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Animal Residue Data Sheet - Tebufenozide

Tebufenozide is registered or approved for use in Australia on avocado, blueberry, citrus fruits, custard apples, kiwifruit, longan, lychee, macadamia nuts, apples and pears, and grapes. Details of the registered use patterns can be found on the approved labels of registered products containing tebufenozide as the active constituent. This Animal Residue Data Sheet provides information on the possible residues in feed commodities obtained from crops treated with tebufenozide, to provide assistance in the formulation of animal diets that should not result in the violation of animal commodity MRLs.

Current MRLs

The Australian MRLs for tebufenozide in food and animal feed commodities, as listed in Table 1 and Table 4 of the MRL Standard [as at 19 June 2003] are shown below. The residue definition of tebufenozide is the parent compound per se.

Code Food Current MRL, mg/kg
Food Commodities
FI 0326 Avocado 0.5
FC 0001 Citrus fruits 1
SB 0716 Coffee beans T0.05
FI 0332 Custard apple 0.3
DF 0269 Dried grapes 4
FB 0269 Grapes 2
FI 0341 Kiwifruit 2
FI 0343 Litchi 2
FI 0342 Longan 2
TN 0669 Macadamia 0.05
FS 0245 Nectarines T1
FS 0247 Peaches T1
FT 0307 Persimmon, Japanese T1
FP 0009 Pome fruits 1
Animal Commodities
MO 0105 Edible offal (mammalian) *0.02
MM 0095 Meat (mammalian) [in the fat] *0.02
ML 0106 Milk *0.01
Animal Feed Commodities
AB 0269 Grape pomace, dry 10
  Pome fruit pomace, dry 10

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Summary of Maximum Feeding Levels and Livestock Dietary Intakes

The Maximum Feeding Level (MFL, the feeding level at which the MRLs are based), the equivalent Daily Dietary Intake For Livestock (DDIL) and the equivalent daily intake of tebufenozide are summarised below.

Species MFL,
ppm in diet
Equivalent DDIL, mg/kg bw Equivalent intake of tebufenozide,
mg/animal/day
Cattlea 6 0.28 132
Sheepb 6 0.25 15
Pigc 6 0.25 15
a Based on actual feeding study data
b Based on a 60 kg animal consuming 2.5 kg DM/day
c Based on a 60 kg animal consuming 2.5 kg DM/day

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Detailed Information

All Feed Commodities

Feed commodities that may contain residues of tebufenozide are listed in the table below. The theoretical maximum proportion of the diet that the commodity can comprise, when residues are present at the MRL, without the significant risk of animal commodity MRLs being violated is also given. It should be noted that the feeding levels assumed by the NRA when setting animal commodity MRLs are theoretical values, and they should not be taken as recommendations of appropriate rations for livestock.

Commoditya Assumed Maximum proportion of diet (%)b Feed intake (kg/animal/day)c MRL
(mg/kg)d
Maximum intake of tebufenozide from commodity (mg/animal/day)e Theoretical maximum proportion of diet (%)f
Cattle (Based on a 500 kg animal consuming 20 kg DM/day)
Pome fruit pomace, dry 20 4 10 40 69
Grape pomace, dry 20 4 10 40 69
Citrus pulp 20 4 1 4 100
Sheep (Based on a 60 kg animal consuming 2.5 kg DM/day)
Pome fruit pomace, dry 20 0.5 10 5 69
Grape pomace, dry 20 0.5 10 5 69
Citrus pulp 20 0.5 1 0.5 100
Pigs (Based on a 60 kg animal consuming 2.5 kg DM/day)
Pome fruit pomace, dry 20 1 10 10 69
Grape pomace, dry 20 1 10 10 69
Citrus pulp 20 1 1 1 100
Poultry (Based on a 2 kg animal consuming 150 g DM/day)
Pome fruit pomace, dry 5 0.0075 10 0.075 100
Grape pomace, dry 5 0.0075 10 0.075 100
Citrus pulp 5 0.0075 1 0.0075 100
a The feed commodities that may contain residues of tebufenozide, and may form more than 20% of an animals diet.
b The maximum % of the diet that the commodity is assumed to comprise for the purposes of setting MRLs, based on Stockfeed Information Document 1
c The equivalent amount of feed for an animal of designated weight and feed intake that is assumed for the purposes of setting MRLs
d The MRL for each feed commodity (correction for dry weight basis where required)
e The maximum intake of tebufenozide when the commodity is fed at the maximum assumed level (Column 1) in the absence of other sources of tebufenozide.
f The maximum % of the diet at which the commodity could theoretically be fed without significant risk of exceeding animal commodity MRLs. It is assumed that the residue in the feed commodity is present at the MRL (or dry weight equivalent) and other dietary sources of tebufenozide are absent.

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Abbreviations and Definitions

DM: Dry matter. The feed consumption for livestock and the residue levels in feed commodities are expressed on a dry matter basis.

DDIL: Daily Dietary Intake for Livestock. The level of dietary exposure for a specified chemical in a specified species that should not result in exceedance of the relevant animal commodity MRLs. Expressed in mg chemical/kg bodyweight.

MFL: Maximum Feeding Level. The level of dietary exposure for a specified chemical in a specified species that should not result in exceedance of the relevant animal commodity MRLs. Expressed in terms of ppm in the feed.

MRL: The concentration of a chemical residue, in units of mg/kg, that is legally permitted in or on a food or food commodity.

ppm in the feed: Parts per million in the feed. An alternate way of expressing the level of dietary exposure for a chemical. The level of chemical intake is calculated as though it were present uniformly in the total feed intake. The ppm in the feed is calculated using the following formula: DDIL (mg chemical/kg bw) _ body weight (kg) ¸ daily feed intake (kg). For example: a cow consumes 10 kg of grain containing 10 mg/kg of Chemical X and 10 kg of apple pomace containing 5 mg/kg of Chemical X. The total intake of Chemical X is 150 mg in 20 kg of feed. This is equivalent to 7.5 ppm in the feed [150÷20].

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Attachment 1: Anticipated Maximum Dietary Exposure

The following calculations outline the theoretical diet used to calculate the maximum anticipated dietary exposure, maximum feeding level (MFL) and the daily dietary intake for livestock (DDIL) for cattle, sheep, pigs and poultry.

Cattle

Feed group Feed commodity % in the diet Feed intake, kg/animal/daya MRL, mg/kg % DMb Intake of tebufenozide, mg/animal/dayc
Fruit by-products [2040% maximum] Pome fruit pomace, dry 4020 84 10 - 8040
Grape pomace, dry 10 -
Total   4020 84     8040
aBased on assumed feed consumption of 20 kg dry matter/day
bEstimate of percentage dry matter. Applied to MRLs expressed on a fresh weight basis
cBased on assumed bodyweight of 500 kg
Maximum anticipated dietary exposure: 80 40 mg/animal/day
Equivalent to: 0.160.08 mg/kg bw
Equivalent to: 42 ppm in the diet
MFL (Based on the available animal feeding data (Attachment 2)): 6 ppm in the diet
Equivalent DDIL: 0.28 mg/kg bw*

*Based on actual doses and body weights in feeding study

Sheep

Feed group Feed commodity % in the diet Feed intake, kg/animal/daya MRL, mg/kg % DMb Intake of tebufenozide, mg/animal/dayc
Fruit by-products [4020% maximum] Pome fruit pomace, dry 4020 1 10 - 105
Grape pomace, dry 10 -
Total   4020 1     105
aBased on assumed feed consumption of 2.5 kg dry matter/day
bEstimate of percentage dry matter. Applied to MRLs expressed on a fresh weight basis
cBased on assumed bodyweight of 60 kg
Maximum anticipated dietary exposure: 10 5 mg/animal/day
Equivalent to: 0.170.08 mg/kg bw
Equivalent to: 4 2 ppm in the diet
MFL (Based on the cattle feeding
data (Attachment 2)):
6 ppm in the diet
Equivalent DDIL: 0.25 mg/kg bw

Pigs

Feed group Feed commodity % in the diet Feed intake, kg/animal/daya MRL, mg/kg % DMb Intake of tebufenozide, mg/animal/dayc
Fruit by-products [20% maximum] Pome fruit pomace, dry 20 0.5 10 - 5
Grape pomace, dry 10 -
Total   20 0.5     5
aBased on assumed feed consumption of 2.5 kg dry matter/day
bEstimate of percentage dry matter. Applied to MRLs expressed on a fresh weight basis
cBased on assumed bodyweight of 60 kg
Maximum anticipated dietary exposure: 5 mg/animal/day
Equivalent to: 0.08 mg/kg bw
Equivalent to: 2 ppm in the diet
MFL (Based on the cattle feeding
data (Attachment 2)):
6 ppm in the diet
Equivalent DDIL: 0.25 mg/kg bw

Attachment 2: Residue data

The residue definition of tebufenozide in Australia is the parent compound per se.

Selected residue data for animal feed commodities

Residue data for various crops including pome fruits, grapes and various subtropical fruits (inedible peel) were reviewed (Mimic Insecticide, product number 48462). Residues of tebufenozide in pome fruits and grapes are also reviewed in the 1996 JMPR, at:

http://www.fao.org/WAICENT/FAOINFO/AGRICULT/AGP/AGPP/Pesticid/JMPR/Download/96/tebufen2.pdf.

Selected animal transfer data and metabolism studies

Laying hens —tissues and eggs

Six groups of 10 hens each were dosed with three radiolabelled versions of tebufenozide for 7 days at a dose level of about 30 ppm in the diet. Actual doses were approximately 3.3 mg/day administered in a gelatin capsule. Hens weighed approximately 1.5 kg on average and feed consumption was approximately 110 g feed/day. The doses correspond to around 2.2 mg/kg bw/day. Another 10 birds served as untreated controls. 14C labels were on the ethylbenzoyl (A label), 3,5-dimethyl benzoyl (B label) and tert-butyl (T label) portions of the molecule. Tissues collected within 24 hours of sacrifice.

Results

Sample type 14C-Residues (mg equiv/kg)
  A-label B-label T-label
Liver 0.13 0.18 3.95
Fat 0.13 0.06 0.16
Thigh muscle 0.02 0.01 0.07
Breast muscle 0.006 0.000 0.03
Kidney 0.13 0.12 0.97
Eggs Day 1
Day 2
Day 3
Day 4
Day 5
Day 6
Day 7
0
0.02
0.03
0.04
0.06
0.06
0.07
0
0
0.01
0.04
0.02
0.03
0.03
0
0.03
0.05
0.04
0.09
0.11
0.13

Average residues of tebufenozide parent compound in eggs (labels A, day 5 eggs, label B and T, day 7 eggs) from the three groups was 0.005 mg/kg. Tebufenozide was not detected in muscle or liver and average residues in fat were 0.018 mg/kg.

The feed level used in the metabolism study was approximately 60 times higher than the estimated maximum daily exposure of 0.5 ppm in the diet from Australian use patterns. Residues in poultry tissues and eggs are expected to be non-detectable at the estimated exposure level of 0.5 ppm and no analytical methods were available for poultry matrices therefore no poultry MRLs are considered necessary.

Lactating cows — milk and tissues

Lactating dairy cows were dosed orally by capsule with tebufenozide for 28 consecutive days at approximately 0, 6, 18 and 60 ppm in feed. The feed levels correspond to ca. 0.28, 0.79 and 2.51 mg/kg bw/day. Animals were withdrawn from dosing for 3 days and residues were determined in milk and tissues.

Tebufenozide residues in milk following 28 consecutive daily doses
Days of dosing Average residues in milk at each dose level
6ppm 18ppm 60ppm
-1 0 0 0
0 0 (0.002) (0.004)
3 0 (0.005) 0.025
6 0 (0.004) 0.021
9 0 (0.006) 0.024
13 0 (0.006) 0.017
16 (0.002) (0.007) 0.026
20 (0.002) (0.009) 0.028
23 (0.003) (0.007) 0.019
27 0 (0.004) 0.015
30 (+3) 0 0 0

0 indicates less than the limit of detection or <0.003 mg/kg. The limit of quantitation was reported as 0.01 mg/kg. Results between LOD and LOQ are shown in parentheses.

Tebufenozide residues in tissues following daily dosing for 28 days
Matrix Dose level Days of Residues (mg/kg)
(ppm) dosing (Tebufenozide)
Liver 6 27 0.014, 0.008, 0.009
30 <LOD
18 27 0.041, 0.014, 0.026
30 <LOD
60 27 0.061, 0.101, 0.066
30 <LOD
Kidney 6 27 <LOD (3)
30 <LOD
18 27 0.007, <LOD (2)
30 <LOD
60 27 0.007, 0.043, 0.006
30 <LOD
Muscle 6 27 <LOD (3)
30 <LOD
18 27 0.022, <LOD (2)
30 <LOD
60 27 <LOD, 0.056, 0.028
30 <LOD
Fat 6 27 0.029, 0.011, 0.011
30 0.007
18 27 0.109, <LOD, 0.063
30 0.005
60 27 0.063, 0.380, 0.23
30 0.016

Day 30 of dosing = 3 days withdrawal. LOD 0.003 mg/kg (milk), 0.006 mg/kg (liver, muscle, kidney).