Savaging

There exist multiple environmental factors that increase the rate of savaging demonstrated by pigs. It has been shown that human attitudes and behaviour can affect the behaviour of domestic pigs. For example, annoyance and transmission of emotions can occur in gilts and sows when a new worker enters the farrowing rooms and makes excessive noise, does not feed the animals in a timely manner and/or is frustrated/annoyed. Research suggests that maternal behaviour may improve when workers and pigs are familiar with their environment and on a set schedule. Increased aggression in sows is not always directed towards piglets as sows were just as likely to attack inanimate objects (bricks) as they were to attack piglets. As indicated by the fact that aggressive behaviour can be predicted before parturition begins as indicated by pre-farrowing restlessness and the fact that aggression was directed towards both piglets and inanimate objects, sow aggression is not a result of a response to the sudden appearance of piglets. The influence of nest-building and nest-building materials has been shown to influence negative piglet-directed communication. Access to materials as well as higher quality materials such as straw decreased the amount of negative communication between sows and piglets. Gilts raised in commercial pens are not exposed to piglets nor expecting mothers and thus are not aware of what to expect during gestation and parturition and are not aware of how to raise piglets. In support of this theory, there is strong evidence that parity influences the amount of savaging and piglet-directed aggression displayed among primiparous gilts versus muiltiparous sows. Some studies have found evidence of increased savaging rates in larger litter sizes as well. ==Genetic and biochemical factors==

It has been proposed that the degree of aggressive behaviour displayed prior to farrowing cycles by sows and gilts predicts whether the offspring will be savaged and to what extent. Evidence has also been found that savaging sows may be genetically less likely to crush piglets, which lends to the existing research supporting that savaging sows can be competent mothers. Levels of steroid hormones such as estrogens and progestogens around farrowing correspond with levels of maternal aggression. ==Preventive measures==

The pig industry is investing in research regarding savaging behaviours in hopes to diminish the losses they face when gilts and sows commit infanticide. Sedation techniques following birth have prevented savaging; however, in many cases, the onset of aggression is merely delayed. Light exposure has the potential to prevent or limit savaging in pigs as pigs exposed to light for 16–24 hours a day in farrowing room experienced a decrease in the prevalence of savaging. The industry has also attempted to avoid savaging behavior by limiting reproduction in gilts and sows that have previously savaged their offspring. Efforts to eliminate the behavior include additional care and attention to the mother pig during her farrowing cycles. Access to nesting materials such as straw and peat as well as sufficient pen space and conditions around the time of farrowing are also important factors in limiting savaging and piglet-directed aggression in pigs. Increased social interactions and support from sounders also reduces the rate of savaging and piglet-directed aggression, indicating that would be beneficial to raise pigs in a free-roaming environment, but further research is needed to indicate if this would be economically feasible. Restlessness and aggressive behaviour prior to farrowing have been shown to predict savaging and piglet-directed aggression following farrowing, allowing for the identification of individuals prone to savaging and subsequent treatment, precautionary measures, or supervision. ==Savaging in other species==

Savaging of offspring by the biological mother has been reported in multiple species including farmed silver foxes, farmed wild boar and domestic breeds of farmed pigs. Syrian hamsters are more likely to savage and successfully kill female offspring compared to male offspring and will cannibalize more offspring if metabolic fuels from food or fat stores are insufficient. Silver foxes have been shown to engage in savaging behaviour followed by infanticide and cannibalism of the offspring. Wild boars have shown aggression after parturition towards their offspring; however, they have lower infanticide rates than other species. ==See also==