- Location
- Welshman living in Nottinghamshire
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IgA
- Thread starter Man_in_black
- Start date
- Location
- Montgomeryshire
Are you starting to think your rash change of heart has been premature?
An ebv's based on FEC can only be based on a snapshot, dependient on that animal's worm burden at that particular point in time. An ebv based on IgA result will be based on the genetic ability of that sheep to combat a worm burden, regardless of when it encounters them.
In theory, and as explained to me by a Lleyn breeder participating in the trial work.....
Our local health scheme is hoping to do a research project with this. Not sure exactly what yet though.
Seems to be much less drench resistance (or knowledge of) up here so I'm hoping it will look into that and to highlight the worm resistance (if any) of the native sheep.
Seems to be much less drench resistance (or knowledge of) up here so I'm hoping it will look into that and to highlight the worm resistance (if any) of the native sheep.
As I understand it----
IgA only measures resistance to strongyles not nemo
IgA is more repeatable than FEC
Heritability is about the same (marginally less for IgA?)
You don't have to take IgA samples whilst the animals have a high worm burden
Cost? --I am not sure of the relative costs of IgA and when I last asked (before Xmas no one wanted to commit)
Lleyn boys have done some good work on this and IMO it is one of the most important maternal traits we can measure at the moment
If you are a breeder of maternal sheep and don't record/select/breed for parasite resistance you are doing a pretty poor job (if you are a terminal sire breeder you should also be recording parasite levels so that you can make good decisions on resistance/resilience of your animals )
If you can reduce your ewes worm egg output by 50% in 2 or 3 generations (and subsequently reduce the potential lamb burden by a similar amount) then it must be worth doing?
IgA only measures resistance to strongyles not nemo
IgA is more repeatable than FEC
Heritability is about the same
(marginally less for IgA?)You don't have to take IgA samples whilst the animals have a high worm burden
Cost? --I am not sure of the relative costs of IgA and when I last asked (before Xmas no one wanted to commit)
Lleyn boys have done some good work on this and IMO it is one of the most important maternal traits we can measure at the moment
If you are a breeder of maternal sheep and don't record/select/breed for parasite resistance you are doing a pretty poor job (if you are a terminal sire breeder you should also be recording parasite levels so that you can make good decisions on resistance/resilience of your animals )
If you can reduce your ewes worm egg output by 50% in 2 or 3 generations (and subsequently reduce the potential lamb burden by a similar amount) then it must be worth doing?
The best summary of where we are with this at the moment is here
http://www.signetfbc.co.uk/using-saliva-iga-to-select-sheep-genetically-resistant-to-parasites/
For strongyles the heritability is better than FEC - IgA 0.16 FEC S 0.08
At the moment we are paying £2 per IgA sample (as opposed to £5 or £5.50 for individual FEC) but not sure what the eventual 'commercial' price will be.
http://www.signetfbc.co.uk/using-saliva-iga-to-select-sheep-genetically-resistant-to-parasites/
For strongyles the heritability is better than FEC - IgA 0.16 FEC S 0.08
At the moment we are paying £2 per IgA sample (as opposed to £5 or £5.50 for individual FEC) but not sure what the eventual 'commercial' price will be.
- Location
- Welshman living in Nottinghamshire
Are you starting to think your rash change of heart has been premature?
No no no not at all. In my limited research so far, I think fair to say exlana is about as progressive a breed as you can get. Easycares are purely based on ability rather than looks, so plenty of scope there to make huge genetic gains.
Just trying to get an idea on the future genetic researches taking place.
Saliva samples are taken by putting a dental roll attached to forceps in the pouch between the sheep's teeth and cheek for about 8 - 10 seconds.
For individual FEC samples if you are lucky you will catch a few samples as they go to the loo but otherwise it is a finger in the rectum of the sheep to get a sample - unsurprisingly everyone prefers taking samples from the front end.
- Location
- Welshman living in Nottinghamshire
Not been to Blaenau Ffestiniog have ya.....!!
Heritability's differ between populations ---ours are estimated at FEC S=0.19 & FEC N =0.13 ....not done any IgA yet
Yes the reduction in FEC S heritability has been disappointing. The Lleyn heritability estimates were also FEC S 0.19 and FEC N 0.13 before this latest re-evaluation with a lot more data. At the same time EGENES updated their validation procedures to include more samples with very low values which has made a big difference and I imagine this will be the same for all breeds that have a FEC EBV.