Are Does Predispositioned To Having....

[Mike Belt]

...a certain sexed fawn? Overall fawn births are pretty much split even between males and females but do certain does maybe drop all females while others drop all males? I have a healthy number of backyard does year round. I run a camera there 6 months a year and pull the card at least once a week. Over the years (including the pulls over the last 2 months) I average 1000 pics per pull. In a population of about 12 does I get bookoos of great pics of their fawns and I only have pics of 2 buck fawns. Everything else has been female fawns with everything this winter being female.

 

[BSK]

Studies exist that suggest certain age does tend to have more of one sex offspring than the other. However, a biological mechanism for this process has never been found.

 

[Dbllunger]

Males (bucks) determine the sex of the offspring in mammals. Each parent donates x or y chromosomes. Females have only x chromosomes while males have an x and a y. A XX fawn will be female having recieved an x from both parents. An XY fawn will be male having received an X from mother (all she can give) and a Y from dad.

If you look hard enough you can find a study to support whatever your point of view may be. You have to be able to read between the lines and sort through things yourself.

 

[Deer Assassin]

i had a doe in the yard years ago i had several pics trip bucks but most i see are split 50/50 buck doe

 

[BSK]

Males (bucks) determine the sex of the offspring in mammals. Each parent donates x or y chromosomes. Females have only x chromosomes while males have an x and a y. A XX fawn will be female having recieved an x from both parents. An XY fawn will be male having received an X from mother (all she can give) and a Y from dad.

If you look hard enough you can find a study to support whatever your point of view may be. You have to be able to read between the lines and sort through things yourself.

Yes and no. Environmentally or socially influenced sexual determination of offspring is not that uncommon in the animal kingdom. Numerous species have mechanisms that allow them to produce more or less of a certain sex offspring to meet population dynamics needs. Whitetails might be one of those species, although personally I'm not convinced of that yet.

 

[redblood]

Males (bucks) determine the sex of the offspring in mammals. Each parent donates x or y chromosomes. Females have only x chromosomes while males have an x and a y. A XX fawn will be female having recieved an x from both parents. An XY fawn will be male having received an X from mother (all she can give) and a Y from dad.

If you look hard enough you can find a study to support whatever your point of view may be. You have to be able to read between the lines and sort through things yourself.

x2. regardless of environmental conditions, a doe can only provide an X chromosome

 

[redblood]

there is one variable however. in our business, ovulation time is critical since most of our litters are bred using frozen or fresh chilled semen. a wealth of research adheres to the theory that x sperm cells (female) use up their energy at a slower rate that y's. therefore, if the mating takes place well in advance of ovulation, a greater number of x sperm cells will still be viable and capable of fertiling the ovum. some does, may be receptive further in advance of ovulation, and thus may have a tendency to produce a higher percentage of female offspring. On the flipside, the y sperm cell seems to be mobile and progressive (that is why it utilized its energy reserve quicker). So if mating takes place after ovulation (prime time) they are more likely to be reach the ovum in higher numbers and thus that particular doe may be more likely to mother male offspring. On a side note, peak fertility does not occur at ovulation, but rather a short period of time after. the egg has a protective coating that must dissipate after its release. we have had some success in sex determination by adhering to these principals.

 

[Dbllunger]

there is one variable however. in our business, ovulation time is critical since most of our litters are bred using frozen or fresh chilled semen. a wealth of research adheres to the theory that x sperm cells (female) use up their energy at a slower rate that y's. therefore, if the mating takes place well in advance of ovulation, a greater number of x sperm cells will still be viable and capable of fertiling the ovum. some does, may be receptive further in advance of ovulation, and thus may have a tendency to produce a higher percentage of female offspring. On the flipside, the y sperm cell seems to be mobile and progressive (that is why it utilized its energy reserve quicker). So if mating takes place after ovulation (prime time) they are more likely to be reach the ovum in higher numbers and thus that particular doe may be more likely to mother male offspring. On a side note, peak fertility does not occur at ovulation, but rather a short period of time after. the egg has a protective coating that must dissipate after its release. we have had some success in sex determination by adhering to these principals.

Wow, very interesting stuff. Although I did have a BS in Biology in undergrad, I don't recall getting that in depth in my genetics and various classes. It seems this would possibly support what BSK was referring to earlier. The frisky does that are receptive earlier and bred earlier could very well skew the birth of female offspring past the 50/50 ratio due to the fact that the Y chromosome sperm could be played out before fertilization is possible leaving only the slower swimming x chromosome to finish the job.

 

[BSK]

there is one variable however. in our business, ovulation time is critical since most of our litters are bred using frozen or fresh chilled semen. a wealth of research adheres to the theory that x sperm cells (female) use up their energy at a slower rate that y's. therefore, if the mating takes place well in advance of ovulation, a greater number of x sperm cells will still be viable and capable of fertiling the ovum. some does, may be receptive further in advance of ovulation, and thus may have a tendency to produce a higher percentage of female offspring. On the flipside, the y sperm cell seems to be mobile and progressive (that is why it utilized its energy reserve quicker). So if mating takes place after ovulation (prime time) they are more likely to be reach the ovum in higher numbers and thus that particular doe may be more likely to mother male offspring. On a side note, peak fertility does not occur at ovulation, but rather a short period of time after. the egg has a protective coating that must dissipate after its release. we have had some success in sex determination by adhering to these principals.

Wow, very interesting stuff. Although I did have a BS in Biology in undergrad, I don't recall getting that in depth in my genetics and various classes. It seems this would possibly support what BSK was referring to earlier. The frisky does that are receptive earlier and bred earlier could very well skew the birth of female offspring past the 50/50 ratio due to the fact that the Y chromosome sperm could be played out before fertilization is possible leaving only the slower swimming x chromosome to finish the job.

And that is one theory that has been looked at. In a very large study involving over 10,000 fetal sex and conception dates (actually, a combination of three studies), fairly significant difference were found in the sex of fetuses of different age does. In addition, deer from healthy populations displayed a different offspring sex distribution as deer from very unhealthy (over-populated) herds. One theory was that deer in unhealthy herds have more male offspring, as male offspring are more likely to disperse from the unhealthy conditions and move somewhere else, lessening the over-population trend.

However, although numerous theories were advanced on the actually biological mechanisms that could produce sexual determination of offspring, including the one redblood detailed, evidence supporting each of these theories was not found. So although there IS evidence backing the idea of sexual determination, no mechanism has been identified by which the species could achieve such a result.

 

[woodsman87]

So does this mean we shoot does before or after ovulation?

Sent from my Lumia 900 using Tapatalk

 

[BSK]

So does this mean we shoot does before or after ovulation?

:stir:

 

[444 BLASTER]

NATURE HAS A WAY OF KEEPING THE SEXES BALANCED. IF THE FEMALE IS BREED QUICKLY WHEN SHE'S READY SHE WILL FAVOR FEMALES. PLENTY OF BUCKS ALREADY. IF SHE IS NOT BREED SOON AFTER SHE IS READY SHE WILL FAVOR MALES. THIS IS TRUE IN MANY SPECIES INCLUDING HUMANS. MALE SPERM SWIM FASTER BUT DIE SOONER THAN FEMALE SPERM. IF SPERM IS PRESENT WHEN THE EGG ARRIVES MOSTLY FEMALE SPERM ARE THERE IF SPERM ARRIVES AFTER THE EGG ARRIVES THE FASTER MALES HAVE THE ADVANTAGE. NEWLYWEDS OFTEN HAVE GIRLS FIRST.