Search Results (7)

Although the benefits of rational grazing by polygastric animals are well known, little is understood about how chicken grazing affects soil biological health and its capacity to store organic matter. This study aimed to assess the impact of long-term free-range chicken grazing in an olive grove on the soil chemical and biochemical properties, including the total organic carbon (TOC), total nitrogen (TN), microbial biomass (Cmic), basal respiration, and microbial community structure, as well as the soil’s capability to stock organic carbon and total nitrogen. A field experiment was conducted in an olive grove grazed by chickens for over 20 years, with the animal load decreasing with distance from the poultry houses. At 20 m, where the chicken density was highest, the soils showed reduced OC and TN contents and a decline in fungal biomass. This was mainly due to the loss of both aboveground vegetation and root biomass from intensive grazing. At 50 m, where grazing pressure was lower, the soil OC, TN, and microbial community size and activity were similar to those in a control, ungrazed area. These findings suggest that high chicken density can negatively affect soil health, while moderate grazing allows for the recovery of vegetation and soil organic matter. Rational management of free-range chicken grazing, particularly through the control of chicken density or managing grazing time and frequency, is therefore recommended to preserve soil functions and fertility. Full article

With the aim to characterise the situation of the subsector, 25 poultry farms of the endangered native Utrerana chicken egg-laying-oriented breed (Gallus gallus Linnaeus, 1758) were surveyed in Andalusia (southern Spain) from 2021 to 2023 to investigate the structure of the farms, number of birds, health status, feeding management, and marketing of their products. It was found that the pace of foundation of Utrerana chicken farms accelerated from 2009, and most of the farms were concentrated in the province of Seville. Only 40% of the farms were legally registered. This breed is raised on small farms mainly dedicated to self-supply and raising birds for conformation and their aesthetic values, with limited marketing of eggs and meat, with facilities consisting often of one poultry house and one outdoor enclosure, and with a low number of laying hens per farm (53.5 on average). Current productivity is low, with an average of 139 eggs per hen per year, but hens have a long reproductive lifespan, averaging 4 years. The Partridge variety of the breed was the most common, followed by the Black-barred and Black varieties, while the White variety was very scarce, with only 31 specimens in total. Two-thirds of the farmers also raised other breeds of chickens, in addition to the Utrerana. The management and production system was free-range or backyard, with a certain proximity to the requirements of European Union-certified organic production with regard to stocking densities and generally with a good sanitary status, respect for welfare, and implementation of biosecurity measures on the farms. The feeding of the chickens was based on grazing in outdoor enclosures and on the provision of grains and compound feed, with 40.0% of farmers using commercial compound feed and half preparing feed themselves. Two-thirds of the farmers were affiliated with the National Association of Utrerana Chicken Breeders (“Asociación Nacional de Criadores de Gallinas Utreranas”, ANCGU, in Spanish); almost half of them took part with their birds in fairs and conformation shows, such as the Utrerana Chicken Fair held in Utrera (province of Seville) and more than a quarter of them have sold live birds of the breed at these fairs. The farmers carry out few promotional and advertising activities for their farms and products, predominantly by using social networks, and the market area reached is mainly local. In conclusion, this research has shown that the current alternative production system for Utrerana chicken is similar to that of the hens that originated the breed and consists of a few amateur farms, with a small number of birds, distributed mainly throughout the Andalusian countryside. It has been highlighted that there is a need for the livestock authorities to implement programmes for supporting farmers and promoting the breeding of this endangered avian breed, native to the Spanish zoogenetic heritage. Full article

Rural households all over the world rear backyard chicken mainly for their own consumption and, to a lesser extent, for barter trade. These chickens represent a staple dish with numerous culinary variations and a cheap source of protein. Although some Campylobacter species, and particularly Campylobacter jejuni and Campylobacter coli, have been associated with industrial poultry carcasses, studies concerning the ecology of this genus in rural households do not exist. To assess the prevalence of Campylobacter species in the tissues of backyard chickens, samples were collected from birds Gallus domesticus bred in households in the rural area of Epirus (Greece), and Campylobacter strains were isolated by quantitative methods at 37 °C and 42 °C. In total, 256 strains were identified, belonging to 17 Campylobacter species, with C. jejuni and C. coli being the most prevalent. From the four ecological parameters studied (size of the flock, presence of small ruminants in the same household, presence of other poultry species in the same household, and feeding leftovers of the household), the size of the flock and the presence of small ruminants and/or pigs in the same household mostly affected the distribution of these strains. To study the phenotypical resistance against 14 antibiotics, 215 strains were selected. The results showed a high prevalence of multidrug-resistance (MDR) strains extending to all classes of antibiotics. Further genome analysis revealed the presence of genes coding resistance (bla_OxA-61, tet(O), tet(A) cmeA, cmeB, cmeC, and gyrA (Thr-86-Ile mutation)), with the efflux pump CmeABC being the most prevalent. All antimicrobial resistance-encoded genes co-circulated, except for bla_OXA-61, which moved independently. The minimum inhibitory concentration (MIC) values of two out of three antibiotics (representing different classes) were reduced when the strains tested were exposed to carbonyl cyanide 3-chlorophenylhydrazone (CCCP), a known efflux pump inhibitor. The same result was obtained with the addition of CCCP to the MIC values of bile salts. These results lead to the conclusion that Campylobacter species are present in an impressive diversity in backyard chicken tissues and that they exert a significant resistance to antibiotics, raising a potential danger for public health. Full article

The Campylobacter species is considered as an emerging zoonotic threat to public health. C. jejuni and C. coli are the most studied species, yet a variety of other species of the same genus were found to be the causative agents of other diseases. Chicken meat has been described as an excellent vehicle for the transmission of some Campylobacter species but most of the relevant research has been conducted in urban populations and concerned meat of industrial-grade birds. To investigate the abundance and prevalence of the Campylobacter genus in rural free-grazing chicken, quantitative and qualitative methods at 37 and at 42 °C were employed. The possible correlation of the prevalence with certain epidemiological factors (size of the flock, presence of other poultry species, presence of small ruminants, feeding concentrates, or leftovers) has been also investigated. In total, 242–249 strains (depending on the method) belonging to the following 18 different Campylobacter species have been isolated: C. coli, C. rectus, C. hominis, C. helveticus, C. upsaliensis, C. jejuni, C. avium, C. fetus, C. hepaticus., C. lari, C. sputorum, C. mucosalis, C. gracilis, C. showae, C. hyointestinalis, C. concisus, C. cuniculorum, and C. ureolyticus. The size of the flock and the presence of small ruminants in the same household were the most influential factors affecting the prevalence of most species. Campylobacter species biodiversity can be attributed to environmental, zoonotic, or anthropogenic contamination. Rural populations should be educated about the importance of self-protection measures during their contact with their poultry and the necessity to cook sufficiently the meat. Full article

Toxoplasmosis is one of the most common zoonotic parasitic diseases infecting nearly all warm-blooded animals, including poultry (geese, turkeys, chickens, and ducks). It is caused by Toxoplasma gondii (T. gondii), which is an obligate intracellular protozoan belonging to the Apicomplexa group. In Thailand, duck meat production for domestic consumption and international trade is mainly bred and produced in the central and western parts of the country. Free-grazing ducks in integrated duck–rice production have significant benefits in rice cultivation, accounting for the popularity of this farming system in Thailand. However, ducks are considered particularly susceptible to consuming T. gondii oocysts from water contaminated with cat feces due to the fact of their feeding habits of free-grazing and dabbling. Hence, the prevalence of this zoonotic parasite in a large-scale integrated farming context is particularly challenging with respect to the contamination of the food chain of humans and farm animals. In the present study, we examined the overall prevalence of T. gondii infection in slaughtered free-grazing ducks originating from Central and Western Thailand, setting the stage for an in-depth One Health approach to assess and manage the risks of integrated farming practices. A representative sample size of 161 ducks was calculated using a two-stage sampling method. Specifically, serum samples were collected from 217 slaughtered free-grazing ducks originating in six provinces in Central and Western Thailand. Serum antibodies against T. gondii were detected using an indirect fluorescent antibody test (IFAT). The positive control serum samples were prepared from ducks experimentally immunized with T. gondii. Sixty-eight (31.3%) of the two hundred and seventeen ducks were seropositive with T. gondii. Two groups of fattening ducks and spent layers showed similar seropositivity rates at 29% and 32.3%, with the majority of positive samples being found in the low titer. In addition, a wide distribution of positive serum samples was observed in all six provinces in the present study. To the best of our knowledge, this is the first report on a serological prevalence snapshot in commercially produced duck populations that have high interaction with farmed environments in Thailand, revealing a high infection pressure in areas of integrated duck–rice farming. Importantly, contaminated duck meat for commercial use, as well as offal and carcasses from slaughterhouses, completes the transmission of T. gondii from the environment into the food chain of humans and domestic animals. Hence, from a One Health perspective, it is important to clarify whether this transmission chain extends further to the wild, i.e., predator–prey cycles that are independent of duck farming or are self-contained. Full article

Gold-mining activities have been demonstrated to result in significant environmental pollution by Hg, Pb, and Mn, causing serious concerns regarding the potential threat to the public health of neighboring populations around the world. The present study focused on heavy-metal contamination in the eggs, blood, feed, soil, and drinking water on chicken farms, duck farms, and free-grazing duck farms located in areas < 25 km and > 25 km away from a gold mine in northern Thailand. In an area < 25 km away, Hg, Pb, and Mn concentrations in the eggs of free-grazing ducks were significantly higher than > 25 km away (p < 0.05). In blood, Hg concentration in free-grazing ducks was also significantly higher than those in an area > 25 km away (p < 0.05). Furthermore, the Pb concentration in the blood of farm ducks was significantly higher than in an area > 25 km away (p < 0.05). The concentration of Cd in drinking water on chicken farms was significantly higher for farms located within 25 km of the gold mine (p < 0.05). Furthermore, a high correlation was shown between the Pb (r² = 0.84) and Cd (r² = 0.42) found between drinking water and blood in free-grazing ducks in the area < 25 km away. Therefore, health risk from heavy-metal contamination was inevitably avoided in free-grazing activity near the gold mine. The incremental lifetime cancer risk (ILCR) in the population of both Pb and Cd exceeded the cancer limit (10⁻⁴) for all age groups in both areas, which was particularly high in the area < 25 km for chicken-egg consumption, especially among people aged 13–18 and 18–35 years old. Based on these findings, long-term surveillance regarding human and animal health risk must be strictly operated through food chains and an appropriate control plan for poultry businesses roaming around the gold mine. Full article

Tall fescue (Schedonorus arundinaceus) is a common perennial forage in cattle pastures of the southeastern United States. A mutualistic fungal endophyte normally infects the grass and produces ergot alkaloids toxic to livestock, but fungal biotypes that have no ergot alkaloid production have been developed. Here remote sensing methods were used to assess plant health in 1 ha grazed paddocks with application amongst different combinations of fertilizer sources (inorganic and broiler litter) and endophyte associations (wild, novel–tall fescue MaxQ type with novel endophyte, and free). Broiler litter fertilization is common in the region due to the presence of many chicken farms. Moreover, broiler litter costs are comparable to inorganic fertilizer depending on distance from source to application. Incorporating remote sensing, we tested the sensitivity of three indices: normalized difference vegetation index (NDVI), enhanced vegetation index (EVI), and land surface water index (LSWI) to assess fescue plant health. Indices were obtained from satellite imagery provided by Landsat 7 ETM+ between the years 2005 and 2009. Sensitivity analytics suggested that LSWI was the optimum index to determine fescue plant health. The year experiencing drought (determined by annual precipitation) showed significant difference between fertilizer types (p = 0.05) and a nearly significant difference between endophyte associations (p = 0.08). There was no significant difference in years with normal or wet precipitation rates due to tall fescue endophyte association or type of fertilization. Limited availability of satellite imagery during parts of the five years of study might have influenced outcomes of statistical analyses. Nevertheless, the data and findings point to the potential use of satellite imagery in assessing grazingland tall fescue health and advancing the concept of poultry manureshed in the region or elsewhere where poultry manure production is extensive. Full article