Reproductive performance of rhesus macaques (Macaca mulatta) in two outdoor housing conditions.

This study examined the reproductive performance of rhesus macaques maintained in two different housing conditions: high-density semi-sheltered gang cages and low-density outdoor corrals. Two hundred sixteen subjects were housed in 49 gang cages, each of which contained one breeding male and between one and eight breeding females. Two hundred seven subjects were housed in 13 corrals, each of which contained between two and four breeding males and between 9 and 26 breeding females. Over a 3-year period, pregnancy, live birth, and production rates were significantly greater for females in corrals than for females in gang cages. Fetal death rate was lower in corrals than in gang cages, while neonatal death rates did not differ between housing conditions. These differences did not result from potential confounds such as differential age structures or virological statuses between housing conditions. We conclude that, for rhesus macaques, outdoor corral housing leads to better reproductive performance than does semi-sheltered gang housing, probably as a result of increased individual space and relaxation of intense social stressors.

Rhesus macaque (Macaca mulatta) group formation and housing: wounding and reproduction in a specific pathogen free (SPF) colony.

In the present report, we examined the effects of group formation strategy and corral design on wounding and reproduction rates in rhesus macaques. Specifically, we examined group formation using a staged strategy, in which small groups of animals were introduced incrementally over a period of weeks, and a rapid formation strategy, in which all animals were introduced in 1 day. We also examined group formation using a divided corral design that facilitated visual and social separation of individuals, and an undivided corral design that did not facilitate visual or social separation. Dependent measures were wounding and reproductive rates over each of the 2 years that followed group formation. Results indicate that incrementally releasing subgroups of animals, and using a corral design that provides for visual and social separation of individuals, are effective strategies for reducing rates of traumatic wounding when forming multimale-multifemale rhesus macaque breeding groups. However, it must be noted that differences in formation strategy and corral design did not lead to higher reproductive rates. We conclude that incrementally releasing animals in hierarchical subgroups, and using a divided vs. undivided housing design, reduced intra-group wounding and associated demands on veterinary and animal management resources following formation of rhesus macaque breeding groups.

Cholinergic axonal dystrophy and mitochondrial pathology in prosimian primates.

Progressive cholinergic axonal dystrophy, cholinergic denervation, and generalized gliosis begin in the prosimian primate species Otolemur at 10% of maximum life span. In these same animals, extensive cerebral beta-amyloidosis follows relatively more abruptly at 50% of maximum life span. In contrast, even at maximum life span, the prosimian primate species Galago senegalensis Moholi, Microcebus murinus, and Eulemur fulvus collaris and insectivore species T. belangeri are either spared or much less affected. In this report, we further document this progressive cholinergic denervation in Otolemur which involves first projections of the pedunculopontine nucleus (PPN, CH5-6) and later projections of CH1-4 cholinergic nuclei, as well as other noncholinergic pathways. Affected cholinergic cell bodies and axons contain abnormal mitochondria with increased content of manganese superoxide dismutase (MnSOD). This syndrome correlates with moderate copper deficiency marked by diminished liver copper levels and cuproenzyme activities, carnitine deficiency possibly secondary to renal Fanconi syndrome, and evidence for stress inflammatory response activation. Mitochondrial pathology was observed in pancreatic islet cells, proximal renal tubule epithelial cells, and choroid plexus epithelial cells, and it involved central cholinergic neurons. In Otolemur garnetti, the degree of central cholinergic injury directly correlated to depression of liver copper stores. The Otolemur syndrome involves "sentinel" central cholinergic injury and selective mitochondrial pathology in cell classes defined by high mitochondrial content and/or metabolic activity and high content of nitric oxide synthetase and MnSOD. Environmental factors affecting copper and carnitine metabolism could interact with genetic defects or traits to produce abnormal and aggressive aging of Otolemur. Subclinical, cell-class specific mitochondrial dysfunction in these prosimian primates may be a model for human neurodegenerative diseases.

Hematology, serum chemistry values, and rectal temperatures of adult greater galagos (Galago garnetti and G. crassicaudatus).

Hematological and serum chemistry values, as well as rectal temperatures, were obtained from greater galagos (Galago garnettii and G. crassicaudatus), in order to establish normative values. No species or sex differences were found for four hematological parameters and 15 serum chemistry parameters. Species differences were seen in phosphate, magnesium, cholesterol, alkaline phosphate, G-glutamyl transferase, mean corpuscular volume and leucocyte, neutrophil, and lymphocyte number. Significant sex differences were observed in glucose, hemoglobin, and hematocrit values. Species and sex differences were seen in chloride and erythrocyte number.

Duke University Primate Center.

The Duke University Primate Center houses the world's largest collection of prosimian primates. The Center is a research resource for undergraduate and graduate students, as well as faculty from Duke University and other U.S. and international universities. Researchers have access to the animals for noninvasive studies, to a large collection of preserved tissues and cadavers, and to an extensive collection of Eocene and Oligocene fossils. The Center is also involved in conservation programs in Madagascar which provide opportunities for field research in primatology and conservation.

Scaling of growth and life history traits relative to body size, brain size, and metabolic rate in lorises and galagos (Lorisidae, primates).

A broad range of variation in body size, brain size, and metabolic rate occurs within the primate family Lorisidae, thus providing an opportunity to examine the relationship of these three parameters to variation in growth and life history traits. Data on adult body weight, gestation length, lactation length, age at first estrus, litter size, and growth parameters were collected from a captive colony of four lorisid species, Loris tardigradus, Nycticebus coucang, Galago crassicaudatus, and G. senegalensis. The data presented here constitute the most complete life history information available for these poorly understood prosimian species. Correlation and allometric analyses were performed to determine the relationships between variables. Among the lorisids studied, adult body weight, adult cranial capacity, and relative cranial capacity did not predict variation in life history traits. Adult basal metabolic rate predicted most of the variability in gestation length, lactation length, and growth parameters. Lorisines differ from similarly sized galagines in having lower basal metabolic rates, slower growth rates, slower developmental rates, and smaller litter sizes, resulting in reduced reproductive potential. This may be a consequence of lorisine adaptation to a diet of toxic insects. Metabolic rate and diet may be among the most important parameters to examine in any study of life history evolution.

Progesterone levels during pregnancy in the greater thick-tailed galago (Galago crassicaudatus).

Serum progesterone concentrations in Galago crassicaudatus were quantified at 3-week intervals throughout the 136-day pregnancy. Progesterone concentrations were significantly elevated over those of nonpregnant controls as early as 6 weeks after conception. Progesterone continued to increase throughout gestation. The progesterone profile in pregnant G. crassicaudatus quantitatively resembles that of chimpanzees and qualitatively resembles that of humans. In two animals that aborted, progesterone concentrations after abortion decreased to values comparable to those seen in nonpregnant animals.

Lactation and interbirth interval in the Senegal galago (Galago senegalensis moholi).

Five years of reproductive data on Galago senegalensis moholi at the Duke University Primate Center were examined to determine the effect of lactation on interbirth interval and its component phases, postpartum anovulatory interval and interval from onset of estrous cycles to conception. Females whose infants died within 3 weeks of birth had significantly shorter interbirth intervals and postpartum anovulatory intervals than did females who raised their infants until weaning.

Infant survival and litter size in primigravid and multigravid Galagos.

Eighteen years of birth records for three species of Galago at the Duke University Primate Center were examined to determine the effect of gravidity status on neonatal mortality and litter size. Multiparous Galago senegalensis moholi and G crassicaudatus, but not G garnettii, had significantly higher infant survival rates. Gravidity status had no effect on the percentage of multiple births for any of the three species of Galago.

The effects of bull urine on puberty and calving date in crossbred beef heifers.

The effects of bull urine on the percentage of heifers reaching puberty and on subsequent calving dates were examined with 52 crossbred beef heifers. Heifers were palpated for ovarian condition and classified as prepubertal or pubertal before (Palpation I) and after (Palpation II) eight weekly oronasal treatments with bull urine or water. A larger percentage of urine-treated than water-treated heifers reached puberty during the experimental period (67 vs 32%; P less than .05), supporting the hypothesis that bull urine contains a priming pheromone. Body weight of urine-treated heifers that did not reach puberty by Palpation II was lower than that of water-treated heifers that did not reach puberty (P less than .05), indicating that an association exists between body weight and the response to pheromonal cues in bull urine. There were no treatment differences in pregnancy rate after a 90-d breeding period, and no differences in pregnancy rate between heifers that had reached puberty before the breeding season started and heifers that had not reached puberty. Urine-treated heifers reaching puberty during the experiment calved earlier (P less than .05) in the calving season than did water-treated heifers of the same category. The distribution of these calvings was also different (P less than .01), resulting in a shorter calving season for urine-treated heifers. More heifers that had reached puberty by Palpation II calved in the first 20 d of the calving season that did heifers that had not reached puberty by Palpation II, regardless of treatment group (P = .02). There was a tendency for urine-treated heifers to calve earlier than water-treated heifers, with the exception of urine-treated heifers that had not reached puberty by Palpation II. These data support the hypothesis that there is a priming pheromone in bull urine that can hasten the onset of puberty in beef heifers.