Technical note: Comparing 4 techniques for estimating desired grass species composition in horse pastures.
Abstract: Many methods exist for estimating species composition, but few studies compare those useful in improved horse pastures. The objective of this study was to examine 4 techniques for estimating desirable forage species composition in 2 cool-season horse pastures based on prevalence estimates, repeatability, bias, and practicality, and to select a method for use in a subsequent grazing study. The techniques included Equine Pasture Evaluation Disc (EPED), Line-Point Intercept with 3 transects of 50 observations each (LPI 3-50), LPI with 5 transects of 30 observations each (LPI 5-30), and Step Point (StPt). A generalized linear-mixed effects model procedure of SAS (GLIMMIX) with a logit link was used to test for differences among each species separately. When methods were significantly different (α = 0.05), pairwise comparisons were performed using a paired t-test. The methods did not differ in detecting creeping bentgrass (P = 0.3334) or orchardgrass (P = 0.4207), but there were differences for Kentucky bluegrass (P = 0.0082), tall fescue (P = 0.0314), and other (P = 0.0448). Repeatability plots displayed lower method repeatability as species prevalence increased. Agreement was analyzed between pairs of methods by grass species. Five out of 30 pairs showed significant overall bias (P = 0.0114, 0.0045, 0.0170, 0.0328, and 0.0404), and 3 of them were between LPI 3-50 and EPED. The LPI 3-50 and LPI 5-30 techniques agreed perfectly in prevalence and bias, as did StPt and EPED, meaning they can be used interchangeably. The techniques LPI 3-50 and EPED were the most dissimilar methods. In conclusion, StPt can be used interchangeably with LPI, but StPt was selected due to its thorough representation of the pastures and ease of use.
Publication Date: 2018-04-19 PubMed ID: 29668994PubMed Central: PMC6095353DOI: 10.1093/jas/sky111Google Scholar: Lookup
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- Comparative Study
- Journal Article
Summary
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This research investigates four methods for estimating the composition of desirable forage species in horse pastures. It identifies the Step Point (StPt) method as the best option for its thorough representation and practicality.
Objective of the Research
- The study aimed to compare four different techniques used for evaluating the presence of desirable species of grass in pastures meant for horse grazing. The goal was to measure the effectiveness and biases of these methods, in order to determine one that can be used for a subsequent grazing study.
Methodology
- The methods compared in the study were Equine Pasture Evaluation Disc (EPED), Line-Point Intercept with 3 transects of 50 observations each (LPI 3-50), LPI with 5 transects of 30 observations each (LPI 5-30), and Step Point (StPt).
- The research team utilized a generalized linear-mixed effects model procedure of SAS (GLIMMIX) with a logit link to test for species differences. If the methods displayed significant disparities, pairwise comparisons were conducted using a paired t-test.
Findings
- There were no differences in detecting creeping bentgrass or orchardgrass among the methods. However, differences were noted for Kentucky bluegrass, tall fescue, and other species.
- The study found that repeatability of the method decreased as species prevalence increased.
- Five out of 30 pairs demonstrated significant overall bias. Three of them were between LPI 3-50 and EPED.
- Agreement between the methods depended on the specific species. The techniques LPI 3-50 and LPI 5-30 showed perfect agreement in terms of prevalence and bias, as did StPt and EPED. This finding suggests that these pairs of methods can be used interchangeably.
- The most dissimilar methods were LPI 3-50 and EPED.
Conclusion
- The research concluded that the StPt method could be used interchangeably with LPI. However, the team selected StPt due to its comprehensive representation of the pastures (covering all species of interest) and its ease of use for practical implementation.
Cite This Article
APA
Kenny LB, Ward D, Robson MG, Williams CA.
(2018).
Technical note: Comparing 4 techniques for estimating desired grass species composition in horse pastures.
J Anim Sci, 96(6), 2219-2225.
https://doi.org/10.1093/jas/sky111 Publication
Researcher Affiliations
- Department of Animal Sciences, Rutgers University, Lipman Dr., New Brunswick, NJ.
- Rutgers Agricultural Research and Extension Center, Rutgers University, Bridgeton, NJ.
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ.
- Department of Animal Sciences, Rutgers University, Lipman Dr., New Brunswick, NJ.
MeSH Terms
- Animal Feed / analysis
- Animal Husbandry / methods
- Animals
- Diet / veterinary
- Herbivory
- Horses / physiology
- Poaceae
References
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Citations
This article has been cited 4 times.- Weinert-Nelson JR, Meyer WA, Williams CA. Crabgrass as an equine pasture forage: impact of establishment method on yield, nutrient composition, and horse preference. Transl Anim Sci 2022 Apr;6(2):txac050.
- Weinert-Nelson JR, Meyer WA, Williams CA. Yield, nutrient composition, and horse condition in integrated crabgrass and cool-season grass rotational grazing pasture systems. Transl Anim Sci 2021 Oct;5(4):txab208.
- Kjellander PL, Aronsson M, Bergvall UA, Carrasco JL, Christensson M, Lindgren PE, Åkesson M, Kjellander P. Validating a common tick survey method: cloth-dragging and line transects. Exp Appl Acarol 2021 Jan;83(1):131-146.
- Williams CA, Kenny LB, Weinert JR, Sullivan K, Meyer W, Robson MG. Effects of 27 mo of rotational vs. continuous grazing on horse and pasture condition. Transl Anim Sci 2020 Jul;4(3):txaa084.
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