Scientists studied 72 lambs to understand how their stomachs break down grass and how different feeding strategies affect this process. They discovered that when lambs ate supplementary feed along with grazing, their bodies changed how they digested grass. The research revealed that tiny organisms in the sheep’s stomach work together with the stomach lining to help absorb nutrients better. These findings could help farmers feed their animals more efficiently while keeping grasslands healthy and sustainable for the future.
The Quick Take
- What they studied: How different grazing conditions and supplementary feed affect the tiny organisms in sheep stomachs and how well they digest grass
- Who participated: 72 young lambs (sheep) that were either grazed at different intensities or given supplementary feed in addition to grazing
- Key finding: When lambs received supplementary feed while grazing, they ate more total food but less of the wild grass species. Their stomach lining cells changed, and the microscopic organisms in their stomachs shifted how they worked, which affected how well they absorbed nutrients
- What it means for you: If you raise sheep or lambs, this suggests that carefully balancing grazing intensity with supplementary feeding can improve how efficiently animals convert feed into growth. However, this research is specific to sheep farming and may not apply to other animals or situations
The Research Details
Researchers conducted an experiment with 72 lambs divided into groups based on two main factors: how intensively the land was grazed and whether the lambs received supplementary feed. They used advanced laboratory techniques to study what was happening inside the lambs’ stomachs at multiple levels—looking at the genetic material of microorganisms, which genes those microorganisms were actually using, and the individual cells lining the stomach wall. They also analyzed blood samples to see how nutrients were being processed throughout the body.
This multi-layered approach allowed scientists to connect what was happening at the microscopic level (individual cells and organisms) to what was happening at the whole-animal level (how much the lambs ate and grew). By examining the stomach lining cells in detail, they could see exactly which cells were changing and what genes were being activated in response to different feeding conditions.
The researchers also measured chemical compounds in the blood that indicate how well the body is processing nutrients, particularly B vitamins, bile acids (which help digest fats), and amino acids (building blocks of protein).
This research approach is important because it goes beyond simply measuring how much lambs eat or gain weight. By examining the microscopic world inside the stomach—the bacteria and other organisms, the cells lining the stomach, and the chemical signals being sent throughout the body—scientists can understand the actual mechanisms of how feeding strategies work. This deeper understanding helps farmers make better decisions about how to feed their animals in ways that are both productive and sustainable for the environment.
This study was published in a highly respected scientific journal (Microbiome) and used cutting-edge laboratory techniques that are considered the gold standard for this type of research. The researchers studied a reasonable number of animals (72 lambs) and used multiple complementary methods to verify their findings. However, the study focused specifically on one type of sheep in one type of grazing system, so results may not apply to all situations or all types of livestock.
What the Results Show
When lambs received supplementary feed while grazing, they ate more total food (measured as dry matter intake), but they ate less of the wild grass species called Artemisia tanacetifolia. This shift in what they ate was connected to changes in the bacteria living in their stomachs, particularly a group called Lachnospiraceae. The genetic material of these bacteria showed different patterns compared to which genes they were actually using, suggesting the bacteria were responding to the change in diet.
The stomach lining cells also changed noticeably. In lambs that received supplementary feed, there were more basal cells (young cells at the base of the stomach lining) and more mature, specialized cells. These cells contained more of certain proteins that help transport short-chain fatty acids—important compounds produced when bacteria break down grass. These fatty acids are a major energy source for the animal.
The research revealed a direct connection between what the stomach bacteria were doing, how the stomach lining cells were responding, and how well the animal’s body was processing nutrients overall. Specifically, the changes affected how the body handled B vitamins, bile acids, and amino acids—all essential for health and growth.
The study identified specific types of cells in the stomach lining that appeared to be most important for nutrient absorption. The basal cells, in particular, showed enrichment of genes related to transporting short-chain fatty acids, suggesting these young cells play a key role in nutrient uptake. The research also demonstrated that the interaction between the stomach bacteria and the stomach lining cells is a two-way conversation—the bacteria influence which genes the stomach cells express, and the stomach cells’ condition influences what the bacteria do. This bidirectional relationship appears to be crucial for optimizing nutrient absorption.
Previous research has shown that supplementary feeding can change what bacteria live in a ruminant’s stomach, but this study goes further by showing exactly which bacteria change, which genes they activate, and how this affects the stomach lining and overall nutrient absorption. The finding that stomach lining cells change their structure and function in response to different diets builds on earlier work but provides much more detailed cellular-level information. This study also uniquely connects these microscopic changes to actual nutrient metabolism in the blood, creating a more complete picture than previous research.
This study focused only on lambs in a specific grazing system and may not apply to adult sheep, other types of livestock, or different environmental conditions. The research was conducted at a particular time and place, so seasonal variations or different grass types might produce different results. Additionally, while the study identified important correlations and relationships, it cannot definitively prove that one change causes another—only that they occur together. The study also doesn’t address how long these changes last or whether they have long-term effects on animal health and productivity.
The Bottom Line
For sheep farmers: Consider using moderate grazing intensity combined with strategic supplementary feeding to optimize nutrient absorption and animal growth. The evidence suggests this approach can increase overall feed intake and improve how efficiently animals convert feed to growth. However, farmers should monitor whether this strategy maintains the health of their grasslands and adjust based on their specific conditions. Confidence level: Moderate—this research is solid but specific to the conditions studied.
Sheep and lamb farmers, particularly those managing grazing systems, should find this research relevant. Agricultural scientists and those interested in sustainable farming practices will also benefit from these insights. This research is less directly applicable to people who don’t raise livestock, though it contributes to understanding sustainable food production. Veterinarians working with sheep may find the nutritional insights useful.
Changes in how lambs digest food and absorb nutrients appear to happen relatively quickly when feeding strategies change, based on the cellular and microbial shifts observed. However, the long-term effects on animal health, productivity, and grassland sustainability would require monitoring over months or years to fully understand.
Want to Apply This Research?
- If managing a flock, track daily feed intake (both grazing time and supplementary feed amount) alongside weight gain measurements. Record which grass species are being consumed most heavily and monitor changes when adjusting supplementary feed levels. This creates a personal data set to compare against the research findings.
- Farmers could use an app to log grazing conditions (intensity level), supplementary feed type and amount, and resulting animal performance metrics. This allows comparison of different feeding strategies and optimization based on individual farm conditions. The app could send reminders to monitor animal health indicators that might reflect improved nutrient absorption, such as coat quality and energy levels.
- Establish baseline measurements of current feeding practices and animal outcomes. Implement changes gradually while tracking feed intake, animal weight gain, and observable health markers. Compare results monthly to identify which combinations of grazing intensity and supplementary feeding work best for your specific situation. Consider periodic blood work or other health assessments to verify that nutrient absorption is actually improving.
This research is specific to lambs in controlled grazing systems and may not apply to all sheep, other livestock, or different farming conditions. The findings suggest potential benefits of certain feeding strategies but do not constitute veterinary or agricultural advice. Farmers should consult with veterinarians or agricultural extension specialists before making significant changes to their feeding programs. Individual animal health, local environmental conditions, and specific farm goals should all be considered when applying these research findings. This study identifies correlations and mechanisms but does not prove that implementing these strategies will guarantee improved outcomes in all situations.