Allonursing in Wild and Farm Animals: Biological and Physiological Foundations and Explanatory Hypotheses

Abstract

The dams of gregarious animals must develop a close bond with their newborns to provide them with maternal care, including protection against predators, immunological transference, and nutrition. Even though lactation demands high energy expenditures, behaviors known as allonursing (the nursing of non-descendant infants) and allosuckling (suckling from any female other than the mother) have been reported in various species of wild or domestic, and terrestrial or aquatic animals. These behaviors seem to be elements of a multifactorial strategy, since reports suggest that they depend on the following: species, living conditions, social stability, and kinship relations, among other group factors. Despite their potential benefits, allonursing and allosuckling can place the health and welfare of both non-filial dams and alien offspring at risk, as it augments the probability of pathogen transmission. This review aims to analyze the biological and physiological foundations and bioenergetic costs of these behaviors, analyzing the individual and collective advantages and disadvantages for the dams’ own offspring(s) and alien neonate(s). We also include information on the animal species in which these behaviors occur and their implications on animal welfare.

Handling and Physiological Aspects of the Dual-Purpose Water Buffalo Production System in the Mexican Humid Tropics

“…Several theories have been proposed to explain why these dams allow non-filial calves to suckle and, in the other direction, why calves seek to obtain milk from other females in the herd [ 62 ]. Some theories hold that allonursing reflects the female buffalo’s maternal instincts and that factors such as kinship, reciprocity, parental care, social benefits, milk-dumping, and misdirected care may be involved [ 98 , 99 ]. Other proposals center on the newborn’s efforts to satisfy its requirements, emphasizing phenomena such as milk theft, compensation, immunological benefits, and better nutrition [ 99 ].…”

“…As a result of these studies, allonursing in water buffaloes is not thought to constitute a factor of natural or artificial selection of great significance [ 95 ]. However, when it happens, it may have benefits for both the dam and the newborn, such as increased milk production or better nutrition, though its implementation and the risks involved depend largely on the goals of the production system and the sanitary and innocuity measures applied [ 99 ] ( Figure 12 ).…”

The Neurobiology of Behavior and Its Applicability for Animal Welfare: A Review

“…When social bonds are affected by death or separation, the panic system generates negative states marked by distress and expressed mainly through vocalizations [ 49 ]. The initial affective bond in all mammals is the mother-infant relation that begins at birth [ 86 ]. A warm, secure maternal relation generates secure, emotionally stable young.…”

Dairy Buffalo Behavior: Calving, Imprinting and Allosuckling

“…Water buffalo are a gregarious species with large groups; however, a buffalo cow isolates itself from the herd in order to look for a site that it considers protected [ 42 ]. This behavior, similar to cattle, helps to insure the survival of this species [ 30 ] and to guarantee two events after calving: imprinting and lactation [ 43 ]. Therefore, all these events can be considered as indicators that can be used to recognize the expected course of calving.…”

“…Since one of the objectives of the selective care of ruminants is to provide the offspring with alternatives to decrease the mortality rate, calculated as 15.89% [ 23 ], 19.5% [ 24 ], and as high as 84% during the first month of the calf’s life [ 25 ], bonding is also related to early standing (preventing predator attacks or heat loss) [ 26 ], searching for the udder for prompt colostrum intake [ 27 ], and passive immunity transfer through feeding [ 28 , 29 ]. Moreover, although imprinting represents “exclusive maternal care for a biological calf”, in water buffalo, allosuckling and allonursing, known as the feeding and care of non-filial offspring, are regular practices observed in dairy farms [ 30 ]. Allonursing, although considered as a common event in other wild and domestic ruminants [ 31 , 32 ], has not been reported in numerous cases among water buffalo.…”