intresting reading

Agrivator

Member
Very interesting. In summary:

Ewes fed a diet high in Na, K and P had 70 Males:30 Females.
Ewes fed a diet high in Ca and Mg had 30 Males : 70 Females.
Ewes fed a normal balanced diet had 50 Males: 50 Females.

It would make a useful research project under UK conditions.
 
Indeed, most interesting.
I know some soil types vary widely in the cation : anion ratios. The pasture species grown on the more divergent soils can reflect those differences seasonally, i.e. in early spring when soils are still colder than 5 degrees C, grass species are heavily loaded with K causing a much higher metabolic risk to pregnant ruminants. However autumn grown grass would not be so affected. It would be interesting to see cation : anion profiles across the seasons to see if grazing management could be used to alter foetal gender balance. Or if this factor be used to advantageously manipulate gender balance by special feed mixes prior to mating in circumstances where one gender is more beneficial financially.
 

yellowbelly

Member
Livestock Farmer
Location
N.Lincs
Really interesting. Thanks for posting it @JD-Kid .

We always seem to be a lot 'heavier' with tup lambs in the pedigrees.

Pity it's too late to try something for the next crop. Will definitely try something for 2023.
 

JD-Kid

Member
yea I got me thinking and @Global ovine has some points im thinking of

we scan and record our ewes so know who are the top scanners and who's at the bottom of the list now im thinking
top ewes try and set up for higher ewe lambs
med and lower ones set up for more male lambs
idea being use best rams over less ewes with higher lambing leading to higher input of better geans in ewe flock
lower ones more males so higher weaning weight and faster growth

a vet looked at the paper and said the diffrence in feed is not a huge amount but it is showing that something is going on to change the sex of the lambs

paddocks with plants that are higher in Ca Mg and drenched with ADE or injected 4-6 weeks pre mating hopefully will life ewe lamb numbers
poorer paddocks and grasses with lower Ca Mg. high Na K might lift male numbers

have a tow and fert so could apply some min's to preload the grasses

also sent a copy of paper to a vet at uni I have had dealings with in the past to see what she thinks maybe a student would take it up and do a trial on grass management to change sex out come of off spring
 

Agrivator

Member
yea I got me thinking and @Global ovine has some points im thinking of

we scan and record our ewes so know who are the top scanners and who's at the bottom of the list now im thinking
top ewes try and set up for higher ewe lambs
med and lower ones set up for more male lambs
idea being use best rams over less ewes with higher lambing leading to higher input of better geans in ewe flock
lower ones more males so higher weaning weight and faster growth

a vet looked at the paper and said the diffrence in feed is not a huge amount but it is showing that something is going on to change the sex of the lambs

paddocks with plants that are higher in Ca Mg and drenched with ADE or injected 4-6 weeks pre mating hopefully will life ewe lamb numbers
poorer paddocks and grasses with lower Ca Mg. high Na K might lift male numbers

have a tow and fert so could apply some min's to preload the grasses

also sent a copy of paper to a vet at uni I have had dealings with in the past to see what she thinks maybe a student would take it up and do a trial on grass management to change sex out come of off spring

To begin with, a bolus might be the most convenient way. Or even a block or lick with the appropriate levels of the major elements.
 

Agrivator

Member
Anyone care to interpret the results for simpletons such as myself? Calcium and magnesium via bolus at what stage during season?

We need to know first of all if a bolus is feasible, and if there is a better way of manipulating the mineral balance.

Maybe just spread Magnesian Lime a week or two before the tups go out.
 

yellowbelly

Member
Livestock Farmer
Location
N.Lincs
Anyone care to interpret the results

It seems they were feeding an 18% protein feed to all 3 groups with adjustments to the trace elements for each group.
Unusual for concentrates to be fed to flush ewes here ( maybe not in Saudi Arabia??)
Screenshot (87).png

It doesn't say (unless I missed it) how much they were feeding but let's 'guess' at say, 0.5kg/hd/day.

So, for female pre-selection, as a daily intake, they were getting 1.2% Ca = 6g (which would be about 15g of something like calcium carbonate) and 0.35% Mg = 1.75g (which would be about 6.25g of something like magnesite).
I'm guessing that those types of daily intakes (assuming I've got the maths right) are going to rule out boluses.

They also got 4 IU/g of Vit. D (double the male pre-selection ration and 30% more than the control ration).

Looks like we need some pre-tupping tubs that have Ca, Mg and Vit. D if we're not going to flush ewes with concentrates.
 

JD-Kid

Member
It seems they were feeding an 18% protein feed to all 3 groups with adjustments to the trace elements for each group.
Unusual for concentrates to be fed to flush ewes here ( maybe not in Saudi Arabia??)
View attachment 1003935
It doesn't say (unless I missed it) how much they were feeding but let's 'guess' at say, 0.5kg/hd/day.

So, for female pre-selection, as a daily intake, they were getting 1.2% Ca = 6g (which would be about 15g of something like calcium carbonate) and 0.35% Mg = 1.75g (which would be about 6.25g of something like magnesite).
I'm guessing that those types of daily intakes (assuming I've got the maths right) are going to rule out boluses.

They also got 4 IU/g of Vit. D (double the male pre-selection ration and 30% more than the control ration).

Looks like we need some pre-tupping tubs that have Ca, Mg and Vit. D if we're not going to flush ewes with concentrates.
would just do a few to see if it has that efect hate it to go side ways ...
could become a bit of a game changer if the efect can be made to work tho
farmers targeting better use of rams and also lambs to sell
even studs if ram sales there main driver could set ewes up for males or if wanting to put a better ram in to the ewe flock could target ewes to breed ewe replacements
 

JD-Kid

Member
We need to know first of all if a bolus is feasible, and if there is a better way of manipulating the mineral balance.

Maybe just spread Magnesian Lime a week or two before the tups go out.
think the efect might need to be more than 2 weeks thats were pre loading grass lands might be worth doing or select paddocks early for diffrent breeding outcomes and graze ewes on them depending on what outcome wanted

dose make me wonder if lambs chewing out the clovers in paddock and ewes cleaning up afterwards if the grass only feed is slightly set up for male lambs as grass higher in K and lower in Ca Mg
 

yellowbelly

Member
Livestock Farmer
Location
N.Lincs
would just do a few to see if it has that efect hate it to go side ways ...
could become a bit of a game changer if the efect can be made to work tho
farmers targeting better use of rams and also lambs to sell
even studs if ram sales there main driver could set ewes up for males or if wanting to put a better ram in to the ewe flock could target ewes to breed ewe replacements
I'm keen to try it.

We've also got a year 2 vet student who's done 2 seasons lambing with us - I'm going to send him your link in case he's looking for sometbing to do a bit of research into as part of his degree.
 

Kiwi Pete

Member
Livestock Farmer
makes yer wonder if people using sexed semen for dairy cows have a higher % of drys if cows on a higher Na K and P diet or a few strong swimmers still get to there target
This definitely does track with my observations with bovines - we didn't use sexed semen, but was advised to keep open cows away from "the irrigator paddocks" until after the bulls were in and AI had finished.

(more replacement heifers, more beef bulls)
 
I sent the link to my long time trusted nutrition/production mentor Dr. Pete Fennessy of AbacusBio for his comments. The following points were discussed:
  • Saudi ruminant farming has much more controlled feed inputs than in a grazing situation in the temperate zones.
  • The published data appears fine, but will need replicating elsewhere, with which I totally agree.
  • Pete is also very skeptical of its application in commercial practice due to difficulties in precise implementation.
  • All pastures have differing mineral concentrations and balances due to soil , moisture, species mix and temperature differences. The precise mineral profile will need to be known so they can be manipulated.
  • He points out that there may be a risk of embryo loss if a shift goes too far.
  • Changing diet in dairy herds to achieve an imbalance in calf gender was abandoned for the development of sexed semen technologies. This work needs digging out to see what were the technological road blocks at that time.
My $ worth is this work needs expanding. Those farmers with influence into the prioritising of research programmes/funding (I have now retired from such positions) should initiate discussions with science funding bodies to look into this subject by firstly quantifying its economic opportunity to industry, then identifying the knowledge road blocks for research programmes to eventually get it into a working package for pastoral farming.......or, forgetting it as yet in the too hard basket. However this does not prevent individual farmers from trying to influence lamb gender by simply trying something and seeing if it can be repeated the following year. Best wishes to all who try.
 

JD-Kid

Member
yea ill give it a spin weaning tomorrow and tagging ewe lambs have records of were they were grazing before mating and any health treatments that might of had some efect
might be intresting might be nothing in it
I'll do some home work to see if there was a reson they stoped the diet thing with dairy cows there is alot of papers showing the efect of diet. on off spring and I would be guessing alot of dairy farms with higher inputs than sheep farmers there cows may of been quite well balanced and sexed semen might of been easier or cheeper
 

Whitepeak

Member
Livestock Farmer
Very interesting. Might have a little experiment myself, I have a batch of 10 heifers I'm going to AI in March/April so I think I will offer them high mag buckets as opposed the standard mineral buckets. Be interesting to see if it results in more heifer calves.
 

yellowbelly

Member
Livestock Farmer
Location
N.Lincs
Very interesting. Might have a little experiment myself, I have a batch of 10 heifers I'm going to AI in March/April so I think I will offer them high mag buckets as opposed the standard mineral buckets. Be interesting to see if it results in more heifer calves.
Best sprinkle a bit of limestone flour in those buckets too 😙
 

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Five nature-recovery projects spanning 100,000ha launched

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Written by Michelle Martin from Agriland

Image-source-Savills-field-640x360.jpg
Five nature-recovery projects spanning nearly 100,000ha across the West Midlands, Cambridgeshire, the Peak District, Norfolk and Somerset have been announced by the government and Natural England today (Thursday, May 26).

This is the equivalent in size to all 219 current National Reserves.

The aim of the projects is to deliver nature recovery at a landscape scale, helping to tackle biodiversity loss, climate change and improve public health and well-being.

All five projects will make a significant contribution towards the national delivery of the international commitment to protect at least 30% of land and...
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