Blue Texel Ram

[Bluetex]

Just a question on my Blue Texel Tup, for the third consecutive year he has put out 90% ram lambs, great for stores but not so good for expanding the flock, is this purely coincidence or can the ram determine the sex of the lambs.
He has been put to my Blue texel ewes and my mules with the same results.

 

[primmiemoo]

Off the top of my head, didn't Darwin look into it and conclude it was more to do with the condition of ewes at tupping?

Had a lot of ram lambs in the keepers flock here last year, but plenty of ewe lambs this.

 

[Cowmansam]

Sex is determined by the ram

 

[Cowmansam]

Why you get sexed semen in cows

 

[primmiemoo]

What's the right size of centrifuge for a Blue Texel ram, then?

 

[Cowmansam]

No idea

 

[Cowmansam]

Thought it was done with a laser

 

[primmiemoo]

Good point. There's bound to be a way to guarantee ewe lambs from the elite ewes, but as yet it's eluded this set up.

Going to watch and learn on this one

 

[Cowmansam]

But if I had to guess this would work

 

[primmiemoo]

Beef??

 

[Cowmansam]

could be sure it will take a one way firing off colour texal though

 

[spin cycle]

Just a question on my Blue Texel Tup, for the third consecutive year he has put out 90% ram lambs, great for stores but not so good for expanding the flock, is this purely coincidence or can the ram determine the sex of the lambs.
He has been put to my Blue texel ewes and my mules with the same results.

how many ewes in the mob he went to?

 

[SteveHants]

I have heard some idea that the older a ram is, the more male offspring he throws, but I've never really looked at the science - given that half the rams sperm will be X carrying and half will be Y carrying, and they arise by meiosis, something would have to happen to the X carrying cells, either during spermatogenesis or insemination to make them less viable.....

 

[Highland Mule]

Male sperm are XY and hence smaller, faster and easier tired than females (XX) which have extra dna to carry. If the tup is eager and works fast and before egg release, the males will be speedy in getting up the pipes before the female do, but will tire out and die before the egg is available. If he is a bit slower, and the egg is already on its way, the fast male sperm will have made it to the egg right at the optimum time and the slower female sperm will be left behind.

That’s my theory anyway - a keen young tup seems to leave more females and an older boy more males. One day I’ll crunch the data and confirm.

 

[spin cycle]

Male sperm are XY and hence smaller, faster and easier tired than females (XX) which have extra dna to carry. If the tup is eager and works fast and before egg release, the males will be speedy in getting up the pipes before the female do, but will tire out and die before the egg is available. If he is a bit slower, and the egg is already on its way, the fast male sperm will have made it to the egg right at the optimum time and the slower female sperm will be left behind.

That’s my theory anyway - a keen young tup seems to leave more females and an older boy more males. One day I’ll crunch the data and confirm.

more or less my theory to.....except for the last bit......i think a vigorous tup will repeat servings keeping male sperm in the ascendency whilst a more 'laid back' tup will do the job once and then retire for a fag under a tree thus giving female sperm more chance

mob size is important because in a small flock the tup has nothing else to do but keep going round the ewes repeating (more boys)....but in big spread out flocks he spends a lot of time searching and hasn't time thus more single service (girls)

i keep meaning to graph it according to lambings cos in my theory you should get more rams beginning /end of lambing with max girls in middle when tups were busiest

 

[Highland Mule]

I over supply tups to keep the lambing tight (minimise holidays needed to cover) so will have removed that part. I just remember running an old and a young together and it was almost exclusively one and the other for progeny. This year I’m mostly older tups and seem to have far more tup lambs - will tally at end and see what’s what.

 

[Bluetex]

how many ewes in the mob he went to?

Was 17 ewes last year and 15 this year

 

[Bluetex]

17 in 2020 and 15 this year

 

[spin cycle]

Was 17 ewes last year and 15 this year

thing is his 'capacity' is 60+ ewes so with nothing else to do he was constantly serving those he had whilst in season keeping male sperm in acsendency

 

[primmiemoo]

But doesn't the ewe's system "choose" by variables such as acidity and viscosity?