12 October 2018
Innovis embarked on a frequent weighing programme at Mynydd Gorddu near Aberystwyth as part of its work as a Farming Connect Innovation Site but the strategy has been so successful it will now become part of the farm’s standard procedures.
From eight weeks, 1000 lambs from the main nucleus flock are weighed every two weeks.
The previous weights taken are uploaded in the electronic weighing system and this data flags up any that are not achieving target growth rates, allowing the shepherd to work out the reasons why and to draft lambs accordingly.
Faecal egg counts (FEC) are carried out in tandem with weighing. Treatment is only given if growth rates are below target and mob FEC is above 400 eggs per gram.
“If the worm burden is not high we can immediately eliminate this as a cause of poor growth,’’ says Dewi Jones, managing director of Innovis.
“If we know what’s going on it allows us to make a decision on how to treat overall and provides a useful early indicator for issues such as pasturella.’’
Grass growth measurements are also taken fortnightly and, used in combination with the weighing data, allow timely decisions to be taken on grazing management.
Mr Jones says grazing pressure for underperforming lambs is reduced by drafting them into separate groups to get priority grazing at a lower stocking density ahead of the main mob.
“When sheep are pushed hard in a rotation on grass some don’t cope as well as others, perhaps they might be a triplet on a young ewe.
“By taking away those lambs that aren’t growing from the main mob you remove the grazing pressure and it gives these a chance to catch up.’’
At the next weighing, if their growth is back on track, they join their original group again.
An average of 20-25 lambs from 1,000 animals are mostly pulled out at each weighing.
Regular weighing, says Mr Jones, removes the guesswork from fattening lambs or getting ewe lambs to target tupping weights.
“Some farmers will say they can see whether or not their sheep are growing, but can they?’’
Frequent weighing becomes more relevant the more intensively fields are managed, he suggests.
At Mynydd Gorddu, average field sizes are 10 acres and fields are further sub-divided with solar powered electric fences to match grass growth.
“As people move to rotational grazing to focus on grass they sometimes forget about the animal, they get carried away with grass quality. There is no question that by putting in rotations you get up to 40% more carrying capacity but when you are farming upland units like us, some sheep won’t cope as well as others.
“If you carried on regardless you will have a group of lambs that struggle and will have to go in with hard feed later in the year, which defeats the object of the exercise.’’
Frequent weighing is a way of using management practices to deal with that, he adds.
The aim is to get ewe lambs to between 38-45kg at tupping, depending on the breed.
This year, due to a change in policy, the ram lambs will remain on the farm for the winter instead of being sent away to grower units so the ewe lambs won’t be tupped.
But Mr Jones says the aim has still been to get them to target tupping weight by November despite allowing rams to have priority grazing in the winter.
Due to the challenging weather conditions this year, lambs were weaned early at 10 weeks to allow ewes to be moved off the rotations.
Silage was cut early on some of the heavier ground to allow the wetter fields to be brought into the rotation.
“It means we didn’t get enough silage but we were able to keep the grass quality going for the lambs,’’ says Mr Jones.
“We had to supplement the ewes for three weeks but the lambs haven’t had anything.’’
Due to the difficult grazing conditions, lambs achieved daily liveweight gains (dlwg) of 220g to date, compared to the target of 250g.
The farm is well set up with a good handling system which enables 1000 lambs to be weighed in two hours.
Frequent weighing is only suitable for farms with the right handling facilities, Mr Jones insists.
“If you are going to have sheep hanging around all day in the yard and not grazing whatever benefits you hope to gain will be lost.
“Also, if you have to bring in extra staff because haven’t got the right system you won’t get the benefit either.’’
Lisa Roberts, Farming Connect’s Mid Wales Red Meat Technical Officer, says frequent weighing gives farmers objective measurements to make decisions.
“Weighing lambs at regular intervals in combination with frequent FEC can increase numbers hitting target weight and reduce worming treatments because it allows flock managers to intervene on grazing management and health issues,’’ she says.