Hair/shedding sheep X charollais

[NZDan]

Completely agree that big lambs have a head start compated to smaller ones that never seem to catch up. But they need to be born alive in the first instance...

There is a Romney trial going which amoungst other things is looking at the relationship between birth weight and lamb survival, so far there has been a positive correlation between birth weight and lamb survival, with no upper drop off as was expected, and there is a strong correlation between birth weight and weaning weight. Some of the results have surprised a few people.

 

[neilo]

Ideally we'd all like 7-8kg lambs born, which will generally have high survival rates after birth, and higher growth/weaning weights. The difficult bit is finding a ewe weighing 65kg that can give birth to these things unassisted, whilst not being so slack around the back end that all her insides follow them out too.

 

[Sandpit Farm]

There is a Romney trial going which amoungst other things is looking at the relationship between birth weight and lamb survival, so far there has been a positive correlation between birth weight and lamb survival, with no upper drop off as was expected, and there is a strong correlation between birth weight and weaning weight. Some of the results have surprised a few people.

This is interesting. The correlation between birth weight and 8 week weight is positive, but it is negative with lambing ease. I believe they are working on lamb survival EBVs at the moment.

With the need for over 2000 phenotypic records to generate a rudimentary EBV, I'd be interested to know more about the Romney trial. If it is on a large 'hill country' farm, are ewe deaths measured? And if so, is that a negative for lamb survival? You see what I'm getting at. If you aren't careful it paints the picture that lamb survival is better for big lambs BUT ONLY where the ewe was able to give birth to it.

 

[willy]

A bit more of a close up 1 suftex x wilty and one durnoxwilty

 

[willy]

A nice pair born 2 weeks ago

 

[willy]

That last pair is a meatlinc x easycare

 

[NZDan]

This is interesting. The correlation between birth weight and 8 week weight is positive, but it is negative with lambing ease. I believe they are working on lamb survival EBVs at the moment.

With the need for over 2000 phenotypic records to generate a rudimentary EBV, I'd be interested to know more about the Romney trial. If it is on a large 'hill country' farm, are ewe deaths measured? And if so, is that a negative for lamb survival? You see what I'm getting at. If you aren't careful it paints the picture that lamb survival is better for big lambs BUT ONLY where the ewe was able to give birth to it.

Yes it's a large trial covering get both low ground and steep hard hill country. So far there is a positive correlation between lamb survival and birth weight, there is no drop off in survival as birth weight goes up. There has been no increase in stuck lambs at higher birth weights.