Of the list of 1,972 email addresses to which this survey was sent, 189 U.S. veterinarians completed all the questions. This represents a crude response rate of 9.6 percent. The average time to complete the survey was 32 minutes. Thirty-one (1.5%) participants that started the survey did not complete all the questions and these data were excluded from the analysis.
Demographic information
Veterinarians responding to the survey were grouped according to American Veterinary Medical Association (AVMA) geographic district. The majority of respondents (54; 29%) were from District 7 (Iowa, Minnesota, Missouri, Nebraska, North Dakota, and South Dakota). The second highest participation (26; 14%) came from District 6 (Illinois, Indiana and Wisconsin) and District 9 (Arizona, Colorado, Kansas, New Mexico, Oklahoma, and Utah) (Figure 1).
Respondents were most frequently in the age range of 50-59 years (57; 30%) followed by 30-39 years (46; 24%) (Figure 2). The majority of veterinarians participating in the survey (86; 45.5%) had been in practice for over 20 years. The second largest group of participants (29; 15%) consisted of relatively recent graduates (1-5 years) (Figure 3). Male veterinarians (146) accounted for 77 percent of those that completed the survey. Graduates from Iowa State University (27; 14%), Kansas State University (25; 13%) and The Ohio State University (15; 8%) accounted for over 30 percent of respondents. The majority of the practices represented in this survey comprised one (53; 28%) or two (32; 17%) veterinarians.
Twenty-seven percent of respondents (51) indicated that 11-20% of their gross practice income was derived from beef cattle. Seventy-two respondents (38%) indicated that the average size of beef breeding herds in their practice were between 1 and 49 head with 62 (33%) indicating that average herd size was between 100 and 499 head. Most respondents indicated that they were either not engaged in beef backgrounder operations (50; 26%) or they were involved in backgrounder operations of 100 - 499 head. Most respondents surveyed (117; 62%) were engaged in some aspect of beef feedlot operations. Six respondents indicated that 91 - 100% of their gross practice income was derived from beef cattle.
Similarly, 51 respondents (27%) indicated that 11-20% of their gross practice income was derived from dairy operations. Seventy-one respondents (37%) indicated that the average size of dairy herds in their practice were between 100 and 499 head. Most respondents (70; 37%) were not engaged in custom dairy calf rearing operations. Eight respondents indicated that 91 - 100% of their gross practice income was derived from dairy cattle.
Castration methods
Over 83 percent (157/189) of respondents indicated that in their practices, producers were primarily responsible for performing castrations in perinatal calves less than 90 kg. In contrast, 129 respondents (68%) reported that castration of calves weighing more than 270 kg was conducted by a veterinarian. There were no reports of castrations performed by veterinary technicians (Figure 4).
Surgical castration with a scalpel (108; 57%) followed by testicular removal by either manually twisting the testicles (84; 44%) or use of an emasculator (69/189; 36%) was the most frequently used method (Figure 5). Other methods of surgical castration that were used less often included using a Newberry Knife (61; 32%) or a conventional knife (26; 14%) to incise the scrotum and a Henderson Castration Tool (16; 8%) or surgical ligation (8%) to remove the testicles. Elastrator rubber rings (84; 44%) were the most commonly used non-surgical castration method employed in calves less than 90 kg. This was followed by banders (42; 22%) and the burdizzo clamp (39; 21%).
Approximately 90% of respondents (171) indicated that they do castrate some perinatal calves (calves weighing less than 90 kg). However, the actual number of calves castrated was relatively small with 40 respondents (21%) indicating that they only castrate between 1 and 24 perinatal beef calves per year and 56 (29%) indicating that they do not castrate any perinatal dairy calves (Figure 6). Ninety-five percent of respondents (180) indicated that they castrate light weight calves (90 - 270 kg). Thirty-six respondents (19%) only castrate between 1 and 24 light weight beef calves per year and the same number indicated that they castrate between 100 and 249 light weight calves per year. Fifty-eight respondents (31%) indicated that they do not castrate any light weight dairy calves and 48 (25%) only castrate between 1 and 24 light weight dairy calves per year (Figure 7). Surgical castration with a scalpel (113; 59%) followed by testicular removal with an emasculator (105; 55%) was the most common castration method used in light weight calves (Figure 6). Other methods of surgical castration that were applied less frequently included the use of a Newberry Knife (74; 39%), manual twisting to remove the testicles (74; 39%), surgical ligation of the testicles (37; 19%), the Henderson Castration Tool (28; 15%) and a conventional knife (22; 12%). Banders (85; 45%) were the most commonly used non-surgical castration method in light weight calves followed by the Burdizzo clamp (42; 22%) and elastrator rubber rings (28; 15%).
Approximately 89% of respondents (169) indicated that they castrate heavy weight calves (>270 kg). Fifty-two respondents (27%) only castrate between 1 and 24 heavy weight beef calves per year, however 26 respondents (14%) indicated that they castrate between 100 and 249 heavy weight calves per year. Seventy-six respondents (40%) indicated that they do not castrate any heavy weight dairy calves and 55 (29%) only castrate between 1 and 24 heavy weight dairy calves per year (Figure 8). Surgical castration with a scalpel (100; 53%) followed by testicular removal with an emasculator (96; 50%) was also the most common castration method used (Figure 6). Other methods of surgical castration used included manual twisting to remove the testicles (44; 23%), the use of a Newberry Knife (70; 37%), surgical ligation (52; 28%), a Henderson Castration Tool (27; 14%) and a conventional knife (15; 8%). Banders (97; 51%) were also the most commonly used non-surgical castration method used in heavy weight calves followed by the Burdizzo clamp (28; 15%).
Factors affecting selection of a castration method
For the majority of respondents (70; 37%), risk of injury to the operator was the most critically important consideration in the selection of castration method with 65 respondents (34%) indicating that this was very important (Figure 9). The weight of the calf was considered critically important by 54 respondents (28%) and very important by 82 respondents (43%). Experience with the castration technique was considered critically important by 56 respondents (29%) and very important by 64 respondents (34%). Other considerations, in order of critical importance to the participants, were handling facilities (54; 28%) scrotal circumference (49; 26%), adverse effects (48; 25%), age of calf (42; 22%), painfulness of procedure (26; 13%), time taken to conduct the procedure (15; 8%), and the cost of performing the procedure (12; 6%).
Adverse events associated with castration
In perinatal calves (calves weighing less than 90 kg), 34 respondents (18%) indicated that stiffness/altered gait and recumbency was observed more than half the time following surgical castration (Figure 10). In contrast, 53 respondents (28%) indicated that swelling was observed more than half the time following non-surgical castration (Figure 11). This was significantly more than was reported for surgical castration (p = 0.0023). Furthermore, 50 respondents (26%) indicated that they observed recumbency greater than half the time following non-surgical castration which was significantly more than was reported for surgical castration (35; 18%) (p = 0.0002). However, these results should be interpreted with caution because respondents indicated that the majority of non-surgical castrations in the perinatal calves were performed by producers.
More respondents indicated that swelling, stiffness and recumbency occurred greater than half the time following both surgical and non-surgical castration in light weight calves (90-270 kg) compared with perinatal calves (p < 0.0001) (Figure 12). Furthermore, significantly more respondents reported hemorrhage more than half the time in light weight calves (14; 7%) following surgical castration compared with perinatal calves (6; 3%) (p < 0.0001). Comparison between non-surgical and surgical castration methods in light weight calves suggested that significantly more respondents believed that non-surgical methods produced swelling (45; 24% compared with 31; 16%); recumbency (47; 25% compared with 28; 15%); stiffness (44; 23% compared with 28; 15%) and anorexia (19; 10% compared with 12; 6%) (p < 0.0001) over half the time compared with surgical methods (Figure 13). Participants also associated wound infection more frequently with non-surgical castration (p = 0.02).
More respondents indicated that swelling, stiffness and recumbency occurred more than half the time following both surgical and non-surgical castration in heavy weight calves (>270 kg) compared with light weight calves (p < 0.0001). As was the case with perinatal and light weight calves, veterinarians reported that non-surgical led to more frequent swelling, recumbency and stiffness in heavier calves (>270 kg) than surgical castration (p < 0.0001) (Figures 14 and 15). Hemorrhage was again more commonly observed following surgical castration in this weight class. Respondents also associated anorexia more with non-surgical castration rather than surgical castration.
Ancillary management practices performed at the time of castration
The results of the responses to questions about surgical practices, disease prevention, pain management and ancillary husbandry practices performed at the time of castration are summarized in Figure 16.
Surgical practices
Sixty-two percent (118) of respondents indicated that they did not wear surgical gloves during castration with 19% (35) indicating that they only wear gloves during surgical castration. Seventy-seven percent of respondents (142) indicated that they do not routinely disinfect the scrotum prior to castration with 23% (42) indicating that they only disinfect the scrotum prior to surgical castration. Chlorhexidine (29; 15%) and iodine (25; 13%) were the most commonly used disinfectants prior to castration. Eighty-five percent of respondents (161) indicated that they routinely disinfect equipment between calves. Sixty percent (111) indicated that equipment was only disinfected after surgical castration with the remaining 25% (50) indicating that they disinfect equipment between animals after both surgical and non-surgical castration.
Tetanus prophylaxis
Fifty-two percent of respondents (98) indicate that they routinely used tetanus toxoid injection at the time of castration; 4% (7) indicated that they only provide prophylaxis prior to surgical castration, 34% (65) prior to non-surgical castration and 14% (26) prior to both surgical and non-surgical castration. Only 28% of respondents (52) routinely administered tetanus toxoid to perinatal calves, 48% (90) to light weight calves and 54% (102) to heavy weight calves. Only 12% of respondents (22) routinely used tetanus antitoxin at the time of castration with 6% (12) indicating that this was for non-surgical procedures only. Only 9% of the total respondents (16) routinely administered tetanus toxoid to perinatal calves, 11% (20) to light weight calves and 15% (28) to heavy weight calves.
Antimicrobial administration
Fifty-four percent of respondents (103) indicated that they routinely administer antimicrobials at the time of castration. Of these, 43% (82) indicated that they provide antimicrobial prophylaxis only prior to surgical castration with 11% (21) administering antimicrobials prior to both surgical and non-surgical castration. Sub-classification revealed that 14% (27) did not administer antimicrobials prior to perinatal calf castration and 28 respondents (15%) administered antimicrobials to only 1--10% of perinatal calves. In contrast, 34 respondents (18%) administered antimicrobial prophylaxis routinely to 91 - 100% of light weight calves with 34 respondents (18%) routinely administering antimicrobials to 91 - 100% of castrated heavy weight calves. Beta-lactams were the most common antimicrobial class administered prophylactically by 87 respondents (46%) followed by tetracyclines (42; 22%), macrolides (7; 4%) and florfenicol (6; 3%).
Local anesthetic use
Twenty-two percent of respondents (42) indicated that they routinely administer local anesthetics (eg. lidocaine) prior to castration. Eighty-three percent of these (35/42) provided local anesthesia prior to surgical castration only with the remaining 17% (7/42) administering local anesthesia before surgical and non-surgical castration. Fifty-seven percent (24/42) that indicated they provide local anesthesia did not administer it to perinatal calves. Twenty-four percent of these (10/42) indicated that they either did not provide local anesthesia or they did only to 1-10% of light weight calves with 14% (6/42) indicating that they routinely administered local anesthetics to 91-100% of light weight calves. In contrast, 26% of respondents that administered local anesthetics prior to castration (11/42) did so in 91-100% of castrated heavy weight calves.
Thirty-eight percent of respondents (16/42) that used local anesthesia prior to castration administered a total volume of 5-10 ml of lidocaine with 38% (16/42) using 2-5 ml and 9% (4/42) using >10 ml. Sixty-four percent of respondents (27/42) indicated that they allowed 0-5 minutes to elapse between lidocaine administration and castration with the remaining 36% indicating that they waited 5-10 minutes for anesthesia to take effect.
Systemic analgesic use
Twenty-one percent of respondents (40) indicated that they administer systemic analgesics at the time of castration. Forty-five percent of these (18/40) administered analgesia after surgical castration only, with the remaining 55% (22/40) following both surgical and non-surgical castration. Thirty-three percent of respondents (13/40) that used analgesics indicated that they did not administer these to perinatal calves with 35% (14/40) indicating that they used analgesics in only 1-10% of cases. In contrast, 43% of respondents (17/40) that use analgesics administered these to 1-10% of light weight calves with 13% (5/40) indicating that they routinely administered analgesics to 91-100% of cases. Similarly, 30% of respondents (12/40) that use analgesics administered these to 1-10% of heavy weight calves with 28% (11/40) indicating that they routinely administered analgesics to 91-100% of cases. Flunixin meglumine was the most common systemic analgesic administered by 38 respondents (95%). This was followed by alpha-2 agonists (13; 33%), opioids (4; 10%) and aspirin (4; 10%).
Vaccination
Ninety percent of respondents (171) indicated that they vaccinate cattle at the time of castration. Clostridial vaccines were the most commonly administered vaccines (140/171; 82%) to perinatal calves followed by modified live multivalent viral vaccines against bovine respiratory disease (BRD) pathogens (99/171; 58%). A smaller number of these respondents indicated that they also vaccinate against Mannheimia haemolytica and Histophilus somni (33/171; 19%) and use killed multivalent viral vaccines against BRD (32/171; 19%) in perinatal calves. Similarly, in light weight calves, clostridial vaccines (156/171; 91%), modified live viral BRD vaccines (138/171; 81%), Mannheimia haemolytica and Histophilus somni vaccines (64/171; 37%) and killed viral BRD vaccines (41/171; 24%) were the most commonly used. This was also the case in heavy weight calves with clostridial vaccines (139/171; 81%) and modified live viral BRD vaccines (130/171; 76%) being the most prevalent.
Dehorning practices
Ninety-two percent of respondents (176) indicated that they dehorn calves at the time of castration. In perinatal calves, horn removal with cutting blades (Barnes dehorner) (99; 52%), disbudding with an electric disbudding device (83; 43%), gas disbudding (44; 23%) and caustic paste disbudding (12; 6%) were the most common dehorning methods used (Figure 17). In light weight (153; 81%) and heavy weight (135; 71%) horn removal with cutting blades (Barnes dehorner) were the most common dehorning methods.
Other management practices
In perinatal calves, weaning (8; 4%), hormone implanting (66; 35%), tagging (97; 51%), freeze branding (4; 2%) and hot iron branding (46; 24%) were also performed at the time of castration (Figure 16). These procedures were performed more frequently in older, light weight calves with weaning (60; 32%), hormone implanting (104; 35%), ear tagging (92; 48%), freeze branding (5; 2%) and hot iron branding (39; 21%) reportedly also performed at the time of castration. This is similar to the situation in heavy weight calves where weaning (57; 30%), hormone implanting (99; 52%), tagging (82; 43%), freeze branding (5; 2%) and hot iron branding (33; 17%) were also performed at the time of castration.
Additional comments
Nine respondents provided additional comments indicating that producers were primarily involved in castrating calves in their practice areas. Four respondents indicated that the absence of FDA-approved analgesic compounds and the cost associated with analgesia was an impediment to widespread use at the time of castration. These respondents also indicated that producers were resistant to incurring the additional cost associated with providing analgesia routinely at castration. One respondent indicated that the survey was too long.