Managing sericea lespedeza infestation in native warm season grass pastures utilizing goats

Final report for GNC20-314

Project Type: Graduate Student
Funds awarded in 2020: $14,973.00
Projected End Date: 10/31/2022
Grant Recipients: University of Missouri; The Curators of the University of Missouri
Region: North Central
State: Missouri
Graduate Student:
Faculty Advisor:
Dr. Harley Naumann
University of Missouri
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Project Information

Summary:

Sericea lespedeza, Lespedeza cuneata, is a non-native perennial warm-season legume that is known to be invasive and negatively impacts native plant species in pastures by reducing biomass of desirable forage crops. This project, “Managing sericea lespedeza infestation in native warm season grass pastures using goats” will evaluate the effects of utilizing goats at various stocking rates to control, minimize, or eliminate sericea lespedeza in established native warm season grass pastures. Thus, the main objective will be to determine how goat stocking rate in a rotational grazing system affects plant community composition in a native warm season grass dominated pasture infested with sericea lespedeza.

The experiment consisted of 3 replicated treatments of high, medium and low stocking rates of goats. Each stocking rate was imposed as a grazing unit, divided into rotational paddocks. Each replicated grazing unit consisted of a native warm season grass base (Big Bluestem, Indian grass) and sericea lespedeza. Plant community composition was measured before and after each grazing event or rotation. Animals were assessed for fecal egg counts (FEC) upon completion of the grazing period to look at control of gastrointestinal parasites. An ACUC protocol was developed for this study. 

 

There are Four main outcomes of this project that directly relate to farmers and ranchers. First, they will be able to determine the goat stocking rate that is the most effective for controlling sericea lespedeza. Second, they will become more aware of native plant species and the problems that arise from infestations of sericea lespedeza. This will encourage better management of current resources. Third, by using goats as a management strategy to reduce stands of sericea lespedeza, farmers will decrease use of herbicides. Fourth, including sericea lespedeza in the diet will control gastrointestinal parasites in goats without using anthelmintic drugs.

Project Objectives:

The goals for this project are to provide farmers and ranchers knowledge of:

  • The stocking rate that is best suited to control sericea lespedeza in a managed rotational grazing system.
  • Native plant species and the problems that arise from infestations of sericea lespedeza.
  • Grazing goats as a management strategy to reduce stands of sericea lespedeza without additional cost of herbicides.
  • Using sericea lespedeza in the goat diet to control gastrointestinal parasites without using anthelmintic drugs.

 

Research

Materials and methods:

This project included three goat stocking rate treatments: High (14 head), medium (7 head), and low (4 head). Each treatment was replicated in all three pastures (A, B, and C). 

Prior to grazing plant composition of sericea lespedeza (SL), cool season grasses (CSG), warm season grasses(WSG), other forbe species (OF), grass like species (GL), shrubs(S), and trees (T) were determined. This data was collected using a line point intercept method where linear measurements of plant interception along the length of a stretched line were determined. Multiple lines of data were collected per pasture to determine the plant species composition. 

Grazing began on July 22nd and ended on October 20th of 2021. Paddocks were rotated in each pasture per treatment based on forage availability. Grazing days were calculated and were used to determined grazing days per acre and grazing days per treatment. Goats in each treatment were watered as needed and had free range to mineral blocks at all times. 

Fecal egg counts (FEC) were collected and measured prior to and post grazing for each treatment. The number of eggs were used to determine the number of eggs per gram. This was important to determine the amount of gastrointestinal parasite concentration change while grazing sericea lespedeza. 

Goats were sold at the end of the 2021 grazing season. 

In 2022, the research location was in moderate drought that was not improving. Due to the extreme drought conditions we could not, in good conscience, stock livestock on those pastures. Under extreme drought conditions, the initial grazing event would be detrimental to the forage in terms of regrowth and forage quality. 

Research results and discussion:

Plant composition was determined by using the line point intercept method mentioned above in the materials and methods. Plant species composition was determined by calculating the percent cover of each plant species by averaging the total intercepts along the transect line. The percent cover was then divided by the total cover for all the plant species. Plant composition data were used to determine placement of each goat stocking rate. 

Avg Plant Composition (%)
Species  Pasture A Pasture B Pasture C
Sericea Lespedeza 41% 17% 13%
Cool Season Grasses 6% 44% 33%
Warm Season Grasses 1% 18% 14%
Grass like 29% 9% 19%
Other forbes 23% 11% 20%
Shrubs 0% 0% 0%
Trees  0% 0% 0%

Grazing days/acre per pasture were determined by dividing the total number of days grazed by the number of acres utilized. Pasture A had the greater number of grazing days/acre. Grazing days per treatment were determined by averaging the number of days grazed. The low treatment had the greater number of grazing days and the high treatment had the least number of grazing days. 

Grazing days/acre
Pasture A 241
Pasture B 68
Pasture C 63
Grazing days/treatment
High  73
Medium 148
Low 152

The average acres grazed per treatment varied due to rotations being based upon forage availability upon goat stocking rate.

Average acres used per treatment 
High  1.2
Medium  0.7
Low  0.5

Fecal egg counts (FEC) were determined prior to and post grazing for each treatment. The medium stocking rate had a greater % decrease in fecal egg counts from beginning to end of the grazing season. This data shows that the medium stocking rate could be most effective at managing gastrointestinal parasites in goat populations while grazing sericea lespedeza without the use of anthelmintic drugs. 

Year 1 FEC (# eggs/gram)
Treatment  FEC Begin FEC End % decrease
High Stocking 2018 1479 27
Med Stocking 2090 1014 51
Low Stocking 1608 1091 32
Participation Summary

Educational & Outreach Activities

1 Webinars / talks / presentations
1 Workshop field days

Participation Summary:

392 Farmers participated
Education/outreach description:

Field days and demonstrations were still limited in 2021 and 2022 due to the Covid-19 pandemic and research center resources.  However, fortunately outreach about this project was dispersed to farmers and ranchers verbally when opportunities arose at other events. October of 2022 a video describing and showing effects from 2021 grazing season were presented by Dr. Harley Naumann on the Mizzou Agroforestry page. 

Project Outcomes

Project outcomes:

Our project results show that goats can be an effective sustainable management tool in mitigating sericea lespedeza infestations without the use of pesticides and reducing the concentration of gastrointestinal parasites within the goat population without the use of anthelmintic drugs.

Goat excrements can also contribute to improving soil characteristics without the use of certain fertilizers. Improving the quality of the soil will lead to long term sustainability for soil health with decreased use of pesticides and harsh disturbances to the system. 

 

Knowledge Gained:

Utilizing goats to manage sericea lespedeza infestations seems promising. The inability to conduct the study in 2022, due to moderate drought conditions, presented many challenges in completing our story. For farmers and ranchers this could be an applied learning experience. Missouri pastures are often year to year presented with different levels of drought conditions. Drought directly effects forage availability and forage quality. Therefore, it also effects the stocking rate of livestock that can be placed on that unit of land. 

Recommendations:

Missouri ranks second in the nation for beef production and has increased 213 percent for meat goat production (2007 USDA-NASS). Goats can be used in a mixed species grazing system along with cattle. Goats and cattle present with different dietary preferences. Not only can the goats be used to clean up more woody plants or invasive plants, but they can also be sold at the end of the grazing season as additional income. The woody plant control that the goats contribute to will improve land quality and productivity, to potentially increase the stocking rate for the subsequent grazing season.

 

Information Products

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.