pondering
- Thread starter glover36
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allenfarms
Well-known member
Them bulls r just bad shots i recon :lol:
TheBullLady
Well-known member
I would think it's the dam.. I have a handful of holder cows that have alway had one sex calf.. and I run a different bull every year.
we haev a few cows like that some that only throw heifers and ones that only throw bulls like this amazing milking shorthorn cow that is ranked 4th in canada and hasnt been milked in 2 years and every one wants a bull from her but none lol
generally speaking it is the bull that determines sex of the calf, by contributing either an x (female) or y (male) chromosome, depending on which spermatazoa fertilizes the egg. However, the pH of the cows reproductive tract may favor one sex spermatazoa over another, possibly. but most of the time its just 50:50 odds.
if shes a really good cow dont hold your breath for a heifer.
if shes a really good cow dont hold your breath for a heifer.
Proverbs 12:10
Well-known member
Beefy is correct...bull has x and y chromosome and cow has only y. One out of every 256 cows will have 8 straight heifers and one out of every 256 cows will have 8 straight bull calves. This is not taking into account differences in sperm life and other factors which could slightly alter the odds.
beefy,
can you elaborate on the Ph of the reproductive tract for bulls vs heifers. I remember reading it somewhere, but couldn't find the site again. it was regarding AI and had something to do with the PH of the repro tract starting off more neutral and changing to be more acidic. Think it was said that the x sperm was more tolerant to the acidic environment than the y. If I remember correctly it was to breed early for heifers later for bulls, but I am really not sure which way.
It is female is xx and male is xy
can you elaborate on the Ph of the reproductive tract for bulls vs heifers. I remember reading it somewhere, but couldn't find the site again. it was regarding AI and had something to do with the PH of the repro tract starting off more neutral and changing to be more acidic. Think it was said that the x sperm was more tolerant to the acidic environment than the y. If I remember correctly it was to breed early for heifers later for bulls, but I am really not sure which way.
It is female is xx and male is xy
novatech
Well-known member
randiliana
Well-known member
glover36":3vmyghy4 said:
We had a cow like this. 5 straight bull calves, and all good ones. She finally had a heifer last year, wasn't near the calf that her bull calves were.
The bull is mostly responsible, otherwise the sexed semen deal would have been a total flop. However there are several smaller factors that involve the cow as before mentioned the uterine enviroment may in fact be favorable to one sperm type. The timing of the ovulation to standing heat is rumored in the scientific world to possibly be a factor as well, but this of course goes back to the presumption that X and Y sperm cells behave differently. Dertrimental recessives could be to blame for a small portion of the single gender calves by a given sire or dam. If the recessive gene lines up in one gender only and caused early embryonic death it could explain the swayed results. This would be very rare in my opinion.
Out of ten straws of semen from TC Foreman, we got nine pregnancies. Seven of then (so far) have been heifers, two bulls, with one left to be declared. We don't use bulls natural service at all and it seems that we generally have more bulls than heifers. But I don't know that we've ever had such lopsided results for either gender out of one bull.
Workinonit Farm
Well-known member
I had one cow, that out of 10 calves, only 2 were heifers. All calves by different bulls with the exception of her last two calves. Of those last 2 calves she had one bull and one heifer, they were not twins.
Katherine
Katherine
Victoria
Well-known member
Most times it is determined by the bull. We had one bull that threw 90% heifers, until we put him in with our purebreds so we could get heifers to keep - then suddenly he went down to 50%. Typical. :lol:
