Managing large litters
Practical strategies for split-suckling and teat optimization
By Abigail Jenkins
Benchmarking data show that the top 10% of U.S. farms now average 15.7 liveborn pigs per litter, which is an increase of 2.6 pigs over the past decade1,2. However, recent research has shown that sows in some commercial swine herds average only 13.9 functional teats3.
Research also shows that as litter size increases, colostrum intake per pig decreases4. That mismatch is significant because colostrum is essential for:
Energy needed for thermoregulation and mobility, which reduces crushing risk
Immunoglobulins that support lifetime survivability
Improved pre-weaning growth
Adequate colostrum intake is even more critical for replacement animals. It supports reproductive tract development in gilts, improving age at puberty, born alive over early parities, and litter growth5. In boars, greater colostrum intake has been associated with increased sperm per ejaculate6.
With larger litters and limited teat capacity, many producers have increased interest in management strategies such as split suckling and teat optimization.
Is split suckling worth your time?Split suckling temporarily removes a portion of the litter, typically the heaviest or earliest-born pigs, to allow smaller or later-born pigs better access to the sow’s underline.
Although this practice has been widely used for decades, research support remains limited. In the past 25 years, only eight peer-reviewed studies have evaluated split suckling, and protocols have varied considerably.
Modern research trials have shown no improvement in growth performance and inconsistent effects on mortality when split suckling was practiced.
A recent commercial study involving 22,800 piglets compared split suckling based on birth weight (Heaviest 8), birth order (First 8), and no split suckling (Control). No differences were observed in pre-weaning or lifetime growth or mortality7. Even when pigs were categorized as small (under 2.5 lb), medium (2.5 to 3.1 lb), or large (over 3.2 lb), mortality was unaffected due to split suckling strategy (Figure 1).
If split suckling is not consistently improving survival or growth, labor may be better invested elsewhere.
Higher-return labor investmentsPre-farrow priorities include ensuring adequate feed and water access and intake, assisting gilts in learning feeder and waterer operation, and making sows stand twice daily to detect lameness issues. Early intervention helps prevent farrowing complications.
During farrowing, staff should monitor and assist to shorten farrowing duration and reduce the number of hypoxic, late-born pigs, practice udder training to help pigs nurse quickly and move visibly chilled pigs to heat sources immediately.
In the first 24 to 48 hours post-farrowing, it is critical to check for mastitis or retained pigs, monitor for fever, discolored discharge, or off-feed sows, and intervene quickly to reduce both sow and pig mortality. Time invested in these areas often produces more consistent returns than split suckling.
What is the optimal teat loading strategy?Historically, producers matched the number of pigs to the number of functional teats based on earlier studies showing strong teat fidelity in nursing pigs8. However, when litter size exceeds teat count, producers must decide between artificial rearing, fostering to nurse sows, or allowing the sow to nurse more pigs than teats.
Recent interest in allowing sows to raise more pigs than functional teats has prompted more research in this area9,10,11,12.
In a commercial study involving 1,005 sows, litter sizes ranging from one pig below teat count to two pigs above teat count were evaluated for their impact on lactating sow and litter performance11.
Take-home message:
The optimal litter size relative to functional teat count depends on the performance measure of greatest interest.
To optimize individual performance, including lower pre-weaning mortality, reduced sow body condition loss, and greater piglet weaning weight, minimizing litter size relative to functional teat count is the best option.
To maximize farm throughput, including more pigs weaned per litter, greater litter weaning weight, and more pigs weaned per sow per year (Figure 2), nursing more pigs than functional teats is the best option.
Creating opportunity with over-loadingAllowing sows to nurse one or two pigs above teat count can reduce the need for nurse sows. It can also create newly farrowed sows whose crates are emptied to balance other litters.
These sows can be strategically used for:
Opportunity litters
Viable pigs under 2 lb
Larger litters of 15 or more pigs
Younger parity sows with proven performance
Allows for less competition and more in-depth care
Fall-behind litters
Gaunt pigs that are failing to thrive
Pigs identified early in lactation (d 3 – d 6)
Targeted intervention and balances access
Newly farrowed sows are producing transition milk that contains higher fat and protein concentrations and typically allow more frequent nursing. Together, these factors improve recovery potential and increase the likelihood of weaning full-value pigs that would likely otherwise result in a mortality.
Bottom lineAs litter size continues to increase, labor allocation becomes increasingly important.
Current evidence suggests that split suckling provides inconsistent returns. Focused management before, during, and immediately after farrowing has a more reliable impact on pig survival. Teat loading decisions should align with each system’s economic priorities, whether that is maximizing individual pig performance or total throughput.
In modern production systems, success depends on proactiveness, clear SOPs, and attention to detail when managing large litters.
References1 PigChamp. 2024. Benchmarking Summaries USA. www.pigchamp.com/benchmarking
2 PigChamp. 2014. Benchmarking Summaries USA. www.pigchamp.com/benchmarking
3 Obermier, D. R., J. T. Howard, K. A. Gray, and M. T. Knauer. 2023. The impact of functional teat number on reproductive throughput in swine. Transl. Anim. Sci. 7:txad100. doi:10.1093/tas/txad100.
4 Langendijk, P. 2025. Importance and control of colostrum intake in the neonate pig, a review. Reprod. Domest. Anim. 60:5. doi:10.1111/rda.70077.
5 Vallet, J. L., J. R. Miles, L. A. Rempel, D. J. Nonneman, and C. A. Lents. 2015. Relationships between day one piglet serum immunoglobulin immunocrit and subsequent growth, puberty attainment, litter size, and lactation performance. J. Anim. Sci. 93:2722–2729. doi:10.2527/jas.2014-8535.
6 Flowers, W. L. 2022. Factors affecting the production of quality ejaculates from boars. Anim Reprod Sci. 246:106840. doi:10.1016/j.anireprosci.2021.106840.
7 Spinler, M., S. Swanson, E. M. Due, M. Lashley, J. T. Gebhardt, J. M. DeRouchey, M. D. Tokach, R. D. Goodband, A. Hartman, J. C. Woodworth, and K. N. Gaffield. 2025. Evaluation of split suckling strategies on pre-wean piglet growth and mortality for high-producing sows. J. Anim. Sci. 103:237–238. doi:10.1093/jas/skaf102.259.
8 Alexopoulos, J., D. Lines, S. Hallett, and K. Plush. 2018. A review of success factors for piglet fostering in lactation. Animals. 8:38. doi:10.3390/ani8030038.
9 Vande Pol, K. D., R. O. Bautista, A. Olivo, H. Harper, C. M. Shull, C. B. Brown, and M. Ellis. 2021. Effect of rearing cross-fostered piglets in litters of differing size relative to sow functional teat number on preweaning growth and mortality. Transl. Anim. Sci. 5:txab193. doi:10.1093/tas/txab193.
10 Zanin, G. P., L. Santos, D. M. S. Tomm, D. F. Silveira, F. P. Bortolozzo, R. R. Ulguim, and A. P. G. Mellagi. 2024. Sow and litter performance after cross-fostering one surplus piglet and co-mingling the litters at early lactation. Animal. 101247. doi:10.1016/j.animal.2024.101247.
11 Jenkins, A. K., S. M. Collier, J. M. DeRouchey, M. D. Tokach, J. C. Woodworth, K. N. Gaffield, J. T. Gebhardt, R. D. Goodband, K. Coble, P. Corns, J. Karl, T. Bradley, E. Barrera, M. Arellanes, E. N. Darrington, and R. Robbins. 2025. The effect of litter size relative to functional teat count on lactating sow and litter performance. J. Anim. Sci. 103:42–43. doi:10.1093/jas/skaf102.047.
12 Santos, L. dos, G. P. Zanin, I. C. Lima, A. P. G. Mellagi, F. P. Bortolozzo, and R. Da Rosa Ulguim. 2025. Equalizing light and heavy litters with extra piglet relative to sow functional teats: impacts on lactational performance. Trop. Anim. Health Prod. 57:87. doi:10.1007/s11250-025-04359-x.
Jenkins completed her PhD with the Applied Swine Nutrition team at Kansas State University last year. She now serves as the director of nutrition for Tosh Farms.
