Castration Defined
Castration of a bull (male) calf is the process of removal or destruction of the testicles. A steer is a castrated male calf raised for beef.
Reasons for Castration
Reasons given for castrating beef calves include to:
• stop the production of male hormones and semen
• historically, tame oxen for draught purposes
• prevent mating and reproduction after the age of puberty
• produce docile cattle that are easier to handle compared to bulls
• decrease aggressiveness, mounting activity, injuries, frequency of dark-cutting carcasses
• enhance on-farm safety for animals, producers and employees
• decrease costs associated with fencing and handling facilities compared to bulls
• avoid discounted price that packers pay for bull carcasses
• provide meat products of the quality consumers demand
Managing Male Calves
Owners may choose to manage male calves as intact bulls, castrate early, castrate late, or castrate plus implant with a growth stimulant implant. Which is selected will depend on the available handling facilities, the producer’s ability, the awareness of castration effects and the market available for the calves. Owners with guaranteed buyers willing to purchase green calves (horns and testicles in place), at the same price as processed calves (castrated and dehorned), might be advised to avoid these procedures. However, this buyer is very rare. Most purchasers of green calves are well aware of the risks associated with processing older calves and routinely bid less at auction. Recently, preconditioned (castrated, dehorned, vaccinated, bunk-adjusted) calves have brought a premium price at auctions.
Beef from Intact Bulls
There is a niche market for meat from young, intact bulls. The meat appeals to consumers who oppose castration for welfare reasons, desire meat produced without hormonal implants and prefer lean meat. Intact animals could be marketed one to two months earlier than castrates, which saves feed. Generally, consumers cannot detect differences in taste or tenderness between meat from steers and young bulls.
Immunisation as an alternative to castration
Researchers have shown immunisation/vaccination techniques will suppress male hormone production, reduce testicular development and result in steer-like carcasses. Growth and carcass characteristics of the immunized animals are similar to steers. Researchers also have found that castration by immunisation reduces aggressive behavior and is an effective alternative to surgical castration to manage bulls. However, there is no commercial product available for use. The need for repeated injections likely would discourage its adoption.
Castration Age
Castration at a young age minimizes hazards to the calf, the cow-calf producer and the feedlot owner. Hazards for calves and owners include:
• sickness or death of calves following castration at an older age
• decreased liveweight gains (productivity) in the weeks following castration of older calves
Many producers choose to castrate new-born calves because:
• techniques are easier for the operator
• castration is less stressful on newborn calves
• concerns for animal welfare related to castrating older calves
Although there is no evidence that pain differs between young and older calves, there is less risk with castration of young calves.
Testosterone Effect
Some producers delay castration to take advantage of the growth effects of the male hormone testosterone. Testosterone secretion commences between 3.5 and 5.5 months. The differences in liveweight gain of castrates and bulls are first apparent at four to five months.
Liveweight Gains
Studies of the effects of castration on liveweight gains have been reported from many countries. In general, there are no differences in liveweight gains for bulls and steers in the 21 days following castration at one month of age. However, there are significant differences with castration at older ages. During the 1980s and early 1990s, research focused on methods to recover weight lost by use of hormonal implants. In the past decade or so, research seems to focus on alleviation of pain and animal welfare issues associated with castration.
