Individual behavioral differences and health of golden-headed lion tamarins (Leontopithecus chrysomelas).

Individual behavioral differences may influence how animals cope with altered environments. Depending on their behavioral traits, individuals may thus vary in how their health is affected by environmental conditions. We investigated the relationship between individual behavior of free-living golden-headed lion tamarins (Leontopithecus chrysomelas) responding to a novel object (to assess exploration-avoidance), and their habitat use and health status (endoparasitism; clinical measures: biometric data, heart rate, respiratory frequency, and temperature; fecal glucocorticoid metabolites). As parasite transmission can be affected by individual variation in social contact and social grooming, we also evaluated whether more sociable individuals show higher endoparasite loads compared with less sociable animals. Four groups living in landscapes with different levels of human disturbance were investigated: two in degraded forest fragments in an agricultural matrix (DFAM-higher disturbance), and two in a cocoa agroforestry system (cabruca-lower disturbance) in the Atlantic forest of South Bahia, Brazil. Using a subjective ratings approach, highly correlated adjective descriptors were combined to produce z-score ratings of one derived variable ("confidence"), which was selected to characterize the tamarins' exploration/avoidance responses during a novel object test. The higher the confidence score, the longer female tamarins spent foraging for prey independent of landscape, and the greater their body mass independent of sex and landscape. Only DFAM individuals showed intestinal parasite infection. Endoparasite loads were positively correlated with the number of grooming partners, suggesting an association between social grooming and transmission (more groomers = more endoparasites). Individual behavior, including in a test situation, may thus have some predictive value for behavior in a free-living context, and for its health consequences.

Direct and indirect caecotrophy behaviour in paca (Cuniculus paca).

The colonic separation mechanism in lagomorphs and some rodents, associated with caecotrophy, serves to retain microbial protein. As tropical fruits have low protein concentrations, caecotrophy could be an important microbial protein source in frugivorous rodents such as the paca (Cuniculus paca). Due to conflicting reports on the occurrence of caecotrophy in this species, we obtained digestive tracts of three adult animals and observed the behaviour of four specimens maintained on a diet of a pelleted feed (P) and a supplemental mix of fruits and sweet potato (S, a source of structural fibre). In a Latin square design, P and S were both offered either in the morning (M) or in the afternoon (A), or with one item in the morning and the other in the afternoon (SP or PS). The paca's proximal colon is characterized by a distinct furrow typical for the colonic separation mechanism of hystricomorph rodents. Caecotrophy, both "direct" (from the anus) and "indirect" (from a pile of defecated faeces), was a regular component of the paca's behavioural repertoire, and caecotrophs contained more nitrogen and less fibre than hard faeces. Higher food intake led to less overall caecotrophy. With afternoon feeding of S, the onset of caecotrophy was delayed and the proportion of indirect caecotrophy increased, with hard faeces and caecotrophs often defecated together. No indirect caecotrophy occurred on treatment M. The results suggest that the time available after ingestion of structural fibre determines the efficiency of the colonic mechanism for the separation of hard faeces and caecotrophs.

Protein requirements of collared peccary (Pecari tajacu).

A nitrogen (N) balance digestion trial was conducted to determine the protein requirement of collared peccaries (Pecari tajacu). In a 4 × 4 Latin square design, four captive adult male peccaries were fed four isoenergy diets containing four different levels of N (11.7, 16.3, 22.8, and 26.7 g N/kg of dry matter-DM). After 15 days of adaptation, a total collection of feces and urine was carried out for five consecutive days. Regression analyses between N intake and N in feces and urine allowed to calculate the metabolic fecal nitrogen (MFN = 2.3 g N/kg of dry matter intake-DMI) and daily endogenous urinary N (EUN = 185 mg N/kg0.75). Likewise, by regression analyses between consumption of nitrogen and the nitrogen balance (NB = N ingested - N excreted, mg N/kg0.75), a daily requirement of 514 mg N/kg0.75 was calculated. Therefore, if food intake is unrestricted, collared peccaries require a minimum in their diet of about 5.4% crude protein on DM basis. These values are almost as low as those found for browsing and frugivorous wild ruminants, which reinforce the proposition that peccaries' digestive physiology is nearer to that of domestic and wild ruminants than domestic pigs. This relatively low protein requirement of collared peccary and its great ability to digest protein reveal the relevance of the forestomach for the species on nitrogen/protein metabolism and allow the use of diets with lower crude protein levels than the commercial ones used for the domestic pig, which reduces feed costs.

Nitrogen requirements of white-lipped peccary (Mammalia, Tayassuidae).

A study was conducted to determine the protein requirement of the white-lipped peccary (Tayassu pecari) performing a nitrogen (N) balance digestion trial. In a 4 × 4 Latin square design, four adult captive male peccaries were fed four isoenergetic diets containing four different levels of N (13.3, 19.2, 28.7, and 37.1 g N/kg dry matter). After 15 days of adaptation, the total collection of feces and urine was carried out for five consecutive days. By regression analysis between N intake and N in feces and urine, the metabolic fecal nitrogen (MFN = 3.1 g/kg of dry matter intake) and daily endogenous urinary N (EUN = 91.0 mg/kg(0.75) ) were determined. Likewise, by regression analyses between consumption of nitrogen and the nitrogen balance [NBN consumed-(fecal N + Urine N)] we estimated the daily requirement of 336.5 mgN/kg(0.75) . Therefore, if food intake is unrestricted, white-lipped peccaries require a minimum content in their diet of about 4.5% crude protein as percentage of dry diet. These values are similar to those found in frugivorous wild ruminants, which reinforces the proposition that peccaries have a digestive physiology nearer to that of ruminants than of domestic pigs. Furthermore, the low nutritional maintenance requirements for white-lipped peccary may explain how this species thrive in the Neo-tropical region eating predominantly palm-fruits that normally have low crude protein contents.

Production of multimodal signals to assert social dominance in white-lipped peccary (Tayassu pecari).

In this study we aimed to examine whether the 'redundancy' (a backup function to ensure the signal transmission) or 'multiple messages' (sensory communication system in combination) hypothesis would explain the function of multimodal communication of white-lipped peccaries (Tayassu pecari-WLPs). We also aimed to assess the individual factors (the social rank and sex of the sender) influencing the production of, and responses to unimodal and multimodal signals. We determined the social rank of 21 WLPs living in two captive groups and quantified the production of unimodal and multimodal signals when displaying threatening and submissive behaviors. WLPs most often produce multimodal signals independent of a previous unimodal signal failure, which suggests that they were adding more information, such as the sender's size, rather than merely increasing efficacy by engaging a different receiver's sensory channel. There was no effect of the sender's sex in the production of, and responses to, multimodal signals. However, the higher the sender's social rank, the greater the production of multimodal signals when WLPs were displaying threatening behaviors; whereas the lower the sender's social rank, the greater the production of multimodal signals when displaying submission behaviors. Multimodal signals elicited more non-aggressive responses than did the unimodal signals when displaying a threat. Moreover, the higher the sender's social rank, the greater the occurrence of non-aggressive responses to multimodal signals when displaying a threat; whereas the opposite occurred when displaying submission. Our findings support the 'multiple messages' hypothesis to explain the function of multimodal signaling during agonistic interactions in WLPs. Additionally, both the production of, and responses to, multimodal signals are related to the sender's social rank. These results allow us to suggest that the production of multimodal signals may have a key role in mitigating conflict and thus promoting group cohesion among white-lipped peccaries.

Responses to environmental enrichment are associated with personality characteristics in chestnut-bellied seed finches (Sporophila angolensis).

Environmental enrichment (EE) is used to promote natural behaviours in captive animals and may hold promise as a form of pre-release training, a strategy for improving coping skills of translocated birds. We investigated the use of EE to enhance foraging and vigilance behaviours of captive Sporophila angolensis, which may be related to post-release survival. We also evaluated whether consistent individual behavioural differences affected birds' responses to EE. We submitted 19 captive seed-finches to three short-term challenges: tonic immobility (TI), new environment (NE) and new object (NO) tests. TI behaviour is related to fear/escape response to potential predators and novelty tests (NE and NO) assess neophobia, which are ecologically relevant personality traits influencing the shyness-boldness continuum. We noted a pronounced variability among the individuals' personality traits, both in their fear and escape-related responses in the TI test and along shy/bold z-scores in NE and NO tests. During a period of enrichment, birds spent more time foraging and less time in vigilance states compared with both control phases. Personality traits of the birds affected their responses to enrichment with bolder birds spending more time foraging. The EE-related decrease in vigilance was independent of the birds' personality traits. Our findings highlight interactions between personality and rearing environment that may impact post-release outcomes for translocated animals.

Object Play as a Positive Emotional State Indicator for Farmed Spotted Paca (Cuniculus paca).

We aimed to assess whether object play can be used as a positive emotional state indicator for farmed spotted pacas (Cuniculus paca) by examining its association with other positive welfare markers including affiliative behavior and low-amplitude vocalizations. We submitted six groups of spotted pacas (one male/two females per group) (N = 18) to an ABA experimental design (A1/A2: without ball; B: with three boomer balls). Object play behavior occurred only during phase B (mean = 35.5 s, SE = 6.4). The spotted pacas spent more time in affiliative and exploratory behaviors and less time engaging in agonistic interactions during phase B than in both control phases (A1 and A2) (p < 0.05). Moreover, the spotted pacas emitted more low-amplitude bark vocalizations during phase B than during either control phase (p < 0.05), and such vocalizations have previously been shown to indicate a positive affective state and low arousal level. Because the expression of object play was associated with a decrease in aggression, an increase in affiliative behavior, and an increase in low-amplitude barking, we suggest that object play can be used as a non-invasive indicator of positive emotional state in this species.

Impact of environmental variables on some reproductive metrics of white-lipped peccaries (Tayassu pecari) raised in Atlantic Forest of Brazil.

Knowledge on male reproductive physiology is essential for the development of effective conservation strategies. This study investigated the influence of environmental variables on certain reproductive metrics in white-lipped peccaries (Tayassu pecari) raised in the Atlantic Forest. After anesthetization, testicular and cauda epididymis biometry were evaluated in nine adult male individuals subjected to electroejaculation. Semen was evaluated for volume, pH, concentration, total number of sperm, sperm morphology, membrane integrity, and kinematic parameters. Concurrently, environmental variables were collected from the day before, for the previous 14 days (estimated for sperm maturation in epididymis), and the period of 51-55 days (corresponding to the spermatogenic cycle) before semen collection. Overall, it was observed that rainfall is the most important environmental variable influencing the reproductive parameters of white-lipped peccaries, being positively correlated with the amplitude of lateral sperm head displacement (ρ = 0.62, P < 0.05) and the appearance of proximal cytoplasmic droplets in sperm (ρ = 0.62, P < 0.05). In addition, the testicular biometry of the species is influenced by the set of environmental variables of air temperature, rainfall, and relative humidity (ρ ≥ 0.60, P < 0.05). On the other hand, epididymal biometric data showed numerous correlations between cauda epididymis metrics and sperm parameters (ρ = 0.68, P < 0.05). This information will be useful to improving conservation strategies for these animals, contributing to their management in captivity and to reintroduction programs, especially in the Atlantic Forest where the species is declining.

Temperament, Plasticity, and Emotions in Defensive Behaviour of Paca (Mammalia, Hystricognatha).

Within a species, some individuals are better able to cope with threatening environments than others. Paca (Cuniculus paca) appear resilient to over-hunting by humans, which may be related to the behavioural plasticity shown by this species. To investigate this, we submitted captive pacas to temperament tests designed to assess individual responses to short challenges and judgement bias tests (JBT) to evaluate individuals' affective states. Results indicated across-time and context stability in closely correlated "agitated", "fearful" and "tense" responses; this temperament dimension was labelled "restless". Individual "restless" scores predicted responses to novelty, although not to simulated chasing and capture by humans in a separate modified defence test battery (MDTB). Restless animals were more likely to show a greater proportion of positive responses to an ambiguous cue during JBT after the MDTB. Plasticity in defensive behaviour was inferred from changes in behavioural responses and apparently rapid adaptation to challenge in the different phases of the MDTB. The results indicate that both temperament and behavioural plasticity may play a role in influencing paca responses to risky situations. Therefore, our study highlights the importance of understanding the role of individual temperament traits and behavioural plasticity in order to better interpret the animals' conservation status and vulnerabilities.

Personality and plasticity of defensive behavior in collared peccary (Dicotyles tajacu).

Inter-individual differences in behavior, together with phenotypic plasticity, may play a key role in the reintroduction success of captive-born individuals. Therefore, we aimed to investigate whether and how personality traits affect the plasticity of defensive behavior in collared peccary (Dicotyles tajacu). Twenty-six adult captive-born collared peccaries (12 males and 14 females) were submitted to three short-term challenges for personality assessment. Thereafter, each individual was submitted to four sequential tests, with different degrees of risk, allowing us to assess temporal/context consistencies in personality traits as well as the plasticity of defensive behavior. We noted a pronounced variability among the individuals' boldness trait, while males and females did not differ in their behavioral responses in all tests. Additionally, collared peccaries show behavioral plasticity of defensive behavior across risk conditions. We also verified an association between boldness and defensive behavior in this species: the higher the boldness score, the less time collared peccaries spent on wariness behaviors in the higher risk condition. The link between personality traits and behavioral plasticity of collared peccaries across risk conditions warrants further investigation to understand the impact of this association on the post-release success of this and other species.

Vocal complexity and sociality in spotted paca (Cuniculus paca).

The evolution of sociality is related to many ecological factors that act on animals as selective forces, thus driving the formation of groups. Group size will depend on the payoffs of group living. The Social Complexity Hypothesis for Communication (SCHC) predicts that increases in group size will be related to increases in the complexity of the communication among individuals. This hypothesis, which was confirmed in some mammal societies, may be useful to trace sociality in the spotted paca (Cuniculus paca), a Neotropical caviomorph rodent reported as solitary. There are, however, sightings of groups in the wild, and farmers easily form groups of spotted paca in captivity. Thus, we aimed to describe the acoustic repertoire of captive spotted paca to test the SCHC and to obtain insights about the sociability of this species. Moreover, we aimed to verify the relationship between group size and acoustic repertoire size of caviomorph rodents, to better understand the evolution of sociality in this taxon. We predicted that spotted paca should display a complex acoustic repertoire, given their social behavior in captivity and group sightings in the wild. We also predicted that in caviomorph species the group size would increase with acoustic repertoire, supporting the SCHC. We performed a Linear Discriminant Analysis (LDA) based on acoustic parameters of the vocalizations recorded. In addition, we applied an independent contrasts approach to investigate sociality in spotted paca following the social complexity hypothesis, independent of phylogeny. Our analysis showed that the spotted paca's acoustic repertoire contains seven vocal types and one mechanical signal. The broad acoustic repertoire of the spotted paca might have evolved given the species' ability to live in groups. The relationship between group size and the size of the acoustic repertoires of caviomorph species was confirmed, providing additional support for the SCHC in yet another group of diverse mammals-caviomorph rodents.

Flexibility in the social behavior of captive female capybaras (Mammalia, Rodentia).

Capybara (Hydrochoerus hydrochaeris) lives in stable groups composed of adult males and females with their young. The species shows flexibility in social organization in response to short-term environmental changes, but apparently does not show flexibility in social behavior. To gain insights into mechanisms underlying changes in social relationships, we analyzed the social dominance hierarchy of five captive capybara groups, composed of four to 13 adult females kept in outdoor paddocks ranging from 400 to 4500m2. In addition, we evaluated the effects of group size and space allowance on two complementary properties of social structure: linearity and steepness. Captive female capybaras exhibit a linear social dominance hierarchy. There was also more predictability in the dominance success- hierarchical steepness - in the dominance hierarchy with a decrease in the space per individual. This variability in response to changing circumstances shows flexibility in capybara's social behavior.

The Role of Grunt Calls in the Social Dominance Hierarchy of the White-Lipped Peccary (Mammalia, Tayassuidae).

Grunt-like calls are present in the vocal repertoire of many group-living mammals and seem to facilitate social interactions between lower and higher-ranking members. The white-lipped peccary (Tayassu pecari) lives in stable hierarchical mixed-sex groups and like non-human primates, usually emits grunt-like calls following aggressive interactions, mainly during feeding contexts. We investigated the possible functions of peccaries' grunt-like calls and their relationship to the individuals' social rank, identity, and sexual dimorphism. We observed that low-ranking individuals emitted grunt-like calls more often than high-ranking ones, and that the alpha male never emitted this vocalization. Moreover, the mean minimum frequency of grunt-like calls decreased as the peccary's rank increased. The findings revealed differences among individual grunts, but the low accuracy of cross-validation (16%) suggests that individual recognition in peccaries may be less important than an honest signal of individual social status. In addition, the absence of differences in the acoustic parameters of grunt-like calls between males and females points to the lack of sexual dimorphism in this species. We verified that after hearing grunt calls, dominant opponents were more likely to cease attacking a victim, or at least delay the continuation of conflict, probably decreasing the severity of agonistic interactions. Our findings are particularly important to improve the current understanding of the role of grunt-like calls in herd-living mammals with linear dominant hierarchies, and strongly suggest that they are involved in the maintenance of herd social stability and cohesion.

The effects of feeding unpredictability and classical conditioning on pre-release training of white-lipped peccary (Mammalia, Tayassuidae).

Some authors have suggested that environmental unpredictability, accompanied by some sort of signal for behavioral conditioning, can boost activity or foster exploratory behavior, which may increase post-release success in re-introduction programs. Thus, using white-lipped peccary (Tayassu pecari), a vulnerable Neotropical species, as a model, we evaluated an unpredictable feeding schedule. Associating this with the effect of classical conditioning on behavioral activities, we assessed the inclusion of this approach in pre-release training protocols. The experimental design comprised predictable feeding phases (control phases: C1, C2 and C3) and unpredictable feeding phases (U1- signaled and U2- non-signaled). The animals explored more during the signaled and non-signaled unpredictable phases and during the second control phase (C2) than during the other two predictable phases (C1 and C3). The peccaries also spent less time feeding during the signaled unpredictable phase (U1) and the following control phase (C2) than during the other phases. Moreover, they spent more time in aggressive encounters during U1 than the other experimental phases. However, the animals did not show differences in the time they spent on affiliative interactions or in the body weight change during the different phases. The signaled unpredictability, besides improving foraging behavior, showing a prolonged effect on the next control phase (C2), also increased the competition for food. The signaled feeding unpredictability schedule, mimicking wild conditions by eliciting the expression of naturalistic behaviors in pre-release training, may be essential to fully prepare them for survival in the wild.

Use of the ACP® and BTS extenders for cooling at 15°C white-lipped peccary (Tayassu pecari) semen / Uso dos diluidores ACP® e BTS para refrigeração a 15°C de sêmen de queixada (Tayassu pecari)

Knowledge about reproduction of white-lipped peccary is of great importance to assist with the conservation of this species and enable its rational use in captivity. This study aimed to evaluate the effect of ACP-103®, ACP-116® and BTS semen extenders on sperm viability during cooling of Tayassu pecari semen. Five ejaculates from four adult males were chilled. The animals were submitted to the protocols of sedation and anesthesia for semen collection by the electroejaculation method. After collection, the semen was macro- and microscopically assessed and diluted to reach 35x106 spermatozoa/mL in each of the three different extenders tested. The fresh-extended semen was packed in a BotuFLEX® thermal box to keep samples at 15°C for 24 hours. After cooling, the following semen parameters were analyzed: sperm motility, functional and structural integrity of sperm membranes, mitochondrial activity, chromatin condensation, and the thermoresistance test was performed. The parameters sperm motility, structural and functional integrity of sperm membranes, mitochondrial activity, and chromatin condensation were preserved after use of the extenders tested, and were similar to those of in natura semen (p>0.05). Curvilinear velocity (VCL) (p<0.05) was the only parameter with reduced values after cooling regardless of the extender used. The percentage of sperm with normal morphology was greater in samples cooled using the BTS extender (p<0.05). The ACP-103®, ACP-116® and BTS extenders can be used for the cooling and preservation of white-lipped peccary semen at 15°C for 24 hours.(AU)

Para auxiliar na conservação da espécie e permitir o uso racional do queixada em cativeiro é de grande importância o conhecimento sobre a reprodução da espécie. Objetivou-se avaliar o efeito dos diluidores de sêmen ACP-103®, ACP-116® e BTS na viabilidade espermática durante a refrigeração do sêmen do Tayassu pecari. Foram refrigerados cinco ejaculados provenientes de quatro machos adultos. Os animais foram contidos com auxílio de puçá e submetidos ao protocolo de sedação e anestesia para realização da coleta de sêmen pelo método da eletroejaculação. Depois da coleta, o sêmen foi avaliado macro e microscopicamente e diluído para atingir 35x106 espermatozoides/mL em cada um dos três diferentes diluidores testados. O sêmen diluído foi acondicionado em caixa térmica BotuFLEX® para manter as amostras a 15°C por um período de 24 horas. Depois da refrigeração, os espermatozoides foram avaliados quanto aos parâmetros de movimento espermático, integridade funcional e estrutural das membranas espermáticas, atividade mitocondrial, condensação da cromatina e teste de termorresistência. Os diluidores testados preservaram as características cinéticas, a integridade estrutural e funcional das membranas espermáticas, a atividade mitocondrial e a condensação da cromatina semelhante ao sêmen in natura (P>0,05). O único parâmetro que reduziu com o processo de refrigeração independente do diluidor utilizado foi a Velocidade Curvilinear (VCL) (P<0,05). Foi observado aumento do percentual de espermatozoides morfologicamente normais nas amostras refrigeradas em BTS (P<0,05). Os diluidores ACP-103®, ACP-116® e BTS podem refrigerar e conservar o sêmen de queixada a 15°C por 24 horas.(AU)

Ultrasound call detection in capybara / Detecção de chamados de ultrassom em capivara

The vocal repertoire of some animal species has been considered a non-invasive tool to predict distress reactivity. In rats ultrasound emissions were reported as distress indicator. Capybaras[ vocal repertoire was reported recently and seems to have ultrasound calls, but this has not yet been confirmed. Thus, in order to check if a poor state of welfare was linked to ultrasound calls in the capybara vocal repertoire, the aim of this study was to track the presence of ultrasound emissions in 11 animals under three conditions: 1) unrestrained; 2) intermediately restrained, and 3) highly restrained. The ultrasound track identified frequencies in the range of 31.8±3.5 kHz in adults and 33.2±8.5 kHz in juveniles. These ultrasound frequencies occurred only when animals were highly restrained, physically restrained or injured during handling. We concluded that these calls with ultrasound components are related to pain and restraint because they did not occur when animals were free of restraint. Thus we suggest that this vocalization may be used as an additional tool to assess capybaras[ welfare.

O repertório vocal de algumas espécies de animais tem sido considerado uma ferramenta não invasiva para predizer o distresse. Em ratos, emissões de ultrassom foram registradas como indicador de distresse. O repertório vocal de capivaras foi relatado recentemente e parece haver a presença de chamados em ultrassom que ainda não foram confirmados. Assim para associar o estado de bem-estar empobrecido em capivaras e a possibilidade de ocorrência de ultrassom em seu repertório vocal, o presente estudo teve como objetivo rastrear a presença deste tipo de vocalização em 11 animais submetidos a três condições diferentes: 1) sem contenção; 2) média contenção e 3) alta contenção. O rastreamento revelou a presença de faixas de frequência de 31,8±3,5 kHz em adultos e 33,2±8,5 kHz em filhotes. Estas emissões encontradas na faixa de ultrassom ocorreram apenas durante a alta contenção, quando contidos fisicamente ou feridos durante o manejo. Concluímos que tais emissões, com componentes de ultrassom, estão relacionadas à dor e ao distresse de contenção pois não ocorreram quando os animais estavam livres de contenção. Assim sugerimos que esta vocalização pode ser usada como uma ferramenta adicional para acessar o estado de bem-estar em capivaras.

Aspectos hematológicos de catetos (Tayassu tajacu) mantidos em cativeiro / Hematologic aspects of collared peccary (Tayassu tajacu) in captivity

Este estudo teve por objetivo determinar os valores hematológicos de Tayassu tajacu (catetos) mantidos em cativeiro. Foram utilizados 26 catetos, sendo 21 adultos (13 machos e 8 fêmeas) e 5 filhotes (três machos e duas fêmeas), mantidos na Fazenda Experimental do Almada e no Laboratório de Etologia Aplicada, pertencente à Universidade Estadual de Santa Cruz, Ilheus, BA. Amostras de sangue foram colhidas, da veia cefálica, para realização dos hemogramas. A análise estatística foi obtida por meio do teste "t" de Student, com nível de significância de 95 por cento. Na comparação entre os animais instalados em baias e piquetes não foi observada diferença significativa, no entanto observou-se um maior valor da proteína plasmática total nos machos (p<0,05). Ao se comparar animais adultos com jovens, observou-se diferença no valor do volume globular (p<0,05) e uma relação neutrófilo segmentado/linfócito inversa, com predomínio dos neutrófilos segmentados sobre os linfócitos nos animais jovens. Em relação à mensuração das células observou-se semelhança ao descrito para vacas, gato e cavalos. Estes resultados poderão subsidiar novos estudos, assim como futuras interpretações em animais hígidos ou doentes, com atenção às condições de manejo, clima e principalmente forma de contenção e tipo de população em que os estudos são realizados.

The aim of the study was to determine the blood values for the Tayassu tajacu (collared peccary) in captivity. Twenty-six collared peccary, being twenty-one adults (13 males and 8 females) and five young (3 males and 2 females) were maintained at the Experimental Farm of Almada and the Laboratory of Applied Ethology, belonging to the University Estadual of the Santa Cruz, Ilheus, Bahia, Brazil. Blood samples were collected from the cephalic vein to perform the complete blood count. Statistical analysis was performed using the Student's t-test, with a significance level of 95 percent. There was no significant difference from animals maintained in stalls or pickets, however there was a higher value of total plasma protein in males (p<0,05). When comparing adult animals with young animals, we observed differences in the packed cell volume (p<0,05) and a reverse relationship between mature neutrophils/lymphocytes, with a predominance of mature neutrophils (46,8 percent) on lymphocytes (45 percent) for young animals. Regarding the measurement of the cells was observed similarity to that described for cows, cats and horses. These results could support new studies, as well as future interpretations in healthy or sick animals, with attention how to handle the management of animals, weather and especially the form of restraint and type of population in what these studies are conducted.