Egg residue considerations during the treatment of backyard poultry

Assessing Backyard Poultry versus Small Animal Knowledge of Veterinary Students regarding Husbandry, Prescription Drug Use, and Antimicrobial Resistance

As backyard poultry (BYP) ownership has increased in the US, the demand for veterinarians who treat BYP has also increased. However, veterinarians who treat BYP remain scarce and are mostly small animal veterinarians and exotic animal practitioners who have limited training in food animal regulatory practices. To gauge whether veterinary students are interested in learning more about BYP and what BYP topics to include in an online training program for veterinary students, a BYP knowledge assessment was conducted. Pre-clinical veterinary students were asked to self-rate their level of knowledge on various topics for both small animal practice and BYP using Likert-type ordinal scales. Wilcoxon signed-rank tests of those Likert data showed significant differences (p < .01 at α = .05) between self-assessed knowledge of poultry and small animal medicine for all surveyed topics. Specifically, veterinary students ranked themselves as less knowledgeable on poultry concepts than on small animal medicine concepts. Nevertheless, students expressed interest in an online training program for treating BYP and drug residue avoidance in BYP, despite having chosen future career tracks that are not exclusively poultry. Specific topics students expressed interest in with respect to BYP training included anatomy, husbandry, prescribing medications, treatment options, food safety, antimicrobial resistance, and extra-label drug use.

Quantitative exposure assessment and risk characterization for fipronil residues in laying hen eggs

Poultry production is linked to veterinary drug use to treat diseases. Few ectoparasitic compounds are approved for poultry. Fipronil is a pesticide widely used in agriculture. It is also a drug authorized to control ectoparasites in small animals and, in some countries, in cattle. There has been evidence of fipronil extra-label use in laying hens, mainly to control the red mite Dermanyssus gallinae. Fipronil's popularity is due to its high toxicity to invertebrates. It could be metabolized to more toxic metabolites that potentially damage human health. In the present study, we carry out a quantitative exposure assessment and risk characterization for fipronil residues in laying hen eggs for local consumption in five cities of Buenos Aires province in Argentina, namely, Azul, Balcarce, Juarez, Chaves, and Tandil. Consumption surveys and egg sampling were conducted for three summer periods. Eggs were analyzed by UFLC-MS-MS. Fipronil prevalence, residue concentrations, residue stability to cooking methods, egg consumption, among the most important variables were modeled. The results indicated that 20.7% of samples contained fipronil residues. The highest residue was fipronil sulfone metabolite. Fipronil concentrations quantified ranged between 10 and 2510 ppb (median value = 150 ppb). When eggs were cooked, fipronil residues were stable. The exposure assessment and risk characterization revealed that the highest probability of consuming eggs with fipronil residues above the admissible limits was for young adults (20.8%), followed by babies (16.9%), young children (16.4%), children (13.4%), teenagers (10.3%), older adults (9.41%), and adults (8.65%). These results suggest an unacceptable risk associated with egg consumption with fipronil residues for all age groups. PRACTICAL APPLICATION: Fipronil is widely used as an extra-label way on laying hens since its use is prohibited in poultry production both in Argentina and in most countries. This molecule has been classified as Class II, a moderately hazardous pesticide because it could damage various human organs. Fipronil residues in eggs could be one of the exposure pathways for consumers. Monitoring residual levels and carrying out the health risk assessment in eggs are thus in an urge.

Residue depletion profiles and withdrawal interval estimations of meloxicam in eggs and ovarian follicles following intravenous (Meloxicam solution for injection) and oral (Meloxidyl®) administration in domestic chickens (Gallus domesticus)

Meloxicam is a non-steroidal anti-inflammatory drug (NSAID) commonly prescribed in an extralabel manner for treating chickens in urbanized settings. The objectives of this study were to determine meloxicam depletion profiles in eggs and ovarian follicles and to estimate associated withdrawal intervals (WDI) in laying hens following a single intravenous or repeated oral administration. The observed peak concentration of meloxicam in ovarian follicles were consistently higher than in egg yolk and egg white samples. Terminal half-lives were 31-h, 113-h and 12-h in ovarian follicles, egg yolk and egg white samples, respectively, for repeated oral administrations at 1 mg/kg for 20 doses at 12-h intervals. The terminal half-life following a single intravenous administration at 1 mg/kg was 50-h for ovarian follicles. Meloxicam WDI estimations using ovarian follicle and egg yolk concentration data following 20 doses at 12-h intervals were 36 and 12 days, respectively. Meloxicam WDI estimation using egg yolk concentration data following 8 doses at 24-h intervals was 12 days. These results improve our understanding on the residue depletion of meloxicam from chickens' reproductive tracts and egg products and provide WDIs to help ensure food safety for humans consuming eggs from treated laying hens.

Pharmacokinetic Parameters and Estimating Extra-Label Tissue Withdrawal Intervals Using Three Approaches and Various Matrices for Domestic Laying Chickens Following Meloxicam Administration

Meloxicam is commonly prescribed for treating chickens in backyard or small commercial operations despite a paucity of scientific data establishing tissue withdrawal interval recommendations following extra-label drug use (ELDU). Historically, ELDU withdrawal intervals (WDIs) following meloxicam administration to chickens have been based on the time when meloxicam concentrations fall below detectable concentrations in plasma and egg samples. To date, no studies have addressed tissue residues. ELDU WDIs are commonly calculated using terminal elimination half-lives derived from pharmacokinetic studies. This study estimated pharmacokinetic parameters for laying hens following meloxicam administration and compared ELDU WDIs calculated using tissue terminal elimination half-lives vs. those calculated using FDA tolerance and EMA's maximum regulatory limit statistical methods, respectively. In addition, ELDU WDIs were calculated using plasma meloxicam concentrations from live birds to determine if plasma data could be used as a proxy for estimating tissue WDIs. Healthy domestic hens were administered meloxicam at 1 mg/kg intravenous (IV) once, 1 mg/kg orally (PO) once daily for eight doses or 1 mg/kg PO twice daily for 20 doses. Analytical method validation was performed and meloxicam concentrations were quantified using high-performance liquid chromatography. In general, the terminal elimination technique resulted in the longest ELDU WDIs, followed by the FDA tolerance and then EMA's maximum residue limit methods. The longest ELDU WDIs were 72, 96, and 384 (or 120 excluding fat) h for the IV, PO once daily for eight doses, and PO twice daily for 20 doses, respectively. Plasma data are a possible dataset for estimating a baseline for tissue ELDU WDI estimations when tissue data are not available for chickens treated with meloxicam. Finally, pharmacokinetic parameters were similar in laying hens to those published for other avian species.

Backyard poultry flocks in France: A diversity of owners and biosecurity practices

Over the past few years, the number of backyard poultry flocks has been increasing in France. A mandatory step to improve backyard poultry management is to assess health risks by characterizing the flocks and understanding the owners' motivations for keeping poultry and their husbandry practices. A survey of backyard poultry owners was conducted in France to gather information about their motivations for owning poultry, flock characteristics, and breeding and biosecurity practices. The survey was completed by 1,160 owners. The major motivations for owning poultry flocks were egg consumption (93.3 %), recycling (72.4 %) and having pet animals (53.2 %). Most owners had already heard about avian influenza (96.7 %), but were less aware about other diseases such as Newcastle Disease (41.6 %), salmonellosis (79.1 %), or campylobacteriosis (18.6 %). Owners mainly kept only egg-layers (78.4 %), and the median size flock was five egg-layers. Owners gave eggs to their relatives, occasionally or regularly, in 86.6 % of the cases. Contacts with other family poultry owners were frequent (68.9 %) and biosecurity practices were poorly implemented: 50 % of owners did not wash their hands systematically after visiting the flock and more than 60 % of owners did not wear specific shoes. Drawing from the survey data, five profiles of family poultry flocks were identified with multiple correspondence analysis and hierarchical cluster analysis. The profiles, based on flock characteristics and owners' practices and motivations, illustrate the heterogeneity of the backyard poultry sector: 1) urban poultry, 2) traditional poultry, 3) student poultry, 4) pet poultry and 5) hobby poultry. Urban poultry consisted of recently constituted (< 2 years old), small (< 3 birds) flocks of layers, and traditional poultry of older, medium-sized flocks belonging to retired and older people. These two profiles were characterized by limited contacts (direct or indirect) with other flocks and owners. Student poultry consisted of younger owners (<30 years old) with flocks over 5 years old. Pet poultry consisted of recently established, medium-size flocks of layers located in both rural or urban environments. Hobby poultry consisted of dedicated owners who breed and sell poultry and participate in exhibitions and poultry shows. Pet and hobby poultry profiles were characterized by greater knowledge of diseases and biosecurity practices, more bird movements, and reported more frequent clinical signs. The observation of different profiles can help target veterinary and public health education messages to prevent disease transmission in backyard poultry flocks in France.

Breed differences in the pharmacokinetics of orally administered meloxicam in domestic chickens (Gallus domesticus)

OBJECTIVE

To determine the pharmacokinetics of meloxicam in Wyandotte hens and duration and quantity of drug residues in their eggs following PO administration of a single dose (1 mg of meloxicam/kg [0.45 mg of meloxicam/lb]) and compare results with those previously published for White Leghorn hens.

ANIMALS

8 healthy adult Wyandotte hens.

PROCEDURES

Hens were administered 1 mg of meloxicam/kg, PO, once. A blood sample was collected immediately before and at intervals up to 48 hours after drug administration. The hens' eggs were collected for 3 weeks after drug administration. Samples of the hens' plasma and egg whites (albumen) and yolks were analyzed with high-performance liquid chromatography.

RESULTS

Mean ± SD terminal half-life, maximum concentration, and time to maximum concentration were 5.53 ± 1.37 hours, 6.25 ± 1.53 μg/mL, and 3.25 ± 2.12 hours, respectively. Mean ± SD number of days meloxicam was detected in egg whites and yolks after drug administration was 4.25 ± 2 days and 9.0 ± 1.5 days, respectively.

CONCLUSIONS AND CLINICAL RELEVANCE

Compared with White Leghorn hens, meloxicam in Wyandotte hens had a longer terminal half-life, greater area under the plasma concentration-versus-time curve from time 0 to infinity, a smaller elimination rate constant, and a longer mean residence time-versus-time curve from time 0 to infinity, and drug persisted longer in their egg yolks. Therefore, the oral dosing interval of meloxicam may be greater for Wyandotte hens. Results may aid veterinarians on appropriate dosing of meloxicam to Wyandotte hens and inform regulatory agencies on appropriate withdrawal times.

Transfer of enrofloxacin, ciprofloxacin, and lincomycin into eggshells and residue depletion in egg components after multiple oral administration to laying hens

Regardless of whether antimicrobial drugs are administered to laying hens legally or illegally, residues of these drugs may be present in the eggs. Even if the eggs are not intended for human consumption, byproducts/biowaste, such as eggshells, may contain residues of the drugs used, which may pose a risk to human health and the environment. In the presented research, 2 different groups of laying hens received enrofloxacin (10 mg/kg body weight) and lincomycin (20 mg/kg body weight) once daily for 5 d. Eggs were collected daily and the concentration of enrofloxacin, its metabolite ciprofloxacin, and lincomycin residue in the eggshells, whole eggs, egg yolks, and egg whites were determined by ultra-high-performance liquid chromatography-tandem mass spectrometry. This study demonstrates the transfer of enrofloxacin, ciprofloxacin, and lincomycin into the eggshells and provides evidence for the distribution into the eggshells after administration of these drugs to laying hens. The enrofloxacin residues were detected in the eggshell for 10 d after cessation of treatment, ciprofloxacin and lincomycin were rapidly eliminated and 2 d after finish drugs administration they were no longer detected in the eggshell.

Egg residue and depletion in Rhode Island Red hens (Gallus gallus domesticus) following multiple oral doses of trimethoprim-sulfamethoxazole

Sulfamethoxazole-Trimethoprim residues in eggs can cause risks to human health. The most common cause of residues in eggs results from failure to meet an appropriate withdrawal interval. The aim of this study was to determine the quantity and duration of sulfamethoxazole-trimethoprim residues in eggs and evaluate the drug elimination parameters in egg components and whole egg to better estimate the withdrawal interval of sulfamethoxazole and trimethoprim following oral administration for 7 days at a purposed dosage regimen (time average 46 mg kg^-1 day^-1 for sulfamethoxazole, time average 25 mg kg^-1 day^-1 for trimethoprim). Residues of sulfamethoxazole and trimethoprim in albumen and yolk were analyzed by ultra-performance liquid chromatography mass spectrometry. A greater percentage of sulfamethoxazole was distributed into the albumen (91.53-96.74%) and a greater percentage of trimethoprim was distributed into yolk (63.92-77.36%) during treatment. The residues levels in whole egg declined below or reached the limit of quantification until 13 days for SMZ and TMP respectively. The withdrawal interval for SMZ and TMP were 43 days and 17 days respectively using the FDA tolerance method.

Oral and topical extra-label administration of fipronil to laying hens: Assessment of the egg residue patterns

This experimental work reproduces the fipronil extra-label administration performed by producers in laying hens. The scientific goal was to characterize the residual concentrations in eggs from treated hens and suggest the withdrawal periods that should be respected to avoid risk for consumers. Thirty-four laying hens were allocated into two groups: Group A was treated with fipronil in feed, two single doses of 1 mg kg^-1  day^-1 ; Group B was administered a single dose of 1 mg kg^-1 by the topical route. Fipronil egg residues were quantified by HPLC-MS/MS. Fipronil and its sulphone metabolite (fipronil-SO₂ ) were measured in egg after both treatments. The highest egg residual profile was always for fipronil-SO₂ . Mean maximum egg concentrations (C_max ) of 228.5 ± 79.8 ng/g (fipronil) and 1,849 ± 867 ng/g (fipronil-SO₂ ) were found after fipronil administration in feed. The lowest residual levels were quantified after the topical treatment with C_max of 27.1 ± 4.9 and 163 ± 26 ng/g for fipronil and fipronil-SO₂ . Mean fipronil marker residues and established MRLs allowed calculating the withdrawal periods, the shortest being 74 days after topical administration. Such a long withdrawal period is difficult to meet in egg production systems. Thus, the extra-label use of fipronil in laying hens should not be recommended under any circumstances.

Multi-Class Procedure for Analysis of 50 Antibacterial Compounds in Eggshells Using Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry

In this work, for the first time, Ultra-High-Performance Liquid Chromatography–Tandem Mass Spectrometry (UHPLC–MS/MS) method was developed for qualitative and quantitative analysis of veterinary antibiotics (cephalosporins, diaminopyrimidines, fluoro(quinolones), lincosamides, macrolides, penicillins, pleuromutilins, sulfonamides, tetracyclines, and sulfones) in hen eggshells. The sample preparation method is based on a liquid–liquid extraction with a mixture of metaphosphoric acid, ascorbic acid, EDTA disodium salt dihydrate, and acetonitrile. The chromatographic separation was performed on Luna^® Omega Polar C18 10 column in gradient elution mode and quantitated in an 8 min run. Validation such as linearity, selectivity, precision, recovery, matrix effect, limit of quantification (LOQ), and limit of detection (LOD) was found to be within the acceptance criteria of the validation guidelines of the Commission Decision 2002/657/EC and EUR 28099 EN. Average recoveries ranged from 81–120%. The calculated LOQ values ranged from 1 to 10 µg/kg, the LOD values ranged from 0.3 to 4.0 µg/kg, depending on analyte. The developed method has been successfully applied to the determination of antibacterial compounds in hen eggshell samples obtained from different sources. The results revealed that enrofloxacin, lincomycin, doxycycline, and oxytetracycline were detected in hen eggshell samples.

Assessment of veterinarians' engagement with backyard poultry and small-scale livestock operations in four western states

OBJECTIVE

To assess veterinarian engagement with owners of poultry and livestock in urban and peri-urban areas (UPAs) of 4 western states, to evaluate the knowledge and experience of veterinarians in UPAs for treating domestic poultry and livestock, and to identify barriers to the provision of veterinary services to backyard poultry and small-scale livestock operations.

SAMPLE

880 veterinarians in UPAs.

PROCEDURES

2,400 members of the veterinary medical associations of California, Colorado, Oregon, and Washington who worked in metropolitan areas with a population > 5,000 people were randomly selected and invited to participate in a needs assessment survey. Response data were analyzed with univariable logistic regression and multiple correspondence analysis.

RESULTS

880 (37%) invitees completed or partially completed the survey. Most respondents self-reported working in UPAs (686/825 [83%]) and companion animal only (n = 551) or predominant (211) practices. Although most (656/863 [76%]) respondents perceived an increase in backyard poultry and livestock in their practice areas, few were actively treating such animals primarily because of a lack of facilities, interest, or experience. Most respondents believed veterinarians have an important role in ensuring public health and preventing zoonotic disease.

CONCLUSIONS AND CLINICAL RELEVANCE

Backyard poultry and livestock are increasing in popularity in UPAs of 4 western states, and veterinarians are needed to provide services to such animals. Further research and continuing education are necessary to encourage practitioners in UPAs to engage with owners of backyard poultry and livestock to ensure the health and welfare of those animals and guard public health. (J Am Vet Med Assoc 2020;257:196-209).

Pharmacokinetics and Drug Residue in Eggs After Multiple-Day Oral Dosing of Amoxicillin-Clavulanic Acid in Domestic Chickens

This study examined the pharmacokinetics of orally administered amoxicillin and clavulanic acid tablets (Clavamox, 125 mg/kg PO q12h for 9 doses) in domestic hens and examined both amoxicillin and clavulanic acid concentrations in eggs. Therapeutic plasma concentrations (0.5 µg/mL) of amoxicillin were not reached at any time point, and no amoxicillin was detected in plasma after 2 hours. Pharmacokinetic parameters could not be calculated. The clavulanic acid half-life was 1.1 hours and it was detected up to 8 hours after dosing. No amoxicillin was detected in eggs 4 days postdosing, nor was clavulanic acid detected in any eggs during the same time period. On the basis of these results, orally dosing hens with amoxicillin and clavulanic acid tablets at 125 mg/kg PO q12h does not reach therapeutic plasma concentrations. Additional studies are needed to examine different doses and formulations of medication to determine better dosing and withdrawal recommendations for domestic chickens.

Pharmacokinetics of amantadine after oral administration of single and multiple doses to orange-winged Amazon parrots (Amazona amazonica)

OBJECTIVE

To determine the pharmacokinetics of amantadine after oral administration of single and multiple doses to orange-winged Amazon parrots (Amazona amazonica).

ANIMALS

12 adult orange-winged Amazon parrots (6 males and 6 females).

PROCEDURES

A single dose of amantadine was orally administered to 6 birds at 5 mg/kg (n = 2), 10 mg/kg (2), and 20 mg/kg (2) in a preliminary trial. On the basis of the results, a single dose of amantadine (10 mg/kg, PO) was administered to 6 other birds. Two months later, multiple doses of amantadine (5 mg/kg, PO, q 24 h for 7 days) were administered to 8 birds. Heart rate, respiratory rate, behavior, and urofeces were monitored. Plasma concentrations of amantadine were measured via tandem liquid chromatography-mass spectrometry. Pharmacokinetic parameter estimates were determined via noncompartmental analysis.

RESULTS

Mean ± SD maximum plasma concentration, time to maximum plasma concentration, half-life, and area under the concentration-versus-time curve from the last dose to infinity were 1,174 ± 186 ng/mL, 3.8 ± 1.8 hours, 23.2 ± 2.9 hours, and 38.6 ± 7.4 μg·h/mL, respectively, after a single dose and 1,185 ± 270 ng/mL, 3.0 ± 2.4 hours, 21.5 ± 5.3 hours, and 26.3 ± 5.7 μg·h/mL, respectively, at steady state after multiple doses. No adverse effects were observed.

CONCLUSIONS AND CLINICAL RELEVANCE

Once-daily oral administration of amantadine at 5 mg/kg to orange-winged Amazon parrots maintained plasma concentrations above those considered to be therapeutic in dogs. Further studies evaluating safety and efficacy of amantadine in orange-winged Amazon parrots are warranted.

Assessing farmers' perspective on antibiotic usage and management practices in small-scale layer farms of Mymensingh district, Bangladesh

Background and Aim

Indiscriminate and injudicious use of antibiotics in layer farms is a common practice of Bangladesh for the compensation of Poor management practices and ignorance. Despite this scenario, there is no published documentation on antibiotic usage pattern and farm management practices in layer farms. This study was undertaken to understand the farmers' perspective in small-scale layer farms regarding antibiotics usage and farm management.

Materials and Methods

A questionnaire survey was conducted in 120 small-scale layer farms of Mymensingh district during January-February 2017. We only considered farms in production. Data were analyzed on antibiotic usage, purpose, egg management, understanding of antibiotic residue, withdrawal period, and other issues.

Results

Among 120 farmers, about 94.16% of farmers are using antibiotics without respecting the withdrawal period. Only 39.1% of farmers possess knowledge of residues. In our surveyed farms, 91.83% of farmers are not practicing egg washing before supplying to the market and 52.67% of farmers are unaware of cleaning and disinfection of egg tray. Ten different types of antibiotics of seven classes have found in the survey. Most antibiotics are in the Watch (49%) and Reserve (8%) groups according to the WHO AWaRe categorization and 73% antibiotics are critically important for human medicine and are considered as last resort.

Conclusion

This study found that due to the lack of knowledge and poor management, farmers consider using antibiotics as the most effective practices to control disease and enhancement of egg production. These indiscriminate uses of antibiotics are responsible for antibiotic residual and resistance problem. Here, we also provide some suggestion and guidelines to improve management practices to minimize the emerging problems of antimicrobial resistance through small-scale layer farms.

Effect of cooking on the stability of veterinary drug residues in chicken eggs

The available information on drug residue stability in chicken egg is scarce. The objective of this study was to evaluate the stability of drug residues in egg under different traditional cooking procedures. Fresh eggs were spiked with different drug concentrations of albendazole (ABZ) and its albendazole sulphoxide (ABZSO) and albendazole sulphone (ABZSO₂) metabolites; flubendazole (FLBZ) and its reduced flubendazole (R-FLBZ) and hydrolyzed flubendazole (H-FLBZ) metabolites; amoxicillin (AMX); and enrofloxacin (EFX) and its ciprofloxacin (CFX) metabolite. The egg samples were cooked in different ways, namely, boiling, microwaving, and omelette making. Drug residue concentrations in egg were quantified by HPLC with UV or fluorescence detectors. ABZ and ABZSO concentrations in egg were not affected by boiling and microwaving, while the omelette processing significantly reduced these molecules. Residues of ABZSO₂ in egg were stable or increased after all cooking procedures. In contrast, FLBZ and its metabolites FLBZ-H and FLBZ-R residues in egg decreased after all treatments. The residue concentration quantified for EFX and CFX did not show significant changes after any cooking method. AMX residues were unstable, with extremely significant drug reduction after all cooking processes. Conventional methods of egg cooking cannot be considered a tool to eliminate all veterinary drug residues.

Family poultry: Multiple roles, systems, challenges, and options for sustainable contributions to household nutrition security through a planetary health lens

Achieving sustainable production of eggs by family poultry production systems that meet both environmental health and welfare standards is a complex endeavour. Humans have been raising different species of poultry for thousands of years across many different agroecological zones. The Food and Agriculture Organization of the United Nations has identified four different family poultry production systems: small extensive, extensive, semi‐intensive, and intensive. Each of these systems varies in terms of inputs, outputs, gender dimensions, poultry health and welfare, and environmental impacts. This paper addresses key issues associated with the production of family poultry eggs in support of both improved maternal and child nutrition and sustainable, nutrition‐sensitive agricultural practices. It provides an overview of the history of poultry raising; characteristics of the different family poultry production systems; challenges and solutions to poultry production in low‐ and middle‐income countries; poultry husbandry (including breeds, nutrition, and shelter); infectious disease prevention and control in line with national and international animal health regulations; and food safety (microbial pathogens, toxins, and egg storage). To ensure that bird, human, and environmental health can flourish, it is essential for interdisciplinary research and development teams to work in collaboration with communities to ensure the long‐term environmental and economic sustainability of family poultry production enterprises that are a good fit with local circumstances.

Small-scale and backyard livestock owners needs assessment in the western United States

The number of small-scale and backyard livestock and poultry owners in urban and peri-urban areas has increased greatly over the last 10 years in the U.S. However, these animal owners may live in areas without access to livestock and/or poultry veterinary care. The purpose of this study was to identify potential veterinary service needs of these animal owners in the western US, assess their use of management and husbandry practices with regards to disease prevention, and assess their attitudes about animal health and food safety. A semi-structured survey was made available to small-scale and backyard livestock and poultry owners in Washington State, California, Colorado and Oregon. The survey instrument included questions about types of animals reared, uses of the animals, veterinary services and information-seeking behaviors of owners, attitudes on animal health and food safety, and management practices. Four hundred thirty-five individuals completed at least some portion of the survey. Most described themselves as living in rural areas (76%). Most (86%) owned chickens, 53% owned small ruminants, and 31% owned cattle. Many individuals owned more than one species and most had fewer than 20 animals of a given species. About 74% of respondents utilized their animals’ products for their own consumption but 48% sold animal products (primarily through internet sales (35%) or farmers’ markets (25%)). Overwhelmingly, respondents gained information about animal health (82%) and animal treatment procedures (71%) from the internet. Respondents reported their veterinarian’s practice type as companion animal (26%) or a mixed animal or food animal predominant (66%). Overall, respondents were very satisfied with the level of care (82%), but 43% had not sought animal health care in last 12 months. However, the veterinarian’s primary practice type and owner’s satisfaction with veterinary care were associated with their location (state), species owned, and urban or peri-urban setting. Livestock species type (cattle, small ruminants and swine), and use (personal or commercial) were associated with implementation of different biosecurity practices. The results of this survey highlight some of the needs of these animal owners for veterinary care and information which are location- and species-specific. Veterinary care for these small-scale and backyard animals is vital to the health and welfare of the animals as well as for identification of zoonoses and assurance of the food safety of animal products.

Pyrethroids in chicken eggs from commercial farms and home production in Rio de Janeiro: Estimated daily intake and diastereomeric selectivity

In this study, pyrethroids were determined in chicken eggs from commercial farm (n = 60) and home egg production (n = 30). These pyrethroids were investigated: bifenthrin, phenothrin, permethrin, cyfluthrin, cypermethrin and fenvalerate, including most diastereomers. Quantification was done using GC-MS in a negative chemical ionization mode. Pyrethroids residues were found in 79% of the analyzed samples. Cypermethrin presented the highest occurrence, being quantified in 62 samples (69%) in concentrations (lipid weight - l w.) varying between 0.29 and 6408 ng g^-1, followed by phenothrin (24%), 21-3910 ng g^-1, permethrin (14%), 2.96-328 ng g^-1, and bifenthrin (11%), 3.77-16.7 ng g^-1. Cyfluthrin and fenvalerate were not detected. Home-produced eggs had a higher occurrence of pyrethroids (97%), with a greater predominance of phenothrin. In commercial production, 70% of the samples presented pyrethroid residues (predominantly cypermethrin). This is the first report about the presence of pyrethroids in home-produced eggs and the first description of a selectivity pattern with the predominance of cis diastereomers in chicken eggs. In general, estimated daily intake does not present a risk to human consumption, according to Brazilian and international standards (FAO/WHO). However, one third of the samples (30 eggs) had concentrations above the maximum residue limits (MRLs). The maximum cypermethrin concentration was 66 times the MRL, while the maximum phenothrin concentration was 11 times the limit. Further studies about transfer dynamics, bioaccumulation and metabolic degradation of stereoisomers are required, as well as determining if this selectivity pattern in food can increase consumer's health risk.

Determination of Meloxicam in Egg Whites and Yolks Using Reverse Phase Chromatography

A new method of analysis has been developed and validated for the determination of meloxicam in egg whites and yolks. Following a liquid extraction for the whites and a solid phase extraction for the yolks, samples were separated on an XBridge C18 column and quantified using ultraviolet detection at 360 nm. The mobile phase was a mixture of water with glacial acetic acid and acetonitrile, with a flow rate of 1 mL/min. The procedure produced a linear graph over the concentration range 5-1500 ng/mL with a lower limit of quantification of 5 ng/mL. Intra- and inter-assay variability was 10% or less for both the whites and yolks. The average recovery for whites was 96% and the average recovery in yolks was 97%.

Multiscreening LC-MS/MS Designed for Ten Pesticide and Six Antimicrobial Residues in Eggs

A multiscreening method was experimentally validated for pesticide and antimicrobial residues in spiked eggs at levels of 5, 50, and 500 μg L−1. The residue extraction was performed with acetonitrile and 1% formic acid. The extracted material was stored at −70°C until detection and quantitation within 24-hour period by LC-MS/MS. Pesticide and antimicrobial residue recovery performed adequate standard deviation and the results were from 94.10% (ampa) to 9.20% (carbaryl) for pesticides and from 95.70% (enrofloxacin) to 46.20% (sulfathiazole) for antimicrobial. The method was highly accurate, considering the linearity for all pesticide and antimicrobial residues (r2>0.99), with quantitation limits ranging from 0.78 to 6.25 μg L−1 for pesticides and 0.78 to 3.13 μg L−1 for antibiotics. A highly correlation coefficient (r>0.99) was found, except for carbaryl. Although time extraction and carbaryl recovery remain to be improved, the method has shown a rapid pesticide and antimicrobial residue detection.