The Nutritional Dynamics of Common Weeds in the Rangelands of the Akdağ Mountains, Samsun

Abstract

In this study, common weed species (Anthemis sp., Anthemis tinctoria L., Pilosella hoppeana Schultes, Doranicum orientale Hoffm, Muscari neglectum Guss. ex Ten., Ornithogalum armeniacum Baker, Ornithogalum narbonense L., Ornithogalum wiedemannii Boiss., Anchusa azurea Miller, Echium plantagineum L., Echium vulgare L., Ajuga orientalis L., Stachys germenica L., Juncus sp., Anacamptis pyramidalis L., Ophrys apifera Huds., Carex panicea L., Ranunculus sp., Hypericum perforatum L., Primula elatior L. Hill., and Galium rotundifolium L.) of the rangelands of Akdağ mountains, Samsun were evaluated by principal component analysis (PCA) and cluster analysis (CA). These species were collected at least three times in two consecutive years. The proximate nutrients (organic matter, ash, crude protein, ether extract, neutral and acid detergent fibre, non-fibrous carbohydrate and hemicellulose), neutral detergent fibre properties (nitrogen-free neutral detergent fibre and in vitro neutral detergent fibre digestibility), and forage quality indicators (digestible dry matter, dry matter intake, metabolizable energy, net energy lactation, estimated net energy, total digestible nutrients, relative feed value, and relative forage quality) were assessed by chemical analysis and empirical equations. There were significant variations in the nutritional dynamics among the weed species. The PCA results demonstrated a relationship between the dietary dynamics assessed. Component 1 (65.5%) and component 2 (14.5%) described 80.0% of the total variation, with eigenvalues of 11.788 and 2.609 in the weed species, respectively. The loadings plot of components shows that most forage quality indicators were distributed to Quadrant 1 and Quadrant 4. Three clusters are observed from the CA for the weeds with significant linkage distance, indicating relatively high independence for each cluster. Due to high variation in their nutritional dynamics, the weed species (P. elatior, O. wiedemannii, O. narbonense, and G. rotundifolium) were more similar on component 1 ordination and in Cluster 1 of the dendrogram. In conclusion, our results suggest that the highlighted species have significant potential for grazing livestock as forages and could fulfilling the possible forage gap in the grazing system.