Castration Methods

All methods of castration are typically characterized by the physical, chemical or hormonal damage of the testicles. Most common are the physical methods, which, according to Stafford and Mellor (2005), can be subdivided into methods in which the testicles are removed surgically by using a scalpel or knife, are damaged irreparably or are killed by elimination of its blood supply. The latter usually is performed by using a Burdizzo clamp, a latex band (Banding method) or elastrator rubber rings.

In surgical castration, the distal scrotum is incised or cut off, than the testicles are removed due to dissection of the spermatic cords or by pulling the cords until they break (Stafford and Mellor, 2005).

The principles of application and function of the latex band and the elastrator rubber rings are similar. Using a special applicator, the rings or bands are placed on the neck of the scrotum, above the testicles and as close as possible to them. By doing this, a better blood-vessel constriction is caused and more of the scrotum is left. Because the rubber ring or band cuts the blood supply to the testicles, the testicles and scrotum degenerate after several weeks and fall off. On calves with larger testicles it is more difficult to apply an elastrator rubber ring so as to be effectively, therefore on these calves often the Banding method is performed.

A Burdizzo clamp is made of high quality steel and has large blunt-jawed pincers. The proper application of the Burdizzo clamp causes the crushing of the spermatic cords and associated blood vessels within the scrotum, while the scrotum remains intact. Therefore there is no open wound on the scrotum, that can become infected, what is the major advantage of this method of surgical castration. Burdizzo castration resulted to an atrophy of the testicles.

Molony et al. (1995) observed the swelling of the castration site after Burdizzo castration to increase slightly over 2 d, from a low baseline level on d 1. However, afterwards the swelling decreased to disappear within 15 d. Ting et al. (2005) examined the effect of calf age (1.5, 2.5, 3.5, 4.5 and 5.5 months) on different responses to Burdizzo castration and found physiological stress and inflammation caused by this castration method indicated reduced temperature differences between the core body and scrotal skin. The authors reported also, that scrotal circumferences increased in all calves on d 1 and d 7 following Burdizzo castration, while there was a markedly greater increase in scrotal circumferences in the 5.5-months old castrates compared to the sham castrated intact bulls of the same age. Similar, Murata (1997) found that the scrotums of 3-4 months old calves rapidly became oedematous after castration and remained swollen during 7 days following castration. In 12-months old steers castrated by using Burdizzo method, on d 14 after castration, greater scrotal latitudinal and longitudinal circumferences were observed than in the intact males of the control group (Pang et al., 2008).

About 120 days after Burdizzo castration, testicles found in Holsteins, aged 8 months at castration, had an average weight of nearly 170 g, while the non-castrated control animals a significant higher testicles weight of 520 g (Mach et al., 2008). In that study, 23% of the castrates (total n=50) did not have a complete testicular atrophy.

Also other experimental studies as well as producers` experience indicate, that the Burdizzo castration method can fail to work. Such failure is often reported to be the major disadvantage of Burdizzo castration, therefore a high level of operator skill and experience is required to complete the usage of the Burdizzo clamp successfully.

The popularity of the methods used for cattle castration varies between management systems and countries (Stafford and Mellor, 2005).

Stafford et al. (2000) published the findings of a survey to identify which castration methods are performed on farms in New Zealand, and at which calf age castration is conducted.

According to this survey, 85% of the 2,825 respondents used a rubber ring, 18% castrated surgically, and less than 0.9% used a clamp (Burdizzo castration). Furthermore, 93% of the calves had an age up to 3 months (2.2 months on average), when castrated by the rubber ring method. The surgical castration was performed at an average calf age of 4.3 months, whereas 43% of the calves were castrated during the first 3 months of their life and 39% of the calves were older than 3 months.

A similar survey was directed to cattle farmers in the United Kingdom (Kent et al., 1996).

According to their information, the Burdizzo castration was the most performed method (43%), followed by surgical castration (39%) and the castration by using a rubber ring (32%).

Furthermore, 10% of the respondents in this survey declared to use more than one castration method. Kent et al. (1996) reported that the surgical castration was most preferred to castrate older calves and 43% of all surgical castration procedures were performed by a veterinarian.

67% of the farmers, who castrated using the Burdizzo method, crushed the cords twice. The majority of producers placed the Burdizzo clamp for the second crush properly distal to the first one.

The results of a survey regarding castration methods directed to bovine veterinarians in the United States, were reported by Coetzee et al. (2010). Over 83% of all respondents (189 veterinarians) quoted that in the practices, the famers were primarily responsible for castration of perinatal calves (BW<90 kg), while 68% of the respondents reported that heavy calves (BW>270 kg) were castrated by a veterinarian. The most frequently used method in perinatal calves was the surgical castration with a scalpel (57%), the most common non-surgical castration was the method using a rubber ring (44%), followed by Banding (22%) and the Burdizzo clamp (21%). Also light calves (BW 90 to 270 kg) were mostly castrated by the surgical method using the scalpel (59%). In light calves, Banding (45%) was the most common non-surgical method, followed by Burdizzo (22%) and elastrator rubber rings (15%).

Likewise, the most common method used in heavier calves (BW<270 kg) was the scalpel-used surgical castration (53%), while Banding (51%) and Burdizzo castration (15%) were the two most common non-surgical castration methods.

There is an amount of studies published that examined the effect of the age at castration on the calf. As mentioned before, the recommended ages often vary between the castration methods. It was not the objective of the present thesis to examine different castration ages, therefore findings concerning castration age are not described at this point.