Ewe flock annual mortality rate

[ringi]

Using a raw kg weaned figure will favour bigger ewes. Weight of lambs weaned as a percentage of ewe weight at tupping is the better figure.

Unless cull all oversized ewes before topping.

 

[ringi]

Would require tagging at birth or DNA testing, both of which are expensive.

I not convinced that tagging at birth is costly for small flocks and the saved money/time due to geting same output from fewer ewes could justify it.

 

[Jop]

Do they cull if empty at scanning?
Do they count these culls as loses?
Do they cull based on age?

Yes cull empty’s
No they are culls and part of the 30% replacement figure not the deaths.
Most flocks culled on age at 6 but not all, replacement rate and death rate was no different on flocks that culled on age.
Also interestingly shearlings that are wet dry at tailing were no more likely than any other of the same age group to not rear a lamb the following year.

 

[Guleesh]

That depends on the relative cost of keeping a ewe lamb as a replacement compared to the cull value of a 4 crop ewe. But I would rather see culling based on kg of lambs from each ewe rather then a fixed age of ewe.

I see the bigger problem is that selling at a fixed age is cutting short the chances that the most longed lived ewes will have of proliferating their genes (superior genes to a sheep that dies at an earlier age), effectively replacing their potential lambs with lambs born to less proven ewes. Obviously there's a limit to how long a ewe should be kept for and there's an optimum age to sell, but this age varies by many years between individuals.

 

[ringi]

I see the bigger problem is that selling at a fixed age is cutting short the chances that the most longed lived ewes will have of proliferating their genes (superior genes to a sheep that dies at an earlier age), effectively replacing their potential lambs with lambs born to less proven ewes. Obviously there's a limit to how long a ewe should be kept for and there's an optimum age to sell, but this age varies by many years between individuals.

Can party help with this if replacements are never kept from 1st crop.

 

[unlacedgecko]

Can party help with this if replacements are never kept from 1st crop.

That slows genetic gain.

 

[Guleesh]

Can party help with this if replacements are never kept from 1st crop.

That slows genetic gain.

Using tup lambs bred from oldest ewes seems the most logical way to me.

 

[ringi]

That slows genetic gain.

Using tup lambs bred from oldest ewes seems the most logical way to me.

It depends on how much you trust your data about your younger ewes.

 

[Aspiring Peasants]

That slows genetic gain.

But could you not have older ewes that have better genetics than younger ones born from other ewes, so keeping replacements from the older ones is better?

 

[unlacedgecko]

But could you not have older ewes that have better genetics than younger ones born from other ewes, so keeping replacements from the older ones is better?

Potentially.

However, at a flock level most genetic gain comes from the ram. Therefore younger ewes should have better genetics than older ewes.

 

[Highcountry]

Many factors other than Individual genetic inheritance will determine longevity. 80 years ago the average age of death of men was somewhere around seventy, I forget the precise age, but now is 84. This increase is likely predominantly diet driven and attributable to fortification of foodstuffs with vitamins and trace elements more than being genetically determined. Also of course quality food is widely available. Before world war 2 rickets was relatively common in Britain leading to poor growth and stunting; now that many foods are fortified with vitamins, especially b and d height weight ,and longevity are hugely improved. I suspect that the lack of trace elements and probably also vitamins in sheep may still be somewhat unappreciated and possibly under researched as well as being under treated especially in marginal farming areas. As an example our lambs were cobalt deficient in September despite being given supplements earlier on. This may well have caused some failure to thrive. We are still trying to establish a better b12 regime and continue to explore appropriate measures to enhance other deficiencies.

 

[egbert]

Potentially.

However, at a flock level most genetic gain comes from the ram. Therefore younger ewes should have better genetics than older ewes.

That's working on the premise that each ram is better than the previous....which isn't always the case.

Using tup lambs bred from oldest ewes seems the most logical way to me.

When we're really on it, jnr goes through ewes at tupping, and marks best teeth etc, then using that, we select tup lambs off ewes we like the look/performance off later.
Critically, i want tups off ewes i like.

 

[egbert]

Many factors other than Individual genetic inheritance will determine longevity. 80 years ago the average age of death of men was somewhere around seventy, I forget the precise age, but now is 84. This increase is likely predominantly diet driven and attributable to fortification of foodstuffs with vitamins and trace elements more than being genetically determined. Also of course quality food is widely available. Before world war 2 rickets was relatively common in Britain leading to poor growth and stunting; now that many foods are fortified with vitamins, especially b and d height weight ,and longevity are hugely improved. I suspect that the lack of trace elements and probably also vitamins in sheep may still be somewhat unappreciated and possibly under researched as well as being under treated especially in marginal farming areas. As an example our lambs were cobalt deficient in September despite being given supplements earlier on. This may well have caused some failure to thrive. We are still trying to establish a better b12 regime and continue to explore appropriate measures to enhance other deficiencies.

I thought it was wrapped silage that raised the life expectancy round here. No more 'farmers lung'.
(quad accidents pulled it back a bit soon after mind)

 

[puppet]

Many factors other than Individual genetic inheritance will determine longevity. 80 years ago the average age of death of men was somewhere around seventy, I forget the precise age, but now is 84. This increase is likely predominantly diet driven and attributable to fortification of foodstuffs with vitamins and trace elements more than being genetically determined. Also of course quality food is widely available. Before world war 2 rickets was relatively common in Britain leading to poor growth and stunting; now that many foods are fortified with vitamins, especially b and d height weight ,and longevity are hugely improved. I suspect that the lack of trace elements and probably also vitamins in sheep may still be somewhat unappreciated and possibly under researched as well as being under treated especially in marginal farming areas. As an example our lambs were cobalt deficient in September despite being given supplements earlier on. This may well have caused some failure to thrive. We are still trying to establish a better b12 regime and continue to explore appropriate measures to enhance other deficiencies.

Life expectancy was early 60s then so a big jump. Better housing and diet has helped but the expectancy was lowered by children dying of infections. Some of those would have lived to 100 if they avoided all the diseases which are now preventable by vaccination. Longevity is strongly influenced by genetics and health promotion and improvements helps the genes to do their stuff.
There may be some lessons for farming and sheep.

 

[Hilly]

But when the payment for draft ewes is good there maybe no reason to try keeping past 4crop.

Definitely not .

 

[ladycrofter]

If anyone enjoys a podcast I was listening to the head shepherd podcast the other day where they interviewed a researcher on ewe wastage. Research done in NZ suggested ewe mortality throughout the year was 7-8% and replacement rate close to 30%. Certainly made me feel better anyway

Link please. Thanks.

So glad to read many not keeping them past four crop. We've had some tough discussions over the last year about culling and now the statistics from this year tell us that 4 is enough. We had thought 5 crop but my Dead List says no.

So far:
1 Prolapse - already marked 2023 and missed
2 Prolapse - 5 crop
3 No milk and 2 on the bottle - 5 crop and being generous here
4 Left behind a slightly brain damaged twin - 5 crop and 1 on the bottle ( ok now)
5 Mastitis and lame - 5 crop, one side now working and sound with 1 surviving twin
6 Global health collapse and died with trips inside - 4 crop
7 Died - "old" and no explanation why she's still here

90% the work NOT related to weather has been due to old sheep. Yes we get the rare twitchy gimmer, wobbly lamb, etc. And we have been bringing ones inside born late in the day due to weather, the wind chill was1.2 at 5am today. But bottom line, no longer disputed, 5 crop are going and probably most, if not all, 4 crop. The gubbins just doesn't work as well by then.

 

[ladycrofter]

Definitely not .

+1 Another issue I have with keeping old sheep is that by the time they do go off, they can be quite frail. It's not fair to them after all the work they have done. They deserve a better end. In years past we have actually shot them here or had them die on us. Better a few quid to us rather than the knacker.

 

[egbert]

Somewhat direct spoken dealer Ken Jones reckoned anyone who claimed to lose less than 10% of the lamb crop was 'a f$£%ing liar'

 

[Aspiring Peasants]

There’s lies, damn lies and statistics

 

[Guleesh]

+1 Another issue I have with keeping old sheep is that by the time they do go off, they can be quite frail. It's not fair to them after all the work they have done. They deserve a better end. In years past we have actually shot them here or had them die on us. Better a few quid to us rather than the knacker.

I don't think it's unfair to let a sheep carry on doing what she does for as many years as she is capable, she doesn't think of it as work, she simply wants to live, she isn't hoping to be killed in her prime to avoid frailty in old age.