Random residue monitoring

• Overview
• Performance
• Outlook
• Residue Testing
• Results

Overview

The animal product random monitoring program fulfils the requirements of:

• the Australian Quarantine and Inspection Service (AQIS) for export certification and therefore market access
• trading partners
• state and territory government regulatory authorities in the licensing of domestic meat processing facilities¹
• participating industries in supporting quality assurance initiatives.

Cattle, sheep and pig provided the largest number of samples in the animal product commodities monitored for residues. Other commodities tested were camel, deer, goat, horse, kangaroo, poultry, ratite (emu and ostrich), wild boar, honey, egg and aquatic species (both aquaculture and wildcaught).

Outputs

Outputs of the animal product random monitoring program are:

• provision to stakeholders of independent, authoritative and technically sound residue data reports, and advice on Australian livestock, game, fishery and animal products
• provision of residue monitoring data to meet specific market access support requirements of participating industries and relevant industry client groups.

¹ Australian domestic meat processing facilities are required to comply with the appropriate Australian Standards: AS 4696-2002 Australian Standard for Hygienic Production and Transport of Meat Products for Human Consumption; AS 4465-2001/Amdt 1-2003 Australian Standard for the Construction of Premises and Hygienic Production of Poultry Meat for Human Consumption; AS 5010-2001 Australian Standard for the Hygienic Production of Ratite (Emu/Ostrich) Meat for Human Consumption; AS 4464-1998 Australian Standard for the Hygienic Production of Game Meat.

Performance

Highlights

All animal product residue monitoring plans were reviewed by the National Residue Survey (NRS), in close consultation with the relevant industries and AQIS, and accepted by them. The buffalo industry again suspended its participation in NRS due to the ongoing impact of the drought on the structure of the industry.

On behalf of the cattle industry, NRS is developing a tender process to engage a contractor to undertake residue management audits of selected cattle properties. These audits will be based on the elements of the livestock production assurance (LPA) quality assurance (QA) scheme, which is the largest Australian QA scheme for livestock producers. The contractor chosen through this tender process will also audit property management plans, where they are in place, to manage the risk of organochlorine residues from previous use of such chemicals. These audits will complement existing residue monitoring programs and provide additional assurance that agricultural chemicals and veterinary drugs are used appropriately in the cattle industry.

Performance Indicator One

Acceptance by participating industries, AQIS and trading partners that each project is structured to meet its market access and assurance objectives within the specified budget.

Performance Indicator Two

Delivery of projects in accordance with agreements between NRS and participating industries, including annually reviewed agreements with respect to:

• random monitoring sampling rates
• turnaround time from sampling to presentation of test results
• reporting of contraventions to regulatory authorities.

Performance Indicator Three

Presentation of high-quality and timely plans and reports on results to trading partners, industry and the Australian Government. 

Performance Indicator Four

Interaction and communication with participating industries is effective.

² www.daff.gov.au/agriculture-food/nrs

³ www.animalhealthaustralia.com.au/status/ahsq.cfm

Outlook

Cattle

On behalf of the cattle industry, NRS is developing a tender process to engage a contractor to undertake residue management audits of selected cattle properties. These audits will be based on the elements of the livestock production assurance (LPA) quality assurance (QA) scheme, which is the largest Australian QA scheme for livestock producers. The contractor chosen through this tender process will also audit property management plans, where they are in place, to manage the risk of organochlorine residues from previous use of such chemicals. These audits will complement existing residue monitoring programs and provide additional assurance that agricultural chemicals and veterinary drugs are used appropriately in the cattle industry. The cost of this audit program will be met from industry equalisation accounts (IEAs) within the NRS Special Account.

Egg

NRS anticipates that a project monitoring plan, similar to the 2007–2008 plan, will operate in 2008–2009.

Poultry

The poultry industry has agreed that a monitoring program similar to that of 2007–2008 will operate in 2008–2009.

Honey

The honey industry has agreed that a program similar to that of 2007–2008 will operate in 2008–2009. The plan will include samples for the monitoring of paradichlorobenzene.

Fish products (wildcaught)

NRS will again sample wildcaught seafood during 2008–2009.

Fish products (aquaculture)

Some aquaculture testing will take place in 2008–2009.

Residue Testing

Sample collection and analysis

Sample collection rates are based on production levels of the commodity in Australia, or are directed by overseas market access requirements if the commodity is to be exported. NRS generates all requests for samples for residue monitoring. The collection of product samples is done by relevant government officers who either send the samples directly to the laboratories for analysis or forward the samples to appropriate sample collection points. 

Meat products are sampled by authorised government officers at export abattoirs and by quality control staff at domestic abattoirs. The samples are sent from collection points to a central receival and dispatch facility within NRS, where they are sorted into batches and forwarded to appropriate contract laboratories for analysis. In the sampling plan for random monitoring of meat, the allocation of samples to be taken at abattoirs is affected by the numbers and species of animals being slaughtered at each abattoir. The distribution of samples is designed so that the probability of an abattoir being selected for sampling is proportional to the commodity throughput of that abattoir. NRS sends sample requests to abattoirs each month, specifying the kind of product required and the production period during which samples are to be taken. Animals for sampling are then selected at random along the slaughter chain.

Honey is sampled by authorised officers of state and territory government authorities at appropriate stages of the production chain. The samples are sent directly to appropriate contract laboratories for analysis.

Poultry and egg products are sampled by quality assurance officers at the relevant establishments, and samples are forwarded either to the NRS central receival and dispatch facility or are sent directly to the appropriate contract laboratories for analysis.

Aquaculture products are sampled by AQIS officers, while wildcaught fish products are sampled at fish establishments by officers from AQIS, NRS staff, or state or territory government authorities. The samples are forwarded to the central receival and dispatch facility or are sent directly to the appropriate contract laboratories for analysis.

Results

Summary of animal product results

During 2007–2008, 14 609 samples were collected from 25 animal products in the broad categories of meat, honey, egg and fish. In all, 159 161 analyses were carried out on these samples. Where appropriate, results of these analyses are compared with the Australian Standards (MRL, ERL or ML) applicable to the levels of residues or contaminants that are legally permissible in food. These standards are included in the Australia New Zealand Food Standards Code. For some chemical–commodity combinations (for example, chemicals in inedible tissue) there are no applicable Australian Standards.

The table below summarises the results from all animal product random monitoring projects, and detailed results tables follow:

agvet = agricultural and veterinary chemicals; Aust. Std = Australian Standard; ERL = extraneous residue limit;
ML = maximum level; MRL = maximum residue limit; n/a = Australian Standard does not apply. No limit set or defined.
^a Total number of samples collected from each species or commodity.
^b Most samples are analysed for more than one chemical. This is the total number of chemical–commodity combinations that were tested in each product type.
^c Number of samples observed above the Australian Standard (MRL/ERL). Individual samples may contain more than one residue.
^d Australian Standards are not set for non-edible samples such as urine and faeces. Residue detections are therefore not deemed contraventions.
^e Samples were tested for chlorinated biphenyls and metals.
^f Percentage of samples conforming to relevant Australian Standards.

Ten samples had residues of agricultural and veterinary (agvet) chemicals above Australian Standards (maximum residue limit [MRL] and extraneous residue limit [ERL]) limits. These detections are deemed contraventions. There were no detections where no Australian Standard is set.

Of the inedible samples, 135 contained residues. As there is no standard set for inedible tissues, these were not deemed contraventions.

Environmental contaminants (metals) above Australian Standards (maximum level [ML]) were found in 26 samples. These detections are deemed contraventions.

The results of the residue testing analyses are shown in the tables below, following specific discussions concerning residue detections in the main groups of commodities (meat, honey, egg, fish). Throughout the tables, wherever applicable, the naming of chemicals follows the residue definitions within the Australia New Zealand Food Standards Code (ANZFSC). Abbreviations and acronyms on the tables are defined in the Definitions, abbreviations and acronyms section.

Discussion: meat results

Meat residue monitoring projects are designed to support the access of participating industries to their principal export markets and also to provide information to domestic consumers on the residue levels in these commodities. The broad-based testing approach of the residue monitoring projects also provides evidence of good practice in the usage of agvet chemicals by the participating animal production industries. To address the specific residue monitoring requirements of importing countries, some chemicals are monitored that are not registered for use—nor are likely to be used—in Australian animal production systems.

During 2007–2008, residue monitoring projects covered 12 meat commodities, 14 184 samples and 155 990 analyses. The projects for cattle, sheep and pig (5 398, 5 065 and 2 739 samples respectively) were the largest individual projects.

Thirty-six residues (10 agvet chemicals and 26 environmental contaminants [metals]) were above applicable Australian Standards. Ten residues exceeded relevant Australian Standards for agvet chemicals in edible tissue.

When analysed for environmental contaminants, 15 sheep liver samples had cadmium levels that exceeded the Australian Standard (ML) of 1.25 mg/kg. Five sheep, two cattle, three pig and one emu liver samples (11 in total) contained lead residues higher than the ML of 0.5 mg/kg.

Australian Standards (MRLs and MLs) apply only to residues found in edible tissues. Some residue testing is undertaken in non-edible matrices for monitoring purposes because residues of such chemicals in these matrices can be an indication of illegal or inappropriate use of those chemicals. Sometimes standards have not been set for some environmental contaminants (such as metals) in a particular matrix (e.g. offal in a particular species).

In non-edible matrices (where no Australian Standards are established), chemicals were detected in 135 samples. These detections were hormones in cattle, sheep and horse urine (8, 16 and 6 samples respectively) likely to be endogenous in origin, and zearalenone metabolites in cattle faeces likely to be from feed (105) containing zearalenone. Traceback investigations are initiated only when there are reasonable grounds to believe the residue findings may have been the result of incorrect usage of an agvet chemical, as is discussed below.

Anthelmintics

Three classes of anthelmintics were monitored: macrocyclic lactones, benzimadazoles (triclabendazole in cattle and sheep), and salicylanilides (closantel in sheep). Samples tested were from cattle, sheep, pig, goat, horse, deer and ratite. No residues were detected above the relevant MRL.

Antibiotics

Antibiotic chemicals are used in livestock to treat infections by micro-organisms (e.g. bacteria, protozoa, fungi) that cause a range of diseases.

Monitoring of antibiotic residues comprises a number of analytical and sampling regimes. A general antibiotics screen is performed on kidney and identifies the class of compound present (for example y-lactam, aminoglycoside, tetracycline or macrolide). Where the screen test identifies a class of compounds, confirmation and quantification are carried out by a specific high-performance liquid chromatography or gas chromatography method appropriate for the class of antibiotic.

Specific testing was done for antibiotics, including sulfonamides in kidney, and for chloramphenicol in muscle. Samples were tested from cattle, sheep, pig, poultry, horse, deer and ratites using the general screen for antibiotics. In addition, pig muscle was tested for dimetridazole. One sample of pig muscle contained a residue of dimetridazole at 0.001 mg/kg (Australian MRL is 0.0001 mg/kg). A traceback investigation found that the residue had resulted from a cull animal inadvertently being fed rations intended for breeder pigs. Following this incident, dimetridazole is no longer used at this piggery.

Hormones

Samples from edible (liver) and non-edible matrices (faeces and/or urine) of cattle, sheep and horse were tested for a range of hormonal growth promotants (HGPs). Several HGPs are registered for use in cattle in Australia. Where AQIS is required to certify a product as free of HGPs (e.g. for the European Union and some other markets), special production separation arrangements have been made. Hormone residues may occur legitimately in appropriately treated animals outside any HGPfree supply scheme, may reflect endogenous production of these hormones (especially in young or pregnant animals), or can occur as a result of ingestion of naturally occurring chemicals with hormone-like characteristics (see zearalenone below).

Resorcyclic acid lactones (zeranol)

The HGP zeranol is closely related to the naturally occurring substance zearalenone. Zearalenone is a plant growth regulator produced by some plants and is also produced as a mycotoxin by Fusarium spp., which can infect feed sources (grain and pasture). Livestock can metabolise zearalenone to zeranol (y-zearalanol), taleranol (y-zearalanol), y-zearalenol, 7beta;-zearalenol and zearalanone. Hence zeranol residues can occur in livestock either as a result of treatment with a HGP or by ingestion of feed containing zearalenone.

Zeranol derived from the metabolism of zearalenone in ruminants is indistinguishable from zeranol residues resulting from treatment with a growth promotant. For compliance reasons, it is important to differentiate zeranol residues due to HGP administration from those residues due to natural exposure to zearalenone. Differentiation is based on the profile of zeranol/zearalenone-related residues. When zeranol occurs with other zearalenone metabolites, it is more than likely due to the ingestion of feed containing zearalenone. When zeranol occurs in the absence of other zearalenone metabolites, it is suggestive of the administration of a HGP containing zeranol.

Two y-zearalanol detections were made in cattle liver. Both occurred in the presence of other zearalenone metabolites—an expected finding for dietary exposure to feeds containing zearalenone. Five detections of zearalanone were made in poultry liver. Concentrations were at low levels and consistent with Fusarium infection of feed.

Steroids

Many steroidal compounds included in the testing programs may originate from either normal endocrine function (i.e. they are endogenous) or from the administration of veterinary drugs. There were seven hormone detections in cattle, 16 in sheep and six in horse, from animals that showed (17)y19-nortestosterone residues in their urine. At the levels detected, the residues were most likely from endogenous sex hormone production. There was one detection of boldenone in cattle that was at a low level and did not require any further investigation. The three detections of trenbolone in cattle were consistent with use of an approved product.

Stilbenes

No residues of stilbenes were detected in cattle, horse, pig, poultry or sheep samples tested.

y-agonists

Some >y-agonists are registered in different countries for use as growth promotants. There is currently one >y-agonist, ractopamine, registered in Australia for use only in pigs for enhancement of feed utilisation. Low-level detections of ractopamine were found in 25 samples of pig liver, but, at the levels found, there was no indication of misuse.

Non-steroidal anti-inflammatory drugs

No residues of flunixin, ketoprofen, oxyphenbutazone, phenylbutazone or tolfenamic acid were observed in any of the samples tested.

Pesticides

Organochlorines (OCs), organophosphates (OPs) and synthetic pyrethroid (SP) residues were monitored in 2 453 samples from all meat commodities except poultry, for which no pesticide testing was undertaken.

Organochlorines

Persistent OCs such as DDT, dieldrin, heptachlor, hexachlorocyclohexane (HCH) and hexachlorobenzene (HCB) have not been available for use on livestock since the 1970s. However, they are still present in soils where they were used for spot and broadacre pest control. Grazing livestock can ingest soil contaminated with these persistent OC compounds.

Endosulfan, a relatively non-persistent OC, is registered for use on certain crops, but is not for use on livestock.

One cattle sample and one kangaroo sample contained organochlorine residues above the Australian Standard. The cattle sample contained a residue of dieldrin and aldrin at 0.36 mg/kg (Australian MRL is 0.2 mg/kg). Following the traceback investigation, action was taken against a property manager for failing to follow the property management plan that was in place to manage the risk of organochlorine residues. The kangaroo sample contained a residue of aldrin and dieldrin at 0.56 mg/kg (Australian MRL is 0.2 mg/kg).

The traceback investigation could not identify a specific source of the residue, as kangaroos graze over an extensive area. Low-level OC residues were found in other samples, but none was above the relevant Australian Standards.

Organophosphates

OPs are used to control external parasites such as buffalo fly, blowfly, ticks and lice, and are also used as protectants for grain used in feeds. No OP residues were found in the samples tested.

Synthetic pyrethroids

Synthetic pyrethroids are used as external parasiticides in livestock, insecticides on crops, and as protectants for grain used in feeds. One residue of deltamethrin in fat from cattle was above the Australian Standards at 2.7 mg/kg (Australian MRL is 0.5 mg/kg). The traceback investigation could find no evidence of use of this chemical on the farm. Surface contamination of the sample was the most likely cause of the residue, although this could not be established conclusively.

Benzoyl ureas and other pesticides

Monitoring was also undertaken for benzoyl-urea insect growth-regulators (chlorfluazuron, diflubenzuron, fluazuron and triflumuron) in cattle and sheep, as well as dicyclanil and cyromazine (including its metabolite, melamine) in sheep. No samples exceeded the respective Australian Standards for these chemicals in the species tested.

Environmental contaminants (metals)

The metal residue screen tests for cadmium, lead and mercury in liver. There were 15 cadmium detections in sheep liver above the Australian Standard (ML) of 1.25 mg/kg. The residue levels ranged from 1.30 mg/kg to 3.70 mg/kg. Cadmium residues are commonly found in sheep offal, particularly in older animals across the southern states of Australia. A residue action level of 2.5 mg/kg has been agreed between NRS and state and territory government regulatory authorities for traceback purposes. Twelve residue detections were below the action level. Traceback investigations into the three residues greater than the residue action level found that the residues had occurred in old sheep. The producers concerned were informed of the results, and two were issued with warning letters.

There were 11 lead detections in liver (five in sheep, three in pig, two in cattle and one in emu) above the Australian Standard (ML) of 0.5 mg/kg.

The lead residue levels in sheep ranged from 0.6 mg/kg to 0.85 mg/kg. In two cases, traceback investigations identified old batteries as the source of the residue. In one instance, the remaining animals were placed in detention; in the other, the producer was issued with a warning letter and required to remove the source of contamination. Another residue was linked to animals having access to lead paint on an old shed. The producer was required to fence off the shed. In the remaining two cases, no obvious source of the residue could be located.

The three lead residues in pig ranged from 0.55 to 1.13 mg/kg. Traceback investigations found that in each case the residue had resulted from the use of lead-contaminated zinc oxide as a feed ingredient. The properties were placed into quarantine until subsequent testing demonstrates that the risk of further residues has been eliminated.

The two lead residues in cattle ranged from 1.2 to 2.4 mg/kg, and both animals originated from the same feedlot. A traceback investigation could locate no obvious source, and tests on other animals in the feedlot showed normal lead levels in blood.

The lead residue level in emu was 0.71 mg/kg. A traceback investigation could locate no obvious source.

Meat results tables

Results of analyses of the meat products are presented in the following tables, sorted into alphabetical order by commodity. Throughout the tables, the naming of chemicals follows the residue definitions within the ANZFSC. The heading 'LOR' refers to the limit of reporting: this is the minimum concentration (mg/kg) of a residue used for reporting purposes. Results of analyses lower than the LOR are not included in this report. Typically, the LOR set by NRS is 10–20% of the respective MRL/ERL or ML.

The total number of detections above the LOR is shown in the tables, and, where applicable, the number of detections greater than the relevant Australian Standard. For some chemical–commodity combinations (for example, chemicals in inedible tissue) there are no applicable Australian Standards. In these cases, detections above the LOR are categorised as ‘not set,’ not defined’ or ‘no limit’ as follows:

• ‘not set’: any detection above the LOR in an edible matrix is classed as a contravention
• ‘not defined’: for urine and faeces, results are used as indicators of environmental contamination, or failure to follow good agricultural practice
• ‘no limit’: no standard is applicable for the contaminant, and the ‘as low as reasonably achievable’ principle applies; detections at low levels are allowable.

Not set - No standard has been set for the chemical in the edible matrix and any detection is a contravention of the Australia New Zealand Food Standards Code.

No limit - No standard applicable for the contaminant.  the 'As low as reasonable achievable' principles applies.

Detections at low levels are still allowable.

n/a - Australian standard does not apply.  Not limit set or defined.

Not set — No standard has been set for the chemical in the edible matrix and any detection is a contravention of the Australia New Zealand Food Standards Code.

No limit — No standard applicable for the contaminant. The ‘As low as reasonably achievable’ principle applies. Detections at low levels are allowable.

n/a — Australian standard does not apply. No limit set or defined.

a — Action taken for failure to follow property management plan.

b — No evidence of chemical use on farm. Sample contamination most likely source of residue.

c — Both samples from the same feedlot but no obvious source found for the residue.

Not set – No standard has been set for the chemical in the edible matrix and any detection is a contravention of the Australia New Zealand Food Standards Code.

No limit – No standard applicable for the contaminant. The ‘As low as reasonably achievable’ principle applies. Detections at low levels are allowable.

n/a – Australian standard does not apply. No limit set or defined.

Not set – No standard has been set for the chemical in the edible matrix and any detection is a contravention of the Australia New Zealand Food Standards Code.

No limit – No standard applicable for the contaminant. The ‘As low as reasonably achievable’ principle applies. Detections at low levels are allowable.

n/a – Australian standard does not apply. No limit set or defined.

Not set – No standard has been set for the chemical in the edible matrix and any detection is a contravention of the Australia New Zealand Food Standards Code.

No limit – No standard applicable for the contaminant. The ‘As low as reasonably achievable’ principle applies. Detections at low levels are allowable.

n/a –Australian standard does not apply. No limit set or defined. a – No specific source identified.