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Discussion in 'Turkeys' started by longranger, Jun 18, 2009.
This may be a stupid question but is what is the ratio of Toms to hens in a normal hatch?
I would think 50:50 ....
I was just reading a chapter about that in the book Genetics of the fowl. You can find it on the Cornell University Core Historical Literature of Agriculture
Basiclly the sex ratio comes out to 1 to 1 or close to it. These studies were done using thousands of birds so over time I guess it would tend to even out. We have hatched out batches of poults with a very high % of males and the other way. For us they seem to know if we need hens they throw toms and visa versa.
Another thing turkeys are known for - (some breeds more than others) is Parthenogenesis. Where in the absence of males the female can self fertilize eggs. When this happens the hen throws 100% males. The female eggs don't develop at all or die very very early.
Steve in NC
Quote:Mine know too, but seem to throw whatever is not needed.
Quote:That's what happens in a bee colony. If the queen dies and there are no queen cells a worker (female) will start laying eggs that are all drones that never work. Soon the entire hive is dead.
Wow, I had no idea that turkeys could reproduce without a male. How long do hens need to be without toms for this process to occur?
Where in the absence of males the female can self fertilize eggs. When this happens the hen throws 100% males. The female eggs don't develop at all or die very very early.
GREAT GOOGLEY MOOGLEY!
and ouch - i was so stunned by this i fell right off my chair and hit my head. guess i shoudlnt get rid of ol' TZ just yet. i'd hate to have a whole pen full of toms!!!.. especially since he chased me again today....
and get this - turkey hen #3, Runner The Most Ridiculous Turkey Hen EVER... is laying and is about to set a nest. ... but it had better not be all males so i'll keep good ol' TZ struttin' around just in case. he was making a good case for a turkey fry this weekend with his shenanigans...
geez i fell of my chair again .... ouch....
any darn way - i guess you learn something new every day.
Quote:For the hen to be "clean" you are looking at about 30 days. We have tried this twice and have gotten zero hatches. The second time I counted the eggs and we set 35 from the same Beltsville hen. 2 eggs started to develop and quit within the first week, talking to some people that worked for the USDA and worked with the Belts said the fertilty rate would be in the 4% range or less. They were trying to up the % but could only get it so far. It would have been a very big cost saving for a market turkey. Think about it, all tom offspring, much less breeders to winter over. When AI really took off the interest really died off.
Steve_of_sandspoultry wrote: Another thing turkeys are known for - (some breeds more than others) is Parthenogenesis. Where in the absence of males the female can self fertilize eggs. When this happens the hen throws 100% males. The female eggs don't develop at all or die very very early.
Schuett's article in the Sonoran Herpetologist was very good (no longer online that I know of), a brief summary here:
This is from a paper on unisexual/bisexual derived parthenogens and Varanus lizards (excerpted turk info to breed reptiles of the mind ):
"Facultative parthenogenesis is a rare phenomen, and thorough investigations on numerous individuals are lacking. This type was discovered in birds (domestic turkeys, Olsen, 1975), and described as automixis (automixis with terminal fusion, Suomalian et al., 1987). From Olsens studies, it is known that two meiotic divisions occur as usual, and produce a quadruplet of gametes (the ovum and three polarbodies). The last meiotic division yields an ovum and its sister cell the second polar body. The latter functions in a manner analogous to a spermatozoon, by entering the ovum and fertilizing it (Olsen, 1976). As consequence diploidy is restored and the zygote is homogametic (ZZ or WW). WW is not viable as reported from other species (Kiblisky and Reig, 1966; Olsen, 1976). The combination ZZ produces a male offspring. Schuett et al. (1997) described four cases of facultative parthenogenesis in Thamnophis and Crotalus and associated it with automictic parthenogenesis. They summarized the features of their report: 1) a high incidence of abortive events and developmental abnormalities; 2) the production of only diploid males; 3) parthenogens possess only a subset of the genes of the dam and no paternal genes; 4) high levels of homozygosity and limited levels of heterozygosity; 5) tendency for parthenogens to be less vigorous, and to have abnormal sex organs. Important features of parthenogenesis depend on the chromosomal systems. Heterogamy is the male determining chromosomal state in the XX-XY system and the female determining state in the ZZ-ZW system."
Quote:GREAT GOOGLEY MOOGLEY!
WHAT SHE SAID!
I had no idea.
Knew about the lizards. But birds?
My SLOH is going to wee himself over this!
Are the ZZ male offspring of the parthenogenetic hens normal, fertile toms?