How to Reduce Lamb Mortality Rates

According to South Dakota State University Professor of Animal Science, Jeffery Held, lamb mortality in the United States was about 20% in 2021 with 80% of those deaths occurring within the first two weeks after lambing. To the sheep industry, this obviously makes for a significant hit to production and profitability. Still, this rate can be significantly lowered with prevention plans and good management practices. In this article, Redd Summit Advisors shares our tips on managing your lamb crop and ewes in the weeks following lambing to increase your survival rate. 

Nutrition Plans to Increase Lamb Survival

The nutrition of the ewe prior to lambing and during lactation is one of the primary factors contributing to lamb survival during the first week of life. We talk more specifics on ewe nutrition in our article on preparing for lambing season, but the main takeaway is that you need to ensure that your ewes’ energy, protein, and micronutrient needs are satisfied. It may be necessary to feed a protein supplement in addition to high-quality hay, if possible. 

When it comes to lamb nutrition, colostrum is the star of the show. Lambs should receive 1-2oz of colostrum per pound of body weight within the first 12 hours after birth for adequate nutrition and antibody properties. Once your new lamb crop has reached 3-4 weeks of age, it may be beneficial to begin creep feeding to promote valuable weight gain, stimulate rumen development, and get lambs accustomed to eating grain before weaning. However, keep in mind that creep feeding is primarily beneficial for lambs managed in an intensive early weaning production system where they'll be maintained in a dry lot until market weight. It is not usually ideal for operations whose lambs will be developed on pasture during the spring and summer, as early weight gain will be an additional expense. 

Vaccination and Health Plans for Ewes and Lambs

Like nutrition, your vaccination and health plan to promote lamb survival actually occurs before lambing season begins. Ideally, your ewes would receive vaccinations 4-6 weeks prior to lambing to build antibodies, which are then passed on to the lamb via colostrum. However, once the lambs reach 6-8 weeks of age, they should receive their first CDT vaccinations, which protect them against clostridial diseases, Type C, D, and Tetanus. 

Manage critical control points (CCPs) to Reduce Lamb Mortality

While a good nutrition and vaccine plan is a more generalized approach to limiting your lamb mortality rate, you can have an even greater impact by managing your operation’s specific critical control points (CCPs). This requires an in-depth assessment of your operation and areas where it has struggled with lamb mortality in previous years. By identifying how and when losses occurred in the past, you can better target management areas with the most significant impact potential. Specific control points to pay closer attention to include the following:

Birth Time

When pasture lambing, the ideal time frame tends to be when the soil temperature is above 50℉ to reduce loss due to exposure. On the other hand, though, too much warmth comes with its own host of problems including an increased risk of flystrike. March is typically a happy medium, but this is dependent on your location. 

Environment

Indoor (shed)  lambing programs can reduce losses due to exposure, hypothermia, and starvation by maintaining an ambient temperature above 32℉. This is possible using supplemental dry heat, but this solution is costly. Another option would be to design a facility with well-insulated drop and early rearing areas and rely on the animals’ body heat to keep the area heated. Of course, this does raise concerns about humidity, which can promote pneumonia, scours, and other health concerns. You would need to allow for enough air exchange to reduce humidity without creating excessive drafts, which can be accomplished using ridge vents, adjustable sidewall intake controls, or by designing an airflow ventilation system. 

Birth Time Management

An underlying cause for lamb loss due to starvation and exposure is mismothering, which is why it's important to optimize time in claiming pens and dynamics in mixing pens. One management strategy to promote fostering and decrease exposure and starvation deaths without increasing rearing costs is to concentrate birth periods (assuming labor is not a limiting factor) by synchronizing estrus during breeding. 

Genetics 

While genetics can be an esoteric topic, it also provides a big opportunity to limit your lamb loss over the course of several generations. Maximizing the use of cross-breeding, promoting hybrid vigor and heterosis can reduce lamb mortality by nearly 20%. However, a challenge exists in selecting sheep that are superior in both production and survival, as these traits tend to be negatively correlated. 

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Lamb loss prevention planning and management is largely specific to your own operation and problem areas that you’ve experienced in the past. This is where thorough records come in handy, as it will help you identify management areas that will have the most impact on increasing your survival rate, and therefore your productivity and profitability. For more livestock production information, risk management discussions, and explanations of agricultural insurance products, visit the Redd Summit blog, and subscribe to stay up to date when new articles are released.