Ranching Systems Research Articles

The LTAR Grazing Land Common Experiment at the Jornada Experimental Range: Old genetics, new precision technologies, and adaptive value chains.

Rangelands and the supply chains connected to them are central to the agrifood systems of the Southwestern United States. Local ranchers are simultaneously arid lands managers, herd managers, and marketing managers. To stay in business, they must adapt to unpredictable forage resources and markets while conserving soils and vegetation resources for the long term. As climate warming and drying exacerbate the complexity and difficulty of day-to-day production, producers and policymakers are seeking alternatives to "business as usual." The Long-Term Agroecosystem Research (LTAR)-Jornada team has developed a package of strategies to help producers adapt to the local and inter-regional challenges. The package includes heritage cattle, precision ranching systems, and adaptive value chains. Five ranches across the Southwest have adopted different combinations and are partnering with LTAR and each other to measure their benefits and drawbacks in real-world conditions. Opportunities for controlled experimentation differ among the ranches, so we use LTAR's indicator system to assess and compare results. Even as we invest in co-producing knowledge about these three strategies, we recognize that progressive aridification and urbanization of Southwestern rangelands create challenges for which a single "silver bullet" of agricultural innovation is unlikely to provide durable solutions. We are learning from our customers and stakeholders about ways to adjust the development of new options.

Evaluation of marine ranching socio-ecological system resilience in China

Marine ranching socio-ecological system (SES) resilience refers to how well a marine ranching system can withstand disturbances and bounce back while maintaining its levels of environmental restoration, resource conservation, and sustainable production. However, there is insufficient research on the evaluation of the resilience of marine ranching SESs. To fill this gap and determine how to effectively evaluate marine ranching SES resilience, this study developed an index-based evaluation system using the DPSIR framework. An evaluation model (abbreviated as DTED) was then constructed by combining four methods, namely DPSIR, triangular fuzzy numbers, entropy weighting, and the Dempster-Shafer theory of evidence. The developed DTED model was then applied to the data obtained from 34 marine ranches in China for the period from 2019 to 2022 to determine their corresponding SES resilience. The results showed that most of China's marine ranches have a medium level of SES resilience, with an overall upward trend. Nevertheless, there is still a possibility of risk, and measures should be taken to promote ecological diversification in marine ranching, mitigate impacts on social systems, and enhance the resilience of marine ranching SESs.

The impact of agricultural credit on the cattle inventory and deforestation in Colombia: a spatial analysis

The relationship between agricultural credit and agricultural production as well as the impacts on sustainable development (i.e., poverty alleviation, reduction of inequalities, food and nutrition security, and stimulation of economic growth) have been widely documented. The objective of this study is to analyze the impact of credit on cattle production and deforestation in Colombia through spatial panel data models. For this purpose, a departmental data panel for the period 2011–2020 was built, based on available information from public entities. The results suggest that in Colombia, the relationship between access to credit and cattle production is significant and can be either negative or positive. In addition, there is evidence of spatial dependence, meaning that cattle production in one department is being affected by cattle production in a neighboring department or by all the departments that make up the national territory. Regarding deforestation, results show that, although the number of cattle present in a department does affect its annual deforestation rate due to a poor coverage of sustainably intensified cattle ranching systems, there is no relationship between deforestation and the access to credit nor any spatial correlations.

Deployment of a LoRa-WAN near-real-time precision ranching system on extensive desert rangelands: What we have learned*

Deployment of a LoRa-WAN near-real-time precision ranching system on extensive desert rangelands: What we have learned*

Culling Layer Hen Gastrointestinal Helminth Identification at Wonokromo Market Surabaya

This study aimed to find out and identification gastrointestinal species parasites in cullinglayer hen which sold at in the Wonokromo traditional market Surabaya City. The samples were100 culling layer hen purchased from five merchant. Research design with purposive sampling.The samples was examined by having surgery through the digestive tract and fecal examination.Meanwhile, fecal examination used native methods, sediment and floating. Types of wormsidentified were Ascaridia galli, Heterakis gallinarum, Raillietina tetragona and Mediorhynchusgallinarum through examination the digestive tract surgery. There were Ascaridia galli, Heterakisgallinarum, and Raillietina sp. found in examination of worm egg in fecal. The prevalence ofparasite gastrointestinal in the culling layer hen in sold at in the Wonokromo traditional marketSurabaya City was 85%. The difference in percentage rates were likely due to seasonal factors,maintenance management, feeding and ranching systems.

Exploring The Symbiotic Economic Benefits Between Farmers and Herders to Promote Peaceful Coexistence in Taraba State Nigeria

This paper explored the symbiotic economic benefits between farmers and herders in Taraba State to promote peaceful coexistence. Taraba State is one of the states in the North East region of Nigeria that is mainly affected by the farmers-herders crisis. The paper illustrated the causes of the farmers-herders crisis which include the growing population, abandonment of the grazing reserve system, and proliferation of small arms and light weapons among others. Although the Federal and State Governments have responded in several ways, among which the creation of grazing reserves in 1965, the establishment of the National Commission for Nomadic Education (NCNE) in 1989, the use of the Armed Forces to curb internal security caused by farmers-herders crisis, proposed National Grazing Reserve Bill 2016, proposed Cattle Ranching System 2018, legislation prohibiting open grazing and the Great Green Wall Agency of the Federal Government. All these efforts by the Federal Government and various State Governments could not bring the desired peaceful coexistence between farmers and herders. The crisis still lingered in Taraba State and many other states. Therefore, the paper explored the symbiotic economic benefits that could be enjoyed by farmers and herders leading to peaceful coexistence. Some of the symbiotic economic benefits capable of stimulating peaceful coexistence are; after harvesting crops on their farm, they usually allow cattle to graze on the leftovers, during which excrement from the cows provide manure for the farm, use of yam and cassava peels for preparation of animal feeds, use of rice, guinea corn, maize, and millet chaff for animal feeds and use of animal waste as fertilizer. The author concluded that exploring the symbiotic economic benefits explicated in this paper can bring about peaceful coexistence between farmers and herders which will also result in a peaceful Taraba State. It was suggested that government and private individuals should establish ranches within farming communities in such a manner that herders can get animal feeds from farmers while the farmers get manure from the herders’ farms.

South American Dry Chaco rangelands: Positive effects of cattle trampling and transit on ecohydrological functioning.

Livestock production in drylands requires consideration of the ecological applications of ecohydrological redistribution of water. Intensive cattle trampling and the associated increase of surface runoff are common concerns for rangeland productivity and sustainability. Here, we highlight a regional livestock production system in which cattle trails and trampling surrounding an artificial impoundment are purposely managed to enhance redistribution and availability of water for cattle drinking. Based on literature synthesis and field measurements, we first describe cattle production systems and surface water redistribution in the Dry Chaco rangelands of South America, and then develop a conceptual framework to synthesize the ecohydrological impacts of livestock production on these ecosystems. Critical to this framework is the pioshere-a degraded overgrazed and overtrampled area where vegetation has difficulties growing, usually close to the water points. The Dry Chaco rangelands have three key distinctive characteristics associated with the flat sedimentary environment lacking fresh groundwater and the very extensive ranching conditions: (1) cattle drinking water is provided by artificial impoundments filled by runoff, (2) heavy trampling around the impoundment and its adjacent areas generates a piosphere that favors runoff toward the impoundment, and (3) the impoundment, piosphere, and extensive forage areas are hydrologically connected with a network of cattle trails. We propose an ecohydrological framework where cattle transit and trampling alter the natural water circulation of these ecosystems, affecting small fractions of the landscape through increased runoff (compaction in piosphere and trails), surface connectivity (convergence of trails to piosphere to impoundment), and ponding (compaction of the impoundment floor) that operate together making water harvesting and storage possible. These effects have likely generated a positive water feedback on the expansion of livestock in the region with a relatively low impact on forage production. We highlight the role of livestock transit as a geomorphological agent capable of reshaping the hydrology of flat sedimentary rangelands in ways that can be managed positively for sustainable ranching systems. We suggest that the Dry Chaco offers an alternative paradigm for rangelands in which cattle trampling may contribute to sustainable seminatural production systems with implications for other dry and flat rangelands of the world.

Carbon Stock Assessment in Silvopastoral Systems along an Elevational Gradient: A Study from Cattle Producers in the Sumaco Biosphere Reserve, Ecuadorian Amazon

Silvopastoral system (SPS) has been considered as a sustainable management system contribute to greenhouse gas (GHG) reduction, among other benefits compared with open pasture. However, little research has been conducted on the soil and tree biomass carbon stored in traditional pasture with dispersed trees (PWT) compared with pasture in monoculture (PM). The present study was conducted in the Ecuadorian Amazon Region (EAR), along an elevational gradient from 400 to 2000 masl., within the buffer and transition zone of the Sumaco Biosphere Reserve (SBR), using 71 temporary circular plots of 2826 m2, where 26 plots were stablished in PWT and 45 plots in PM. The main results in PWT show significant differences (p ≤ 0.01) between aboveground carbon biomass (AGCtrees) from 41.1 (lowlands), 26.5 (Middle hills) and 16.7 (high mountains) Mg ha−1 respectively, with an average of 31.0 Mg ha−1 in the whole study area. The total carbon pool along the altitudinal gradient in five components: (AGCtrees), belowground carbon (BGCtrees), pasture carbon (AGClitter+pasture) and carbon in soil components (0–10 and 10–30 cm) for PWT ranged from 112.80 (lowlands) to 91.34 (high mountains) Mg ha−1; while for the PM systems assessing three components (AGClitter+pasture) and carbon in soil components (0–10 and 10–30 cm) ranged from 52.5 (lowlands) to 77.8 (middle zone) Mg ha−1. Finally, the paper shows the main dominant tree species in pasture systems that contribute to carbon storage along elevational gradient and concludes with recommendations for decision-making aimed at improving cattle ranching systems through a silvopastoral approach to mitigate the effects of climate change.

Research on the Acoustic Conditioning Taming on Fish and Application in Marine Ranching

Acoustic conditioning taming technology is one of the key tools for controlling and managing the behavior of target organisms in marine ranching. In this study, juvenile Pagrus major (Red Seabream) were subjected to acoustic conditioning taming with 400 Hz of square–wave continuous tones for 8 days in laboratory and 15 days in an open-sea area. At the same time, the elimination of conditioned reflexes to sounds and applications in marine ranching were tested. The Gaussian model was used to regression-fit the distribution of fish in the tank, and the fitting degree was 91.79%. Good conditioning was established after four days of acoustic conditioning taming, and the efficiency index was 44.49 in the laboratory. The average response time, aggregation time, and residence time of the test group were 0.95 s, 3.35 s, and 21.15 s, respectively. The aggregation rate of the test group showed an upward trend, and it remained at 100% from the 4th day to the 8th day. It took longer to establish the conditioned response to sound in the open-sea area, and good conditioning was established after the 18th acoustic conditioning taming. Juvenile Pagrus major with established acoustic conditioning were tagged before release. On the 18th day, 0.2% of released fish swam to a sound source when the sound was played, and from the 24th day, there was no fish presence in the area near the sound source. The conditioned response of fish to sound was gradually eliminated using the negative feedback mode of playing the sound without feeding bait. After 22 negative feedback tests, the sound was no longer attractive to the fish, meaning that the “sound–food” neural connection established by the acoustic conditioning taming had been eliminated. The results of this study show that acoustic conditioning taming technology was an effective method of fish behavior control, and it is feasible to apply this technology in the construction of marine ranching systems. A number of acoustic conditioning taming devices can be established in marine ranching to continuously tame the released fish and strengthen the impact of the sound. At the same time, the multi-point deployment of automatic taming devices can form an acoustic conditioning taming network to increase the action area and effects.

One Tree at a Time: Restoring Landscape Connectivity through Silvopastoral Systems in Transformed Amazon Landscapes

Due to the continued expansion of pastures and illicit crops, the Andes-Amazon foothills in Colombia are one of most threatened biodiversity hotspots in the country. Halting and restoring the connectivity of the landscapes transformed over the last 40 years and now dominated by extensive cattle ranching practices, represents a challenge. Silvopastoral systems (SPSs) have been proposed as a strategy to help conserve the biodiversity by improving landscape connectivity. However, understanding the contributions of SPSs to biodiversity conservation still requires additional research. At the farm scale (here called farmscape), we compared different landscape fragmentation and connectivity metrics under two SPS conditions (with and without). Overall, the adoption of SPSs increased the probability of connectivity (PC) index in all cases. However, the contributions of SPSs to landscape connectivity were not linear. Greater PC increases were observed in highly degraded farmscapes (ΔPc = 284) compared to farmscapes containing patches that were better connected and had larger habitat areas (ΔPc = 6). These variables could play a fundamental role in enhancing the landscape connectivity through restoration activities that seek to improve biodiversity conservation. Even if they are relatively small and scattered, in highly degraded cattle ranching systems, SPSs could significantly improve the landscape connectivity, which in turn could improve wildlife conservation.

Evaluation of resources and environmental carrying capacity of marine ranching in China: An integrated life cycle assessment-emergy analysis

Resources and environmental carrying capacity (RECC) describes the ability of a system to achieve healthy and sustainable development. Various marine ranching enterprises have emerged in China in recent years, which have aroused concern and debate about the RECC of marine ranching systems. By taking the environmental impact calculated by life cycle assessment (LCA) into consideration in emergy analysis (EA), this study evaluated the comprehensive RECC performance of the whole system and each stage of a marine ranching system in China. The resource use efficiency (RUE) and system carrying ratio (SCR) of the system were reasonably good. However, its environmental loading ratio (ELR), emergy yield ratio (EYR), and emergy sustainability index (ESI) were unsatisfactory. First, the nonrenewable resources dominated the emergy input. Second, the emergy input from the purchased resources was much greater than that of local resources. Third, the potential environmental impact mainly came from the construction stage. Fourth, serious overload of RECC was observed in the maintenance stage. The results indicate that the system is efficient, and its RECC is in a safe state, but the system has deficiencies in environmental protection and the exploitation and utilization of local resources. The proposed analysis framework helps us comprehensively understand the marine ranching RECC performance and provides a research paradigm reference for the sustainability analysis of other complex eco-economic systems.

Agronomic qualities of Pennisetum clandestinum in association with Acacia koa for the mitigation of the effects of ranching and promotion of conservation in a silvopastoral context on the island of Maui, Hawaii

ABSTRACT Upper-elevation mesic Hawaiian forests have been transformed by cattle ranching and invasive ungulates within the past 200 years. Although the flora and fauna of the Hawaiian Islands have been radically altered by the introduction of invasive species, there is a movement of agriculturalists within the islands interested in reintroducing native species and reforestation in agricultural spaces. One of the keystone species in the Hawaiian Islands is the endemic tree species Acacia koa, known for its ecosystem services and cultural importance. This species is valuable for nitrogen fixation, aquifer recharge, habitat for biodiversity and usefulness in agroforestry systems. This investigation is focused on the relationship between the tree species A. koa and the forage grass species Pennisetum clandestinum (kikuyu) in a silvopastoral context, at an elevation of 5,200 feet above sea level (1585 masl) on the island of Maui. The site of investigation is called Pu’u Makua in Hawaiian and is situated on the southwestern flank of Haleakalā (10,023 feet above sea level–3055 masl) and is part of Ulupalakua Ranch. A total of n = 28 forage samples of P. clandestinum were taken in dry season, 21 of which were taken from underneath the canopies of koa trees (which had been planted in densities of 3, 4, and 6 m apart). The other seven samples were taken in full sun (where no koa trees were growing). This same protocol (sampling n = 28) was repeated in the wet season. Forage samples were then sent to the Agricultural Diagnostics Laboratory at the University of Hawai`i at Manoa for forage analysis to compare attributes of kikuyu under different canopy densities of A. koa. To better understand the leaf area index (LAI) of the canopy of various densities of A. koa, hemispheric (180 degree) photos were taken and then input into Gap Light Analyzer Software for LAI. LAI data of A. koa as well as forage attributes of P. clandestinum were then input into the statistical software InfoStat to investigate relationships between canopy cover and forage quality at each specific location. It was found through Pearson correlation analysis that there are in fact significant relationships between koa and the quality of kikuyu. Measurements of koa trees were also taken to estimate biomass and the amount of carbon sequestered within each tree. These measurements were input into allometric equations specific to koa growing on the Island of Maui that were created by the United States Forest Service. Lastly, to better understand the knowledge of ranchers on Maui, we conducted surveys regarding various ranchers’ perceptions of native and non-native trees and their usefulness for silvopastoral ranching systems. Ranchers also identified various tree species that were of use (or harmful) to their operations. Since A. koa was on this list of helpful trees and conferred various ecosystem services and agroecological benefits, the incorporation of koa into ranching systems on the island of Maui is recommended in zones appropriate for its growth.

Current Knowledge on the Lagune Cattle Breed in Benin: A State of the Art Review

This paper summarizes the information on the Lagune cattle breed and its production systems in Benin available in peer-reviewed journals, conference papers and research reports covering the period from 1970 to 2020. Lagune cattle are kept in two production systems in Benin: the improved ranching system established at the Governmental farm of Samiondji, where most of the published studies on this breed have been achieved, and the village traditional production system. This breed has a small size with short horns. Reported adult weight varied from 140 to 180 kg for male and from 100 to 140 kg for female. Lagune cows are bad dairy. The breed plays an important role in the livelihoods of the rural people and has many functions, including cultural, ecological, socio-economic, savings and income provision roles. Most of the reports emphasizes its low productivity, which might rather be more related to its poor management conditions than to its genetic potential. The Lagune breed is reported to have adaptive traits such as tolerance to drought and heat, and resistance to ticks and diseases. In 1975, the Government of Benin, having realized the risk of the disappearance of this breed, devoted the Samiondji Farm to its ex situ conservation and set up a purebred multiplication herd. Since then, there have been very few efforts to comprehensively characterize this breed and its productivity under smallholder production systems. Consequently, the opportunities for its in situ conservation, management and sustainable use by the rural communities are not sufficiently explored.

Resource-based induced conflict and socio-economic effects on crop and cattle farmers in Nigeria

Abstract This study investigated the socio‑economic effects of crop and cattle farmers’ natural resource‑based conflicts in Osun State, Nigeria. A total of 228 crop and cattle farmers were sampled in six communities (Ila, Faje, Esa‑Oke, Esa‑Odo, Patara and Adana), using a multistage sampling procedure. The data were analysed using both descriptive and inferential statistics such as Pearson Product Moment Correlation (PPMC), Chi square and independent t‑test (at α 0.05). Majority (73.7%, 100%) of crop and cattle farmers, respectively, were male. Accessibility of natural resources and damage/stealing of crops were identified as major causes of the conflicts. Crime and criminality, and poor training on conflict prevention and resolution were rated as major constraint to conflict resolution. Sustainable land management practices and alternative fodder production for crop and cattle farmers, respectively, were identified as major climate smart training needs to mitigate conflicts. Reduction in quality of social relationships and interruption in education of children for crop farmers; and displacement and reduction in quality of social relationships for cattle farmers were the major social effects suffered. Reduction of agricultural outputs and inability to repay loan were the most common economic effects suffered by the respondents. Causes of conflict, farm/herd size and years of respondents’ experience significantly related with overall socio-economic effects, while constraints to conflict resolution mechanisms (t = −2.672, p = 0.008), methods of conflict resolution (t = −6.649, p = 0.000) and socio-economic effects (t = 3.317, p = 0.008) differed among the respondents. Furthermore, the effect of the conflict was more severe among the crop farmers than among cattle farmers. Based on these new findings it is essential that a coordinated effort between religious institutions, the government, and non-governmental organisations give the ongoing efforts more momentum and include convincing herders to consider other options for producing livestock under ranching system for a more effective and sustainable livelihood practices.

Effect of Clipping Heights on Rangeland Yield, Productivity, Carrying Capacity and Utilization Check A Case study from the tropical savanna grassland, South Darfur, Sudan

A plot of one fed an (4200 m2 ), in a ranching system of the Southern Darfur savanna grassland – Gazala Gawazat, Animal and Range Research Station, was selected and fenced for artificial grazing experiment for a couple of seasons . The total forage mean yield (Kg/ha) at three different clipping heights (5cm, 15cm and 35cm) varied significantly (P < 0.05). The clipping,(harvesting) at a height of 5cm level produced a better harvest yield of forage for maintaining grazing animals at a certain grazing management system when applied. Higher forage yield (1588.68Kg/ha) and carrying capacity (211.82 AU/ha/d) for 5cm clipping height then followed by the 15 cm clipping height in terms of forage yield (641.18 Kg/ha) and carrying capacity (85.84 AU/ha/d).Based on the argument that cattle consumes about 2.5 Kgs DM /day/100Kg L.wt. On the other hand, 35 cm clipping height produced lower yield (488.56Kg/ha) and low carrying capacity (81.41 AU/ha/d), revealing that smaller number of grazing animals can be allowed to graze for shorter period. On average seasonal basis, season 2019 was much better than grazing season 2018 on 5cm clipping height in terms of forage yield (414.99Kg/ha & 390.17 Kg/ha ) respectively . As such, continual harvest with particular management system, gives more chance offered for grasses to regenerate vigorously to increase the total forage (harvest) yield, with the optimum allocation of grazing animals to utilize the range site. Accordingly, more animal’s units accommodated per unit area of that type of management.

Silvopastoral Systems Enhance Soil Health in the Amazon Region

Silvopastoral systems (SPS), an integrated farming system in which tropical grasses are combined with trees and shrubs, have been implemented in the last years in the Amazon region in order to mitigate the impacts generated by the traditional cattle ranching system. However, despite the multiple SPS’s benefits to soil and ecosystem, there is a paucity of comprehensive studies revealing the potential soil health (SH) restoration through SPS. Here, by developing an overall SH index using local native vegetation (Amazon rainforest) as a reference, we aimed to assess SH changes induced by the land transition from the traditional livestock production system to the SPS in the Colombian Amazon region. A chronosequence conformed by three areas: (i) native vegetation, (ii) traditional pasture and (iii) silvopastoral system was established in two study sites located in the Colombian Amazon, specifically in Caquetá State, the second hotspot of deforestation in the Amazon Basin. The results indicated high soil compaction and loss of macrofauna diversity and richness due to pasture management, causing a loss of 9% of soil capacity to function. In contrast, by integrating 31 soil indicators, our SH assessment revealed that SPS was an effective strategy for the recovery of SH, impacting positively multiple soil functions related to nutrient dynamics, water retention and supply, and biological activity.

Assessment of the Risk of Foot and Mouth Disease among Beef Cattle at Slaughter from East African Production Systems.

Endemic foot and mouth disease (FMD) in East African cattle systems is one factor that limits access to export markets. The probability of FMD transmission associated with export from such systems have never been quantified and there is a need for data and analyses to guide strategies for livestock exports from regions where FMD remains endemic. The probability of infection among animals at slaughter is an important contributor to the risk of FMD transmission associated with the final beef product. In this study, we built a stochastic model to estimate the probability that beef cattle reach slaughter while infected with FMD virus for four production systems in two East African countries (Kenya and Uganda). Input values were derived from the primary literature and expert opinion. We found that the risk that FMD-infected animals reach slaughter under current conditions is high in both countries (median annual probability ranging from 0.05 among cattle from Kenyan feedlots to 0.62 from Ugandan semi-intensive systems). Cattle originating from feedlot and ranching systems in Kenya had the lowest overall probabilities of the eight systems evaluated. The final probabilities among cattle from all systems were sensitive to the likelihood of acquiring new infections en route to slaughter and especially the probability and extent of commingling with other cattle. These results give insight into factors that could be leveraged by potential interventions to lower the probability of FMD among beef cattle at slaughter. Such interventions should be evaluated considering the cost, logistics, and tradeoffs of each, ultimately guiding resource investment that is grounded in the values and capacity of each country.

Research and development of a large-scale modern recreational fishery marine ranch System☆

The main problems facing the development of China's marine aquaculture industry include improper use of marine resources, overfishing, and seawater pollution. Large-scale marine ranch based on ecological environment provides a promising solution for solving the above problems and achieving the sustainable development of the marine aquaculture industry. Therefore, this study presents a novel design of a large-scale recreational fishery marine ranch system, which consists of three major subsystems including 1) management platform, 2) deep-sea cage group, and 3) environmental supporting facilities (such as artificial reefs, algae planting areas and seagrass beds, etc.). The management platform is a multifunctional system combining areas and subsystems for living, entertainment, leisure, monitoring, and automatic feeding management, etc. The usage of deep-sea cage group makes the most of the ocean space. When being integrated with those ecosystem-based environmental supporting facilities, it also addresses the seawater pollution issue that is generally encountered by conventional cage-based farming systems. Preliminary calculation and simulation results show that the expected design goals can be basically achieved. The overall goal of this research is to combine the sustainable development of the marine aquaculture industry, assist the development of the tertiary industry, and the continuous improvement of the living environment, which in turn will maximize the comprehensive benefits.

Food Web Trophic Structure at Marine Ranch Sites off the East Coast of Korea

Understanding the trophic ecology of the giant Pacific octopus Enteroctopus dofleini is challenging in developing marine ranches and in reestablishing its regional stocks against the severe stress of fishing. We adopted carbon and nitrogen stable isotope techniques (termed δ13C and δ15N, respectively) to identify the trophic niche (i.e., pathways and positions) of this species systematically in the entire food webs of two marine ranches off the east coast of the Korean peninsula. While a slight spatial shift in the isotopic nestedness of faunal communities was observed, the δ13C and δ15N values of consumers were distinct and separate among functional groups at both ranches. The consumer δ13C values spanned a broad range between pelagic and benthic sources of organic matter, and their δ15N values recorded a stepwise trophic-level enrichment, indicating that suspension feeders and herbivore-deposit feeders served as baselines of pelagic- and benthic-based trophic pathways, respectively. The δ13C values of predators, including E. dofleini, were arrayed between the two primary consumer groups. Neither δ13C nor δ15N values showed any remarkable variations with increasing octopus weight. Dietary mixing-model calculations indicated that E. dofleini is a generalist predator relying on both benthic- and pelagic-affinity prey, similar to some teleost species that consume a diverse spectrum of prey. In contrast, other teleost groups showed prevalent trophic links with either pelagic- or benthic-based pathways. The trophic-level estimations revealed that E. dofleini occupies an intermediate position slightly below the teleosts. A lack of discrete trophic positions between E. dofleini and teleosts seemed to be indicative of the released teleost predation but instead reflects the imposed food competition. Overall, the results demonstrated that despite compositional changes in the taxa constituting individual trophic groups, E. dofleini occupied a very similar trophic niche in both ranching systems. Finally, as extracted from information based on octopus marine ranches launched on natural rocky bottoms, our isotopic evidence provides a greater understanding of the trophic ecology of this octopus species in nearshore natural habitats along the southwestern margin of its distribution range.

Carcass and commercial cuts yields of caiman (Caiman crocodilus yacare) farmed in a ranching system in the Brazilian Pantanal.

Given the growing use of alternative sources of protein, studies on the commercial viability of amazonians wild species, based on the yield of their carcass, are still scarce in the literature. To evaluate yields of carcass and commercial cuts of caiman meat (Caiman crocodilus yacare), according to sex and weight categories, besides analyzing their revenue. Thirty animals in termination phase were selected, separated by sex and weighed. The cuts analyzed was of 59.7% in relation to total live weight, and of 70.7% in relation to the carcass. Regarding the yields of the cuts, the average weight difference in detriment to the sex of the animals was minimal, however, in the weight categories, animals classified as intermediate and heavy (5.9-9.1 kg) resulted in higher cut weights (p < 0.01) and consequently in revenue for most of the meat cuts (66.7%), especially for tail, back, and sirloin fillets. It can be concluded that the carcass yield of caiman is high, and that heavy animals resulted in higher yields of prime cuts, emphasizing the need to carry out studies that prioritize the cost/benefit ratio taking into account the age and weight of the animals.