Savaging
Savaging is a term used in the study of
Environmental factors
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.[1] Another environmental factor that has been examined is the amount of time spent by humans in the farrowing room. Decreased disturbance of the sows by human intrusions during farrowing has indicated a decrease in savaging behavior.[3] 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.[4] 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.[4] A study by Gonyou and Harris found that increasing light exposure in the farrowing rooms to 16–24 hours per day decreased piglet deaths due to savaging. In the same study, it was found that increased piglet vocalizations around the time of farrowing did not help gilts adjust to the sudden presence of piglets, and instead was shown to increase the amount of piglet-directed aggression.[5] The influence of nest-building and nest-building materials has been shown to influence negative piglet-directed communication.[6] Access to materials as well as higher quality materials such as straw decreased the amount of negative communication between sows and piglets.[6] Similarly, limited space and poor pen conditions have been shown to increase the amount of piglet-directed aggression.[6] Pigs are social animals and a female's social support network can play an important role in postpartum piglet-directed aggression. Free ranging pigs form sounders, or small social units, give young gilts the opportunity to observe gestation and parturition and exposing them to normal maternal behavior.[7] 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.[7] 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.[4][6][7] Some studies have found evidence of increased savaging rates in larger litter sizes as well.[1]
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.
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.[8] 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.[5] 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.[6] 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.[7] 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.[4]
Savaging in other species
Savaging of offspring by the biological mother has been reported in multiple species including farmed
See also
- List of abnormal behaviours in animals
- Infanticide (zoology)
- Pigs
- Ethology
- Zoology
- Aggression
- Cannibalism
References
- ^ doi:10.4141/A02-111.
- doi:10.1016/j.applanim.2007.02.008.)
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: CS1 maint: multiple names: authors list (link - doi:10.4141/A02-001.
- ^ .
- ^ ISSN 0008-3984.
- ^ S2CID 201405193.
- ^ PMID 29485618.
- ^ .
- S2CID 23767562. Archived from the original(PDF) on 2017-12-01.
- ^ S2CID 26335169.
- ^ .
- .
External links
- Prairie Swine 2001 article about savaging.
- Description Archived 2006-11-24 at the Wayback Machine and details at ThePigSite.com