REPRODUCTIVE ENDOCRINOLOGY IN BIRDS 



nil 



TABLE 18.4 

 Comparison of the in vitro metabolism of bull and rooster spermatozoa under various experimental conditions 



References, 



1. van Tienhoven, Salisbury, VanDemark and 5. Blackshaw, Salisbury and VanDemark, 1957. 



Hansen, 1952. 6. Flipse and Almquist", 1958. 



2. Mann, 1954. 7. Lorenz, 1959. 



3. Bishop and Salisbury. 1955. 8. van Tienhoven, unpublished, 1959. 



4. Flipse, 1956. 9. van Tienhoven, 1960. 



incidence of abnormalities was linearly pro- 

 portional to the concentration of chloride 

 ions. Replacement of chloride ions by phos- 

 phate or glutamate prevented the sperm ab- 

 normalities and partly prevented the de- 

 crease in metabolic rates (El Zayat, 1960). 

 On further investigation, it was found that 

 l)hosphate decreased the initial metabolic 

 rates, whereas glutamate did not. Gluta- 

 mate was found to "spare" the utilization 

 of fructose ; apparently, glutamate itself was 

 metabolized to yield COo . In many of the 

 experiments in which efforts were made to 

 store semen in vitro, the diluents contained 

 chloride ions which from our observations 

 clearly seem to damage the sperm. Replac- 

 ing chloride with glutamate in a diluent 

 might prevent the loss of fertilizing capac- 

 ity during storage. Lake (1958) has shown 

 that a diluent high in glutamate can support 

 the maintenance of the fertilizing capacity 

 of sperm for at least 24 hours. Thus, one of 

 the main differences between bull and 

 rooster semen may lie in a difference in 

 sensitivity to chloride ions. Foote (1950) 

 has shown that a Tyrode solution supported 

 bull sperm viability better than any other 

 synthetic diluent. It remains to be deter- 

 mined whether glutamate would improve 

 sperm viability in a bovine semen diluent. 



Some other differences between bull and 

 rooster sperm are tabulated in Table 18.4. 

 At the moment the significance of these dif- 

 ferences is not known, partly because not 

 enough data are available for rooster sperm 

 to correlate nr vitro findings with fertilizing 

 capacity. 



III. The Female 



A. THE GONADS 



1. The Right (Rudimentary) Gonad 



With few exceptions such as Accipitrinae, 

 Falconinae, Buteoninae, Cathartidae, birds 

 normally have only one functional (left) 

 ovary, the right gonad is either absent or 

 very small (Domm, 1939; Stanley and 

 Witschi, 1940) . This asymmetry of gonadal 

 development is already noticeable during 

 embryonic development. In the duck (Anas 

 platyrhynchos) primordial germ cells mi- 

 grate to the left and right gonad primordium 

 in equal numbers until the 28 to 37-somite 

 stage is reached (75 to 85 hours of incuba- 

 tion) . After this, more primordial germ cells 

 migrate to the left, and after about 125 

 hours of incubation a difference in the 

 asymmetry between different embryos led 

 van Limborgh (1957) to deduce that an 



