ABSTRACT
Among mammals, alloparental care can be influenced by hormones as well as by previous experience and sensory stimuli from the infants, such as sight and sound, smell, and physical contact with the infant. To determine the responsiveness of common marmoset (Callithrix jacchus) nonreproductive females and males with and without previous experience in caretaking to infant sensory cues, we exposed 12 females and 12 males to vocalization recordings for 10 min under two conditions: (1) exposure to adult conspecific vocalization recordings, and (2) exposure to infant vocalization recordings. We recorded the frequency of approach toward the sound source, the time spent near it and locomotion frequency of males and females in the cage under both conditions. Blood samples were collected after each test for cortisol measuring by EIA method. The infant vocalization affects the behavioral and hormonal responses of males and females of common marmosets. The animals approached and spent more time near the sound source and showed an increase in locomotion during infant vocalization exposure compared to the adult vocalization. However, there was no significant difference in the behavioral response of animals when previous experience and the sex were taken into account. In both sexes, cortisol levels were significantly higher following infant vocalization exposure compared to the adult vocalization. These findings suggest that the infant vocalization appears to be an effective cue that facilitates the approach of the caregiver and maintaining their responsiveness and that the cortisol seems to be important for alertness to sensory stimuli, modulating their motivation to interact with the infant.
Subject(s)
Callithrix , Smell , Vocalization, Animal , Animals , Cues , Female , Hydrocortisone , Immunoenzyme Techniques , MaleABSTRACT
Summary Background: the allonursing effect on daily milk production (DMP) and total milk production (TMP) has been little explored. Objective: to evaluate the effect of nursing behavior, sex of the calf and parity order (PO) on DMP and TMP of buffalo cows. Methods: 35 buffalo cows and their calves were evaluated. Observations were performed monthly (three consecutive days) from May to November. The nursing behavior was characterized as: 1) Isolated filial nursing (IFN); 2) Collective filial nursing (CFN), and 3) Non-filial nursing (NFN). Cows were grouped into four categories to study the effects of nursing behavior on DMP and TMP: 1) Non-permissive (NP); 2) Filial permissive (FP); 3) Filial and collective filial permissive (FCFP); and 4) Filial, collective filial and non-filial permissive (FCFNFP). DMP was recorded three days per month and TMP was calculated as DMP*270 days of lactation. Results: sex of the calf and second and third PO had an effect on nursing behavior (p<0.05). DMP and TMP were significantly affected by calf sex and nursing behavior (p<0.05). PO had no effect on DMP and TMP. Conclusion: our results suggest that nursing behavior is associated with milk production in buffalo cows. Buffalo cows that accept all types of nursing behavior were had the highest DMP and TMP. Sex of the calf influenced nursing behavior, DMP, and TMP, so that buffalo cows with male calves displayed more frequent allonursing behavior and yielded more milk.
Resumen Antecedentes: el comportamiento del alo-amamantamiento sobre la producción diaria de leche (DMP) y producción total de leche (TMP) ha sido poco explorado. Objetivo: evaluar el efecto del comportamiento de amamantamiento, el sexo del becerro y el orden de parto (PO) en la DMP y TMP de bufalas. Métodos: se evaluaron 35 hembras bufalinas y sus crías. Las observaciones se realizaron mensualmente (durante tres días consecutivos) entre mayo y noviembre. El comportamiento de amamantamiento se caracterizó como: 1) Amamantamiento filial aislado (IFN); 2) Amamantamiento filial colectivo (CFN) y 3) Amamantamiento no filial (NFN). Para evaluar los efectos del comportamiento de amamantamiento en la DMP y TMP, las vacas fueron agrupadas en 4 categorías: 1) No permisivas (NP); 2) Permisiva filial (FP); 3) Permisiva filial y colectiva filial (FCFP) y 4) Permisiva filial, colectiva filial y no colectiva (FCFNFP). La DMP se registró tres días por mes, y la TMP fue calculada como DMP*270 días de lactancia. Resultados: el sexo del becerro, el segundo y tercer PO tuvieron efecto sobre el comportamiento de amamantamiento (p<0.05). La DMP y la TMP se afectaron significativamente por el sexo del becerro y el comportamiento de amamantamiento (p<0.05). El PO no tuvo efecto sobre la DMP y la TMP. Conclusiones: nuestros resultados sugieren que el comportamiento de amamantamiento está asociado a la producción de leche en vacas bubalinas. Las bufalas permisivas a todo tipo de amamantamiento presentaron mayor DMP y TMP. El sexo del becerro influyó en el comportamiento de amamantamiento, en la DMP y en la TMP. Las bufalas con becerro macho presentaron comportamiento de alo-amamantamiento más frecuente y produjeron mayor cantidad de leche.
Resumo Antecedentes: o comportamento de alo-amamentação sobre a produção de leite diária (DMP) e produção de leite total (TMP) tem sido pouco explorado. Objetivo: avaliar o efeito do comportamento de amamentação, sexo dos bezerros e ordem de parto (PO) na DMP e TMP em vacas bubalinas. Métodos: trinta e cinco fêmeas e suas crias foram avaliadas no estudo. As observações foram realizadas mensalmente (três dias consecutivos) de maio a novembro. O comportamento de amamentação foi caracterizado como 1) amamentação filial isolada (IFN); 2) amamentação coletiva filial (CFN) e 3) amamentação não filial (NFN). Para avaliar os efeitos do comportamento da amamentação na DMP e TMP, as vacas bubalinas foram agrupadas em 4 categorias: 1) não permissiva (NP); 2) permissiva filial (FP); 3) permissiva filial e coletiva filial (FCFP) e 4) permissiva filial, coletiva filial e não filial (FCFNFP). A DMP foi registrada três dias para cada mês e a TMP foi calculada como DMP*270 dias de lactação. Resultados: o sexo dos bezerros, a segunda e terceira PO tiveram efeitos no comportamento de amamentação (p<0.05). A DMP e TMP foram significativamente afetadas pelo sexo dos bezerros e comportamento de amamentação (p<0.05). A PO não teve efeito na DMP e TMP. Conclusões: nossos resultados sugerem que o comportamento de amamentação estão associados a produção de leite em vacas bubalinas. As vacas bubalinas que são permissíveis a todos os tipos de amamentações foram aquelas com maior DMP e TMP. O sexo dos bezerros influenciou o comportamento de amamentação, DMP e TMP, sendo que as vacas bubalinas que possuem bezerros machos apresentaram frequente comportamento de alo-amamentação e produziram maiores quantidades de leite.
ABSTRACT
Parental care in mammals is influenced by sensory stimuli from infants, such as sight and sound, and by changes in the hormone levels of caretakers. To determine the responsiveness of common marmoset (Callithrix jacchus) adult males with and without previous experience in caretaking to newborn sensory cues, we exposed twelve males to infant vocalization recordings and assessed their hormonal and behavioral responses. Males were placed in the testing cage for 10 min under two conditions: (a) control condition (exposure to adult conspecific vocalization recordings), and (b) experimental condition (exposure to infant vocalization recordings). We recorded the frequency of approach towards the sound source, the time spent near it and locomotion frequency of males in the cage under both conditions. Blood samples were collected after each test for cortisol, measured by the enzyme immunoassay method. Infant vocalization affects the behavioral and hormonal responses of non-reproductive male common marmosets. All males approached and spent more time near the sound source and showed an increase in locomotion during infant vocalization exposure compared to the control condition. Successive exposure to infant vocalization increased the responsiveness in inexperienced males. Cortisol levels were significantly higher following infant vocalization exposure compared to the control condition. These findings support the assumption that sound stimuli from the newborn are critical in initiating and maintaining caretaker responsiveness and that cortisol seems to be important for alertness to sensory stimuli, modulating their motivation to interact with infants.