Behavioral aspects of electronic bull separation and mate allocation in multiple-sire mating paddocks1

Abstract

Controlling spatial positioning of cattle through use of electronic collars could provide new ways to farm under extensive conditions. This study examined the potential for bulls to be controlled during mating using mild electric shocks delivered through radio-controlled collars. Eighteen Belmont Red bulls were fitted with collars containing the Global Positioning System and that were able to emit a mild electric shock (500 mW) at the top of the neck behind the poll. Eighteen Belmont Red cows were fitted with Global Positioning System collars only. The experiment was replicated 3 times in 3 paddocks. Each paddock contained 2 bulls and 1 cow in induced estrus. On d 1, the bulls were either assigned to the cow or not assigned to the cow, and on d 2, the assignments were reversed, and bulls received the other treatment using a new cow. Treatments were applied for 2 h on each day. The nonassigned bull received a mild electric shock on approach to either the cow or to a bull, whereas the assigned bull received a mild electric shock on approach to the other bull only. The electric shock was applied when the bulls were within approximately 10 m and moving toward the nonallowed animal. The electric shock was terminated when the animal responded by stopping movement toward the nonallowed animal. In the first 10 min, nonassigned bulls spent less time within 5 m of the cow (P = 0.03) than assigned bulls. Assigned bulls spent more time close to the cow during the entire 120 min on d 1 than on d 2 (P = 0.014). On d 1, the assigned bulls moved more toward the cow and the nonassigned bull than they did on d 2 (P = 0.02). Assigned bulls displayed more sexual behaviors than nonassigned bulls (P = 0.004). Nonassigned bulls were sometimes observed not to approach the cow despite a change in its location. This suggests that the bull associated the electric shock with the cow and not with the location in which it received the electric shock. Instances were observed in which the cow pursued the nonassigned bull, in which case the bull did not receive an electric shock, and this may reflect the preference of the cow. This study demonstrated that bulls can be separated and prevented from approaching a cow in estrus using a mild electric shock. However, mate allocation was not completely successful due to the potential for cow preference for certain bulls.

Potential for using visual, auditory and olfactory cues to manage foraging behaviour and spatial distribution of rangeland livestock.

“…Most field studies to date have attempted to contain animals within a polygon that is either held stationary on the landscape [62,72] or that can be moved spatially and temporally across the landscape at various rates based on management goals [62,73]. In addition, virtual fencing has been successfully used to exclude selected bulls from a polygon that contained a cow in induced oestrus in Australia [71,74].…”

Spatiotemporal Cattle Data—A Plea for Protocol Standardization

“…Several researchers [30,48,57,[60][61][62][63][64][65][66][67] have adapted various models of Garmin GNSS products while the Magellan 315 has also been successfully used [68]. Several researchers have also used GNSS devices incorporated into electronic systems manufactured either by individuals [69] or university departments or research organizations with electronic/computer engineering expertise [16,[70][71][72][73][74][75][76][77][78][79][80][81]. For those who choose to use commercial equipment designed specifically for free-ranging animals, a number of companies are listed on the World Wide Web.…”

Virtual herding for flexible livestock management – a review

“…avoiding consumption of poisonous plants due to abrupt weather changes (Ralphs et al 1994), excluding foraging in the habitat of an endangered plant species (Warshauer and Jacobi 1982), protecting nesting bird habitat (Schultz 2010), designing fuel accumulation protocols for later burning (Diamond et al 2009), or controlling mating within a multi-sire herd (Lee et al 2008). These and other management issues could be addressed using VF to positively benefit vegetation (Stahlheber and D'Antonio 2013) as well as livestock.…”