Experienced Polypay producer, John Anderson of Lambshire Polypays in Ohio, shares some sage advice and techniques on how he successfully lambs in the fall without the use of CIDRs or other artificial methods. John lambs exclusively in the fall now after nearly 40 years of accelerated lambing using both the STAR system and three times per year.

Why lamb in the fall?

There are many benefits to lambing in the fall. Fall born lambs often bring better prices at market than those born in the spring. Pasture lambing in the fall can match fall forage growth. In many parts of the country, temperatures tend to be favorable in the fall for avoiding heat stress or hypothermia. Cooling temperatures in fall/winter encourage lambs to eat more and grow better. There is less chance of fly strike. Ewes and lambs on pasture in the fall usually have fewer parasite problems than the same ewes and lambs would have in spring lambing situations. Fall born replacements, if nursed on pasture with some parasite exposure, should have a better immune response when they are re-exposed the next spring/summer than winter or spring born lambs would at that time. Their previous exposure (and age) results in a better immune response in their first spring

Disadvantages

Not all ewes will breed in the spring. Rams may have lower libido and lower fertility in the spring. Ewes lambing in the fall may have fewer lambs. Fall born lambs may have lower birth weights than spring born lambs. Nutrition is probably more critical at breeding in the spring than in the fall. In general, spring breeding requires better management than fall breeding. It is more difficult to get fall born ewe lambs to breed in the spring to lamb at 12 months old. This presents a problem if you only lamb once per year.

Factors contributing to fall lambing success without using CIDRS

It is possible to get good lamb crops in the fall without the use of CIDRS or other artificial techniques, but it takes a combination of good management, appropriate nutrition, the right genetics and adequate ram power. Lambing only once per year in the fall, we get roughly 95% of our mature ewes bred with at least a 210% drop rate. Of ewe lambs exposed at 7-8 months of age, approximately 50% are bred with over a 180% drop rate.   

Genetics

The ability to fall lamb has a genetic component. One of the easiest things you can do to improve fall lambing is to use rams from proven fall lambing genetics. Some breeds excel at fall lambing, but there are fall lambing genetics in many breeds. To be most successful, both ewes and rams should have fall lambing genetics. Heterosis might help if crossbreeding is an option.

Feeding

Ewes, especially ewe lambs, might require better nutrition before and during breeding in the spring in order to encourage them to lamb in the fall. A high-quality mineral supplement should be available at all times. Ewes should be in a body condition score (BCS) 3 or better and improving when rams are introduced, although there may be some variation in the ideal BCS depending on the breed. Fall-born ewe lambs should be well fed all winter to get them fat enough for breeding. For example, I give my fall born Polypay ewe lambs 2 + lbs of concentrate plus good hay (balage) all winter to achieve a BCS of 4 or better at breeding. In 2024 our ewe lambs averaged 110 lbs at breeding and a BCS 4. Good pasture in the spring can help with flushing, but don’t cut back the concentrate supplement before or during breeding. Slowly reduce concentrate after breeding. It helps to keep ewe lambs on some grain supplement right through their first lambing and lactation.

Don’t forget about keeping rams in good flesh. Check scrotal circumference over the winter to make sure rams don’t lose fertility. Rams in good flesh with better scrotal circumference should have higher libido and be able to cover more ewes.

Ram Power

A strong “Ram Effect” is very important for a good fall lamb crop. A ram’s genetics and management both play a role in his ability to initiate estrous in ewes. Use fertile rams that have a high libido. When possible, use multiple rams. If you need to know the sire, try running one fertile ram and one or more (preferably smaller) teaser rams together. This helps with the ram effect. Keep ewes well away from rams for two months before breeding. Introduction of teaser rams before breeding is another way to get ewes cycling/synchronized. Rams of another (fall lambing-capable) breed may improve the ram effect and could be considered for use as teasers. Consider breeding soundness exams (BSE) on rams before putting them with ewes.

Management

Pay attention to animal health in general, including worm load, hoof health, etc. Use a marking harness to assess breeding activity. Don’t be too patient. If you don’t see any activity after a couple days, try to mix things up. Try new rams, change the ewe group makeup, etc. It may help to put the rams with ewes in a confined area for a few days to help amplify the ram effect. (I haven’t been doing this).

Ewe lamb breeding groups should probably be separate from mature ewe groups, as cycling ewe lambs may not seek out the rams and 7-month-old ewes lambs require better nutrition. However, it may be helpful to include a small number of mature ewes with the ewe lambs as they may act as “social glue” on pasture and are more likely to start cycling right away. This may help start ewe lamb breeding (I don’t have proof). I have included a few thinner ewes (who could benefit from better nutrition) with the ewe lambs the past couple of years. I think of them as primer ewes.

Moving from spring lambing to fall lambing.

One way to change your lambing from seasonal (spring) to out-of-season is by moving in 8–10-month intervals until you get to your preferred time of year. For example, if you normally lamb in April, you could wean at 60 days, so around mid-June. Then give the ewes a month to recover with good nutrition and expose them again in mid-July or August. If you expose ewes around August 8, you might start lambing around January 1. This lambing period would lead to a mid-March weaning and an April breeding period for September/October lambing. While you are accelerating (moving from spring to fall lambing) you will probably get fewer ewes to breed. If you’re serious about breeding only in the fall, cull the ewes who do not breed in the spring.

Nutrition is key when accelerating your flock. Ewes should not be allowed to get too thin at any point. Don’t take ewes off water at weaning and allow them access to a mature stemmy hay at weaning. You might remove grain for a about a week before weaning and about a week after weaning. Usually grain in the ration is needed to get a flock to accelerate, but this may depend on genetics and quality of forages.

Lining up your flock management

Cooler temperatures in the spring help at breeding. Early spring joining is usually more successful than late spring as ewes are more likely to enter anestrous by June and July. Keep ewes and rams well away from each other for at least two months prior to breeding. Start supplementing one or two months prior to breeding, especially if body condition scores are 2.5 or less. At breeding, ewes should be in a BCS of 3 and improving (BCS 4 for ewe lambs). Manage ewes and ewe lambs separately, including at breeding time (a few primer ewes may help). Shear wool sheep prior to breeding. Rams should have a BSE performed before breeding and having extra rams available with good libido is good insurance in the spring.

By: John Anderson, Lambshire Polypays, Wooster, Ohio