Most of the ewes that make up the New Zealand ewe flock are high-performance animals, and many are sitting on a metabolic knife-edge as they get closer to lambing.
Ben Allott from North Canterbury Vets says 30 years ago, ewes averaged 55kg and scanned an average of 110%. Today, ewes are 70-75kg, are scanning 190% and more, and are similar to high-performance dairy cows.
Most of these ewes will be carrying twins and triplets and it is important farmers understand the feed requirements of these animals going into lambing.
In the last 30-40 days of pregnancy, energy requirements increase in line with demands from the fetuses and in these later stages of pregnancy, ewes are less resilient to feed restrictions and stress.
Shearing is the single most stressful management practice ewes are subjected to, so pre-lamb shearing in late pregnancy is particularly hard on ewes.
Mustering the ewes into the yards, holding them off feed and the significant increase in energy demand in the 10 days after shearing are all very stressful on ewes.
“We are taking ewes right on the knife-edge and shearing them three weeks out from lambing, or putting them on the conveyor a few days from lambing and then we are surprised when we get high peri-natal lamb losses.”
He encourages farmers to think about the timing of shearing in relation to feed intake, reproduction and animal welfare.
Similarly, set-stocking going into lambing is a complex issue that can, if not managed correctly, stress ewes at the point of lambing.
Ben says too often everything is done at once, with ewes taken off winter feed, walked and often held in holding areas off feed, before receiving pre-lamb animal health treatments. They are then walked out to their lambing blocks.
“The change of feed type is enough of a stress let alone standing them off feed for a day while they are vaccinated or drenched.”
He urges farmers to consider carrying out animal health procedures a month out from set-stocking, or transitioning sheep on to their lambing blocks if they are a long distance from where the ewes have been wintered.
“Think about the stress and the impact it has on animals at such a critical time and think about ways to reduce that stress.”
Ben advocates farmers using a fence at the top of the cliff approach to animal health, rather than using vets as the ambulance at the bottom.
Animal health plans, tailored to the individual farm, take a proactive and long-term approach to animal health with a focus on driving both productivity and profitability.
Ben says in the North Canterbury area where he practices, he has been involved in the development of 70 active animal health plans for sheep and beef farmers and these are used to inform livestock management decisions.
While animal health plans are a requirement of some processor compliance programmes, Ben says they can add real value to the business by identifying current and potential animal health issues and making a plan to manage them.
He recommends farmers talk to their vets about working together to develop an animal health plan for their business.
- For more information about peri-natal ewe management go to https://beeflambnz.com/search?term=ewes+lambing.
Supplied by Beef +Lamb NZ sheep milk
