Abstract: The pathophysiology and lesions associated with vitamin E deficiency are similar between domestic and exotic species, and circulating plasma concentrations are also similar between comparable groups. However, many ecological variables must be considered for the most relevant comparisons. Tissue values of vitamin E, apart from plasma, are unknown for most exotics. Dietary vitamin E requirements of exotic species and domestics appear to differ; based on natural foodstuff analyses and clinical observations, between 50 and 200 mg vitamin E/kg DM are necessary to prevent vitamin E deficiency, 5- to 10-fold higher than current livestock recommendations.

Abstract: Leptospirosis is a zoonotic bacterial disease caused by Leptospira interrogans. There is a serologic evidence that horses are exposed to L. interrogans and, as a shedder of these organisms, can be a threat to humans. We examined risk factors associated with the risk of testing seropositive to three L. interrogans serovars (L. icterohaemorrhagiae, L. grippotyphosa, and L. canicola) in the horses of New York State, in order to understand the epidemiology of the disease and suggest strategies to control and prevent equine leptospirosis. To carry out this study, blood samples were collected from a random sample of 2551 horses and tested for the presence of antibodies to the above serovars using the microscopic agglutination test. Samples with a titer $100 were considered positive. Clinical and demographic data were collected on each horse, the farms' management practices and ecology. Logistic regression analysis was used to develop a multivariate indexing system and to identify factors significantly associated with the risk of leptospirosis. Four indices were developed based on the possible sources of exposure: rodent exposure index; wildlife exposure index; soil and water index; and management index. The soil and water index was significantly associated with the risk of exposure to all three serovars. Management was positively associated with L. icterohaemorrhagiae and L. canicola. Density of horses turned out together was positively associated with the risk of exposure to L. grippotyphosa. We concluded that indirect exposure of horses to L. interrogans through contaminated soil and water appears to be significantly associated with the risk of exposure to all three serovars. Management appears to play an important role in the exposure to L. interrogans. Modification of management practices might reduce the horses' risk of exposure and hopefully minimize the human hazards.

Abstract: Plains zebra live in harems that include one to six adult mares. Between these mares is a strong order of social hierarchy. The social rank of an equid mare is typically correlated with her age. Further, high-ranking captive plains zebra mares produce more surviving offspring than low-ranking mares. The objectives of this study were to, first, examined the factors that influence social rank of captive plains zebra mares, and second, test if high-ranking mares conceive earlier and if they have shorter inter-birth intervals than low-ranking ones. We observed three herds of captive plains zebra (a total of 18 mares) at the Dvur Kralove Zoo, Czech Republic. During the 831 h of observation, we recorded 1713 aggressive interactions (biting and offensive kicking) between the mares. These data were used to determine, for each mare, the total number of mares that dominated her in each period of social stability. The GLMM model revealed that older mares were dominated by a lower number of mares than the younger mares. We also found that the probability that a mare would conceive declined with the increasing number of dominant mares. Further, we tested the relationship between the number of dominant mares and the inter-birth interval using 29 intervals for 15 mares. These inter-birth intervals were divided into two groups. When a stallion was continuously present in the herd, the intervals lasted from one birth to the next birth (natural intervals). When a herd was without a stallion, the intervals lasted from the release of the stallion into the herd to the birth of foal (stallion-influenced intervals). The analysis revealed that the inter-birth intervals decreased with an increasing number of dominant mares and the natural intervals decreased with an increasing number of offspring successfully reared by a mare. This finding is the first one in equids and contributes to the previous findings that suggest that social status influences reproductive success.

Abstract: The behavior of nine lowland gorillas (Gorilla gorilla gorilla) living in three social groups at Zoo Atlanta was compared in an indoor holding area versus an outdoor exhibit. Focal animal data were collected for each animal during 15 min observation sessions, alternating between indoors and outdoors. A variety of solitary and social behaviors differed in the two conditions. All individual and social behaviors that showed a difference, except eating, occurred more indoors than outdoors. These included aggressive displays, reclining, self manipulation, and social examination of others. Additionally, the gorillas spent more time closer together in the indoor condition. A variety of other behaviors measured did not change between the two environments. There was a clear effect on behavior of the different housing conditions in which the gorillas were kept. It is suggested that the differences in aggressive behavior may be related to environmental complexity. It is further suggested that zoos should be aware that differences in behavior reported by caretaking staff, researchers and visitors may be a reflection of the differing environmental circumstances in which the animals are observed.