[silkwoodzwartbles]

Has anyone found that a particular management/feed/etc tactic pre-tupping has regularly resulted in greater numbers of ewe lambs born? Or that particular rams throw more females?

I've Googled and only found one article on the subject which suggests that feeding a diet rich in Omega 3 results in more ram lambs whilst one high in Omega 6 results in more ewe lambs - has anyone else found this to be the case?

Really interested in what I can do (other than be lucky!) to increase the number of females born in my flock each year.

Thanks!

[Marches Farmer]

Our Southdowns generally throw 50:50 or sometimes 40:60 rams:ewes, the Badger Face around 50:50 every time.  The ram decides the gender.

[Buttermilk]

I put it down to luck.  Last year I only got 4 ewe lambs from 12 ewes, this year I already have 9 ewe lambs from 8 ewes.  There is a theory floating about that the temperature at tupping time affects the sex but I think that is just hearsay.

[SallyintNorth]

There’s an old farmers’ tale that tups and bulls throw more female offspring when they’re younger and more males as they age.  I did some analysis one year on the moorland farm, where we had nine tups working across 530 ewes, and couldn’t see any pattern. Not all the tups threw 50:50 that year, but one of the youngest threw the most male lambs, the oldest threw slightly more males than females but another older tup threw slightly more females than males.   

I don’t know that it’s correct to put all the cause on the tup.  I know the X and Y genes come from the male, but there are a gazillion ways in which the female can influence which sperm gets to and fertilises the eggs. Acidity of fluid in the vagina, other factors which might influence the motility of one sperm over another; the constituents of the membrane around the ovum, which may be more permable to one sperm than another....  Not much research on all these factors yet, I think. 

[Tim W]

1400 lambs every year for the last 25 years or more , the last 12 years data i have in front of me and there are 94 more ewe lambs than ram lambs born in that time ---insignificant
I would be interested to know how to alter this ratio if anyone can shed any light

[Steph Hen]

You can do it for humans    with over 94% accuracy.

https://www.ncbi.nlm.nih.gov/pubmed/21987941

Timing based on fertility. I've no idea how could be done for sheep though, unless each ewe had measurements taken each day or even more frequently and was only put in with tup after a delay. I have a feeling the mechanics might work in the same way for sheep? The paper and 'Billings method' is easy to understand (and I can recommend it!)

[Badger Nadgers]

Sexed semen for the articial insemmination of cattle is possible, not heard of it for sheep.

[Jukes Mum]

Simple- pray for girls and you'll get more boys. Need more boys, get more girls. Fact 

[silkwoodzwartbles]

Thanks all - some useful and interesting stuff there! Just thought I'd update the thread to say, my final ewe lambed last night. A ram lamb....and (drumroll please!) a ewe lamb Phew! One out of 6!

[Buttermilk]

My total this year is 9 ewe lambs and 10 ram lambs out of 8 ewes.

[silkwoodzwartbles]

Very impressive Buttermilk! Did you sponge/PMSG/flush/use teasers to achieve that %? I was reasonably pleased with 6 lambs from 4 ewes!

[Buttermilk]

No sponging or flushing but I did run a teaser ram in with the girls for a few weeks before tupping.  My hope was to tighten up my lambing but they still took 4 weeks over the job.