The best diet that you can offer your lambs is good quality colostrum, followed by milk that they consume straight from their healthy, well-fed dam. Unfortunately, things do not always go as planned and all shepherds should be ready to, at least temporarily, supplement or replace a lamb’s colostrum needs in case their dam is unable to do so.

What is colostrum?

The “milk” that ewes produce in the days leading up to lambing and is available to her lambs on the first day after lambing is called colostrum. It is “liquid gold” that contains antibodies to all the diseases that the ewe has been exposed to. Colostrum also has antioxidants, antimicrobial substances, as well as growth factors and vitamins. Colostrum is also higher in fat and protein than milk and contains compounds with a slight laxative effect to help lambs pass meconium (the first, black stool that a lamb passes). Ingesting adequate amounts of good-quality colostrum will set your lambs up for a good start.

The best quality colostrum comes from a healthy, adult ewe that has spent her whole life on your farm. This colostrum works best when consumed by a lamb that is born and will be growing up on your farm because the antibodies are targeted to the disease-causing organisms it is likely to encounter. Colostrum is thicker than milk and more yellow in color. When you strip milk from a ewe just after birth, be sure to look at the color and consistency of her colostrum. If it looks like regular milk there is a problem and you should supplement her lambs with colostrum.

The quality of a ewe’s colostrum rapidly decreases with time after lambing. The initial colostrum has the highest concentration of antibodies and as she is milked out, or the lambs suckle, the colostrum starts to be diluted out and turn into regular milk over the next 24-36 hours.

Why do lambs need colostrum?

Lambs are born without antibodies, as the type of placenta that sheep have does not allow large proteins to pass from the ewe’s bloodstream to her lamb(s). This leaves lambs vulnerable to disease until their own immune system fully matures and they are able to produce their own antibodies, at about eight weeks old. Luckily, they are able to absorb antibodies from their intestinal tract in the first 24-36 hours after birth.

A lamb is born with the ability to absorb large molecules like antibodies into their bloodstream from their GI tract. Over the first 24 hours of life, they gradually lose this ability and are no longer able to absorb antibodies after 24-36 hours. They are most efficient at absorbing antibodies right at birth (they are able to absorb 100% of the antibodies in colostrum), and even though they might have some ability to absorb antibodies at 36 hours, they are much less efficient at it (they are only able to absorb less than 10% of the antibodies in colostrum offered at this time).

The ability of a lamb to absorb large molecules from the GI tract for the first day puts them at higher risk for absorbing bacteria and toxins, too. Lambing in a clean environment and limiting the contact that lambs have with fecal pellets, or dirty wool tags during this time can greatly improve outcomes. If you need to tube feed or bottle feed colostrum to a lamb, make sure that you thoroughly clean the tube and bottle-feeding supplies between lambs and handle them carefully so they do not become contaminated with fecal material in the barn.

Colostrum is also more nutrient dense than ewe milk to ensure that lambs have adequate nutrition to get off to a good start as they are figuring out how to navigate life outside the womb.

It was speculated that lambs do not respond well to CDT vaccination in the first few weeks after birth because the antibodies that they get from colostrum interfere with the vaccine. A study done to see when the best time is to vaccinate lambs for CDT found that lambs are simply not able to respond to vaccines in the first few weeks after birth, regardless of the levels of antibodies that they have. As you can see in the graph below that is labeled “Ewes”, when ewes are vaccinated three weeks before lambing there is a rapid increase in their antibodies that gradually decreases over the weeks before and after lambing to approach the levels in unvaccinated ewes 12 weeks after lambing. In the graph labeled “Lambs” you can see that the lambs born out of vaccinated ewes start with high antibody titers that gradually decrease to the levels in unvaccinated lambs by 10 to 12 weeks old. They compared lambs out of vaccinated ewes to lambs out of unvaccinated ewes to see if they respond differently to CDT vaccination at different times. They divided the lambs into 6 groups.

• Lambs out of vaccinated ewes that did not get any vaccines
• Lambs out of vaccinated ewes, vaccinated at birth and given a booster at 3 weeks old
• Lambs out of vaccinated ewes, vaccinated at 3 weeks old given a booster at 6 weeks old
• Lambs out of unvaccinated ewes that did not get any vaccines
• Lambs out of unvaccinated ewes, vaccinated at birth and given a booster at 3 weeks old
• Lambs out of unvaccinated ewes, vaccinated at 3 weeks old and given a booster at 6 weeks old

You would expect the lambs to show an increase in antibodies after vaccination like the ewes had, however they found no difference in how the lambs responded (antibody levels to toxin produced by Clostridium), as can be seen in the graph below. The non-response was not due to interference from the antibodies lambs out of vaccinated ewes had, as all the lambs had the same lack of response. It appears that lambs are simply not able to mount an immune response to a vaccine (or an infection) at that age. They are totally dependent on the protection provided by the antibodies they absorbed through colostrum. You can find the whole study here.

As can be seen from the results above, lambs just do not have the ability to respond well to infection or vaccination early in life. About 50 % of lambs that die between birth and weaning do so in the first day or two of life. Ensuring that lambs receive an adequate amount of high-quality colostrum in the first 24 hours of life can go a long way to preventing lamb losses. It is a race against the clock from both sides; the ewe’s colostrum quality decreases and the lamb’s ability to absorb it decreases over time, so ensure adequate colostrum ingestion as close to lambing as possible.

How much colostrum does a lamb need?

Recommendations for how much colostrum a lamb needs varies by source. British and Canadian sources recommend 50 ml/kg (roughly 0.75 fl oz per pound) colostrum in the first 6 hours after birth, and a total of 200 ml/kg within the first 24 hours. Below is the calculation for an 8-pound lamb:

The table below shows the amount to feed for a few weights if you want to skip the math. I rounded the ml volumes up or down to 5 ml increments.

The recommendations for how much colostrum to give are based on good quality colostrum with high levels of antibodies. Lower quality colostrum will require larger volumes to be given. Make sure your lamb gets at least the recommended total volume of colostrum in the first 24 hours. Shepherds do need to get some sleep during lambing season, so if you are not able to evenly spread out the feedings, focus on the first 12 hours after lambing as the lambs will absorb the antibodies better.

When do I need to supplement?

Unfortunately, not all ewes produce enough high-quality colostrum for all their lambs. Lambs that have full bellies, most likely ingested adequate amounts of colostrum. A refractometer can be used to check the brix level (a measure of dissolved solids in a liquid) of colostrum if you prefer to have an exact cut off for when colostrum quality is inadequate. You need to check colostrum quality right at lambing as the quality decreases as the lambs start suckling. Good quality colostrum should be above 22%, if brix is below 20%, the lambs will need supplementing.

Below is a list of conditions that might prevent a ewe from providing enough high-quality colostrum for all her lambs in the first 24 hours of life.

• Sick ewes – ewes that require treatment for pregnancy toxemia, hypocalcemia or any other disease in late pregnancy.
• Injured or painful ewes – ewes that are in labor for a long time or need a lot of intervention during lambing can be too painful or tired to let their lambs nurse for the first few hours after lambing. Make sure to provide adequate pain control and help lambs to nurse while the ewe is resting.
• Ewe lambs and yearlings produce less milk when compared to adult ewes; they also produce less colostrum. When they have multiple lambs, especially triplets, there might not be enough colostrum for everyone.
• Ewes that are new to your farm do not have as many antibodies to infectious diseases specific to your farm. If you have colostrum from ewes on your farm available, it will be beneficial to give some to these lambs for more targeted protection.
• Ewes with quads, or ewes with low milk production that have triplets.
• Ewes with pendulous, low hanging udders, large teats or udder edema. Lambs can have trouble figuring out how to nurse from these udders, losing precious time for colostrum absorption. Milk out these ewes and feed the lambs colostrum. Often one or two milkings helps to empty their udders enough that lambs can start to figure out how to nurse.
• Ewes that developed subclinical mastitis after weaning her last litter of lambs can have one nonfunctional udder half. If you notice reduced milk flow or no milk when stripping teats, be sure to supplement the lamb(s). Often ewes will want to direct one lamb to the non-functioning side so you might only have to supplement one, but be sure to watch these lambs closely.
• Ewes in poor body condition often do not produce adequate volumes of high-quality colostrum, especially if they have multiple lambs.
• Ewes that reject their lambs. If you do not intervene, the lambs will not receive colostrum in a timely manner. Milk her or hold her and make sure all the lambs get a chance to nurse before putting her in a head gate. Be sure to go back and check in a few hours to make sure that the lambs are nursing.
• Orphan lambs. Even though it seems like a macabre thing to do, you can often milk enough colostrum from a ewe that died to give an initial feeding to her lambs, although you will probably not get enough for a full 24-hour supply.
• Grannies may feed their colostrum to the lambs they steal and not have enough available for their own lambs when they lamb.
• If you do not separate already lambed ewes from those that have not yet lambed, lambs can steal colostrum from ewes that have not lambed yet.

Keep a closer eye on ewes with the above circumstances to see if you need to intervene. Hungry lambs tend to be more vocal and try to nurse more frequently than lambs that are well fed. They then progress to being hunched up and listless and eventually become unresponsive due to low blood glucose. Check if lambs have full bellies a few hours after birth, you can see how to do that at 2:40 in the video below. The best insurance for lambs with empty bellies would be to bottle/tube feed them colostrum right away and keep checking and feeding them until you are sure that they are feeding well and have full bellies. This video has good instructions on how to tube feed a lamb. https://www.youtube.com/watch?v=-BlNgFDxjd4

Colostrum replacer

Once you identify lambs that are not likely to get enough (or any) colostrum from their dams, what are your options to get them off to a good start?

Option 1: Colostrum from a healthy adult sheep in your flock should be your first choice. This colostrum will have the most appropriate antibodies for lambs on your farm.

A healthy, adult ewe in good body condition that has grown up on your farm is the best candidate to collect colostrum from, especially a ewe that has lost one or all of her lambs. You can collect colostrum multiple times from the same ewe over the first 8-12 hours after lambing but note the order of collection on your colostrum when you store it. The closer to lambing the better the quality. The biggest downsides are that you are taking colostrum away from other lambs in your flock (unless the donor ewe lost all her lambs) and it is not always available at the time that you need it.

Colostrum is very nutritious, so it is a great medium for bacteria to grow in. Collect it cleanly and refrigerate or freeze it as soon as possible if you are not using it right away. Do not refrigerate it for more than 24 hours; if you are keeping it longer, then freeze it. Colostrum should not be frozen and thawed multiple times, so freeze it in 2 – 4 oz portions so you can easily thaw out just as much as you need at a time. Ice cube trays work well, or snack size Ziplock bags.

High temperatures will cook antibodies and denature them so they have no positive effect for lambs. Ideally thaw out small amounts at room temperature and gently heat it to body temperature just before feeding by immersing the container in warm (up to 140’F) water. NEVER MICROWAVE COLOSTRUM.

Option 2: Colostrum from another flock or animal (goat or cow)

This colostrum will not have antibodies specific to your farm, and you also risk introducing diseases like Johne’s and Mycoplasma to your flock.

Colostrum cannot be pasteurized to prevent disease transmission as the high heat will denature the antibodies. Colostrum can be heat treated to mitigate disease risk. Heat treatment involves heating colostrum to 60C (140F) for 60 minutes. This is hard to do well without dedicated equipment as you need to ensure that the whole volume of colostrum stays at least at this temperature while preventing it from overheating and denaturing the proteins. To ensure this you need to continuously agitate it. You might be able to source heat treated colostrum from large dairies.

Very rarely lambs that are fed cow colostrum can develop fatal autoimmune anemia. Certain individual cows make “anti-sheep” antibodies, causing autoimmune reactions to red blood cells and blood platelets in lambs that consume their colostrum. The lambs usually start getting sick when they are 7-10 days old. The “anti-sheep” antibodies are thought to be produced due to cross reactivity with proteins on the surface of certain bacteria or protozoa that the cow has been exposed to. This is a very rare condition that most of us are not going to see, but if you use cow colostrum, be aware that this can happen and if you see it in lambs, stop giving cow colostrum to your new lambs right away.

Option 3: Commercial colostrum replacer

This is readily available; you can buy it from the farm store when needed, although it’s relatively cheap insurance to have some on hand before lambing starts, just in case. It is usually made from cow colostrum and does not contain antibodies specific to your farm. But it is convenient, no need to defrost colostrum, you can just mix it up.

When buying colostrum replacer, be sure to read the label. There are colostrum replacers and colostrum supplements. Colostrum supplements contain lower levels of IgG and are not adequate for providing immunity to lambs that have had no other sources of colostrum. Colostrum replacer should have high enough levels of IgG to provide immunity to lambs that have not received any colostrum from their dams. The label should say what concentration of IgG it contains – more is better. There is no downside to giving more antibodies than what the lamb needs; if you’re going to the trouble to supplement a lamb, you might as well give the best possible option. When comparing the levels of IgG, be sure you’re comparing like to like – IgG levels can be shown per feeding, per pouch or per pound. Most of these will have one set of instructions for how to mix it for use as a colostrum replacer and another for mixing it as a colostrum supplement. Be sure to use the replacer instructions. Note the recommended water temperature for mixing. Feed colostrum replacer according to the information on the label. Use colostrum replacer that is labeled for lambs (they are usually lamb and kid combination) or all species colostrum that has sheep listed as one of the species. Ideally the first ingredient listed under “Ingredients” is “dried colostrum”, “dried bovine colostrum” or “bovine serum globulin”

Whichever option you choose, make sure that lambs are warm before you feed them. If they are cold, they need to be warmed up before feeding. If you are tube feeding lambs that are penned with their dam, feel their bellies before feeding. If they are already full, they probably figured out nursing and do not need more help. Re-check them when the next feeding is due to make sure they are maintaining a full belly. You can find some good information on warming lambs here.

I missed the 24-hour window, now what?

If you miss the 24-hour window and only then find out that you have a lamb that likely did not get colostrum you will not be able to supply antibodies by feeding the lamb colostrum. Luckily you can still help by giving antibody rich serum. Two commercial products are available that are INJECTED if you missed the window for supplying colostrum: Bovi-sera
and Ovi-shield. These products do not provide any nutritional value, they are just antibodies, if you have problems with disease organisms not covered by these products your lambs will not be protected.

By: Isabel Richards, EAPK Communications Committee

References

https://www.sciencedirect.com/science/article/abs/pii/S0921448820301292

https://u.osu.edu/sheep/2021/01/26/newborn-lamb-care-management/

https://www.extension.purdue.edu/extmedia/as/as-657-w.pdf

https://u.osu.edu/sheep/2014/01/14/the-importance-of-colostrum-management/

https://www.sciencedirect.com/science/article/pii/S1751731114003243

https://www.sciencedirect.com/science/article/pii/S0022030215000089