Measurement of cognitive bias and cortisol levels to evaluate the effects of space restriction on captive collared peccary (Mammalia, Tayassuidae)

We use the judgement-bias paradigm to evaluate whether space restriction in metabolism pens affects the emotional state of collared peccary (Pecari tajacu) during a nutritional experiment. We trained individual adult males to ‘go’ to a specific location within 30 s when a positive auditory cue (whistle; CS+) was given in order to receive cassava root pieces as a reward, and to ‘no-go’ when a negative cue (caxixi percussion instrument; CS−) was sounded to avoid punishment (jet of water) and no reward. An ‘ambiguous’ auditory cue (a drumstick hitting an aluminum plate; CSA) was presented to probe decision-making under ambiguity. Individuals were subjected to five 8-day housing conditions in the order: H1 (control-no space restriction-metabolism pen and additional area), H2 space restriction without environmental enrichment (metabolism pen only), H3 (control-no space restriction), H4 (space restriction with environmental enrichment), and H5 (control-no space restriction). On the eighth day of each housing condition, each animal was exposed to 10 judgement bias trials of each of the three cue types: CS+, CS−, and CSA. We recorded whether animals showed the ‘go’ or ‘no-go’ response after each type of cue and collected fecal samples to assess fecal glucocorticoid metabolite concentrations. Peccaries learnt to discriminate CS+ and CS− and maintained this discrimination during the five housing conditions tested. The response to the ambiguous cue (CSA) varied according to the housing condition. During H1, the peccaries made a similar proportion of ‘go’ responses to all three types of cue (Ps > 0.07). During H2 and H3, ‘go’ responses to CSA and CS− cues occurred in similar proportions (Ps > 0.70), but peccaries showed more go responses to CS+ (Ps < 0.03) indicating that they were responding to CSA as if it were more likely to predict the waterjet than food. During H4 and H5, peccaries again made a similar proportion of ‘go’ responses to all three types of cue, as in H1. During H2 and H3, fecal glucocorticoid metabolite concentrations were higher than during the other tests (208.0 ± 16.4 vs. 141.6 ± 25.9 ngg−1 dry feces, Ps < 0.03). Our results suggest that space restriction may induce physiological stress and influence judgement bias and affective state in peccaries, and that these effects may be offset by environmental enrichment. However, the possibility of a general habituation to the housing conditions across time cannot be ruled out

Intake and digestion of non-traditional feedstuffs by farmed collared peccary (Mammalia, Tayassuidae)

To assess the ability of the collared peccary (Pecari tajacu) to digest dietary fiber, four adult male collared peccaries were randomly assigned to a 4 × 4 Latin square design to determine the effects of feeding non-traditional feed ingredients, taken from palm trees with different levels of dietary fiber, on intake and coefficient of total tract apparent digestibility (CTTAD) and mean retention time. Four experimental diets were provided ad libitum: corn and soybean meal-based control diet; corn and palm kernel cake-based diet; corn and peach palm byproduct-based diet; and hay, palm kernel cake, and peach palm byproductbased diet. The CTTAD of neutral detergent fiber and acid detergent fiber (ADF) were 0.80±0.09 and 0.61±0.21, respectively. Increasing levels of ADF in diets also linearly decreased the CTTAD of crude protein and gross energy, while increasing non-fiber carbohydrate linearly decreased the CTTAD of ADF. These results confirm the ability of peccaries to digest fiber. However, the intake of a high-moisture and lignified ingredient, as the peach palm byproduct, decreased feed intake of peccaries due to their relatively small forestomach volume, which in turn may decrease their performance when used for prolonged periods. Despite of that, collared peccary gain a significant benefit in digestibility of dietary fiber due to its complex stomach in which fermentation occurs. © 2018 Sociedade Brasileira de Zootecnia

Aspectos hematológicos de catetos (Tayassu tajacu) mantidos em cativeiro

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%. 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

Ultrasound call detection in capybara

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