Health & Management / Ruminants Pain Management / Techniques and protocols OVERVIEW:
Pain Prevention for Calf Castration:
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Introduction and General Information

Castration of bull calves is a management procedure which is carried out in  many parts of the world.

Current welfare concerns call for re-evaluation of the need for such traditional husbandry practices as standard (P61.53.w1) and for consideration of ways in which pain and distress associated with such procedures may be minimised. (P61.53.w1)

Methods of castration

  • Surgical:
    • An incision is made into each side of the scrotum, the testis is withdrawn, the mediastinum testis and vas deferens are separated from the testis and cut, and traction is placed on the testis to tear the blood vessels above the pampiniform plexus. (J24.66.w1)
  • Rubber ring: A rubber ring is placed around the scrotum above the testes. This cuts off the blood supply to the testes and scrotum; this tissue shrivels and falls off after a few weeks, leaving a scar. (D153.II.w2)
  • Bloodless castrator: A specially designed instrument, such as the Burdizzo, is applied to both spermatic cords in such a manner as to crush the spermatic cords (thereby damaging the blood supply to the testes) without breaking the skin. (D153.II.w2)
  • Chemical:  Various chemicals have been used, injected into the testes for example:
    • An 88% lactic acid solution (Chem-Cast, Bio-Ceutic Laboratories, Inc., Missouri, USA) is injected into each testis to destroy the spermatogenic and hormone producing cells. (J24.66.w1)
    • Injection of a sterile solution of alpha-hydroxypropionic acid into each testis. (J294.70.w1)
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Reasons for the procedure

  • Bull calves are commonly castrated to make the animals easier to handle and to control unwanted sexual activity and breeding. (J284.55.w1), P61.53.w1, J294.70.w1)
  • Operators of feedlots may avoid bulls because they are more difficult to manage than are steers. (J294.73.w1)
  • It is thought that castrates may be less susceptible than bulls to stress leading to "dark-cutting" meat and a lower price for the carcass. (J294.70.w1)
  • Differences in colour, texture and fat distribution of meat from bulls may affect consumer acceptability. (J284.55.w1)
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Arguments against use of the procedure

The Farm Animal Welfare Council (FAWC) has stated that "Calf castration is an undesirable mutilation which should be avoided if at all possible. It should only be carried out to avoid worse welfare problems." (D154)
  • Success of bull beef systems have shown that, at least in some management systems, castration of bull calves is unnecessary. (P61.53.w1)
  • Continued testosterone secretion in animals which have not been castrated may confer some benefits in terms of faster growth rates and a leaner carcass, which may be desirable. (P61.53.w1)
  • Haemorrhage may occur with surgical castration. (J24.63.w1, J294.70.w1)
  • Infection may occur following surgical castration. (J294.70.w1)
  • Intact males may use food more efficiently and produce a higher-yielding carcass. (J284.55.w1)
  • Daily weight gain and gain/feed may be reduced following castration. (J284.70.w1)
    •  A study of calves castrated at 70, 230, 320 or 410 days of age, or left uncastrated to slaughter at 14-15 months, found that intact males had faster weight gains (P<0.05) and more efficient feed conversion (P<0.05). Castration at 320 days depressed average daily weight gain compared to castration at 70 days. Castration at the two earliest ages produced greater marbling of meat than castration later or no castration. Intact males had lower marbling than those castrated at 70 or 230 days, and lower yield grade scores than for those castrated at 70 or 230 days. It was suggested that male calves could be left intact "to increase feedlot performance, efficiency and carcass leanness". (J284.64.w1)
    • A study of bulls castrated at eight to nine months old, by surgical or Burdizzo castration, or left intact, found that  surgical castrates grew most slowly, with 68-73% reduction in average daily weight gain over the first 28 days after castration compared to intact bulls; Burdizzo castrated animals showed a 51-53% reduction in average daily weight gain over the same time. Over the 112 days to finishing, intact bulls grew faster than castrates (P<0.05).(J294.73.w1)
    • A study on bull Friesian calves castrated at 5.5 months old showed that castration reduced average daily feed intake (ADFI) and average daily weight gain (ADG) in the first week after castration, reduced in vitro production of interferon-γ (thus suppressing this portion of the immune response), and increased plasma haptoglobin and fibrinogen levels. Reduced interferon-γ production was concurrent with increases in acute phase protein concentrations in plasma and may be associated with the inflammation seen following castration. (J284.75.w2)
    • A study on bulls (Angus, Angus x Friesian and Simmental) castrated at 14 or 9 months of age showed that castration resulted in a decreased growth rate. Animals castrated by banding (with a band designed for older animals - (Callicrate Bander, No-Bull enterprises, St Francis, Kansas, USA)) grew more slowly than those castrated surgically. (J24.79.w1)
    • A study of 50 Holstein x Friesian bulls castrated at 11 months old showed that surgical castration resulted in acute increase in cortisol secretion and acute phase protein production, suppressed production of interferon-γ from leucocytes in vitro in response to conconavalin A, and reduced feed intake and weight gain. (J284.81.w1)
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Signs/Evidence of pain associated with the procedure

A number of studies have shown that castration of calves of various ages is painful to the calves, as indicated by behavioural signs and plasma cortisol concentrations.
  • A study of calves (4-11 weeks old, 39-78 kg, Friesian and mixed beef breeds) found that during surgical castration without anaesthesia, calves showed "quite severe struggling and kicking of the back legs" and that most calves stood very still for about one to two hours after the procedure before resuming grazing. Calves castrated by application of rubber rings showed "less severe struggling and stamping of their hind legs"; after the application of the rings some individuals showed "various movements to bring the affected area into contact with the ground or their legs or muzzle"; all resumed apparently normal behaviour within one hour. Salivary cortisol levels were elevated in castrated calves compared to control calves (non-castrated females) at 15 minutes to three hours after castration, but not at four hours, 24 hours or six days. Salivary cortisol levels were significantly higher in surgically castrated calves than in those castrated by application of rubber rings at 15 minutes to two hours after castration. (J24.63.w1)
  • A study of calves castrated surgically (knife plus emasculator) or chemically (using injection of a sterile solution of alpha-hydroxypropionic acid into each testis) found that plasma cortisol levels were significantly raised in castrated calves compared with control calves at three and six hours after castration and were significantly higher for the surgically castrated than for the chemically castrated calves at both these times; highest cortisol levels in surgically castrated calves occurred at six hours post castration and for chemically castrated calves at three hours. There were no significant differences in plasma cortisol at 12 hours or daily up to seven days after castration. The study concluded that acute stress occurred for a period of six to 12 hours after castration and was greater following surgical than chemical castration. (J294.70.w1)
  • A study comparing responses of lambs, kids and calves to castration found that hand-reared calves raised in isolation showed no significant acute cortisol response to application of rubber bands. Subtle changes in posture were seen sometimes, including standing with the head and neck lowered and back legs slightly splayed, and also occasionally, while standing or lying, turning to face the hind quarters or to lick the flank or scrotal area. It was suggested that the unexpected lack of responses might be due to the physical isolation of the rearing and be related to "hiding" behaviour of young calves, in which lack of a distress response to noxious stimuli may be advantageous, making the calf less likely to draw the attention of potential predators. (J21.51.w1)
  • A study compared behavioural and physiological (plasma cortisol levels) responses of calves of three ages (six, 21 and 42 days) to castration by Burdizzo, surgical castration or rubber ring castration, and to control handled but not castrated calves. (J21.56.w1)
    • Abnormal behaviours and posture were seen less frequently in the six-day-old calves than in older calves. 
    • Rubber ring castrated calves showed significantly higher frequencies of restlessness, tail wagging, foot stamping and head turning than control handled, Burdizzo or surgically castrated calves; within the rubber ring castrated group these behaviours were seen significantly less in the six day old than in the older calves. 
    • Castrated calves ate and suckled for less time than did control calves; this difference was significant for the 21 and 42 day old groups. 
    • Rubber ring castrated calves showed a decrease in normal lying postures and an increase in abnormal lying postures, particularly abnormal ventral lying. 
    • Significantly more total abnormal standing was seen in all castrated groups compared to control handled calves, except for six-day-old calves and for the surgically castrated 21 day old calves. Time spent in abnormal postures was significantly greater for the rubber ring castrates and for the 42-day-old surgical castrates.
    • Plasma cortisol concentrations rose sharply and peaked between 12 and 24 minutes after castration for the surgically castrated and Burdizzo calves. Peak levels were significantly greater for the surgically castrated calves than for the handled (control) rubber ring or Burdizzo calves. Peak levels in the Burdizzo calves were significantly greater than in the control handled calves but returned to normal within 72 minutes. Peak levels in surgically castrated calves were significantly higher in six- and 42-day-old calves than in 21-day-old calves; the raised level was sustained for longer in the 42-day-old individuals. For the rubber ring castrated calves, a small peak in plasma cortisol concentration was seen at 12 minutes, similar to that seen in control handled calves. The level then rose again between 36 and 90 minutes with a peak lower than for surgical or Burdizzo castrated calves but being sustained for longer; responses were lower in the 21-day-old calves than in those of other ages. 
    • The study concluded that all three methods of castration caused acute pain; the least pain appeared to result from use of Burdizzo castration, particularly in younger calves. Behavioural observations suggested that pain from rubber ring castration may be less in six-day-old than in older calves, but that some pain was suffered for more than two hours. It was considered that Burdizzo may have resulted in more intense pain than rubber rings, but of shorter duration. It was not decided whether calves castrated surgically, which showed apparent reluctance to move, and high cortisol levels, were in more or less pain than calves castrated by rubber rings, which showed active abnormal behaviours and a lower cortisol level. 

    (J21.56.w1)

  • A study comparing the effects of Burdizzo or surgical castration on calves of three ages, found that rises in plasma cortisol concentration following castration indicated that castration caused stress detectable by this physiological measurement in older calves (approximately 167 days old) but there was no stress detectable by this measurement in calves castrated at about 78 days old. For the older calves the data indicated that physiological stress measures by plasma cortisol concentration was greater for calves castrated surgically than for those castrated by Burdizzo. (J294.70.w1)
  • Studies have shown that rubber band castration in calves results in behavioural indications of pain during the first three hours after application of the band, while abscess formation and chronic pain may occur for up to seven weeks. (J3.138.w3, J288.46.w1)
  • A study measuring behavioural, physiological (plasma cortisol) and clinic-pathological (scrotal area changes) effects of different methods of castration of 5-7-day-old calves found that use of rubber rings clearly resulted in more chronic pain than did either surgical castration or Burdizzo castration; it was considered to be unclear which of surgical or Burdizzo castration caused least acute pain, but probable that the Burdizzo method was the most humane. (J288.46.w1)
    • Surgical castration resulted in acute pain, as indicated by a significant increase in plasma cortisol, peaking at 12-24 minutes after castration and with smaller peaks at 60 and 96 minutes, and behavioural signs of significantly increased statue standing, abnormal standing and abnormal lying. Lesion scores indicated that there was rapid healing, with limited swelling for less than nine days and no infections. (J288.46.w1)
    • Burdizzo castration resulted in acute pain as indicated by a significant increase in plasma cortisol, peaking at 24 minutes, but lower than for surgical castration, and behavioural signs of significantly increased statue standing and abnormal standing postures. Lesion scores indicated that swelling increased slightly from day one to days two and three then decreased, disappearing by 15 days. (J288.46.w1)
    • Rubber ring castration resulted in a lower initial cortisol peak than surgical or Burdizzo castration but with the response sustained by later peaks and lasting longer than after Burdizzo castration. Active behaviours, both individual (restlessness, foot stamping/kicking, stretching, easing the hind quarters) and all active behaviours combined were significantly higher in these calves than in control handled calves and Burdizzo castrated calves; some indices were also higher than in surgically castrated calves. Abnormal standing and abnormal lying were both significantly increased while normal lying was significantly decreased. Lesion scores indicated that severe swelling, inflammation and infection occurred both at the rubber ring and proximal to it from about six days after application as the ischaemic skin's structural integrity began to break down. Lesions peaked in severity at 27 to 30 days; the scrotum and rubber ring fell off at mean 40 days (SD +/-5.6 days) and healing was not always complete at 51 days when the experiment stopped. There were significant increases in lesion licking for calves in this group during 48 days after castration and head turning without lesion licking also occurred most frequently in these calves. (J288.46.w1)
    • Rubber ring castration combined with Burdizzo applied distal to the rubber ring for ten seconds, immediately after the rubber ring had been applied, resulted in an initial peak between those seen for Burdizzo alone or rubber ring alone, with a second peak at about 84 minutes, about the same time as the later peaks seen with rubber ring alone. Active behaviours, both individual (restlessness, foot stamping/kicking, stretching, easing the hind quarters) were reduced compared to the use of the rubber ring alone, the decrease being significant for foot stamping/kicking, easing the hind quarters and all active behaviours combined. Statue standing, standing abnormally and lying abnormally were all increased significantly compared to control calves, while time spent lying normally was significantly reduced. Lesion scores indicated that severe swelling, inflammation and infection occurred both at the rubber ring and proximal to it from about three days after application as the ischaemic skin's structural integrity began to break down. Lesions peaked in severity at 15 to 18 days, with the scrotum and rubber ring falling off at 29 days (mean, SD +/- 5.8 days), significantly sooner than with rubber ring alone. There were significant increases in lesion licking for calves in this group during 48 days after castration. (J288.46.w1)
  • A study compared control calves with those castrated surgically or by Burdizzo, with or without local anaesthesia, at about 5.5 months of age. It was found that all methods of castration resulted in an increase in plasma cortisol concentration and decreases in average daily weight gain (ADH) and average daily food intake (ADFI) compared to control calves. Cortisol response was greater following surgical castration than following Burdizzo castration (higher and with a greater area under the cortisol versus time curve). Administration of local anaesthesia (8 ml of 2% lidocaine injected into each testicle and allowed to diffuse into the spermatic cord, with 15 minutes between injection and castration) significantly reduced the cortisol response of calves castrated surgically within the first 1.5 hours after castration, and also reduced the cortisol rise following Burdizzo castration, although the effect was less pronounced. ADFI was reduced in Burdizzo castrated calves in the first five days after castration, whether or not local anaesthesia was used, and in surgically castrated calves (with or without local anaesthesia) and those castrated by Burdizzo with local anaesthesia at days 6-10 post castration, but not at days 11-20. Average daily weight gain (ADG) was significantly (P<0.05) reduced in surgically castrated calves (with or without local anaesthesia) and those castrated by Burdizzo with local anaesthesia than control calves, with the ADG of surgical castrates being significantly (P<0.05) lower than that of those castrated surgically with local anaesthetic. Cortisol response of castrated calves was reduced by administration of local anaesthesia, while injection of local anaesthetic agent alone had no effect on cortisol levels, indicating that at least part of the cortisol rise was due to the influence of pain-associated afferent nervous activity. There was no effect of lidocaine on cortisol responses beyond the period 0.25-2.5 hours; this is not unexpected as lidocaine administered without an added vasoconstrictive agent has a duration of effect of approximately one hour. It was noted that use of a local anaesthetic with a longer duration of action, such as bupivacaine, may be more effective. Scrotal swelling occurred in Burdizzo castrated calves and was prolonged in Burdizzo castrated calves treated with local anaesthetic. (J284.74.w1)
  • A study of Friesian calves castrated at 5.5 months old showed that peak plasma cortisol concentrations were significantly higher (P<0.001) than in controls and the area under the cortisol versus time curve to 12 hours was significantly (P<0.001) higher for castrated than for control calves. (J284.75.w2)
  • Bulls castrated surgically with local anaesthesia at 14 months old showed more foot stamps and more tail swishes (P <0.001) during the afternoon on the day of castration than did uncastrated animals or those castrated with bands (Callicrate Bander, No-Bull enterprises, St Francis, Kansas, USA). There was a mild and transient decrease in grazing behaviour. However, wound resolution was prolonged with banding in comparison to surgical castration, particularly in 14-month-old animals but also in nine-month-old animals, and this was reflected in a lower weight gain, with banded animals of nine months old showing significantly lower weights by day 56 after castration in comparison with entire bulls, while surgical castrates had weights in between those of bulls or banded animals. (J24.79.w1)
  • A study comparing five methods of castration, without analgesia, with local anaesthetic, or with local anaesthetic plus a NSAID (ketoprofen) in two- to four-month-old calves, found that all methods of castration cause a significant cortisol response, indicative of pain and distress. (J21.73.w1)
  • A study comparing the effects of surgical castration of 5.5 month old calves with those given the NSAID ketoprofen prior to castration found that surgical castration (incision of the scrotum followed by removal of the testes using an emasculator) resulted in a significant acute cortisol response (as indicated by both peak cortisol and the area under the cortisol versus time curve). (J284.80.w1)
  • A study on fifty 11-month-old Holstein x Friesian bulls found that surgical castration significantly increased plasma cortisol levels. (J284.81.w1)
  • A study on bull calves castrated surgically, by Burdizzo clamp or by elastrator rings, at about seven weeks old, found that castration by rings caused more pain both immediately after castration and in the weeks following, than either of the other two methods. All methods resulted in a significant (p<0.001) decrease in weight gain in the four weeks following castration. The reduction in weight gain in calves castrated by elastrator rings was greater than that seen following castration by either of the other methods, during the third week after castration. In calves castrated by rings there were behavioural signs of discomfort in the hour after castration and refusal of the afternoon feed by three of 28 calves. In three calves there was pain at one and two weeks; ulceration and pain developed around the ring of all calves by three or four weeks, with pus formation noted at seven weeks and some indications of pain and swelling at eight weeks after castration. In calves castrated by Burdizzo clamp no pain was noted following the crushing of the spermatic cords; there were signs of discomfort, swelling of the scrotal sac and pain on palpation at seven days but the swelling had decreased by 14 days and there was little pain on palpation, and none by 21 days. It was noted that "crushing of the cord inevitably produces tissue reaction and oedema which are responsible for more pain during the 2 weeks immediately following castration than is seen in the calf castrated by incision." In calves castrated surgically the behaviour was considered to be normal immediately following castration; 14 of 28 calves showed some swelling of the severed cord at seven days, but with no indication of pain on palpation, one individual developed swelling, infection and pain by 14 days, which had healed by 21 days, at which time one calf showed swelling and none showed pain on palpation; calves in this group did not show pain in later weeks. (J3.70.w3)
  • A study on the growth rates of barley beef calves castrated by different methods indicated that castration by rubber Elastrator rings should be avoided and that if castrating at 168 to 224 lb, surgical castration was preferable to Burdizzo (in terms of effect on weight gain) while if castrating at 224 to 336 lb, surgical or Burdizzo clamp castration would be appropriate. (J35.120.w1)
    • The study found that the growth rate was considerably slowed following rubber ring castration at about 120 lbs bodyweight (P<0.001 for data to four weeks after castration) with return to normal growth rates taking eight weeks, and that there was still a significance in growth to 24 weeks after rubber ring castration; in contrast surgical castration (at 16 weeks after the other calves were castrated by rings) caused hardly any retardation of growth. When calves were castrated at about 200 lb live weight, Burdizzo castrated calves showed slower growth than surgically castrated calves for the first four weeks after castration while growth rate of calves castration at approximately 258 lb was not significantly different between castrated-castrated or surgically castrated calves; by six months after castration there was no significant difference between calves castrated by Burdizzo or surgically. It was noted that all three methods resulted in some swelling of the scrotal area and that "many" animals showed "some evidence of stiffness" for up to seven days after castration. (J35.120.w1)
  • A study comparing surgical and chemical (88% lactic acid solution; Chem-Cast, Bio-Ceutic Laboratories, Inc., Missouri, USA) injected into each testis) castration, concluded that chemical castration caused more pain and more prolonged healing than surgical castration. With chemical castration there appeared to be some pain when the needle was inserted into the testis and during the initial injection period, with "more intense pain" while the last 25% of the recommended dose was injected. It was considered that pain in surgically castrated calves was similar to that seen in the initial stages of the chemical injection. At eight hours after castration, all calves showed substantial scrotal swelling "and were in considerable discomfort" but had only mild reactions to scrotal palpation. Signs of pain and discomfort, including stilted gait, reduced walking, reluctance to move, lying down and reduced interest in either their dams or one another, were noted over the next two days, with normal behaviour considered to have returned by the end of the third day post-operatively. In surgically castrated calves at 22 days healing was advanced, being complete in three of six calves by 36 days and complete in all except one side of one calf by 55 days. In chemically castrated calves at 22 days firm granulation tissue was present in both sides of the scrotum, with a 2 to 3 cm diameter area of necrosis at the distal end of the scrotum in two of six calves; at 36 days there was still firm granulation tissue in the scrotum, with the necrotic areas replaced by granulation tissue, and by 55 days the scrotum still contained firm granulation tissue and the distal scrotal areas which had been necrotic were in advanced stages of healing. (J24.66.w1)
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Suggested methods of pain prevention

The Farm Animal Welfare Council (FAWC) has stated that "Calf castration is an undesirable mutilation which should be avoided if at all possible. It should only be carried out to avoid worse welfare problems." (D154)

It has been recognised for many years that castration should be carried out in such a manner as to cause the minimum pain, haemorrhage and infection, and therefore minimise the effects of castration on health and growth. (J3.70.w3)

Age considerations:

  • In one study behavioural observations suggested that pain from rubber ring castration may be less in six-day-old than in older calves, but that some pain was suffered for more than two hours. (J21.56.w1)
  • A study showed that when bulls of about 21 months old were castrated surgically (with local anaesthetic) or by use of a special rubber tubing, surgical castration, but not banding, elicited an immediate acute stress response as indicated by an increase in blood cortisol concentration, and both procedures elicited an increase in cortisol and in white blood cell (WBC) count by two days after castration, with response duration being similar following either procedure. Performance in terms of average daily weight gain tended to be lower than that for uncastrated bulls but was similar for the two procedures. White cell counts, although elevated above those of uncastrated controls, remained within the normal range; it was suggested that castration at this age did not compromise the health of the animals. (J284.73.w1)
  • Different methods may be preferable at different ages. 
    • A study comparing bulls castrated at nine or 14 months old by surgical castration (with local anaesthetic) or by banding with special rubber tubing (Callicrate Bander, No-Bull enterprises, St Francis, Kansas, USA) indicated that banding resulted in fewer acute effects (behavioural signs such as tail swinging and foot stamping) but that banding in the older animals resulted in prolonged wounds and slower growth and that surgical castration (with proper pain relief, haemostasis and fly control) was probably preferable, particularly in the older animals. (J24.79.w1)

Use of least painful methods:

  • Available methods include surgical removal of the testes, Burdizzo (castration clamp) to crush the spermatic cords, application of rubber rings (or in older animals rubber tubing) to the scrotum, and chemical castration by injection of a sterile solution of alpha-hydroxypropionic acid into each testis. There may be differences in the methods which are used or available for use in different countries. (J284.73.w1, J3.138.w3, (J21.73.w1)
    • In the UK, rubber ring, Burdizzo and surgical castration are used. Rubber rings may be used only in calves up to one week old. Surgical castration or use of a Burdizzo may be carried out without anaesthesia up to two months old and by a lay person (non-veterinary surgeon) up to two months old. In older animals anaesthesia must be used and the procedure must be carried out by a veterinary surgeon. (J3.138.w3, J288.46.w1)
    • In New Zealand, castration of cattle over nine months old must, under the Animals Protection Act 1960, be carried out by a veterinarian or under veterinary supervision, and using effective analgesia. A survey in 1998-1999 found that the commonest method used for castration was application of a rubber ring, usually in calves of up to three months old; this method was used by 85% of those farmers who castrated their bull calves, while 18% used surgical castration (in calves of average age 4.3 months) and very few used a castration clamp (Burdizzo) (only 25 of 2,825 farmers). Only 3% used local anaesthesia; this was used on calves castrated with rubber rings (4,534 calves) or surgically (1,425 calves). Anaesthesia was used on only 10% of calves castrated surgically at 9 months old or older. 60% of farmers castrated calves before twelve weeks old and only 2% at over six months of age. It was considered "worrying" that anyone would use rubber rings to castrate calves of 12 months old. (J10.48.w3)
  • Experimentally, Burdizzo (clamp) castration has been found to produce the lowest overall behavioural and cortisol responses to acute pain and to have the smallest effect on growth rate. (J3.70.w3, J3.138.w3, J21.56.w1, J21.73.w1, J288.46.w1) However some veterinary surgeons have concerns regarding pain associated with the initial crush and the subsequent swelling. (J3.138.w3)
    • A study comparing five methods of castration, without analgesia, with local anaesthetic or with local anaesthetic plus a NSAID (ketoprofen) in 2-4-mounth old calves, found that the lowest cortisol response occurred following clamp (Burdizzo) castration, followed by surgical castration with the spermatic cords cut or pulled, while ring castration resulted in a greater cortisol response and band castration (Callicrate Bander, No-Bull enterprises, St Francis, Kansas, USA) in the highest response. Band castration also resulted in calves lying on their sides with their hind legs extended, a posture indicative of severe pain. Ring, band, and surgical castration with the spermatic cords pulled, all produced a maximal cortisol response mimicking that from injection of ACTH, suggesting that these methods produced the most severe initial pain and distress. The authors did note that the least painful method, Burdizzo castration, was not completely successful for castration of all calves. It was noted that healing occurred most rapidly with surgical castration (by 48 days), while healing after ring or band castration took longer (by 58 days) and some testes were still palpable (although much reduced in size) at 63 days following clamp castration. (J21.73.w1)
    • A study comparing responses of calves to surgical, chemical or Burdizzo castration found differences in distance travelled in an open-field test; greatest distances were travelled by control calves, followed in order by chemically castrated and Burdizzo treated calves, with least distances travelled by surgical castrates at two hours and two days after castration. Distance travelled was significantly different between treatments on both occasions (P=0.01). There were also differences between treatments in neutrophil counts two hours after castration (P=0.04) and in platelet counts two days after castration (P=0.05). Castration stress was considered to be higher for surgically castrated than the other calves at two hours after castration. (J284.63S1.w1)
    • A study comparing responses to surgical, Burdizzo, chemical or sham (control handled) castration, found that cortisol concentrations were greatest in surgical castrates at 20, 60, 90 and 120 minutes after the procedure; concentrations were second highest in Burdizzo castrated calves at 20 and 60 minutes but at 90 and 120 minutes levels were higher in chemically castrated calves than in Burdizzo castrated calves. It was noted that "generally, surgical castration appeared more stressful than the other methods." (J284.65S1.w1)
    • A study of bulls castrated at eight to nine months old, by surgical or Burdizzo castration, or left intact, found that bloodless castration produced less depression in average daily weight gain than did surgical castration. (J294.73.w1)
  • While claims have been made that chemical castration causes only minor pain, a study found that injection of the recommended dose, particularly the last 25% of the recommended dose, appeared to cause more pain than surgical castration, and that time to healing was longer with chemical castration. (J24.66.w1)

Correct application of methods:

  • Non-veterinarians who are carrying out castration of calves should be suitably trained and competent to carry out the procedure. (D154)
  • A survey found that 28% of farmers applying the Burdizzo twice were applying the second crush above (proximal to) the first crush, apparently not realising that this will inflict further pain on the calf. Correct application involves the second crush being applied below (distal to) the first crush, in the area in which the innervation has already been destroyed. (J3.138.w3)

Use of analgesics:

  • This is a legal requirement in some countries. 
    • In the UK, provision of anaesthesia is required for the castration of cattle over two months of age, under the Protection of Animals (Anaesthetics) Act 1954 (as amended). (D158)
    • In Ireland the Protection of Animals (Amendment) Act 1965 requires the use of anaesthesia for surgical or Burdizzo castration of cattle over six months of age. (J284.81.w1)
    • In the USA provision of local analgesia is recommended for castration of cattle older than 2-3 months of age. (J284.74.w1)
  • A study comparing five methods of castration, without analgesia, with local anaesthetic, or with local anaesthetic plus a NSAID (ketoprofen), in two- to four-month-old calves, found that the acute cortisol response to ring or band (Callicrate Bander, No-Bull enterprises, St Francis, Kansas, USA) castration in the first eight hours after castration was eliminated by either local anaesthetic given into the testes and distal scrotum twenty minutes before castration, or by local anaesthetic plus ketoprofen. The acute cortisol response to surgical castration with either the spermatic cords broken by traction or the spermatic cords cut with an emasculator was eliminated by use of local anaesthetic plus ketoprofen, but not by local anaesthetic alone. For Burdizzo clamp castration there was a (non-significant) reduction in acute cortisol response following application of local anaesthetic and the acute cortisol response was eliminated by the combined administration of local anaesthetic and ketoprofen. (J21.73.w1)
  • A study compared the effects of the NSAID ketoprofen alone, ketoprofen in combination with local anaesthesia, and local anaesthesia alone, in their effects on the cortisol, immune and acute phase responses to surgical castration using an emasulator to crush and cut each spermatic cord. The study concluded that systemic analgesia using ketoprofen (3 mg/kg bodyweight) administered intravenously was more effective in relieving the pain and stress response associated with surgical castration than was local anaesthesia using lidocaine (2% lidocaine, 6 ml injected into each testis and a further 3 ml injected subcutaneously along each of the subsequent incision sites of the scrotum). (J284.80.w1)

Use of local analgesics:

  • For open castration, subcutaneous local anaesthetic solution may be used to block the incision site on the scrotum, while blockage of nerve fibres in the spermatic cord can be achieved either by injecting 5-10 ml local anaesthetic solution into each spermatic cord at the neck of the scrotum or by injecting 5-25 ml into each testis (amount varying depending on the size of the animal). (B205.12.w12)
    • It is assumed that following injection of local anaesthetic into the testis the drug passes along lymphatics and, after diffusion, blocks the nerve fibres in the spermatic cord. (B205.12.w12)
    • Excessive doses must be avoided due to risk of toxicity, since much of the dose will reach the bloodstream. (B205.12.w12)
  • For Burdizzo castration about 10-20 ml is used on each side, injected into the neck of the scrotum subcutaneously and into the spermatic cord. (B205.12.w12)
  • Short-acting local anaesthetics such as lidocaine injected into the testes prior to castration have a role in reduction of acute pain associated with castration, but appear to be less effective at alleviating the overall stress response as indicated by plasma cortisol concentration. (J284.74.w1)
  • It has been suggested that local anesthetic alone, injected into both testes and the distal scrotum, may be effective for ring or band (Callicrate Bander, No-Bull enterprises, St Francis, Kansas, USA) castration, while use of lidocaine plus an NSAID may be required to eliminate pain associated with surgical or Burdizzo clamp castration. (J21.73.w1)
    • Lidocaine injected into both testes and the distal scrotum twenty minutes prior to application of a castration ring or band (Callicrate Bander, No-Bull enterprises, St Francis, Kansas, USA) has been shown to effectively eliminate the acute cortisol response to banding. Injection of local anaesthetic into the neck of the scrotum does not appear to be necessary, nor was additional NSAID required. (J21.73.w1)
    • Lidocaine injected into both testes and the distal scrotum twenty minutes before surgical castration did not significantly reduce cortisol responses but did minimise pain-related behaviour during the surgery: calves stood still, which was not the case with calves not given local anaesthetic. (J21.73.w1)
    • Lidocaine injected into both testes and the distal scrotum twenty minutes before Burdizzo castration did partially reduce cortisol responses and minimised pain-related behaviour during the application of the clamp: calves stood still, which was not the case with calves not given local anaesthetic. (J21.73.w1)
  • A study on 13-month-old Holstein x Friesian bulls castrated by Burdizzo found that administration of local anaesthetic (2% lidocaine, injected 20 minutes prior to castration), significantly decreased the peak cortisol (P <0.05) (reduced by about 30%) although this was still significantly higher than in control animals (P <0.05), but did not reduce the area under the cortisol against time curve (integrated cortisol response). Abnormal standing postures were significantly reduced in comparison to those animals castrated without anaesthetic, but were still significantly higher than the level seen in control uncastrated animals, and combined abnormal behavioural postures were not significantly reduced, whereas these were reduced by other treatments (ketoprofen or epidural anaesthesia). It was considered that the study implied that local anaesthesia did not provide optimum analgesia for relief of stress produced by Burdizzo castration of 13-month-old cattle. (J284.81.w2)
  • The Farm Animal Welfare Council (FAWC) suggests that "As soon as a satisfactory and practical way of producing analgesia, or administering an anaesthetic without the necessity of injecting it via a syringe and needle, becomes available it must be adopted for use on calves of any age before castration." (W550.Dec04.w2)

Use of NSAIDs:

  • For surgical castration, or castration with Burdizzo, of two- to four-month-old calves, ketoprofen has been shown to have a significant effect on the acute cortisol response. (J21.73.w1)
  • Injection of 3 mg/kg bodyweight ketoprofen prior to surgical castration of 5.5-month-old Friesian bull calves significantly (P <0.05) suppressed the acute cortisol response to castration, reducing both the peak cortisol level (P <0.05) and the area under the cortisol versus time curve (P <0.05). This treatment also had a beneficial effect on the acute phase protein response and on the growth rate of the calves to seven days after castration. (J284.80.w1)
  • A study on 11-month-old Holstein x Friesian bulls found that intravenous injection of 3 mg/kg bodyweight ketoprofen 20 minutes prior to surgical castration effectively reduced the cortisol response to surgical castration; no advantage was seen if the dose was divided with 1.5 mg/kg given 20 minutes prior to castration and 1.5 mg/kg given at the time of castration. Ketoprofen did NOT prevent the acute elevation of cortisol in these animals (peak elevation not significantly different from control animals castrated without ketoprofen) however cortisol levels from 2-8 hours post surgery were significantly lower in the groups treated with ketoprofen and the integrated cortisol response (area under the cortisol against time curve) was significantly (P <0.05) lower for individuals treated with ketoprofen compared to those castrated surgically without ketoprofen. Ketoprofen also reduced the amount of time for which calves stood in abnormal postures following castration, and reversed the decrease in time spent ruminating which was otherwise seen following castration. Repeating the ketoprofen at 24 hours after castration did not affect the acute-phase protein response nor the immune response. There was no consistent effect of ketoprofen on the reduction in average daily weight gain (ADG) in the period to 35 days after castration. (J284.81.w1)
  • A study on 13-month-old Holstein x Friesian bulls castrated by Burdizzo found that administration of the NSAID ketoprofen (3 mg/kg intravenously) significantly decreased the peak cortisol (P <0.05) (reduced by about 30%) although this was still significantly higher than in control animals (P <0.05), reduced the area under the cortisol against time curve (P <0.05) and was significantly more effective than either local anaesthesia or epidural xylazine/lidocaine at reducing the cortisol concentration for the periods two to six hours and 6.5 to 12 hours post castration. Ketoprofen also significantly (P<0.05) decreased the occurrence of abnormal standing behaviours following castration (although abnormal standing postures were seen more than in control animals), while time spent ruminating was similar to that seen in control animals and was significantly greater than that seen in animals castrated without anaesthesia or with either local anaesthesia or epidural. Additionally, ketoprofen reduced the castration-related increase in the acute-phase protein haptoglobin on day one after castration, tended to ameliorate the reduction in interferon-γ production by white blood cells in vitro in response to conconavalin A seen on day one (although interferon-γ production was still reduced on day three), and partly decreased the reduction in average daily weight gain seen after castration. (J284.81.w2)

Use of alpha 2 agonists:

  • Intravenous injection of 0.02 mg/kg xylazine and 0.07 mg/kg butorphanol 90 seconds prior to castration did not produce any apparent analgesic effect on six- to nine-month-old bull calves at castration. (J284.70.w1)

Use of epidural anaesthetic:

  • Epidural anaesthesia had some effects on behavioural and physiological indicators of pain following castration.
    • A study using caudal epidural injection of 0.07 mg/kg xylazine (based on weight estimates) diluted with 0.09% sodium chloride to give 7.5 ml, to castrate mature bulls of 300-600 kg, found that by the initiation of surgical castration at 30 +/- 14.11 minutes after injection (range 11 to 75 minutes), the degree of surgical analgesia was "good" in 80.5% and "adequate" in 19.5%; no animals showed poor analgesia. Additionally, adequate sedation was shown in 97.4% of individuals, with 2.6% showing profound depression and sedation (two animals who received relatively high doses), and no or only slight ataxia was seen in 83.1%, with moderate ataxia in 14.3% and severe ataxia in 2.6% (two animals who received relatively high doses). The responses to spermatic cord traction or emasculation seen in 19.5% was considered possibly due to visceral pain; somatic pain appeared totally blocked (no response to scrotal incision). The technique was considered to be simple, time efficient (bulls were injected in a chute starting with the animal closest to the leading squeeze chute, and once all were injected starting castration at the head of the chute), and effective in terms of sedation and analgesia. It was noted that the technique provided some post surgical analgesia. (J215.15.w1)
    • A study on 13-month-old Holstein x Friesian bulls castrated by Burdizzo found that administration of epidural anaesthesia (2% xylazine at 0.05 mg/kg bodyweight combined with 2% lidocaine at 0.4 mg/kg bodyweight, by slow injection into the first intercoccygeal space) significantly decreased the peak cortisol (P <0.05) (reduced by about 30%) although this was still significantly higher than in control animals (P <0.05) but did not reduce the area under the cortisol against time curve (integrated cortisol response). Abnormal standing behaviours were significantly reduced in comparison to those animals castrated without anaesthetic and were not significantly different from levels seen in control uncastrated animals; in particular, less tail swishing was noted. Epidural anaesthesia did not significantly affect the reduction in feeding and ruminating activities which occurred following castration. (J284.81.w2)
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Reasons why adequate pain relief is not always provided

Pain alleviation techniques may not be used because they are not perceived as being required, because the benefits gained are not adequate to offset pain or distress associated with application of the pain prevention (e.g. local anaesthesia injection may itself distress an individual) or because of practical and/or economic constraints. (P61.53.w1)

Reasons why adequate pain prevention may not be provided are described in detail in: Reasons for Failure to Provide Pain Relief. In brief, these include:

  • Attitudes towards pain in animals;
  • Tradition;
  • Failure to recognise pain;
  • Failure to recognise the importance of the adverse effects of pain;
  • Concern about removing possible protective effects of pain [this concern is generally excessive];
  • Concern that providing pain relief may itself stress the animal and have a negative impact on it;
  • Concern that treating pain may interfere with diagnosis;
  • Lack of information about analgesics;
  • Concern about toxicity and side-effects of analgesics;
  • Concerns about the safety and legislative controls associated with some analgesics such as opiates;
  • Economic and practical considerations.

Specific published reasons for failure to provide pain relief for castration of calves are indicated below.

Economic and practical considerations:

  • Castration of calves is generally carried out without the anaesthesia which would be expected under normal surgical principles, due to considerations of economics and convenience. (B356.14.w14)
  • Studies have shown that rubber band castration in calves results in behavioural indications of pain during the first three hours after application of the band, while abscess formation and chronic pain may occur for up to seven weeks. (J3.138.w3, J288.46.w1) Nevertheless this method of castration may be preferred because: 
    • Application of rubber bands in calves under one week of age is easy and rapid, requiring only one person and not requiring any handling equipment. (J3.138.w3)
    • With application of rubber bands it is simple to confirm that the animal has been successfully castrated. (J3.138.w3)
    • Few failures are reported. (J3.138.w3)
  • Surgical castration causes some acute pain but rapid healing and less chronic pain than application of rubber rings. An advantage is that there is unequivocal evidence of castration in the form of the removed testes. However skills required for correct application of surgical castration are considerable, involving knowledge of surgical principles, hygiene and anatomy (J288.46.w1). More than one person is required for this procedure. (J3.138.w3)
  • Burdizzo method castration causes some acute pain, which is probably less than that caused by surgical castration. However, considerably knowledge of the underlying anatomy, and skill in application, are required for successful castration to be achieved, together with proper maintenance of the instrument. (J288.46.w1) There are also variations in the specifications of instruments, and lack of detailed studies on the optimum use in terms of force, time of application and jaw profiles. To carry out this procedure requires more than one person. (J3.138.w3, J288.46.w1)
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Authors & Referees

Authors Dr Debra Bourne MA VetMB PhD MRCVS (V.w5)
Referee A.B.Forbes BVM&S.,CBiol.,MIBiol.,DipEVPC.,MRCVS (V.w66)

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