Below is some information about how to artificially rear lambs that I have accumulated over 15 years of doing it both professionally and personally.
Today I have covered the basics of feeding methods and infrastructure. There is so much more that goes into raising lambs, but that would require a book, not just an article. If you would like to know more about the health issues, nutrition and management of artificially reared lambs, let me know. For now, we'll stick with how, why and what to feed them, along with how to house them.
Feeding techniques, milk powders and concentrates
How you feed your lambs will, in part, be influenced by your infrastructure, but also by your personal choice. Each method has pros and cons, which are listed below. Consider what is important to you. What will make your life easier, what is financially viable and what do you expect out of your lamb rearing?
Milk powder choices
One thing we haven’t yet achieved on the lamb-rearing front is a diet that accurately matches the lamb's requirements. A ewe's milk gradually increases in protein throughout lactation and the lamb's requirements change almost by the day, therefore it’s almost impossible to cater for it artificially on any sort of scale.
Most milk powders have a CP/ME ratio of 11/MJ, which isn’t enough for a newborn lamb and is far too much for an older lamb close to weaning. You can adjust this by changing milk powders, but that increases the risk of gut issues from transition and also adds to the complexity of management.
There is a little flexibility with older lambs, as you can adjust concentrate feed levels. But with newborn lambs, you don’t have that option.
Casein vs whey
The most common milk powders are casein-based, but recently whey-based milk powder has become available to us. Both proteins are components of milk - and both are good foundations for replacement milk powder - but they are quite different in their composition. Whey digests faster than casein and has a slightly higher content of essential amino acids. Whereas casein is closer to the composition of a ewe’s milk. There is quite a rabbit hole of science you can go down to compare the two, but I won’t do that today.
The choice often comes down to what kind of lamb-rearing system you are going to have. Many people don’t really have the time or budget to rear lambs but they do it anyway. This means that sometimes lambs are fed late (or early) and things may not be as clean as they should be. This is okay, as long as you set up your system accordingly. Establish whether you’re going to be on time with feeding every single day and can commit time each week to disinfecting milk lines and teats. If so, then casein may be for you. But, if you’re fitting lamb rearing around an already busy schedule, and things may slip up sometimes, I highly recommend whey-based powders.
The reduced risk of abomasal bloat on whey-based milk powders is the main selling point for me. Abomasal bloat is more common in casein-based powders for a few reasons. One is the speed at which the milk passes through the gut. Casein-based milk sits in the digestive tract for longer, allowing for the build-up of bad bacteria. Casein-based milk powders are also higher in lactose, which supports the growth of those bacteria too (be that in the gut or in the milk feeders/lines/teats). Lambs gorging on milk can also cause this to happen. Abomasal bloat often kills larger, ready-to-wean lambs. It is very costly to the system (and your mental health).
Another factor is the behaviour of the animals on each powder. Anecdotally, I have found that lambs reared on whey-based powders act more like a naturally reared lamb than those on casein. Whey-based milk powders also mix more easily and are far easier to clean off equipment than casein.
The first downside of whey is that lambs will scour more. It is also slightly harder to get lambs to week one on whey-based milk powders but, once they are there, there is less risk of them dying of a burst abomasum five weeks down the line. Lambs on whey-based powders also have slightly lower average daily gain (ADG) whilst still predominantly being fed on milk. However, I believe this lower ADG is worth it for a better-performing ruminant at the end of it. Lambs on casein-based powders act like kids fed McDonald’s. They get fat, quickly, but their gut health is sub-par.
This is not to say you shouldn’t use casein-based powder. As I said, if you can promise a regular feeding and cleaning schedule for 6-10 weeks, then it could be a good option for you.
Concentrate options
Concentrates are a cheaper form of energy and protein than milk powder. So, the sooner lambs are eating whatever it is you choose, the better.
It is my personal preference to feed lambs a muesli from day two up until around week three, which is when they tend to get picky and start sorting through it. Then, I’ll transition to a small whole pellet that has everything combined in it.
The initial muesli offered needs to be appealing to a naive lamb. Molasses is usually added to most store-bought mixes. But if you find what you purchased to be too dry, simply add molasses or even sugar. I recommend making sure your muesli includes a coccidiostat if you are planning on raising more than 20 lambs. Lambs can recover from coccidiosis if they are healthy, but it is an unnecessary challenge that can avoided.
Feeding concentrate and roughage both improve development of the rumen papillae, which will lead to faster finishing times (or a more efficient mature animal). Offer hay or straw for the lambs to chew on. If you do not offer something for them to chew, they will opt for their bedding, which could be contaminated and cause them to get sick.
Water
I always come across some resistance to my thoughts on water but, so far, my lambs turned out okay. My rule of thumb?
DON’T OFFER WATER UNTIL YOU KNOW THE LAMB IS 100% TEAT-TRAINED.
See why it comes up against some resistance? It’s understandable. But here’s my argument: a lamb that is stubborn to teat-train will inevitably get mildly dehydrated. If there is water on offer in its pen, a lamb’s instinct when dehydrated will be to drink the water and it will then fill itself up on water and not milk. To an untrained eye, the lamb will look full and content.
This is especially tricky to keep an eye on if you are using an automatic milk machine. It would be easy to presume the lamb is simply drinking when you’re not around. It isn’t until day five that the lamb starts to show signs of being ‘off’. At that point the lamb has learnt to drink from a water bucket and maybe eat the meal that was on offer. It will look full until the lack of fat, calcium and protein (which its not getting from milk) starts to show. And let me tell you, trying to re-train a five-day-old lamb back onto an artificial teat is a nightmare.
So, unless you’re 100% certain the lamb is getting its daily allowance of milk via a teat and the lamb is healthy and bright, don’t offer water. This, even with the most stubborn of lambs, is usually achieved by day two or three. And how many two-day-old lambs do you see drinking water?
Scours: bentonite or OptiCalf
People often associate orphan lambs with scours and they have a point. However, it’s not always bacteria or viruses that cause scours in lambs. Sometimes it’s gorging, sometimes it’s a poor immune system due to being an orphan lambs. Whatever the reason, we need a plan in place to deal with them.
My favourite defence is either calcium bentonite or a product called OptiCalf. The lambs love it and it works as a great binder for scours. The difference is noticeable in a few days.
Work with what you’ve got
There are many different ways to rear lambs. Your budget, infrastructure and resources will determine how you go about it. It’s your job to create a shed design that maximises your potential.
It is unlikely you will be building an entirely new structure for your lamb rearing unit (LRU), so take stock of what you have and figure out how you can make it work. There are several important requirements to consider and often you will not manage to meet all of them initially. In order of importance, consider:
- Space: Lambs need 0.4m2 minimum per lamb until they reach 15 kg, when that increases to 0.6m2. Work out how much space you have and work backwards. This will the maximum number of lambs you can have whilst keeping them healthy. If you are expecting to rear more than this, find more space.
- Drainage: Lambs produce roughly ½ a litre of urine per day, if not more. Make sure your chosen site has adequate drainage, either with a concrete slope or an absorbent ground material.
- Resources: Being close to water and power is almost a necessity, one for the use of heat lamps and two to reduce labour input transporting milk back and forth.
- Sunlight: Although lambs can be raised under artificial light, given the chance to sit in the sun, they will. This means any spots that the sun hits need to be clean and dry, as the lambs will group in this spot.
The key to a good shed design is a combination of all of these aspects and really thinking about the implications of each decision. After a few years of doing it, you’ll notice the changes you need to make to finesse your LRU and, hopefully, you can implement these over time.
'Spaces' required
Now you have figured out what you’re working with and how you’re going to work it, you can figure out the potential of your space. I find a LRU needs two or three specific areas.
ICU/heat box: This is where new lambs on death's door go. Anything not able to stand up should be separated from those that can. This area needs to be cleanable to remove the risk of infection spreading amongst the rest of the lambs. Hot air circulating will warm lambs up more quickly than a direct heat source. I have seen baths, fruit boxes and fish containers used and they work well.
Days zero to two: I recommend you have a specific pen for the first two days of life. Your young lambs will need a small space that has minimal airflow, possibly close to a power source so that you can use a heat lamp. They are then moved from this area once they are successfully standing up and feeding alone. A smaller pen will encourage lambs to join together for warmth, but too small and they may smother.
Day two to four weeks: The number of ‘growing’ pens you require is determined by the number of lambs you have. Ideally, I wouldn’t have any more than 20 to a pen for the first four weeks. With an allowance of 0.4m2 per lamb, this is 8m2. Once they’re bigger than 15 kg, that allowance goes up to 0.6m2 per lamb so, if you intend to keep them indoors until weaning, they will need more room.
Within the pens themselves, consider where you will feed lambs both milk and concentrate, provide water, as well as where the lambs will lounge and sleep. You want the lounging area away from the feed area, if you can, so there is easy access to food for other lambs. If there’s a sunny spot, don’t put feed there as it will collect lounging lambs.
You want as much access around the roughage as possible, so try placing it in the middle of a pen or wall. The same goes for feeding concentrate. Water is less of a priority, but try putting it closest to the point of drainage in case it leaks.
When it comes to where you feed lambs, the optimum height for teats is 25cm from the ground, so there needs to be a structure to allow for that. Gates and railings are usually the common supports for milk troughs. Feeders also leak, so put them close to the point of drainage if you can.
Week four and beyond: Ideally at this age lambs should be outside on grass, topping up their diet with a cheaper feed however they still need access to milk, water, concentrates and roughage. If they stay inside their space requirements go up to 0.6m2, if not more.
Lamb behaviour management
I’m a firm believer in the fact that lambs should be in pens with other lambs the same size as them. Bullying is very much a real thing when it comes to artificially rearing lambs. A small lamb will remain small if it's in a pen with lambs twice the size of it. The problem here is, if you’re only raising a 10-25 lambs, keeping 5 tiny wee triplet lambs separate from the rest isn’t always practical.
Lambs have a social structure, meaning they make friends amongst their group of lambs. If you move a lamb from one pen to another, it will bleat its little head off for as long as two days. After that, it settles and makes new friends and everyone is happy. However, this is a stress that shouldn’t be put on lambs unnecessarily.
If you have a band of bad weather coming in, and you know you’ll inevitably end up with 20+ lambs over the course of a few days, consider keeping them in body weight groups from a young age. That way, you end up with three groups of even-sized lambs at 1-3/4/5 days old that will continue on in the rearing shed in a group of lambs that are a similar size and a similar age. It is better to have a lamb alongside a lamb with five days between them in age, rather than 5 kg.
As I said at the start, there is far, far more to lamb rearing than I could write in just one article, But, hopefully, this has helped you begin to think about different ways you could possibly raise lambs on your farm. Feel free to pop any questions you may have down below.
