Understanding mammary activity in red-rumped agouti and implications for management and conservation of this Neotropical game species

Abstract

The red-rumped agouti (Dasyprocta leporina) produces precocial young and is the most hunted and farmed game species in several Neotropical countries. An understanding of the reproductive biology, including the relationship between litter size and teat functionality is crucial for conservation management of this animal. In precocial mammals, as the red-rumped agouti, maintaining maternal contact to learn foraging patterns may be more important than the energy demands and nutritional constraints during lactation and suckling may not play important roles when compared to altricial mammals. Therefore, in this study we evaluated the relationship between mammary functionality with litter size, litter birth weight, and parturition number in captive red-rumped agouti. Functionality was assessed by manual palpation of teats from un-sedated females (N=43). We compared the average birth weight of all newborns, male newborns and female newborns among agoutis with different litter sizes and different parturitions by one way ANOVA's, while Pearson's Chi-squared tests were used to detect relationships between teat functionality, litter size, and parturition number. Parturition number had no effect on the mean birth weight of all young (F 0.822 , P > 0.05), male young (F 0.80 , P > 0.05) or female young (F 0.66 , P > 0.05) in the litters. We found (i) no significant correlations (P > 0.05) between teat functionality and litter size and (ii) no significant correlations (P > 0.05) between teat functionality and parturition number. This suggests that whilst all teat pairs were functional, functionality was a poor indicator of litter size; suggesting that female agouti young may not have a high dependency on maternal nutrition; an possible evolutionary strategy resulting in large wild populations; hence its popularity as a game species.Keywords: animal reproduction, agouti, Dasyprocta leporina, teat functionality, weaning age. Compreendendo a atividade mamária na cutia e as implicações para o manejo e a conservação desta espécie cinegética Neotropical ResumoA cutia (Dasyprocta leporina) produz filhotes precoces, e é a espécie cinegética mais caçada e criada em muitos países neotropicais. O entendimento da biologia reprodutiva, incluindo a relação entre o tamanho da ninhada e a funcionalidade das glândulas mamárias é crucial para o manejo conservacionista deste animal. Nos mamíferos precoces, como a cutia, manter o contato materno para a aprendizagem de padrões de forrageamento pode ser mais importante do que a demanda energética e de restrição nutricional durante a lactação, e a amamentação pode não desempenhar um papel importante quando comparado aos mamíferos altriciais. Portanto, neste estudo nós avaliamos a relação entre a funcionalidade mamária com o tamanho da ninhada, peso ao nascer da ninhada, e o número de partos em cutias cativas. A funcionalidade foi avaliada por meio de palpação manual das glândulas mamárias em fêmeas não sedadas (N=43). Nós comparamos a média do peso ao nascer de todos os recém-nascidos, macho ...

Mammary Diseases in a Captive Reared Agouti (Dasyprocta leporina) in Trinidad

“…The agouti ( D. leporina ) has four pairs of mammary teats; one cranial teat pair, two abdominal teat pairs and one caudal teat pair. In captivity, all eight mammary teats were reported to be functional with females producing 1–3 offspring per parturition [ 3 , 28 ]. In this study, the agouti produced one offspring that died within a week after parturition.…”

Reproductive Technologies Used in Female Neo-Tropical Hystricomorphic Rodents

“…At the top of the clitoris were two hard, protruding lateral keratinized spicules, between which the urethra, with an opening to the urethral ostium, was located. It should be noted that the female had four pairs of functional mammary glands (cranial teat pair, two sets of abdominal teat pairs, and caudal teat pair) [ 27 ].…”

“…These rodents have a gestation period of 103–104 days [ 19 , 23 ], with an average litter size of 1.7–2 precocial young [ 24 , 25 , 26 ]. Single birth weights were higher than multiple ones with offspring weighing 209–310 g [ 26 , 27 ]. The interval between two young being birthed was approximately one hour, with the female squatting while exhibiting contractions.…”

Morphology of the stifle in agouti (Dasyprocta prymnolopha, Wagler 1831)

“…This species has a maximum length of 50 cm, is approximately 23 cm high, and weighs between 2 and 4 kg (Carreiro et al, 2018; Singh, Singh, & Garcia, 2018). It feeds on fruits and seeds with occasional consumption of insects, fibers, and leaves.…”