Worst Invasive Species Research Articles

Allelopathy and Allelochemicals of Imperata cylindrica as an Invasive Plant Species.

Imperata cylindrica is native to Southeast Asia and East Africa and has become naturalized in humid tropics, subtropics and warmer temperate zones of the world. The species is one of the top ten worst weeds in the worlds and is listed among the world’s top 100 worst invasive alien species. It is an aggressive colonizer and forms large monospecific stands in several countries. Possible evidence of the allelopathy of I. cylindrica has been accumulated in the literature over three decades. The extracts, leachates, root exudates, decomposing residues and rhizosphere soil of I. cylindrica were found to suppress the germination and growth of several plant species, including woody plant species, and to reduce their rhizobium nodulation and mycorrhizal colonization. Several allelochemicals, such as fatty acids, terpenoids, simple phenolics, benzoic acids, phenolic acids, phenolic aldehydes, phenylpropanoids, flavonoids, quinones and alkaloids, were also found in the extracts, leachates, root exudates and/or growth medium of I. cylindrica. These observations suggest that allelochemicals may be synthesized in I. cylindrica and released into the rhizosphere soil and surrounding environments either by the leachates, root exudation or decomposition process of plant parts, and certain allelochemicals may contribute to the alteration of the microbial community, including rhizobia and mycorrhizal fungi, suppressing the regeneration process of native plant species through the inhibition of their germination and growth. Therefore, the allelopathy of I. cylindrica may support its invasiveness, naturalization and formation of large monospecific stands. This is the first review article focusing on the allelopathy of I. cylindrica.

The Little Fire Ant (Hymenoptera: Formicidae): A Global Perspective

AbstractWasmannia auropunctata (Roger) is an invasive tramp ant species that has been transported globally since [at least] the early twentieth century. It is often claimed that despite the negative impacts associated with this species and its listing among the world’s worst invasive species, very little research attention has been paid to W. auropuntata. Although the need for future research exists, there is currently a considerable body of research from around the world and spanning back to the 1920’s on this species. Here we synthesize over 200 peer reviewed research manuscripts, book chapters, conference presentations, and media reports of new distributions spanning 1929–2022 culminating in a comprehensive literature review on W. auropunctata. This review covers all current knowledge on this species and is intended to serve as a quick reference for future research and provide the reference resources for those seeking more in-depth information on specific topics. Topics included in this review include taxonomic identification, current global distribution and pathways, life history, impacts, detection, and control. We discuss where consensus and ambiguity currently lie within the research community, identify contextual considerations for future researchers when interpreting data, and suggest where we believe more research or clarifications are needed.

Risk assessment for the native anurans from an alien invasive species, American bullfrogs (Lithobates catesbeianus), in South Korea

The invasive species are of global concern, and the Invasive American Bullfrog (IAB; Lithobates catesbeianus) is one of the worst invasive amphibian species worldwide. Like other countries, South Korea is also facing challenges from IAB. Although many studies indicated impacts of IAB on native anurans in Korea, the actual risk at the specific level is yet to evaluate. Considering the putative invasiveness of IAB, it is hypothesized that any species with the possibility of physical contact or habitat sharing with them, will have a potential risk. Thus, we estimated and observed their home range, preferred habitats, morphology, behavior, and ecology. Then, comparing with existing knowledge, we assessed risks to the native anurans. We found a home range of 3474.2 ± 5872.5 m2 and identified three types of habitats for IAB. The analyses showed at least 84% of native anurans (frogs and toads) were at moderate to extreme risks, which included all frogs but only 33% of toads. Finally, we recommended immediate actions to conserve the native anurans based on our results. As this study is the first initiative to assess the specific risk level from the invasiveness of L. catesbeianus, it will help the managers to set conservation priorities and strategies.

Seasonal variation in structure and function of gut microbiota in Pomacea canaliculata.

Gut microbiota is associated with host health and its environmental adaption, influenced by seasonal variation. Pomacea canaliculata is one of the world's 100 worst invasive alien species. Here, we used high‐throughput sequencing of the 16S rRNA gene to analyze the seasonal variation of gut microbiota of P. canaliculata. The results suggested that the predominant gut microbial phyla of P. canaliculata included Firmicutes and Proteobacteria, which helped digest plant food and accumulate energy. The gut microbiota of P. canaliculata in summer group showed the highest diversity, whereas the winter group possessed the lowest, probably due to the shortage of food resources of P. canaliculata in winter. Principal coordinate analysis analysis based on unweighted unifrac and weighted unifrac indicated that the composition of gut microbiota of P. canaliculata significantly varied across seasons. Bacteroidetes tended to be enriched in summer by linear discriminant analysis effect size analysis. Actinobacteria and Cyanobacteria were extremely abundant in autumn, while Fusobacteria and Cetobacterium enriched in winter. In conclusion, the structure of the gut microbiota of P. canaliculata was significantly different among seasons, which was beneficial to the environment adaptation and the digestion and metabolism of food during different periods.

Allelopathy and Allelochemicals of Leucaenaleucocephala as an Invasive Plant Species.

Leucaena leucocephala (Lam.) de Wit is native to southern Mexico and Central America and is now naturalized in more than 130 countries. The spread of L. leucocephala is probably due to its multipurpose use such as fodder, timber, paper pulp, shade trees, and soil amendment. However, the species is listed in the world’s 100 worst invasive alien species, and an aggressive colonizer. It forms dense monospecific stands and threatens native plant communities, especially in oceanic islands. Phytotoxic chemical interactions such as allelopathy have been reported to play an important role in the invasion of several invasive plant species. Possible evidence for allelopathy of L. leucocephala has also been accumulated in the literature over 30 years. The extracts, leachates, root exudates, litter, decomposing residues, and rhizosphere soil of L. leucocephala increased the mortality and suppressed the germination and growth of several plant species, including weeds and woody plants. Those observations suggest that L. leucocephala is allelopathic and contains certain allelochemicals. Those allelochemicals may release into the rhizosphere soil during decomposition process of the plant residues and root exudation. Several putative allelochemicals such as phenolic acids, flavonoids, and mimosine were identified in L. leucocephala. The species produces a large amount of mimosine and accumulates it in almost all parts of the plants, including leaves, stems, seeds, flowers, roots, and root nodules. The concentrations of mimosine in these parts were 0.11 to 6.4% of their dry weight. Mimosine showed growth inhibitory activity against several plant species, including some woody plants and invasive plants. Mimosine blocked cell division of protoplasts from Petunia hybrida hort. ex E. Vilm. between G1 and S phases, and disturbed the enzyme activity such as peroxidase, catalase, and IAA oxidase. Some of those identified compounds in L. leucocephala may be involved in its allelopathy. Therefore, the allelopathic property of L. leucocephala may support its invasive potential and formation of dense monospecific stands. However, the concentrations of mimosine, phenolic acids, and flavonoids in the vicinity of L. leucocephala, including its rhizosphere soil, have not yet been reported.

Comparison of Fecundity Traits between Mauremys reevesii and Trachemys scripta based on Gene Family Analysis

Background: Chinese pond turtle (CPT, Mauremys reevesii) is a typical species with temperature-dependent sex determination (TSD). Pond slider turtle (PST, Trachemys scripta) is considered one of the worst invasive species in the world. In order to analyze the adaptive evolution of fecundity traits in CPT and TSD, the rapidly evolving gene families were obtained and functional enrichment analysis was performed. At the same time, CPT and PST species-specific genes were also enriched for their fecundity traits. Methods: Orthofinder software was employed to search homologous genes based on protein sequence. CAFÉ software was used to obtain the expansion and contraction gene families of CPT and PST. Then, GO terms and pathway enrichment analyses were performed using TBtools software and Swissprot database. Result: In CPT, 159 rapid expansion gene families GO enrichment results showed that the reproductive activities related pathways were mainly three significant enrichment process, spermatogenesis, steroid hormone mediated signaling pathway and male gamete generation. 2 rapidly contraction gene families showed that there was no significant enrichment pathway related to reproduction. The pathway of significant enrichment were RNA biosynthetic process, regulation of RNA metabolic process and regulation of cellular metabolic process. The gene families unique to the species were significantly enriched in pathways DNA replication-dependent nucleosome organization, DNA replication-dependent nucleosome assembly and negative regulation of megakaryocyte differentiation. In PST, 15 rapid expansion gene families GO enrichment results showed that the most significant GO terms mainly consisted of biological processes which were involved in endocrine process, regulation of endocrine process and cellular response to steroid hormone stimulus, but spermatogenesis and male gamete generation gene families also expanded. 58 rapidly contraction gene families showed that the pathways of significant enrichment were endocrine process, cellular response to steroid hormone stimulus and regulation of endocrine process. At the same time, estrogen secretion, binding of sperm to zona pellucida and sperm-egg recognition gene family also rapidly contraction. The gene families unique to the species were significantly enriched in pathways adenylate cyclase-activating G protein-coupled receptor signaling pathway, double-strand break repair and regulation of potassium ion transport.

Climate change impact on the population dynamics of exotic pathogens: The case of the worldwide pathogen Phytophthora cinnamomi

Worldwide, Mediterranean-climate type forests are seriously threatened by climate change and Phytophthora cinnamomi, an extremely aggressive soilborne pathogen listed among the 100 worst invasive alien species. This study examines for first time the effects of annual and seasonal changes in temperature and rainfall under different climatic scenarios on P. cinnamomi dynamics in a Mediterranean forest naturally infested. We followed seasonally and during four years (2016–2020) P. cinnamomi abundance in the soil taking advantage of a climate change infrastructure that simulates a 30% rainfall reduction using rainout shelters and an increase in soil temperature using open top chambers. Seasonal abundance of P. cinnamomi was strongly linked to spring precipitation: the large inoculum density during this season suffered a strong decrease during the dry summer that was maintained until the next spring, despite of fall rains. Thus, inoculum density in spring may be considered the best indicator of the potential of P. cinnamomi infection in natural ecosystems. The two climatic treatments had significant effects on P. cinnamomi abundance, but only in some combinations of seasons and years. Rainfall exclusion had a negative effect on the spring abundance of P. cinnamomi mostly in wet years, causing a reduction as large as 30% in comparison with the control treatment. Meanwhile, warming effect varied from slightly negative in winter to positive in spring and early summer, causing increases as large as 31% in comparison with the control treatment. Overall, we provide novel experimental evidence suggesting that a drier climate might limit the abundance and activity of P. cinnamomi in water-limited forests, but that this negative effect might be at least partly counteracted by the positive effects of warming. These results also imply that P. cinnamomi represents an increasing threat under climate change for the conservation of forest ecosystems where water is not a limiting factor.

Impacts of changing climate on the distribution of Solenopsis invicta Buren in Mainland China: Exposed urban population distribution and suitable habitat change

As one of the 100 worst invasive alien species in the world, the red imported fire ant (Solenopsis invicta Buren) is of great concern because of its impact on human health, human health, economic development, and native biodiversity. With the ongoing global climate change situation, there is an increased public health threat from the invasion of S. invicta. To understand the distribution of suitable habitats for S. invicta under current and future climate scenarios in mainland China, nine species distribution models were constructed and compared to which one is more suitable to predict the distribution of S. invicta. The performance of Random Forest (RF) model was the best among all the evaluated models. The results showed that current suitable habitats for S. invicta were predicted to exist in the south of Mainland China. The urban population residing on the southeast coast was primarily exposed to suitable habitats of S. invicta, with an exposed urban area of approximately 130000 km2. Annual mean temperature and precipitation of the warmest quarter were considered as important predictors among climate variables. Under future climatic scenarios, the suitable habitats originally held by S. invicta will remain stable, and suitable habitats area for expansion will increase over time. The expansion direction of suitable habitats tends to expand towards the north. Our study can provide a reference for understanding the change of S. invicta suitable habitats and exposed urban population distribution.

How vegetation cover characteristics response to the spread of Prosopis juliflora: a time-series remote sensing analysis in southern Iran.

Plant invasion is recognized as the second most severe threat to biodiversity, following habitat loss. As one of the world's worst invasive alien plant species, Prosopis juliflora (Mesquite) has severely affected the majority of the Earth's dry ecosystems. Hence, this study attempted to identify the distribution, dominance, and changes in the vegetation characteristics of Mesquite-invaded regions along a series of coastal ecosystems in Southern Iran. Mesquite and other tree/shrub types were successfully classified using a temporarily-median-filtered Landsat 8-OLI image with acceptable kappa coefficient and overall accuracy values of 80.66 and 84.75, respectively. The multi-resolution segmentation was used to divide the region into spectrally homogenous parcels, then calculating the percentage cover (dominance) of Mesquite relative to other tree/shrub types. Analysis of MODIS NDVI products in highly invaded parcels showed a steady increase in NDVI values from 0.27 to 0.53 during 2000-2020 with a significant difference (z = -3.12, 0.183, sig ≤ .05, 2-tailed) from that of the low-invaded regions whose NDVI values oscillated constantly in a range between 0.15 and 0.28. Mesquite distribution also showed a local invasion pattern from areas with a steady or saturated status to neighboring parcels. In regions susceptible to Mesquite invasion, constant investigation of uncommon changes in NDVI whose vegetation characteristics differ significantly from that expected in poor dry vegetation covers of southern Iran can be considered as a conservation tool to identify and manage areas with early Mesquite establishment.

Re-evaluating invasive species in degraded ecosystems: a case study of red-eared slider turtles as partial ecological analogs

Exotic species are often vilified as “bad” without consideration of the potential they have for contributing to ecological functions in degraded ecosystems. The red-eared slider turtle (RES) has been disparaged as one of the worst invasive species. Based on this review, we suggest that RES contribute some ecosystem functions in urban wetlands comparable to those provided by the native turtles they sometimes dominate or replace. While we do not advocate for releases outside their native range, or into natural environments, in this review, we examine the case for the RES to be considered potentially beneficial in heavily human-altered and degraded ecosystems where native turtles struggle or fail to persist. After reviewing the ecosystem functions RESs are known to provide, we conclude that in many modified environments the RES is a partial ecological analog to native turtles and removing them may obviate the ecological benefits they provide. We also suggest research avenues to better understand the role of RESs in heavily modified wetlands.

Taxonomic revision of the Pheidole megacephala species-group (Hymenoptera, Formicidae) from the Malagasy Region.

BackgroundThe Malagasy Region, one of the top megadiversity regions, hosts one of the highest numbers of endemic and threatened organisms on earth. One of the most spectacular examples of ant radiation on the island has occurred in the hyperdiverse genus Pheidole. To this date, there are 135 described Madagascan Pheidole divided into 16 species-groups, and 97% of Malagasy species are endemic to the island. This study is a taxonomic revision of the Pheidole megacephala group, one of only two species-groups comprising a combination of native, endemic taxa and widely distributed introduced species.MethodsThe diversity of the Malagasy members of the megacephala group was assessed via application of qualitative morphological and DNA sequence data. Qualitative, external morphological characteristics (e.g., head shape, gaster sculpture, body colouration) were evaluated in order to create a priori grouping hypotheses, and confirm and improve species delimitation. Mitochondrial DNA sequences from cytochrome oxidase I (COI) gene fragments were analyzed to test the putative species previously delimited by morphological analyses.ResultsWe recognize three species belonging to the megacephala group: P. megacephala (Fabricius, 1793), P. megatron Fischer & Fisher, 2013 and P. spinosa Forel, 1891 stat. nov. Pheidole spinosa is redescribed and elevated to the species level. The following names are recognized as junior synonyms of P. spinosa: P. megacephala scabrior Forel, 1891 syn. nov., P. picata Forel, 1891 syn. nov., P. picata gietleni Forel, 1905 syn. nov., P. picata bernhardae Emery, 1915 syn. nov., and P. decepticon Fischer & Fisher, 2013 syn. nov. The results are supplemented with an identification key to species for major workers of the megacephala group, high-resolution images for major and minor workers, and comments on the distribution and biology of all Malagasy members of the group. Our study revealed that Pheidole megacephala, a species listed among the 100 worst invasive species worldwide, occurs in both natural and disturbed sites in the Malagasy region. The two remaining members of the megacephala group, most likely endemic to this region, are also present in anthropogenic habitats and often co-occur with P. megacephala. It appears that the Malagasy members of the group are generalists and dominant in anthropogenic habitats. Additionally, we documented the presence of supermajors in colonies of P. spinosa—a phenomenon previously not known for this group.

On the occurrence of the invasive Atlantic blue crab Callinectes sapidus Rathbun 1896 (Decapoda: Brachyura: Portunidae) in Sicilian inland waters

The Atlantic blue crab Callinectes sapidus Rathbun, 1896 is included among the worst invasive alien species in the Mediterranean Sea. Here, we report the finding of the species in two Sicilian rivers, the Irminio and the Imera Meridionale, where it was collected up to 6 km from the river mouths. Although several records of the species are already available from Italy, this is the first evidence of the occurrence of this invasive crab so far from the coastline in the whole country. In the light of the well-known impact of the Atlantic blue crab on the invaded water bodies, the monitoring of the species and appropriate mitigation strategies should be implemented in order to protect the threatened native biota of Sicilian inland waters.

Seed removal decrease by invasive Argentine ants in a high Nature Value farmland

Seed dispersal by ants is an important ecological process that maintains the structure anddiversity of natural communities, however, it is vulnerable to biological invasions. Argentine ants are one of the worst invasive ant species and cause severe changes in ecosystem processes and native ant biodiversity declines in invaded sites. Here, we studied seed removal by ants combining observations and a cafeteria experiment with seeds of four myrmecochorous plant species (Centaurea sphaerocephala, Rosmarinus officinalis, Silybum marianum, and Ulex australis) in two sites (invaded and uninvaded) located in the Mediterranean Montado ecosystem and classified as High Nature Value farmland (HNV). Significant differences in daily seed removal rates were found between the two study sites. In uninvaded sites, several native ant species were attracted to the seeds, resulting in all seeds being removed rapidly. The majority of seed removal events were carried out by two key seed disperses Pheidole pallidula (71%) and Aphaenogaster iberica (26%) with a clear preference for diaspored with larger and heavier elaiosome (i.e., C. sphaerocephala, S. marianum). By contrast, while the Argentine ant showed some interest (68% of seeds were interacted with), no seed removal events were observed. The extirpation of the local ant fauna by the Argentine ant and its inability to ensure seed dispersal services may lead to the interference and eventually to the collapse of seed dispersal of the four studied myrmecochorous plants in the invaded site in the future. We argue that these discrete but severe consequences of an invasive species on a key ecological process may strongly affect the functioning of the Montado ecosystem.

Phenotypic plasticity of the invasive apple snail, Pomacea canaliculata, in China: a morphological differentiation analysis

ABSTRACT Pomacea canaliculata is listed among the world’s 100 worst invasive species, for threatening rice production and wetland biodiversity. We compared morphological and genetic characteristics of the 14 P. canaliculata geographic populations in mainland China to explore morphological differentiation in relation to geographical isolation and climate effects. The results showed that the average shell height, standing height and body width of P. canaliculata samples were 29.39, 18.52 and 19.91 mm. Morphological characteristics were significantly different among the P. canaliculata geographic populations. The changes in morphological characteristics fitted a linear model. Geometric measurement showed a significant difference in centroid size among the 14 populations. Canonical variates analysis revealed three distinct clusters and that four geographic populations were independent in shell shape variation. Mahalanobis distances showed significant relationships among all populations except Pingtang vs. Zhangzhou. The cumulative contribution of PC1, PC2 and PC3 in principal component analysis reached 80%. The overall identification accuracy was 97%. However, only 3.9% of pairwise Coefficient of Difference values exceeded 1.28. The difference in morphological traits did not conform to the isolation-by-distance model. The P. canaliculata phenotype was closely related to local climatic factors. In summary, the adaptation of Chinese P. canaliculata populations is ongoing.

First record of Achatina fulica Bowdich, 1822 (Mollusca, Achatinidae), for the state of Rio Grande do Sul, Brazil

Achatina fulica Bowdich, 1822, is here officially recorded for the first time for Rio Grande do Sul State, Brazil. It is now known to occur in every Brazilian state. The species is on the list of the 100 worst invasive species in the world. One young specimen of giant African snail was found in a garden of a residential building in the municipality of Porto Alegre. A hypothesis is that it was accidentally introduced through gardening. It can cause economic losses and diseases in human beings.

INVASIVENESS IDENTIFICATION: A STUDY CASE FROM LANTANA

Invasion by invasive species represents one of the greatest threats to biodiversity worldwide, causing degradation and loss of habitat. Among them, one species belonged to the Verbenaceae family, namely Lantana camara, which includes 100 of the world’s worst invasive species. Distinguishing invasive from non-invasive species based on morphology alone is often difficult for plants in a vegetative stage, especially in Lantana, where they have complex morphological characters. In this regard, DNA barcoding may become a good alternative. This study aimed to select and provide a DNA barcode region that capable of distinguishing the invasive and non-invasive Lantana. Four DNA Barcode markers available in the sequence database (NCBI and BOLD), namely matK, rbcL, psba-trnh, and ITS2, were used to identify the invasiveness of various Lantana. A total of 132 data sequences from 17 species of Lantana were collected. The sequences were aligned and constructed into a dendrogram using MEGA X through the Neighbor-Joining method. This study shows that it is possible to distinguish Lantana camara from a series of closely related congeners by plastid base gene (matk and rbcl). The constructed phylogeny tree shows that invasive species Lantana camara was in a different clade with non-invasive Lantana.

Predicting Current Potential Distribution and the Range Dynamics of Pomacea canaliculata in China under Global Climate Change.

Simple SummaryPomacea canaliculata is one of the 100 worst invasive alien species in the world, causing significant effects and harm to native species, ecological environment, human health, and social economy. In this study, we used species distribution modeling (SDM) methods to predict the potential distribution of P. canaliculata in China and found that with climate change, there would be a trend of expanding and moving northward in the future.Pomacea canaliculata is one of the 100 worst invasive alien species in the world, which has significant effects and harm to native species, ecological environment, human health, and social economy. Climate change is one of the major causes of species range shifts. With recent climate change, the distribution of P. canaliculata has shifted northward. Understanding the potential distribution under current and future climate conditions will aid in the management of the risk of its invasion and spread. Here, we used species distribution modeling (SDM) methods to predict the potential distribution of P. canaliculata in China, and the jackknife test was used to assess the importance of environmental variables for modeling. Our study found that precipitation of the warmest quarter and maximum temperature in the coldest months played important roles in the distribution of P. canaliculata. With global warming, there will be a trend of expansion and northward movement in the future. This study could provide recommendations for the management and prevention of snail invasion and expansion.

Prey selectivity of the invasive largemouth bass towards native and non-native prey: an experimental approach

Abstract Non-native predators are known to cause ecological impacts through heightened consumption of resources and decimation of native species. One such species is Micropterus salmoides. Often introduced for sport fishing worldwide; it has been listed by International Union for Conservation of Nature and Natural Resources as one of the 100 of the world’s worst invasive species. Whilst impacts conferred towards native prey are well known, its relationship with other non-native species has received much less attention. Therefore, the aim of this study was to experimentally investigate the feeding preference of M. salmoides towards native prey (Geophagus iporangensis) compared to non-native prey (Oreochromis niloticus and Coptodon rendalli) using comparative consumption and the Manly-Chesson selectivity index. We found a higher consumption by M. salmoides towards the non-native prey and a tendency for this non-native preference to increase when prey availability increased. Our results are in line with the hypothesis that the invasion of the non-native predator can be facilitated by the high abundance and reproductive rate of the non-native prey. This is relevant considering the interaction of multiple invaders in an ecosystem, in particular environments modified by humans. Interspecific relationships are complex and their understanding is necessary for environmental management decision-making.

Status of Invasive Alien Plant Species in Urban Forest of Hetauda, Nepal

This paper explores the status of Invasive Alien Plant Species in an urban forest of Hetauda, Nepal. The study is based on a quadrate survey (130 quadrants) within the transect line at an interval of 30 m within different six habitat types. This study identified a total of 22 invasive alien plant species representing 20 genera and 12 families out of recorded 26 species representing 24 genera and 15 families in the country. This study identified four species namely Chromolaena odorata, Eichhornia crassipes, Lantana camara and Mikania micrantha in the study area that were listed as the world’s 100 worst invasive species. The invasion was found to be negatively correlated with canopy cover. The higher the canopy cover; the lower the abundance of invasive alien species. Regarding the habitat type, settlement area had the highest number of invasive species followed by forest and roadside. Mikania micrantha, Lantana camara, Ageratum houstonianum and Chromolaena odorata were mostly abundant in forest whereas Eichhornia crassipes was highly abundant in wetlands. Mikania micrantha was mostly abundant in settlement area and Senna tora was confined to open land. The relative abundance of Ageratum conyzoides, Senna occidentalis, Ageratum adenophora, Leersia hexandra, Mimosa pudica, Bidens pilosa, Oxalis latifolia, Ipomoea carnea, Amaranthus spinosus, Argemone mexicana, Esosphaerum suaveolens were lower.

EFFECTS OF FEEDING Lantana camara LEAF HAY ON ANIMAL PERFORMANCE AND HEALTH IN SMALL EAST AFRICA GOAT BREEDS

<p><strong>Background:</strong> <em>Lantana camara</em> is listed as one of the worst invasive species worldwide and is considered poisonous to livestock. However, in invaded Zimbabwean rangelands, voluntary intake by domestic livestock especially goats of this shrub is common, yet, little is understood about the effect of this browse on animal performance. <strong>Objectives:</strong> To assess the effects of feeding graded levels of <em>L. camara</em> (LC) leafy hay on the performance, digestibility, nitrogen balance and microbial protein synthesis in Small East Africa Goat Breeds. <strong>Methodology:</strong> Eighteen, six to ten months old castrated goats with a mean± (SD) weight of 13.6±4.9 kg were randomly assigned to the six treatment diets in a completely randomised design. Each goat was housed separately in a metabolism cage for the entire experimental period of 21 days. <em>Lantana camara</em> leaf hay was incorporated in goat feed as a protein source at 5%, 10%, 15%, 20%, and 25% inclusion levels. Commercially bought, goat feed was used as the sixth and control treatment diet. Veld hay was used as a basal diet and water were offered <em>ad-libitum</em>. <strong>Results</strong>: The average daily dry matter intake was above the minimum recommended of 3% of the animal’s metabolic body weight (kg<sup>0.75</sup>). Goats fed on 10%LC consumed significantly lower quantities of hay than 5%LC but were not significantly different from goat feed (GF), 15%LC, 20%LC and 25%LC. Apparent digestibility coefficient values ranged from 62% to 71%. Higher nitrogen intakes was observed with diets that were highly palatable such as commercial goat feed and 5% <em>L. camara</em>. Higher microbial protein supply was observed in groups fed diets with high levels of <em>L. camara</em>. <strong>Implications:</strong> The use of invasive <em>L. camara</em> biomass as a source of goat feed at 5% inclusion is a promising method to control its spread in while addressing the nitrogen deficiencies experienced by livestock that subsist on poor quality feeds in invaded rangelands. <strong>Conclusion:</strong> Supplementing goats with <em>L. camara</em> leafy hay improves dry matter feed intake and degradability. Contrary to expectations, no negative effects were observed with <em>L. camara </em>leafy meal inclusion in goats diets at 5 to 25 percent inclusion level.</p>