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After weaning, the focus has traditionally gone onto the lamb crop, but for ewes, the period between weaning and mating in Autumn is important for reproductive efficiency.
Body Condition Scoring
Weaning is one of the key times to Body Condition Score (BCS) ewes (the others are pre-mating and scanning) as it allows for targeted management and better feed use efficiency. Lighter condition ewes can be priority fed over summer while ewes at a BCS of 3 and above can be used for pasture control or maintenance.
Running ewes in one mob over summer means feed is wasted putting extra condition on ewes that have already reached their optimal BCS while lighter ewes are struggling to compete, creating a tail of skinny ewes.
Extra feed is better to be partitioned into lifting the bottom end of the flock, so these ewes are going to the ram at an optimal BCS of 3.
A BCS of 3 at mating is critical to achieving a high pregnancy rate and establishing a pregnancy that is more likely to result in healthy lambs at docking. It takes time to lift ewe condition, especially if feed is limited and growth rates are low. Ewes need 1.0 to 1.3 kg of average to good quality dry matter per day to just hold at BCS 3 over summer.
Management options to increase the BCS of lighter ewes include running the ewes with ewe lambs, rotating them ahead of the main ewe flock or using a summer feed crop.
While repeat offenders can be culled, multiple-bearing ewes should be given the opportunity to regain condition over summer before a culling decision is made.
If feed is particularly tight, consider selling younger ewes which are under BCS 3 and keep older ewes of a BCS of 3 and above.
Udder checks
While many farmers check ewes’ udders at weaning, research led by Massey University’s Dr. Anne Ridler found that four to six weeks after weaning is the best time to find the maximum number of ewes with udder defects.
Studies carried out on farms in the lower North Island found on average five percent of mixed-age ewes had udder defects.
Lambs born to ewes with udder defects have a reduced chance of survival, with a death rate three to four times higher than lambs born to ewes with normal udders. Those that do survive have reduced daily growth rates so ewes with udder defects will wean an average 11kg less lamb liveweight per ewe than those with healthy udders.
To effectively check udders, they need to be palpated, ideally when ewes are standing in a race.
Both halves of the udder should be gently felt and squeezed and where possible, the teats rolled between the fingers.
Mastitis
Generalised hardness of the udder is often called mastitis. If the infection is recent the udder will be hot and swollen and if it has been there for some time, the affected half or halves will feel hard all over.
Ewes with generalised hardness or mastitis in one or both udder halves should be culled.
At weaning, udders can feel firm because they are full of milk, however an udder affected by mastitis will be very firm/hard.
Lumps
Udder lumps can range in both size and number. They are usually only found in one half of the udder but can occasionally be found in both.
As a rule of thumb, ewes with lumps in their udders should be culled as their lambs are more likely to die or have slower growth rates.
It is normal for some ewes to have lumps just in front of or just behind the udder. While these are attached to udder, they are not within the udder tissue.
At weaning, around 3 percent of ewes will have these lumps and by four to six weeks after weaning only 1.5 percent of ewes will have these lumps. As they are normal, ewes with these lumps can be retained.
Burst abscesses
These can be seen or felt on the outside of the udder and are usually the result of infections within the udder tissue. Ewes with these abscesses should be culled.
Teat defects
Ewes with missing and very damaged teat ends should be culled. Ewes with a thickened core down the centre of one or both teats four to six weeks after weaning should also be culled. It is important to note that a thickened core is not a problem if present at weaning.
FOR INFORMATION ON EWE BODY CONDITION SCORING GO TO KNOWLEDGE SEARCH | BEEF + LAMB NEW ZEALAND
Udder checks: beeflambnz.com/news/ checking-ewe-udders-post-weaning
Factsheet: beeflambnz.com/knowledge-hub/PDF/ examining-ewes-udders.pdf