Reproduction in Domestic Animals

Captive Breeding of Cheetahs in South Africa 71(a)(b)(c) (d) (e) (f)(g)(h)(i)Fig. 7. (a) Morphologically normalcheetah sperm (SEM) – MP =mitochondrial sheath, PP = principalpiece, E P = end piece; (b)lateral view of cheetah sperm head(SEM) – A = acrosome, CP =connecting piece, MS = mitochondrialsheath; (c) planar view ofcheetah sperm head (SEM); (d)SEM showing cheetah sperm withcoiled tails and bent midpiece; (e)lateral view of cheetah sperm withacrosomal defect (TEM) – A =acrosome, AC = acrosomal cyst,PC = proximal centriol; (f) lateralview of cheetah sperm with acrosomaldefect (SEM) – AC =acrosomal cyst, MP = mitochondrialsheath; (g) phase contrastmicrograph (PCM) of an underdevelopedcheetah sperm with anucleus and cytoplasm; (h) twocoiledtails and a ‘Dag’ defect incheetah sperm (PCM); (i) Cheetahsperm with bent midpieces (PCM);(j) three (arrows) spermatogeniccells with vacuoles in a semensmear; (k) typical head morphologyof normal lion sperm (PCM)(a–f: Coubrough et al. 1976, 1978;Coubrough and Soley 1982)(j)(k)morphology. Secondly, semen evaluation reflects awindow in time and may take place as many as4 months prior to actual mating of a female. Thirdly,semen quality, especially sperm count, is likely to beaffected by prior sexual activity. According to Amannand Almquist (1976) the daily sperm production in dairybulls is 11 million ⁄ g testicular tissue. Cheetahs havesmall testes with a mean combined volume of 8 ml(n = 28; »8 g), meaning that the daily sperm productionis limited to approximately 88 million per day. Inaddition the epididymal tails are small with a limitedcapacity for sperm storage. The mean number of spermper cheetah ejaculate was found to be 22.9 million,which is approximately 26% of daily estimated production.Nevertheless, semen evaluation remains the mostvaluable criterium for selection of males. An investigationinto poor fertility in a pair of Gir forest lions at theZurich Zoological gardens illustrates the importance ofsemen quality and fertility (Bertschinger et al. 2006a).Asian lions are known to less heterozygous than mostfree-ranging African lions (Gaur et al. 2006) and Wildtet al. (1987b) showed that inbreeding of large catscauses poor semen quality. The Asian lioness in questionproduced her last cubs in July 1998 and then had eightpresumed pseudopregnant cycles (35–74 days in length)and one anovulatory cycle (16 days long) before sheproduced cubs 27 months later. The male was examinedduring the same month that she conceived and found toÓ 2008 The Authors. Journal compilation Ó 2008 Blackwell Verlag