The rate of decline of a-and pbenzene hexachloride residues in contaminated pigs NSW Agriculture, Wollongbar Agricultural Institute, Wollongbar, New South Wales 2477
SA SPENCE EB DETTMA"
Tweed-LismoreRural Lands Protection Board, Lismore, New South Wales 2480
JM WILSON
Screening for organochlorine residues in livestock has been carriedoutsince 1975inNew SouthWales.UndertheNewSouth Wales Stock (Chemical Residues) Act 1975 any stock with chemical residues exceeding the maximum residue limit (MRL) are detaineduntil their residuesfall to the MRL or less. The MRL for benzene hexachoride (BHC) in meat fat is 0.3 mghcg. Organochlorines accumulate principally in the fat of animals. When an animal is removed from the source of contamination the organochlorines are slowly eliminated from the body by metabolismand, to a lesser extent, by excretion.Rapidly growing young animals have an increasing total amount of fat in their bodies which, in effect, dilutes their residue so lowering the concentration measured. The same effect is seen if the animals become fatter. When residues occur in a piggery it is not profitable to feed pigs beyond a certain point while waiting for their residues to fall below the MRL. The value of pigs drops dramatically when they no longer fit the market specificationfor bacon pigs and become backfatters at around 100 kg body weight. In general, if the residue does not fall below the MRL by the time the pigs reach 100 kg, it is more profitable to kill and dispose of them than to keep feeding them. Minimising the economic impact of the contamination depends upon being able to predict the rate of decliie of residue in the contaminated pigs. In June 1986a 150-sow commercialpiggery was found to have pigs with BHC concentrations exceediig the MRL. The source of BHC contamination was found to be a load of 17 t of barley, which had been delivered 3 weeks previously and added to a silo already containing approximately 50 t of barley. All pigs older than 12 weeks of age were fed the barley-based diet. Pigs under 12 weeks were fed a wheat-based diet. When investigations began, the mixed feed based on barley contained 3 m a g a-BHC. Barley in the silo had concentrations varying from 0.12 m a g a-BHC at the top to 2.5 m a g a-BHC in the base of the silo. Most of the contaminated barley had already been consumed. Grower pigs aged 14 to 24 weeks had residues up to 4 m a g total BHC (t-BHC). Unweaned piglets were exposed to residues since BHC was detected in sow's milk.Residuesjust above MRL were detected in pigs less than 12 weeks old that were on wheat-baseddiets. This included piglets whose mothers had not been on contaminated feed before weaning. It was thought that contamination of the wheat-based feed had occurred through inconplete emptying of the mixer between feed formulations. We did not find any information on the rate of decliie of a-and EBHC in pigs and considered that all pigs below 12 weeks of age at the time the contamination was detected would be below MRL when they reached slaughter weight. This proved to be the case. Feeding of contaminatedfeed stopped 6 days after the problem was detected. To remove BHC contamination from the piggery various procedures were undertaken. The mixer was steam cleaned and as much dust aspossible was removed with a vacuum cleaner and washed from the piggery buildings. As the wooden walls of feed bins were found to contain BHC, these bins were lined with sheet metal. Australian VeterinaryJournal, Vol69, No 1, January 1992
The pigs to be sampled were sedated with maperone* 20 min before surgery. The biopsy site was the medial aspect of the sciatic tuber. The site was surgically prepared and anaesthetised with a craniocaudal linear infiltration of 2% lignocaine with adrenalin. An incision (about 4 cm)was made along the l i e and about 10g of fat removed by dissection The incision was closed with interrupted sutures of chromic 2 surgical catgut. Pigs recovering from sedation were not placed with unsedated pigs. Initially it was planned to sample 12pigs in each of 3 different age groups every 3 weeks until their residues fell to below the MRL. The age groups selected were 14,18 and 22 weeks of age at the time the commination was detected. The situation changed as a result of a commercial decision by the piggery owner to slaughter 416 animals 6 weela after the contamination was detected. The owner also requested that we stop the sampling of replacement gilts as they were becoming extremely difficult to handle within the piggery. These two factors meant that most of the animals in the sampling groups were no longer available. Six boars from the initial 14-week-old group were retained for experimentalpurposes. These boarswere on a maintenance diet so were in lean condition. Their condition and the frequency of sampling meant that it was extremely difficult to get adequate individual samplesfrom these animals. The final sampling strategy involved sampling 12 pigs from each of 3 age groups at intervals of 3 weeks on 3 occasions. Fat samples were collected from 69 of the 416 slaughteredpigs. Six boars from the initial 14-week-old group were sampled 4 times at irregular intervals, the last occasion being 10 1/2 months after the contamination was initially detected. Surplus sows were sampled at the time they were culled. A total of 201 biopsy samples was taken and an additional 69 fat samples were collected at slaughter. The samples were analysed using the assisted distillation technique of Heath and Black (1979) with modifications by McDougd (1980). Over time it became apparent that the rate of decline of BHC was similar in all ages of pigs. For this reason the data from all animals were grouped. The linear relationship between log [a-BHC] (YA), log [p-BHC] (YB), log jt-BHC] (YT) and time elapsed in days (x) (with standard errors of regression coefficientsin brackets) are:
-
YA = 0.3583 0.0057 (0.0003)X; YB = 0.0158- 0.0037 (0.0004)X; YT = 0.5021 - 0.0046 (0.0003)X; The half-lives, that is the times for the residues to drop to half the present level, were 53 days, 82 days and 65 days for a-BHC, p-BHC and t-BHC, respectively. The relationship between log t-BHC and time elapsed is not linear (the rate of decrease slowed down below t-BHC levels of 0.25 m a g ) SO that the half-life is not strictly applicable over the full range of concentrations found The simple exponentialdrop, which has to be postulated to allow calculationsof a half-life is extremely simplistic and can only be used as a rough indicator of the complex underlying biological systems that determine how fast residue levels will drop. Analysis of fat samples obtained 6 weeks after the pigs were taken off contaminated feed revealed that some animals had increased levels of residue. This was assumed to reflect the loss of body fat in these growing animals on a maintenance diet, Sows had lower residue concentration than boars when last tested in May 1987 at which time all animalstested were below the MRL. Although lactation data for sows were not available, lactation would be expected to increase the rate of decliie of residue concentrations as the organochlorines are actively excreted with milk fat. This would explain the difference in concentrations observed between sows and boars at the end of this study. Stresnil? Boehringer lngelheim Pty Ltd, Artarmon, NSW 2064 17
Thef d g s in thisepisoderelate topigs on a maintenancediet. Lower half-lives may be achievable in pigs on a fattening diet due to the dilution effect that occurs when the proportion of fat intheii bodies is inUnder the conditions that occurred in this episode of BHC -C ' 'onin a piggery with residuesin pigs of up to 4 m a g t-BHC, the half-life of a-BHC was 53 davs. the half-life of BBHC was 82 days and the half-life of t-BHCwas 65 days. References Heath AB Pnd Black RR (1979). J Arsoc OflAnol Chun 62759 McDougall KW (1980)Jhsoc O f f W C h 6 3 : 1 3 5 5
(Acceptedfor publication 1S~oVember1991)
TABLE 1 Effwt of bupivacraine(experiment I) and Irobutaiome ( a m m e n t 2) On C h W W In feed i n w e (@id)Over varlou8 time Interval8 on the day of beak-trimmingcompared with the previous day Experiment 1 Treatmentgroup
0.5h
2h
2.5h
24 h
Beak-trim no analgesic
3.6
4.50
4.4'
18.4'
3.e
2.3
2.e
1.3&
Q.?
1.F
1.4
0.9
4.5b
1.p
3.&
3.0
3.2
7.6
4.0
Shambeak-trim Beak-trim and anwesic LSD (Plo.05)
Analgesic therapy of beak-trimmed chickens South Australian Department of Agriculture, Parafield Poultry Research Centre, 230 SalisburyHighway, ParalieId Gardens, South Australia 5 107
PC GLATZ
QueenslandDepartment of Primary Industries, LB MURPHY Pig and Poultry Branch, AP PRESTON GPO Box 46,Brisbane,Queensland 4001
Beak-trimmingof chickens involves the use of a red-hot blade to cut and cauterise the beak, and is a common practice in the Australianegg industry to control cannibalism, bullying, feather and vent pecking. The beak, however, is a complex organ containing many sensory receptors. Beak-trimming excites nociceptorsin the beak leading to short-termacutepain (Breward 19W. Glatz 1983, chronic pain (Breward and Gentle 1985) and a reductionin feed iutake (Glatz 1987). One potentialmethod for reducing acute pain and improving the welfare of poultry after beak-trimming is to use analgesics. To our knowledge there is no informationon feeding responses of commercial poultry treated topically with a local anaesthetic or an anti-inflammatoryagent after beak-trimming. This paper reports work examining the potential for using analgesic therapy in beak-trimmed chickens. Two experimentswere conducted with 6-weeks-oldlayer-type commercial crossbreds housed individually in grower cages in a light-proof controlledenvironmentshed. In the fmt experiment, treatment with analgesic occurred immediately after each individual bird had been trimmed and involved appl * g a 5050 mixture of bupivacaine* and dimethyl rmlphoxide topically to thecut portion of the beak with a muonwad. The c o n ~ nwad was saturated with analgesic and rolled over the wound to ensure all cut surfaces were treated. cOmparisons were made with shamtrimmedandaimmedbirdsnottreatedwithanalgesic.There were! 10 replicates in each treatment. Time and behavioural activities, includingbouts of pecking at feed, chinking, preening, sitting and number of pecks made at the cage and other birds in adjacent cages, were recorded. Feeding rate was also & t e r m i d and calculated as the grams of feed consumed divided by the time spent pecking at feed and llheasufedover the 0.5 h period M e . diately after nimming. Video records of birds were made for 30 min immediately after himming and for a 30 min period beginning 2 h after appbcation of analgesic, and at a cOrreSpOndlIl ' g
F
' Marcain0.5%RD,Astra Pharmaceuticals ptU LM, North Ryde, NSW t Domoso gel@,Syntex, Thomleigh, NSW $ Super V DebeakelQbLyon, San O w ,CA, USA
I
lsobutalone Gel@ containing in each gram phenylbutazone sodium 50 mg, i q m p y b n i i o n e 40 mg and dmeihyl sulphoxide 80 mg, Apex Laboratories Pty Ltd, St Marys. NSW
I8
Experiment 2
NS
2 4 7
Means within dumns with different supersaipts are significantly different (P4.05). NS = Not significant in analysis of variance.
time on the day before brimming. Feed intake was measured at 0.5 4 2.0 h, 2 5 h and 24 h after treatment and over the COTresponding periods on the day before preament, Each bird was used as its own control and changes in feed intake and behaviour measurementswere compared on the day before trimming to the day of rrimming, and results analysedusing analysisof variance. Beak-trimming involved the use of a trimmiog machine* to remove one-half of the upper beak and one-third of the lower beak as specified by the Australian Bureau of Animal Health (1983). In the second e x p e r h a , which was of the samedesign, a mixture containing phenylbutazonep was applied topically to thebeak. Incontrastwiththeuntreatedgroup,trimmedbirdstreatedwith bupivacainewere able tomaintaintheirpre-trimmingfeedintake levels over the first 24 h a€ter the opaation. In the case of isobutalonetreatment,feed intake was improved comparedwith the untreated trimmed birds ("able 1). Feeding rate of the bupivacaine and isobutalone treated b d in the 0.5 h following trimming was 0.7 ginin and 0.4 g h i n higher, respectively,than untreated birds. The significant reduction in the feed intake of control birds in the fmt 24 h after trimming relative to treated birds probably reflects the effectsof handling on performance of birds and suggests that the drugs used not only produced analgesia in birds but also stimulated their feeding activity. In the
seco~experiment,beak-eimmingdidnotreducethefeedintalre of birds to the same degree as the first experiment which adds further observationsto what is a variable picture for the effects of beak-trimming on feed intake. We could not detect any 0th differences in the behaviour of birds in the first few how after trimming as a result of applying the aualgesic except with birds treated with isohtalcme. These birds showed an increase in the number of cage pecks (increaseof 41 pecks in the first 05 h), relative to the unrreated group. They wexe also seen attempting to wipe the s t i c e isobutalone htheir beals. InAustralia,millionsof~ialpoultxyarebealr-eimmed eachyear. Ourworkhas shownrhat analgesicshavethepotential to maintain the feed intake of chickem in the first day aftea trimming, which probably indicates that %ome of tbe acute pain had been relieved. The practicalities of using snalgesics appear to be quite simple as it takesonly seconds to apply. Immediately after nimming,the beak of each bird couldbe dipped h a dish of analgesic or held against a sponge saturated with analgesic.
References Aumrlirn Boccm d Animrl Hahh (1983) In Cadc OfPracticefathe We!fiare 4th DonvJlic Fowl, p 10 B r c w d J (1984)JP]r)aid346:56 BrcwxdJmdGmtleMJ(198S)Erpctirnb41: 1132 Ghtz PI:(1987) Br P o d Sci 28: 601
(Acceptedforpublication 27September 1991)
Am@alianVeterinaryJownal, Vol69, No 1, January 1992
SA SPENCE EB DETTMA"
Tweed-LismoreRural Lands Protection Board, Lismore, New South Wales 2480
JM WILSON
Screening for organochlorine residues in livestock has been carriedoutsince 1975inNew SouthWales.UndertheNewSouth Wales Stock (Chemical Residues) Act 1975 any stock with chemical residues exceeding the maximum residue limit (MRL) are detaineduntil their residuesfall to the MRL or less. The MRL for benzene hexachoride (BHC) in meat fat is 0.3 mghcg. Organochlorines accumulate principally in the fat of animals. When an animal is removed from the source of contamination the organochlorines are slowly eliminated from the body by metabolismand, to a lesser extent, by excretion.Rapidly growing young animals have an increasing total amount of fat in their bodies which, in effect, dilutes their residue so lowering the concentration measured. The same effect is seen if the animals become fatter. When residues occur in a piggery it is not profitable to feed pigs beyond a certain point while waiting for their residues to fall below the MRL. The value of pigs drops dramatically when they no longer fit the market specificationfor bacon pigs and become backfatters at around 100 kg body weight. In general, if the residue does not fall below the MRL by the time the pigs reach 100 kg, it is more profitable to kill and dispose of them than to keep feeding them. Minimising the economic impact of the contamination depends upon being able to predict the rate of decliie of residue in the contaminated pigs. In June 1986a 150-sow commercialpiggery was found to have pigs with BHC concentrations exceediig the MRL. The source of BHC contamination was found to be a load of 17 t of barley, which had been delivered 3 weeks previously and added to a silo already containing approximately 50 t of barley. All pigs older than 12 weeks of age were fed the barley-based diet. Pigs under 12 weeks were fed a wheat-based diet. When investigations began, the mixed feed based on barley contained 3 m a g a-BHC. Barley in the silo had concentrations varying from 0.12 m a g a-BHC at the top to 2.5 m a g a-BHC in the base of the silo. Most of the contaminated barley had already been consumed. Grower pigs aged 14 to 24 weeks had residues up to 4 m a g total BHC (t-BHC). Unweaned piglets were exposed to residues since BHC was detected in sow's milk.Residuesjust above MRL were detected in pigs less than 12 weeks old that were on wheat-baseddiets. This included piglets whose mothers had not been on contaminated feed before weaning. It was thought that contamination of the wheat-based feed had occurred through inconplete emptying of the mixer between feed formulations. We did not find any information on the rate of decliie of a-and EBHC in pigs and considered that all pigs below 12 weeks of age at the time the contamination was detected would be below MRL when they reached slaughter weight. This proved to be the case. Feeding of contaminatedfeed stopped 6 days after the problem was detected. To remove BHC contamination from the piggery various procedures were undertaken. The mixer was steam cleaned and as much dust aspossible was removed with a vacuum cleaner and washed from the piggery buildings. As the wooden walls of feed bins were found to contain BHC, these bins were lined with sheet metal. Australian VeterinaryJournal, Vol69, No 1, January 1992
The pigs to be sampled were sedated with maperone* 20 min before surgery. The biopsy site was the medial aspect of the sciatic tuber. The site was surgically prepared and anaesthetised with a craniocaudal linear infiltration of 2% lignocaine with adrenalin. An incision (about 4 cm)was made along the l i e and about 10g of fat removed by dissection The incision was closed with interrupted sutures of chromic 2 surgical catgut. Pigs recovering from sedation were not placed with unsedated pigs. Initially it was planned to sample 12pigs in each of 3 different age groups every 3 weeks until their residues fell to below the MRL. The age groups selected were 14,18 and 22 weeks of age at the time the commination was detected. The situation changed as a result of a commercial decision by the piggery owner to slaughter 416 animals 6 weela after the contamination was detected. The owner also requested that we stop the sampling of replacement gilts as they were becoming extremely difficult to handle within the piggery. These two factors meant that most of the animals in the sampling groups were no longer available. Six boars from the initial 14-week-old group were retained for experimentalpurposes. These boarswere on a maintenance diet so were in lean condition. Their condition and the frequency of sampling meant that it was extremely difficult to get adequate individual samplesfrom these animals. The final sampling strategy involved sampling 12 pigs from each of 3 age groups at intervals of 3 weeks on 3 occasions. Fat samples were collected from 69 of the 416 slaughteredpigs. Six boars from the initial 14-week-old group were sampled 4 times at irregular intervals, the last occasion being 10 1/2 months after the contamination was initially detected. Surplus sows were sampled at the time they were culled. A total of 201 biopsy samples was taken and an additional 69 fat samples were collected at slaughter. The samples were analysed using the assisted distillation technique of Heath and Black (1979) with modifications by McDougd (1980). Over time it became apparent that the rate of decline of BHC was similar in all ages of pigs. For this reason the data from all animals were grouped. The linear relationship between log [a-BHC] (YA), log [p-BHC] (YB), log jt-BHC] (YT) and time elapsed in days (x) (with standard errors of regression coefficientsin brackets) are:
-
YA = 0.3583 0.0057 (0.0003)X; YB = 0.0158- 0.0037 (0.0004)X; YT = 0.5021 - 0.0046 (0.0003)X; The half-lives, that is the times for the residues to drop to half the present level, were 53 days, 82 days and 65 days for a-BHC, p-BHC and t-BHC, respectively. The relationship between log t-BHC and time elapsed is not linear (the rate of decrease slowed down below t-BHC levels of 0.25 m a g ) SO that the half-life is not strictly applicable over the full range of concentrations found The simple exponentialdrop, which has to be postulated to allow calculationsof a half-life is extremely simplistic and can only be used as a rough indicator of the complex underlying biological systems that determine how fast residue levels will drop. Analysis of fat samples obtained 6 weeks after the pigs were taken off contaminated feed revealed that some animals had increased levels of residue. This was assumed to reflect the loss of body fat in these growing animals on a maintenance diet, Sows had lower residue concentration than boars when last tested in May 1987 at which time all animalstested were below the MRL. Although lactation data for sows were not available, lactation would be expected to increase the rate of decliie of residue concentrations as the organochlorines are actively excreted with milk fat. This would explain the difference in concentrations observed between sows and boars at the end of this study. Stresnil? Boehringer lngelheim Pty Ltd, Artarmon, NSW 2064 17
Thef d g s in thisepisoderelate topigs on a maintenancediet. Lower half-lives may be achievable in pigs on a fattening diet due to the dilution effect that occurs when the proportion of fat intheii bodies is inUnder the conditions that occurred in this episode of BHC -C ' 'onin a piggery with residuesin pigs of up to 4 m a g t-BHC, the half-life of a-BHC was 53 davs. the half-life of BBHC was 82 days and the half-life of t-BHCwas 65 days. References Heath AB Pnd Black RR (1979). J Arsoc OflAnol Chun 62759 McDougall KW (1980)Jhsoc O f f W C h 6 3 : 1 3 5 5
(Acceptedfor publication 1S~oVember1991)
TABLE 1 Effwt of bupivacraine(experiment I) and Irobutaiome ( a m m e n t 2) On C h W W In feed i n w e (@id)Over varlou8 time Interval8 on the day of beak-trimmingcompared with the previous day Experiment 1 Treatmentgroup
0.5h
2h
2.5h
24 h
Beak-trim no analgesic
3.6
4.50
4.4'
18.4'
3.e
2.3
2.e
1.3&
Q.?
1.F
1.4
0.9
4.5b
1.p
3.&
3.0
3.2
7.6
4.0
Shambeak-trim Beak-trim and anwesic LSD (Plo.05)
Analgesic therapy of beak-trimmed chickens South Australian Department of Agriculture, Parafield Poultry Research Centre, 230 SalisburyHighway, ParalieId Gardens, South Australia 5 107
PC GLATZ
QueenslandDepartment of Primary Industries, LB MURPHY Pig and Poultry Branch, AP PRESTON GPO Box 46,Brisbane,Queensland 4001
Beak-trimmingof chickens involves the use of a red-hot blade to cut and cauterise the beak, and is a common practice in the Australianegg industry to control cannibalism, bullying, feather and vent pecking. The beak, however, is a complex organ containing many sensory receptors. Beak-trimming excites nociceptorsin the beak leading to short-termacutepain (Breward 19W. Glatz 1983, chronic pain (Breward and Gentle 1985) and a reductionin feed iutake (Glatz 1987). One potentialmethod for reducing acute pain and improving the welfare of poultry after beak-trimming is to use analgesics. To our knowledge there is no informationon feeding responses of commercial poultry treated topically with a local anaesthetic or an anti-inflammatoryagent after beak-trimming. This paper reports work examining the potential for using analgesic therapy in beak-trimmed chickens. Two experimentswere conducted with 6-weeks-oldlayer-type commercial crossbreds housed individually in grower cages in a light-proof controlledenvironmentshed. In the fmt experiment, treatment with analgesic occurred immediately after each individual bird had been trimmed and involved appl * g a 5050 mixture of bupivacaine* and dimethyl rmlphoxide topically to thecut portion of the beak with a muonwad. The c o n ~ nwad was saturated with analgesic and rolled over the wound to ensure all cut surfaces were treated. cOmparisons were made with shamtrimmedandaimmedbirdsnottreatedwithanalgesic.There were! 10 replicates in each treatment. Time and behavioural activities, includingbouts of pecking at feed, chinking, preening, sitting and number of pecks made at the cage and other birds in adjacent cages, were recorded. Feeding rate was also & t e r m i d and calculated as the grams of feed consumed divided by the time spent pecking at feed and llheasufedover the 0.5 h period M e . diately after nimming. Video records of birds were made for 30 min immediately after himming and for a 30 min period beginning 2 h after appbcation of analgesic, and at a cOrreSpOndlIl ' g
F
' Marcain0.5%RD,Astra Pharmaceuticals ptU LM, North Ryde, NSW t Domoso gel@,Syntex, Thomleigh, NSW $ Super V DebeakelQbLyon, San O w ,CA, USA
I
lsobutalone Gel@ containing in each gram phenylbutazone sodium 50 mg, i q m p y b n i i o n e 40 mg and dmeihyl sulphoxide 80 mg, Apex Laboratories Pty Ltd, St Marys. NSW
I8
Experiment 2
NS
2 4 7
Means within dumns with different supersaipts are significantly different (P4.05). NS = Not significant in analysis of variance.
time on the day before brimming. Feed intake was measured at 0.5 4 2.0 h, 2 5 h and 24 h after treatment and over the COTresponding periods on the day before preament, Each bird was used as its own control and changes in feed intake and behaviour measurementswere compared on the day before trimming to the day of rrimming, and results analysedusing analysisof variance. Beak-trimming involved the use of a trimmiog machine* to remove one-half of the upper beak and one-third of the lower beak as specified by the Australian Bureau of Animal Health (1983). In the second e x p e r h a , which was of the samedesign, a mixture containing phenylbutazonep was applied topically to thebeak. Incontrastwiththeuntreatedgroup,trimmedbirdstreatedwith bupivacainewere able tomaintaintheirpre-trimmingfeedintake levels over the first 24 h a€ter the opaation. In the case of isobutalonetreatment,feed intake was improved comparedwith the untreated trimmed birds ("able 1). Feeding rate of the bupivacaine and isobutalone treated b d in the 0.5 h following trimming was 0.7 ginin and 0.4 g h i n higher, respectively,than untreated birds. The significant reduction in the feed intake of control birds in the fmt 24 h after trimming relative to treated birds probably reflects the effectsof handling on performance of birds and suggests that the drugs used not only produced analgesia in birds but also stimulated their feeding activity. In the
seco~experiment,beak-eimmingdidnotreducethefeedintalre of birds to the same degree as the first experiment which adds further observationsto what is a variable picture for the effects of beak-trimming on feed intake. We could not detect any 0th differences in the behaviour of birds in the first few how after trimming as a result of applying the aualgesic except with birds treated with isohtalcme. These birds showed an increase in the number of cage pecks (increaseof 41 pecks in the first 05 h), relative to the unrreated group. They wexe also seen attempting to wipe the s t i c e isobutalone htheir beals. InAustralia,millionsof~ialpoultxyarebealr-eimmed eachyear. Ourworkhas shownrhat analgesicshavethepotential to maintain the feed intake of chickem in the first day aftea trimming, which probably indicates that %ome of tbe acute pain had been relieved. The practicalities of using snalgesics appear to be quite simple as it takesonly seconds to apply. Immediately after nimming,the beak of each bird couldbe dipped h a dish of analgesic or held against a sponge saturated with analgesic.
References Aumrlirn Boccm d Animrl Hahh (1983) In Cadc OfPracticefathe We!fiare 4th DonvJlic Fowl, p 10 B r c w d J (1984)JP]r)aid346:56 BrcwxdJmdGmtleMJ(198S)Erpctirnb41: 1132 Ghtz PI:(1987) Br P o d Sci 28: 601
(Acceptedforpublication 27September 1991)
Am@alianVeterinaryJownal, Vol69, No 1, January 1992
