Intensive Production Systems Research Articles

Using an Uptake Enhancer to Mitigate Nitrogen Leaching While Enhancing Uptake Efficiency

Nitrogen (N) has the most crucial influence on raising agricultural productivity of all other plant nutrients given to crops. However, 50% of the N given to crops is dissipated to the environment globally, resulting in environmental concerns due to leaching. Current research shows that intensive agricultural production systems, which are still used in a large proportion around the world, are prone to N loss. This study aimed to investigate the effect of uptake enhancer applications on N movement in the soil profile based on 10 cm depth intervals, as well as its effects on N uptake and vegetative growth of oats at 4-week intervals over a 16-week period, using sandy soil as a growing medium. Oats were cultivated in a glasshouse setting in polyvinyl chloride (PVC) columns of 60 cm in height. Six treatments were employed at the 3rd leaf growth stage, and each was replicated four times. The experiment had a constructive and a destructive part, which was employed to monitor crop N uptake at four growth stages. Analyses of soil and plant samples were carried out in all the growth stages. The treatments containing the uptake enhancer prevented N from leaching, particularly at the top 20 cm soil depth, with impressive reductions of 194% at 0–10 cm depth and 186% at 10–20 cm depth, during the first 4 weeks after planting. The uptake enhancer also promoted early vegetative growth and crop performance with 15%. In conclusion, the study revealed that employing the uptake enhancer can improve the efficacy of N fertilizer, thereby reducing the application rate of the fertilizer in agroecosystems.

Horticultural Irrigation Systems and Aquacultural Water Usage: A Perspective for the Use of Aquaponics to Generate a Sustainable Water Footprint

The expansion of food production is becoming more important due to a rising world population, which is relying on food security on regional and local scales. Intensive food production systems exert a negative impact on the regional ecosystem because of agrochemical pollution and nutrient-rich water discharging into nearby rivers. Furthermore, these systems highly depend on regional water resources, causing water scarcity and soil erosion due to the overexploitation of natural resources in general. The objective of this article is to review the water usage in the two most water-intensive food production systems, agriculture and aquaculture, showing lacking areas like system management and climate change, which must be considered in the implementation of a sustainable water footprint. In addition, the review includes an analysis of the combination of both production systems in aquaponic food production and the possibilities of water saving. There are a variety of analyses related to water usage for crop and aquatic animal production, but in these analyses, there is a lack of information about system management in general, which includes cleaning processes, water substitution, pond removal, water evaporation, and, especially in aquaculture, the water usage required for industrially elaborated fish feed.

Agronomic response, transpiration and water productivity of four almond production systems under different irrigation regimes

In recent years, more intensive production systems have been developed, coinciding with a growing scarcity of water resources. This context underscores the imperative of prioritizing water productivity (WP) as a critical factor in choosing the optimal production system to minimize agricultural water use. This study aims to contribute by evaluating WP in almond orchards under four production systems: open vase with severe pruning (open vase), open vase with minimal pruning (open vase (MP)), central axis and hedgerow. Three irrigation treatments were applied over two consecutive growing seasons: fully irrigated, mild stress and severe stress. Crop transpiration was monitored over the two years using both sap flow sensors and the two-source energy balance (TSEB) model with remote sensing. The severe stress treatment exhibited a notable reduction in kernel yield and nut load of 31.6 % and 34.5 %, respectively, in the second year of water deficit. The hedgerow system tended to have similar kernel yield to the open vase (MP) and central axis systems, and higher compared to the open vase system. Additionally, both transpiration measurement methods revealed that hedgerow exhibited lower transpiration rates across all irrigation treatments. Therefore, the highest WP was observed in the hedgerow system throughout both studied years. Similar findings were derived from the analysis of long-term data. Our findings indicate that the hedgerow production system had the highest WP, averaging 0.43 kg m−3 historically, compared to 0.33 kg m−3 for the open vase, 0.34 kg m−3 for the open vase (MP), and 0.36 kg m−3 for the central axis systems.

Seroprevalence and risk factors of Toxoplasma gondii infection among goats in Algeria

Toxoplasmosis is one of the most common zoonotic parasitic diseases worldwide and is caused by Toxoplasma gondii. It is implicated in reproductive disorders in small ruminants. This study aims to determine, for the first time in Algeria, the seroprevalence and associated factors of T. gondii infection in goats. The study was conducted in four regions, Ghardaia, Laghouat and Djelfa, southern Algeria, and Jijel region, northern Algeria. A total of 92 blood samples were collected including 74 females and 18 males. All sera were tested using an enzyme-linked immunosorbent assay (ELISA) to detect the T. gondii antibodies. The presence of anti-T. gondii antibodies was detected in 35 out of 92 goats (38.04%) (95% CI: 31.64%–44.44%) and in all flocks (100%). Risk factors that have a significant influence on the seroprevalence of T. gondii infection are breed, regions, production system, presence of cats, clinics and abortion history. However, variables such as age and gender were note significantly associated with toxoplasma infection in goats. The highest seroprevalences of infection was observed in saanen (52.94%) (p<0.001) and cross-breed race (44%) (p<0.01) in comparison with other breeds. Regarding regions, Jijel and Laghouat were most infected with seroprevalences of 50% (p<0.001) and 40.91% (p<0.01), respectively. Animals in intensive production systems were most infected, showing a seroprevalence of 51.85%, in comparison with extensive (28.13%) and semi-intensive systems (36.36%) (p<0.001). The presence of cats in farms was significantly associated with high seroprevalence (44.64%) (p<0.001). The infection was more prevalent in previously aborted females (50%) than females that had never aborted (3.35%) (p<0.001)and animals that have diarrhoea or poor health (41.67%) were significantly more infected than healthy animals (37.50%) (p<0.01). Seroprevalence in males (38.89%) was very close to those in females (37.84%) (p>0.05). Age-related seroprevalence did not vary significantly (ranged from 36.37% to 40%) between the three age classes. These results indicate that goat toxoplasmosis is widespread in Algeria, and goats may represent a high risk of contamination for humans. This requires more attention during consumption of goat meat.

Exploring the Potential of Biostimulants to Optimize Lettuce Cultivation in Coupled and Decoupled Aquaponics Systems: Growth Performance, Functional Characteristics and Metabolomic Analysis

Zero-discharge and low-input aquaponics systems are a promising alternative to the intensive agricultural and aquacultural production systems currently used, ensuring high environmental sustainability. However, new approaches and management practices are needed to increase their productivity to reach the yields of classic production systems. In this context, the present study investigated for the first time the potential of two biostimulants to improve lettuce performance in aquaponics, whether coupled or decoupled, with hydroponics serving as a control. A comprehensive evaluation was conducted to assess the plant functional (focusing on the photosynthetic process evaluation) and growth responses at the whole-plant level. In addition, the nutritional state of the leaves was determined and metabolomic analysis was performed at the cellular level, the latter also for the first time in aquaponics research. The results demonstrated the limitations that coupled aquaponics poses in relation to lettuce growth, function and metabolism, which were already obvious from the 12th day of the experiment. Indicatively, the plants grown under coupled aquaponics exhibited a notable decrease in the leaf fresh weight, potassium content and nitrogen content, with reductions of 80%, 60%, and 30%, respectively, in comparison to the hydroponics control. However, the combined physiological and metabolomic data indicate that these plants down-regulate processes and metabolism to acclimate to low nutrient levels in lettuce leaves rather than experiencing damage. The application of biostimulants did not significantly optimize the plants’ performance, though one of them appeared to be effective in improving some aspects of the photochemical efficiency. The decoupled and hydroponics systems resulted in similarly high yields and efficiency in terms of plant function, without any marked contribution from the biostimulants. We conclude that the decoupled aquaponics system has been successful in achieving yields comparable to those of hydroponics, with lower chemical inputs. Future studies should focus on examining other biostimulants in this system to further improve its performance while maintaining its environmental benefits within a circular economy framework.

N Fertilizer Reduction Combined with Organic Amendment Enhances Soil Multifunctionality by Altering Nutrient Availability and Fungal Community Structure in an Intensive Grain Production System

N Fertilizer Reduction Combined with Organic Amendment Enhances Soil Multifunctionality by Altering Nutrient Availability and Fungal Community Structure in an Intensive Grain Production System

Assessment of welfare of Pekin ducks reared in intensive production system in Poland using transect method

Abstract The aim of this study was to evaluate the practical application of the Transect Walk (TW) method on a commercial farm, focusing on different ages of Orvia ST5 Pekin ducks. The study was conducted in four flocks of Orvia ST5 ducks, reared in two identical buildings. Flocks 1 and 3 were housed in Building 1, while flocks 2 and 4 occupied Building 2. A total of 8,000 ducklings were allocated to rearing, with 2,000 in each flock. The welfare of the ducks was assessed at 5, 6, and 7 weeks of age using the TW method, which involved assessing indicators such as immobility, lameness, dirtiness, small size, head wounds, back wounds, tail wounds, feather loss, illness, terminal illness, being flipped, or being deceased. Information regarding factors contributing to reduced carcass quality was gathered from the slaughterhouse. It was observed that all welfare indicators, except for head and tail wounds, were equally effective in assessing duck welfare and accounted for up to 82.13% of the variation in welfare. Lameness emerged as the most prevalent factor associated with reduced welfare, showing a strong correlation with immobility. Both indicators exhibited a significant interaction with age and flock (P = 0.001 and P = 0.029, respectively). Feather loss emerged as another crucial indicator of reduced welfare in the examined flocks. The percentage of featherless ducks varied from 0.29% to 3.50% and was significantly influenced by both duck age and flock (both P&lt;0.001). Additionally, it showed a significant and positive correlation with immobility (P&lt;0.05). The primary issues identified during duck culling were associated with skin problems and leg and joint issues. Statistically significant variations were noted among flocks concerning the frequency of indicators linked to reduced welfare. This variance was attributed to the specific building where the ducks were raised. The findings of this study suggest the incorporation of the TW method in future welfare assessments, utilizing the 10 welfare indicators employed while excluding head and tail wounds.

Use of multi-agent systems and the Internet of Things to monitor the environment of commercial broiler poultry houses through specific air enthalpy

The intensive production system for broilers requires the availability of an environment (aviary) that promotes an artificial microclimate that favors both animal well-being and productive performance; therefore, monitoring this environment is critical for production success, especially in tropical countries. This criticality opens up a range of research opportunities for monitoring because of the currently available technologies, especially in the areas of the Internet of Things and Expert Systems. Thus, this study presents a proposal for the environmental monitoring of an aviary using an Internet of Things technological apparatus combined with multi-agent systems to monitor climatic variables with the guidance of thermal comfort indicators. The experiment took place in a Cobb broiler aviary located in the countryside of the State of São Paulo, Brazil. With this objective in mind, the production period of Cobb broilers was analyzed through the construction of an Internet of Things system to collect air temperature, relative humidity, and atmospheric pressure variables combined with a data transfer mechanism for cloud recording. These variables were then analyzed by computational agents using the Java programming language with the Jade framework, which generated animal comfort indicators. The results showed that real-time monitoring of environmental variables is possible with the combination of the Internet of Things with agents that can determine animal comfort conditions according to the specific enthalpy of the air through the orchestration of a deliberative agent and with the participation of several reactive agents.

Assessment Of the Factors that Limit Rabbit Production Under an Intensive Production System in Zanzibar

A study was conducted to assess the factors that limit rabbit production under an intensive production system in Zanzibar. A total of 390 farmers from three districts each has 130 respondents were interviewed in a cross-sectional survey. The results revealed that 48.2% of farmers had kept rabbits and 51.8% did not, while 53.2% of the farmers kept medium breeds and 46.8% of them kept small breeds of rabbits. In terms of management systems was significant (ρ≤ 0.038) in the feeding system was 60.2% of farmers used an intensive system and 39.8% employed semi-intensive systems, whereas a higher number of farmers 88.6% of main diets fed the rabbits with green grass than 11.4% utilized kitchen wastes. In the observed marketing of rabbits and their products, the proportion of respondents who had sold rabbit parts was significantly higher (ρ≤ 0.007), that is 73.0% had sold rabbits than 27.0% who did not sell any rabbit parts. However, it was not statistically significant concerning the types of rabbit products sold and marketing challenges at ρ≤ 0.836 and ρ≤ 0.475 respectively. The disease infection was reported by 58.9% of farmers their rabbits were affected by the disease and 41.1% of them did not. However, no statistical significance was associated with the causes of disease infection at ρ≤ 0.299. Likewise, rabbit production in Zanzibar is at an immaturity stage and is constrained with many drawbacks. Therefore, proper animal husbandry practices and extension service delivery are recommended.

Molecular Detection and Serological Investigation of Newcastle Disease in Intensive, Semi-Intensive, and Backyard Production Systems in Central and Southwestern Areas of Ethiopia.

The purpose of this research is to detect Newcastle disease virus and to assess the seropositivity among backyard, semi-intensive, and intensive farms located in central and southwestern areas of Ethiopia. A total of 239 oropharyngeal and cloacal swab samples were collected from symptomatic birds found in Holeta, Burayu, Jimma towns as well as Seka Chekorsa and Nadhigibe woredas of Jimma Zone. In addition, ninety blood samples were collected from wing veins of unvaccinated birds found in the study areas of Jimma zone. Side-by-side information related to risk factors estimated to contribute to the susceptibility of the disease was collected by interviewing owners of sampled birds. Reverse transcription polymerase-chain reaction (RT-PCR) was conducted to detect NDV. Likewise, Enzyme-linked immunosorbent assay (ELISA) was performed to determine the seropositivity of ND. The proportion of samples where NDV was detected was 24.6%. Similarly, 68.9% of the sampled birds were seropositive. It was observed that adult birds were more likely to encounter the disease than youngs (OR = 11.6; 95% CI: 4.0-33.3; P = 0.000). Birds owned by respondents who leave diseased birds in the flock were more likely infected (OR = 6.2; 95% CI: 1.8-21.2; P=0.004) as compared to those isolated and mode of disposal of dead chicken significantly affect exposure (OR = 0.13; 95% CI: 0.10-4.88; P = 0.044). Likewise, access to veterinary services highly likely reduces susceptibility to the disease (OR = 12.4; 95% CI: 3.2-46.9; P = 0.000). It was also found that birds farmed intensively were the most at risk (OR = 2.8; 95% CI: 0.58-13.71; P = 0.199). Detection of ND from a significant proportion of sampled birds and their high seropositivity percentage revealed the circulation of the virus in the study areas.

Evaluating different green manuring plant species and stool destruction methods for enhancing sugarcane yield at Wonji-Shoa Sugar Estate, Ethiopia

The long-term intensive production system employed in the Sugar Estates in Ethiopia, characterized by monoculture, preharvest burning, and excessive tillage, has led to soil degradation with a concomitant decline in sugarcane yield. Therefore, a study was conducted at Wonji-Shoa Sugar Estate (WSSE) with the objective of evaluating the effectiveness of different green manuring plant species and cane stool destruction methods (SDMs) in improving cane yield. To that end, seven green manure plant species (sunn-hemp, lablab, cowpea, soybean, mungbean, dhaincha, and sugarcane trash) were evaluated under three SDMs (cultivating-out, spraying-out with herbicide, and maintaining the stool as it is) using a split-plot design. The experimental fields were established on two major soil types, with green manure crops incorporated into the soil before planting the sugarcane. The dry matter production and nitrogen contribution of the green manure plants, as well as the height, population, diameter, and yields of sugarcane, were determined and subsequently subjected to statistical and economic analysis. The results showed that cowpea, followed by lablab, dhaincha, and sunn hemp, were the most effective green manures in terms of improving cane performance, with up to 17–20 % yield advantage and 21–40 % net economic benefits over the control treatment. Additionally, the spraying-out MSD was as effective as the cultivating-out MSD, but both outperformed maintaining the stool. In conclusion, utilizing these green manuring crops in combination with the spraying-out SDM presents notable advantages for improved cane yield and enhanced economic benefits in a sustainable manner. Adoption of these practices, therefore, holds significant potential for reversing the constantly declining sugarcane yields at WSSE.

Factors Associated with Chemical Composition of Camel Milk from Different Production Systems in Sudan

In this study, the impact of different management systems, parity orders, stages of lactation and age of she camels on the chemical composition of milk were evaluated. The study was conducted during August to October 2018 to compare camel milk from three production systems that include the traditional nomadic in Kuma locality (North Darfur State) to the semi-nomadic (Red Valley in Eastern Nile and Hamid Well in Western Omdurman (Khartoum State) and the intensive in El Huda in Western Omdurman (Khartoum State). The milk samples investigated belong to three groups; parity orders, lactation stages and ages; of she-camels. The samples (n=120) were examined to determine the percent of fat, solids not fat, lactose, protein and density in camel milk. The results showed significant (P≤0.05) differences between milk samples obtained from camels reared in different management systems. The semi-nomadic system in Hamid Well area recorded high values for the chemical constituent in comparison to other systems and locations. Stages of lactation of she-camels kept in the intensive production system showed significant effect on the values of SNF, protein, lactose and the density of milk. However non-significant differences were recorded on milk chemical composition depending on parity orders and age of she-camels. In conclusion, the variations of the values of the chemical composition of camel milk from different locations is strongly correlated to the management systems that influenced by the availability of water and feed as well as other factors including lactation stages.

Can individual variation in food neophobia explain variability in dairy calf feeding behavior patterns and performance?

Food neophobia is the avoidance of novel feeds, arising from an attempt to avoid potentially toxic and unwanted feeds, and is very common in ruminants. In commercial dairy settings, hesitancy to consume novel feeds is detrimental to animal performance and may be associated with other traits that can negatively affect animals in intensive and modern production systems. The aim of this study was to investigate the relationship between food neophobia and the development of solid and milk feeding behaviors, and consequently with calf performance up to two weeks post-weaning. We subjected dairy calves at 83 ± 3 d of age to a food neophobia test with a novel feed (corn silage-based total mixed ration), a familiar feed (alfalfa hay), and an empty container. Behaviors measured from this food neophobia test were condensed into three factors using a principal component analysis: ‘Feed Avoidant’, ‘Active’, and ‘Attentive’. A regression analysis was performed to assess if scores for the three factors were associated with feeding behavior patterns measured via an automatic feeder system, including total milk intake, rewarded and unrewarded visits to the milk feeder, total calf starter intake, and age at which calves first consumed ≥ 1 kg of calf starter. Factor 1 (‘Feed Avoidant’) was positively associated with the number of rewarded visits to the automated milk feeder but was not associated with intake of calf starter or milk replacer, nor performance of dairy calves. The other factors identified from the food neophobia test showed associations with feeding behavior patterns and performance. Factor 2 (‘Active’) was positively associated with calf starter intake during the weaning, post-weaning, and total periods, and was associated with a younger age at which calves consumed 1 kg of calf starter. Factor 3 (‘Attentive’) was positively associated with number of rewarded visits to the feeder during preweaning, increased calf starter intake during weaning and total periods, and higher preweaning ADG. These results suggest that individual variation in the willingness to interact with novel and familiar feeds may not play a large role in the development of solid feeding behaviors or performance of group housed dairy calves, but other traits identified from the food neophobia test are associated with performance and feeding behavior that can be measured in standardized tests.

Strategies and Public Policies for Soil and Water Conservation and Food Production in Brazil

There is an urgent demand to change our intensive crop production systems, replacing them with soil use and management systems that recover, preserve, or improve soil health and are environmentally sustainable, producing healthy and good-quality food. In this work, we compile and present strategies and public policies aimed toward soil and water conservation and food production in Brazil. The results presented may help Brazilian farmers adopt practices to recover, maintain, or improve soil health and politicians to create or modify public policies for healthy soil and food, without the necessity of increasing agricultural areas. Food insecurity was also addressed, with family farming playing an important role in food production and decreasing food insecurity. But these challenges need the combined efforts and engagement of the whole society.

Assessment of Welfare Problems in Broilers: Focus on Musculoskeletal Problems Associated with Their Rapid Growth.

The growth of the broiler industry has been accompanied with concerns over the environmental and social impacts on intensive production systems, as well as the welfare of the animals themselves. As a result, since the 2000s, there has been growing interest in alternative production systems that improve animal welfare and sustainability. In this context, it is important to prioritize the welfare of broilers in commercial production systems and to use reliable welfare indicators to provide consumers with information about the welfare of the animals they consume. Resource-based measures (RBM) are based on assessing the resources available to the birds in terms of their housing, environment, and management practices, such as stocking density, litter quality, lighting and air quality, etc. Outcome-based measures (OBM), also known as animal-based measures, focus on assessing the actual welfare outcomes for the birds, such as footpad dermatitis, hock burn, contamination or damage to feathers, gait score, mortality, etc. These OBM-based measures are one of the more direct indicators of welfare and can help identify any welfare issues. The present review highlighted the factors that affect animal welfare indicators focused on OBMs which can be used in the commercial broiler farms.

Optimizing Feed Formulation Strategies for Attaining Optimal Nutritional Balance in High-Performing Dairy Goats in Intensive Farming Production Systems

Abstract Genetic factors play a pivotal role in shaping feed formulation strategies for dairy goats, influencing milk production, composition, and overall productivity through the modulation of genetic parameters and polymorphisms associated with milk protein fractions and yield. Moreover, environmental challenges, including heat stress and feed availability fluctuations, pose significant hurdles in achieving optimal nutrition and performance, necessitating precision livestock farming and the utilization of local by-products to mitigate their impact on herd health and productivity. In addition, nutritional interventions, such as supplement utilization and alternative feed incorporation, offer promising avenues for addressing specific deficiencies and enhancing overall performance, from fatty acid supplementation to herbal feed additives, while balancing rations to meet evolving nutritional needs and ensuring long-term sustainability remains paramount for optimizing herd nutrition, health, and performance in intensive dairy goat production systems. The aim of this study was to explore the multifaceted influences of genetic factors, environmental challenges, and nutritional interventions on feed formulation strategies and overall herd nutrition, health, and performance in intensive dairy goat production systems.

GLOBAL FEED PRODUCTION DOWN SLIGHTLY IN 2023. Р.2

Alltech’s Agri- Food Outlook estimates that global feed tonnage totaled 1.29 billion metric tons (BMT) in 2023, a decrease of 2.6 million metric tons (MMT) — or 0.2% — from 2022*. The overall lower demand for feed was due, in part, to the more efficient use of feed made possible by intensive production systems that focus on using animal nutrition, farm management and other technologies to lower feed intake while producing the same amount of protein, or more. Slower production of animal protein, in response to tight margins experienced by many feed and animal protein companies, also contributed to lower feed demand. The feed tonnage rate — defined as the amount of feed produced and distributed per unit of livestock or poultry — is influenced by multiple factors that affect the demand and supply of feed, as well as the efficiency and profitability of animal production. Changing consumption patterns caused by inflation and dietary trends, higher production costs and geopolitical tensions also influenced feed production in 2023.

Environmental Performance of a Mixed Crop–Dairy Cattle Farm in Alexandria (Romania)

Agricultural specialization has increased considerably in Europe over the last decades, leading to the separation of crop and livestock production at both farm and regional levels. Such a transformation is often associated with higher environmental burdens due to excessive reliance on exogenous inputs and manure management issues. Reconnecting crop and livestock production via mixed farming systems (MFSs) could improve circularity and resilience, leading to reduced environmental impacts. The objective of this study was to evaluate the life cycle environmental performance of a commercial mixed crop–dairy cattle farm in Romania and to compare it against the corresponding specialized systems. The evaluation covered both dairy cattle production (milk and meat) and cash crops. Overall, the results show that the coupled system improves environmental performance by reducing the over-reliance on high-impact inputs like synthetic fertilizers and exogenous feed. The carbon footprint for the milk production of the studied system (1.17 kg CO2 eq.) per kg of fat- and protein-corrected milk (FPCM) was 10% lower than the mean value of common intensive milk production systems. The eutrophication impacts (2.52 × 10−4 kg P eq and 2.67 × 10−4 kg N eq./kg of FPCM) presented values of one order of magnitude less than their specialized counterparts. However, the impacts of the studied MFS, albeit lower than those for comparable specialized systems, still remain relatively high. In particular, methane emissions from enteric fermentation (0.54 kg CO2 eq./kg FPCM) were a major contributor to the carbon footprint. This highlighted the need to address the elevated emissions from enteric fermentation with better feed management, as well as improving and reinforcing the system’s self-sufficiency.

Characterization of diarrheagenic Escherichia coli from different cattle production systems in Brazil

Diarrheagenic E. coli (DEC) can cause severe diarrhea and is a public health concern worldwide. Cattle are an important reservoir for this group of pathogens, and once introduced into the abattoir environment, these microorganisms can contaminate consumer products. This study aimed to characterize the distribution of DEC [Shiga toxin-producing E. coli (STEC), enteroinvasive E. coli (EIEC), enteropathogenic E. coli (EPEC), enterotoxigenic E. coli (ETEC), and enteroaggregative E. coli (EAEC)] from extensive and intensive cattle production systems in Brazil. Samples (n = 919) were collected from animal feces (n = 200), carcasses (n = 600), meat cuts (n = 90), employee feces (n = 9), and slaughterhouse water (n = 20). Virulence genes were detected by PCR in 10% of animal samples (94/919), with STEC (n = 81) as the higher prevalence, followed by EIEC (n = 8), and lastly EPEC (n = 5). Animals raised in an extensive system had a higher prevalence of STEC (average 48%, sd = 2.04) when compared to animals raised in an intensive system (23%, sd = 1.95) (Chi-square test, P < 0.001). From these animals, most STEC isolates only harbored stx2 (58%), and 7% were STEC LEE-positive isolates that were further identified as O157:H7. This study provides further evidence that cattle are potential sources of DEC, especially STEC, and that potentially pathogenic E. coli isolates are widely distributed in feces and carcasses during the slaughter process.

Ecologically Based Management of Pineapple Mealybug Wilt: Controlling Dysmicoccus brevipes Mealybug Populations with Salicylic Acid Analogs and Plant Extracts

Mealybug wilt of pineapple (MWP) is a destructive disease worldwide caused by a parasitic complex that includes Pineapple Mealybug Wilt-associated Viruses (PMWaVs) and mealybugs (Dysmicoccus brevipes), which concurrently act as vectors for these viruses. Reducing the mealybug population is key to managing MWP, which is achieved in intensive production systems through the use of insecticides. SA (salicylic acid), ASM (acibenzolar-S-methyl), BABA (β-aminobutyric acid), and MeSA (methyl salicylate) are key components of systemic acquired resistance (SAR), the defense mechanism of plants against biotrophic agents such as mealybugs. In this study, these compounds were applied either as pure chemicals and/or as a major constituent of plant extracts. Both the Hawaiian hybrid MD-2 and Queen Victoria tissue culture plants, as well as suckers used for vegetative propagation, were treated with these compounds by direct application on the soil of pineapple pots. Subsequently, five mealybugs were released on each plant or each daughter plant in case of a transgenerational experiment; then, after 45 days, the number of mealybugs was counted. Exogenous SA, ASM, and MeSA reduced the population of mealybugs by a minimum of 50% and up to 80%. These SAR-inducing treatments could be an interesting alternative for controlling mealybugs and are already used in other pathosystems. The SAR mechanisms behind this effect are yet to be confirmed by molecular and enzymatic markers. ASM and MeSA are promising treatments for pineapples using tissue culture plants or traditional shoots.