conditions. The cumulus cells were mechanically removed from zygotes and grown using a co-culture with granulosa cells in sequential media SOF1-SOF2. With regard to sperm collection, epididymis 1 produced 29 straws of sperm (0.25 mL, 136 × 106 sperm mL−1) and epididymis 2 produced 32 straws of sperm (0.25 mL, 68 × 106 sperm mL−1). The sperm sample used for IVF had TM of 60% and PM of 30%. Live dead staining of fresh sperm showed 68% live (i.e. intact cell membranes) and 28% post-thaw. Regarding DNA integrity, only 2% of sperm had DNA fragmentation at 0 h. Of 15 Grade 1 oocytes used for IVF, 4 cleaved (27%), with 1 developing to blastocyst stage (25%). The results show that frozen–thawed epididymal sperm collected from a recently deceased Desert Bighorn ram can provide a valuable source of sperm for IVP of embryos. These results also provide new information on Desert Bighorn sheep reproductive parameters for use in health assessment, or reproduction and conservation management through gene banking and assisted reproductive techniques.

Identification of novel variants of interferon-tau gene in Bighorn sheep (Ovis canadensis mexicana), Pelibuey sheep (Ovis aries) and its expression in hybrid blastocysts (Ovis canadensis × Ovis aries)

Palma-Irizarry, M., Damian-Matsumura, P., Betancourt, M., Romo, S., Perales, G., Lagunas-Martínez, A., Madrid-Marina, M. V., Mejía, O. and Ducolomb, Y. 2012. Identification of novel variants of interferon-tau gene in Bighorn sheep ( Ovis canadensis mexicana ), Pelibuey sheep ( Ovis aries ) and its expression in hybrid blastocysts ( Ovis canadensis×Ovis aries ). Can. J. Anim. Sci. 92: 275–283. The major signal for maternal recognition of pregnancy (MRP) in ruminants is interferon-tau (IFNT). Four novel sequences of the IFNT gene were isolated from genomic DNA obtained from blood samples of Bighorn, Pelibuey or the hybrid ewes. The deduced amino acid sequence of the hybrid ewe showed 100% identity with one Bighorn sheep IFNT sequence, suggesting that this sequence was inherited from Bighorn sheep. The high degree of identity between Pelibuey and Bighorn sheep sequences could be a possible explanation for the successful MRP in some Bighorn hybrid pregnancies. In vivo and in vitro domestic sheep (Ovis aries) and hybrid sheep (Ovis aries×Ovis canadensis) blastocysts were obtained, and IFNT expression was measured by semiquantitative RT-PCR. In vivo and in vitro hybrid blastocysts showed lower expression of IFNT when compared with domestic blastocysts. In conclusion this study showed that there exists an effect of hybridization on IFNT expression and this can affect the MRP.