A Comparison between Perennial and Perennial/Annual Combination Forage Systems under Mixed-Species Grazing

Livestock producers are increasingly interested in including annual forages along with perennials in forage systems for grass-fed livestock. Annual forages can be a quick-growing, high-quality, and high-yielding forage option and can increase forage availability across the growing season; however, establishing annual forages does require additional time and financial inputs. To explore this, a study was started at the Western Maryland Research and Education Center to compare a perennial-only versus a perennial/annual combination forage system under mixed-species grazing. The objectives of the study are to compare forage production, forage quality, livestock performance, and soil health between these grazing systems, along with the economic feasibility of using a perennial/annual combination system compared to a more traditional perennial-based forage grazing system.

Livestock producers are increasingly interested in including annual forages along with perennials in forage systems for grass-fed livestock.

Methods

In 2023, a mixed-species herd consisting of 30 lambs and 19 calves were utilized for this study. Livestock were sourced from a local Maryland producer, with all animals coming from one farm to ensure similar pre-study background and care. Livestock were transported to the research center on May 2, 2023. After a brief acclimation period, all animals were weighed and measured, blocked by age, bodyweight, and body condition score, and randomly assigned to treatment system.

Animals in the perennial-only forage system (PER; n=15 lambs and 9 calves) were rotationally grazed across 13 acres of cool-season perennial mixed pasture. Dominant pasture species in the PER system included orchardgrass, tall fescue, red clover, white clover, and alfalfa. Animals in the perennial/annual combination forage system (ANN; n=15 lambs and 10 calves) were rotationally grazed across 13 acres of both perennial and annual pastures. Perennial pastures in this system consisted of a similar cool-season perennial mixture, and annual pastures were established on a seasonal, rotating basis using cool-season annuals followed by warm-season annuals. For both treatment groups, pastures were subdivided into approximately 0.5 to 0.9-acre paddocks and animals were rotated to a new paddock every 1-7 days depending on forage availability. Animals in both groups also had ad libitum access to a commercial mineral mix to ensure appropriate mineral intake. An overview of the pasture layout for both groups is shown in Figure 1.

Animals in both treatment groups grazed from the beginning of May through the end of September 2023. Grazing was originally planned to continue into the late fall/winter months; however, a D2-D4 drought across the region led to limited forage regrowth and reduced forage availability and ultimately resulted in grazing ending earlier than anticipated. Throughout the grazing season, animals in the ANN forage system alternated between annual and perennial pastures based on forage availability and growth. In 2023, the ANN group grazed perennial forages from May 8 through July 10, annual forages from July 10 through September 20, and perennial forages from September 20 through September 26.

Throughout the study, both treatment groups were measured every two weeks to determine bodyweight, body condition score (1-5 scale for lambs; 1-9 scale for cattle), and FAMACHA© score (lambs only). Fecal samples were also collected to monitor parasite load via fecal egg counts. Forage samples were collected every two weeks to determine forage yield and forage nutritive value; for each treatment group, samples were collected from the subsequent paddock in the rotation prior to grazing.

Results

Analysis of the results for this study are in progress, but some preliminary results from the 2023 grazing season are presented here. The average nutrient composition of the perennial pastures grazed by the PER group and the perennial and annual pastures grazed by the ANN group are shown in Table 1.

Animal performance data for the two treatment groups is presented in Table 2 (lambs) and Table 3 (calves). All numbers are presented as averages; statistical analysis still needs to be completed on the data. On average, the PER lambs gained 0.24 pounds per day compared to 0.28 pounds per day for the ANN lambs; the PER calves gained 1.43 pounds per day compared to 1.55 pounds per day for the ANN calves. Average daily gains for all animals was variable across weigh periods; this variability in daily gains was likely due to a number of factors, including individual animal variability, changes in forage type, availability, and quality over time, and varying weather conditions throughout the grazing season.

Lamb FAMACHA© scores remained low (1-2) for both treatment groups throughout the course of the grazing season. No lambs received a FAMACHA© score higher than 3 at any point, and a FAMACHA© score of 3 was only given three times throughout the year. This was somewhat expected, as some of the pastures were newly established (formerly crop fields) and none of the pastures had been grazed the previous year, so parasite pressure was likely very low in all pastures.

Conclusions and Future Plans

Preliminary results of this study show that lambs and calves are able to grow and maintain good body condition on both a perennial-only and a perennial/annual combination forage system. Initial results suggest that using annual forages in combination with perennial forages may be a successful strategy to increase average daily gains for pasture-based livestock systems. 

Data on fecal egg counts, forage production, and soil health implications for each of these pasture systems is still being compiled. This study is also being repeated during the 2024 and 2025 grazing seasons. Moving forward, a full analysis of this study will be completed, along with a comprehensive analysis comparing the economics behind each of these systems.

Producers looking to improve grazing systems on their farm should begin by exploring simple management changes including the implementation (or increased intensity) of rotational grazing practices. Incorporation of annual forages into the grazing system may also help improve animal performance and can offset the reduced summer growth (i.e. summer slump) in perennial pastures, particularly during dry years.

Acknowledgements

We are grateful for the assistance provided by the staff at the Western Maryland Research and Education Center in support of this study. Funding for this study comes from the Northeast Sustainable Agriculture Research and Education program.

This page's content is updated annually with the latest results from the research trial. The information was last updated on 4/17/2025.