Urinary excretion of oestrone conjugates and gonadotrophins during pregnancy in the Goeldi's monkey (Callimico goeldii)

Oestrone conjugate and LH/CG were measured in the urine of 4 Goeldi's monkeys during 6 pregnancies. The gestational length was a mean of 148.8 days from the post-partum LH/CG peak to parturition. CG was first detected a mean of 18.8 days after the LH/CG peak and values remained elevated for a mean of 44.8 days. Three different gonadotrophin assays were used to detect LH/CG: the mouse in-vitro interstitial cell bioassay, a mixed heterologous LH RIA, and a monkey CG RIA. The mouse in-vitro interstitial cell bioassay was useful for measuring both the LH peak which occurred post partum and the CG concentrations during pregnancy. However, both immunoassays were inconsistent in measuring LH due to poor cross-reactivity or lack of specificity; CG concentrations were measurable. Oestrone conjugates became elevated at the time of the LH/CG peak and concentrations continued to increase throughout pregnancy, reaching peak levels before parturition. The postpartum interval, pregnancy and parturition can therefore be monitored in the Goeldi's monkey by the use of urinary assays: those for bioactive LH and immunoreactive oestrone conjugates to determine the post-partum LH peak and those for immunoreactive LH/CG and immunoreactive oestrone conjugates to follow pregnancy and parturition.     

Hypoglycemia of squirrel monkey neonates: implications for infant survival

Neonatal deaths are a serious problem in breeding colonies of squirrel monkeys. Seriously ill neonates in our colony are always hypoglycemic on presentation. To determine normal glucose values for squirrel monkey infants of various ages, serum glucose determinations were done at 1, 3, 7, 10, 14 days and 1 month of age using a standard laboratory test for serum glucose. Glucose concentration increased from a low of 49 +/- 3 mg/dl (Mean +/- SEM) at 1 day (n = 21) to 109 +/- 4 mg/dl at 1 month of age (n = 17). Glucose values for 1, 3 and 7 day-old infants were significantly lower than 1 month-old infants (P less than .05). To provide a time-averaged indication of blood glucose, glycosylated hemoglobin (GHb) measurements were made at 1 day, 1 week, 2 weeks, 1 month, 2 months, 1 year of age and in adults (greater than 3 years of age). GHb values ranged from 2.6% +/- 0.1 for 1 day old infants (n = 13) to 4.0 +/- 0.2 for adults (n = 10) with a steady increase during the first 2 months of life. Animals 1 year of age and younger had significantly lower glycosylated hemoglobin than adults. These studies indicate that blood glucose concentration is significantly lower in squirrel monkey neonates than in older infants, juveniles and adults. Maternal rejection, trauma, and associated problems occur commonly in socially reared squirrel monkeys. The marginal hypoglycemic state of these infants places them at high risk for clinical hypoglycemia as a sequel to such perturbations.     

Responses of mother squirrel monkeys to dead infants

The responses of mother squirrel monkeys to infants were examined by testing the mothers with bodies of their own and other infants. Mothers whose infants were stillborn or died at one day of age showed strong and equivalent maternal responses to all the bodies with which they were presented, while those whose infants died after two weeks of age responded mainly to the body of their own infant. These results suggest that the female squirrel monkey becomes more selective in responding to the body of a dead infant with the passage of time after parturition. The female's post-parturient condition appears to be the prime cause for changes in her responsiveness, although other factors related to the infant's growth and development might also be important.Supported by Grant HD 04905 from the National Institute of Child Health and Human Development.     

Some aspects related to conception of the Japanese monkey (Macaca fuscata)

The season of birth, age of the first parturition, gestation period, and vaginal bleeding and mating after conception were surveyed with Japanese monkeys (Macaca fuscata). The analyses of the former two items were dependent on the birth records in the Ohirayama troop collected from 1957 to 1973, and the analyses of the latter two items were dependent on data obtained by a 48-hour mating in a laboratory. Birth in the Ohirayama troop converged into the months from March to July, especially from April to June. The age of the first parturition was three years and 11 months at the earliest, and nine years and two months at the latest. The monkeys giving their first birth at the age of five or thereabouts were most frequently observed (68.6%), and most of the monkeys had their first parturition from about the age of four years to about the age of six years. The gestation period calculated from 17 cases, which was defined as the period from the first day of a 48-hour mating to the day before parturition, was 173 ± 6.9 days ranging from 161 to 188 days. In 25 out of 28 cases, the vaginal bleeding was observed after conception. It began slightly later (between 16 and 24 days after mating) than the forecasted time of the next menstrual hemorrhage, and usually lasted longer than bleeding of the usual menses. Each of three female monkeys caged together with a male monkey 30 days after conception was observed to have copulated, and the male was observed to have ejaculated.     

Changes in circulating inhibin levels during pregnancy and early lactation in the Japanese monkey

Changes in immunoreactive (ir-) inhibin concentrations in serum throughout pregnancy and early lactation up to one month after parturition were characterized in 6 Japanese monkeys (Macaca fuscata fuscata) by a heterologous radioimmunoassay (RIA) based on a bovine RIA. Serum levels of FSH, LH/monkey chorionic gonadotropin (mCG), estradiol-17 beta, and progesterone were also monitored for the entire period. Ir-inhibin levels in the serum were low (under 0.5 ng/ml) before conception. Three marked increases in serum ir-inhibin levels were found during pregnancy. The first increase was noted during early pregnancy, with a peak (2.2 +/- 0.2 ng/ml) at Day 22 of pregnancy (Day 0 = day of LH surge). The second increase was noted after Day 38 until Day 72 of pregnancy, when a peak value was noted (19.0 +/- 1.4 pg/ml). Plateau levels were maintained until late pregnancy, and a final rise was evident near the term with a peak (36.7 +/- 3.8 ng/ml) at Day 158 of pregnancy, 5 days before parturition. After parturition, ir-inhibin levels in the serum plummeted to nonpregnant levels within one day, and were maintained during early lactation. The first rise in serum inhibin during pregnancy was parallel to the rise of mCG and estradiol-17 beta, and the second and third rise were well correlated with serum estradiol-17 beta. Serum FSH was maintained at low levels throughout pregnancy, followed by a slight increase after parturition when serum inhibin decreased abruptly. Both bioactivity and immunoreactivity of inhibin were detected in the placental homogenates obtained at 120 days of pregnancy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Endocrine profiles during doe-litter separation and the subsequent pregnancy in rabbits

This study was carried out to determine the effects of a transient doe-litter separation on plasma prolactin, LH, FSH, estradiol-17beta and progesterone concentrations before artificial insemination and during the subsequent pregnancy. Control does (n=12) had free access to nursing, whereas separated does (n=12) were kept away from their litters for 48 hours before artificial insemination. Both groups were inseminated on day 11 after parturition. Teat stimulation by suckling caused a high increase in prolactin concentrations in separated does (p < 0.0001). Basal prolactin concentrations were observed in both groups on days 8 and 18 of pregnancy. No effect of the treatment was detected on LH and FSH concentrations during the sampling period. A rise of estradiol-17beta concentrations was observed 48 hours after doe-litter separation, compared to control does and to previous values (p < 0.003). Both groups showed low progesterone concentrations before artificial insemination. Pregnant rabbits in both groups showed increased progesterone concentrations on days 8 and 18 of pregnancy. Lower estradiol-17beta concentrations were observed in control does on day 18 of pregnancy compared with separated rabbits (p < 0.003). The results suggest that a transient separation of nursing does from their litters before artificial insemination may promote high follicular steroidogenesis activity leading to increased estradiol-17beta concentrations. This hormonal change could be a result of several stimulatory actions probably triggered by the absence of suckling episodes and may affect the luteotrophic function during the subsequent pregnancy.     

Endocrine profiles during doe-litter separation and the subsequent pregnancy in rabbits

This study was carried out to determine the effects of a transient doe-litter separation on plasma prolactin, LH, FSH, estradiol-17β and progesterone concentrations before artificial insemination and during the subsequent pregnancy. Control does (n=12) had free access to nursing, whereas separated does (n=12) were kept away from their litters for 48 hours before artificial insemination. Both groups were inseminated on day 11 after parturition. Teat stimulation by suckling caused a high increase in prolactin concentrations in separated does (p<0.0001). Basal prolactin concentrations were observed in both groups on days 8 and 18 of pregnancy. No effect of the treatment was detected on LH and FSH concentrations during the sampling period. A rise of estradiol-17β concentrations was observed 48 hours after doe-litter separation, compared to control does and to previous values (p<0.003). Both groups showed low progesterone concentrations before artificial insemination. Pregnant rabbits in both groups showed increased progesterone concentrations on days 8 and 18 of pregnancy. Lower estradiol-17β concentrations were observed in control does on day 18 of pregnancy compared with separated rabbits (p<0.003). The results suggest that a transient separation of nursing does from their litters before artificial insemination may promote high follicular steroidogenesis activity leading to increased estradiol-l7β concentrations. This hormonal change could be a result of several stimulatory actions probably triggered by the absence of suckling episodes and may affect the luteotrophic function during the subsequent pregnancy.     

Nursing does affect the duration of the post-partum to ovulation interval in cotton-top tamarins (Saguinus oedipus)

Reports on callitrichid monkeys have not revealed a significant effect of nursing on interbirth intervals or on post-partum to ovulation intervals. We examined 25 post-partum intervals in cotton-top tamarin females to determine whether nursing infants would affect the length of the post-partum to ovulation interval. Urinary LH/CG and oestrone conjugates were measured in urine samples collected in the 6 weeks after birth. The post-partum to ovulation interval is the number of days between parturition and the rise of urinary LH and oestrone conjugates associated with ovulation. There was an 84% conception rate post partum. Neither mother's parity nor sex of the infants influenced the length of the post-partum to ovulation interval. The post-partum to ovulation interval for females nursing 2 infants was twice as long as for those not nursing or nursing 1 infant (P less than 0.05). The range of post-partum to ovulation interval lengths was more variable in nursing than in non-nursing females (P less than 0.01). Females spent less than 50% of observed time in contact and less than 20% of observed time nursing their infants. Neither the number of tamarins within the family nor the amount of time the mother was in contact with infants correlated with the length of the post-partum to ovulation interval. However, there was a positive correlation between the percentage time that mothers nursed 1 infant at a time and the length of the post-partum to ovulation interval (r = 0.75, P less than 0.02). The underlying mechanisms of suckling-induced delay of ovulation are present in the cotton-top tamarin as in other primate species. However, these nursing effects do not cause the substantial delay in fertility post partum that is associated with non-callitrichid primates.     

Infant Development and Parental Care in Free-Ranging <Emphasis Type="Italic">Aotus azarai azarai</Emphasis> in Argentina

Studies of infant development and parental behavior in free-ranging owl monkeys have been constrained by their nocturnal habits. Taking advantage of the cathemeral activity pattern of Aotus azarai azarai in the Argentinean Chaco, we describe the development of a cohort of free-ranging infants born in an owl monkey population in Formosa Province. We observed 7 infants, whose birth dates are known to the nearest week, to record details of their development and care between October 1999 and March 2000. We collected 92 h of behavioral data in 76 sessions. The infants were almost never off the parents during the first 4 wk of life, and we observed no infant being transported by a nonadult. The parent carrying the infant traveled most frequently in the middle of the group, sometimes first, but rarely last. The mean duration of 33 nursing episodes is 69 sec. After nursing, the infant was more likely to return to the nonnursing adult than to remain with the mother suggesting that in owl monkeys the infant may be primarily attached to the adult male in the group. Infants began to explore, to manipulate and to consume solid foods during the second month. Our observations are comparable to ones on captive breeding groups of Colombian owl monkeys (Aotus lemurinus) and Bolivian owl monkeys (A. azarai boliviensis) under controlled conditions of temperature, illumination and food availability.     

A comparison of hematological and serum biochemical values between two groups of female cynomolgus monkeys reared under different conditions

The influence of long term rearing conditions on the hematological and serum biochemical values in laboratory-bred female cynomolgus monkeys (Macaca fascicularis) was studied under the following two conditions. Group A: New born infants were nursed by their mothers for at least 12 weeks after birth. After weaning, four monkeys of approximately equal age and body weight were kept in a relatively small cage (90 cm W x 60 cm D x 60 cm H) and reared to five years of age. These rearing conditions are commonly used in the breeding program of our primate center. Group B: One male and five females of wild origin were introduced into a relatively large cage (180 cm W x 180 cm D x 160 cm H). Female monkeys born in these cages were used in this study. All of them were reared by their own mothers and grew well in these cages. Male monkeys born in these cages were removed at about 3.5 years of age. Hematological and serum biochemical values between the two groups in each age class were compared and analyzed by the canonical discriminant analysis (the discriminant analysis with reduction of dimensionality). Age correlated highly with the value of the first canonical variate. The second canonical variate detected a difference in the blood hematology and biochemistry probably induced by the difference in rearing conditions.     

Age-related hormonal differences in cycling squirrel monkeys (Saimiri boliviensis boliviensis)

This study was planned to evaluate the poor reproductive performance of aged squirrel monkeys in a self-sustaining breeding colony. Two groups of monkeys aged 6–8 years (Group 1), and >12 years (Group 2) were evaluated. During the midbreeding season, daily blood samples were obtained for a period of 35 days from 10 animals in each group. Blood samples were assayed for serum estradiol (E), progesterone (P), and bioassayable luteinizing hormone (bio-LH) concentrations and the data were analyzed by ANOVA (analysis of variance). Bio-LH surges were less frequent in the aged breeders (Group 2). Total P output during periovulatory period (day ?;3 to day + 3) and the total P output during the luteal phases of the estrus cycles were significantly lower in aged squirrel monkeys (Group 2, P < 0.003). Although E peaks occurred less frequently in Group 2, they had higher concentrations as compared to Group 1 (P < 0.003). Cumulative periovulatory and luteal phase E levels did not differ between the two groups. The reduction in P output in aged squirrel monkeys may interfere with proper implantation, thus contributing to the lower pregnancy rate observed in this age group. The decreased frequency of bio-LH surges indicated less frequent ovulations in the aged animals which may further impair reproduction with aging. © 1994 Wiley-Liss, Inc.     

Cord transferrin and ferritin values for erythropoiesis in newborn infants of diabetic mothers

Neonatal polycythemia is a perinatal complication in infants of diabetic mothers. The cord CBC (complete blood counts), serum iron, transferrin and ferritin concentrations were studied in newborn infants of 9 GDM (gestational diabetes), 21 NIDDM (noninsulin-dependent diabetes mellitus), and 8 IDDM (insulin-dependent diabetes mellitus) mothers. The RBC (red blood cell) count, Hb (hemoglobin) and Hct (hematocrit) of these infants were higher than control infants. There was no difference between the serum iron concentration of the infants of each group diabetic mothers and the infants in the control group, but the transferrin concentration was significantly higher and the ferritin was significantly lower in the infants of diabetic mothers than in those of control mothers. There was a significant negative correlation between transferrin and ferritin (r = -0.491 p less than 0.001). Erythropoiesis is considered to be enhanced in the fetuses of diabetic mothers, and the iron needed for erythropoiesis is reportedly transported from the mother to the fetus according to the demands of the fetus, but the iron storage was shown to be reduced in the fetuses of diabetic mothers.     

Mothers, not fathers, determine the delayed onset of male carrying in Goeldi's monkey (Callimico goeldii)

In biparental species, females are thought to accept and even to seek male assistance in rearing of the young. In this study, we present data that suggests that Goeldi's monkey females (Callimico goeldii) actually reject male parental care for a certain period. In Callimico, which have biparental care, mothers carry the infant exclusively for the first three weeks despite the fact that fathers are interested in their infants directly after birth. Fathers initiated significantly more body contact with their mates when newborn infants were present and retrieved one-day-old infants that were experimentally presented to them. The onset of paternal carrying in our colony was 27.5 days compared to 11.5 days (medians) observed in the field. However, presentation of a live potential predator induced earlier onset of paternal carrying by about 10 days. Additional costs to maternal carrying such as foraging and predator avoidance are likely factors influencing the decision of the mother as to when to share the cost of infant carrying with the father. We conclude that Goeldi's monkey fathers start carrying their infants so late because they do not get them earlier from the mother. We suggest that one ultimate explanation for that delay might be increased infant mortality when infant transfer starts at an earlier stage.     

Hematological and plasma biochemical values for captive tufted capuchin monkeys (Cebus apella)

Hematological and blood biochemical parameters are of great importance in medical and veterinary practice. Unfortunately, normal reference range intervals for hematological and serum biochemical values in the tufted capuchin monkey (Cebus apella) have seldom been reported. The study reported here is based on data from blood samples collected from 44 monkeys over an 8-year period. Male and female data are displayed separately within two age categories: juveniles and adults, and effects for sex and age are examined. Significant differences between males and females are found for erythrocytes, hemoglobin, hematocrit, and α(1) globulin. Significant differences between juveniles and adults are found for neutrophils, calcium, aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase, inorganic phosphorus, glucose, total protein, serum iron, and some serum protein parameters and albumin/globulin ratio. These values are compared with values we previously reported, and their importance in care and well-being of captive tufted capuchin monkeys is discussed.     

Tactics of care for young infants by forest-living ruffed lemurs (Varecia variegata variegata): Ground nests,parking, and biparental guarding

Over a 4 month period, systematic and ad libitum observations were conducted on two adult female black-and-white ruffed lemurs (Varecia variegata variegata) and their infants in a 3.5 ha forest enclosure. The females were mother and daughter, members of a family group that had been semifree-ranging for 2 years and 3 months at the time of the births. One to two weeks before parturition, the females independently constructed nests, in which they kept their infants during the first few weeks following parturition. The older mother, cage-reared herself, prepared at least one nest. Her daughter, who has lived in the forest since late juvenescence, prepared at least four. Two to three weeks after parturition, the mothers moved their infants high into trees. During periods of maternal absence, the infants were often alone, and they rarely or never moved, vocalized, or groomed themselves. The mothers often kept their infants together after nests were no longer used. Each infant nursed freely from both lactating females. The infants were carried orally only by their mothers and were never transported by clinging to the pelage of any group members. Previously, researchers suggested that ruffed lemurs build nests for care of infants high up in trees. The present observations, however, suggest that two major modes of neonate care in Varecia exist: serial use of multiple ground nests and “parking” of infants high in trees. Advance preparation of several nest sites, relative lack of large predators, alternate maternal and paternal guarding of infants, infant immobility during absence of mother, and rapid infant development make this tactic of care for neonates plausible.     

Attachment and social preferences in cooperatively-reared cotton-top tamarins

In many primate species a close attachment between mother and infant provides a secure base for the infant when the infant is frightened or under stress. In cooperatively breeding primates infant carrying is divided among several individuals in the group, with the mother often doing little more than nursing. In these species it is not clear which individual would best serve as a secure base for the infant. We studied eight infant cotton-top tamarins from birth through 20 weeks of age, noting who carried the infant during the first 100 days, who transferred food with the infants, and, as infants became independent, with whom they associated during social play and affiliative behavior. From week 9 to week 20, when infants were independent of carriers most of the time, we presented families with six trials (once every 2 weeks) with a threatening stimulus (a human dressed in a lab coat and wearing an animal mask). Infants played primarily with their twin or youngest sibling and had affiliative interactions with many family members. However, in fearful situations, infants ran to those who had carried them and transferred food with them the most-their father or oldest brother (never to the mother). Although adults increased rates of mobbing calls in response to the threat, infants significantly reduced their vocalization rate. For these cooperatively breeding monkeys, the attachment object for infants is the family member that invested the most effort in carrying the infant and transferring food with the infant. These results parallel and extend results from bi-parental infant care species in which the father serves as the primary attachment figure.     

Corticotropin-releasing hormone-binding protein in primates

In humans, placental corticotropin-releasing hormone (CRH) production has been linked to the determination of gestational length, and a late gestational fall in CRH-binding protein (CRH-BP) has been linked to the onset of parturition. Expression of placental CRH mRNA is limited to primates, and only in man has a circulating CRH-BP been described. As the fall in CRH-BP in late gestation has been associated with parturition in humans, we sought to determine whether a CRH-BP circulated in the plasma of other primates. It is unclear whether maternal plasma CRH concentrations are elevated in New World monkeys and prosimians. We have therefore performed CRH plasma measurements in the blood of pregnant marmosets, in several species of lemur, and in pregnant and fetal rhesus monkeys as a positive control. Using gel chromatography, CRH-BP was detected in the human, gorilla, chimpanzee, orangutan, gibbon, macaque, squirrel monkey, and marmoset, but was absent in the mandrill, spider monkey, and lemur. CRH was detected in the plasma of pregnant marmosets and rhesus monkeys. CRH was also detected in the fetal rhesus monkey, but at lower concentrations than in maternal plasma. CRH immunoreactivity was not detectable in the plasma of pregnant lemurs or in extracts of lemur placenta. In conclusion, a circulating binding protein for CRH exists in all species of apes but occurs variably among New World and Old World monkeys and is absent in lemurs. The variable occurrence of the CRH-BP does not support a role for this protein in the mechanism of parturition in primates. Maternal CRH is elevated in the pregnant marmoset and rhesus, and may play a role in the pregnancy of New and Old World monkeys.     

Plasma cortisol levels and dominance in peer groups of rhesus monkey weanlings.

Determinations of plasma cortisol levels in rhesus monkey infants were obtained before and shortly after they were separated from mother and placed together in small social groups. Differences in pregrouping (baseline) plasma cortisol levels between two infants were good predictors of the direction of the social dominance relationship established between them. This association between lower baseline cortisol values and dominance was not dependent on sex or small differences in age and weight between the infants.     

Species preference by infant macaques with controlled social experience

In Experiment 1, infant Japanese monkeys and rhesus monkeys were artificially reared in pairs with conspecific or heterospecific monkeys. Preferences of these monkeys for a variety of pictures of Japanese monkeys and rhesus monkeys were repeatedly tested during the first 1 or 2 years of life. The duration of lever-pressing responses to see those pictures was a measure of the preference. All monkeys, Japanese or rhesus, preferred pictures of rhesus monkeys to pictures of Japanese monkeys, without regard to their social experiences. Experiment 2, with an adult Japanese monkey as the subject, and Experiment 3, with different pictures as stimuli, suggested that this preference was not a consequence of any bias in the pictures used. In Experiment 4, a Japanese monkey reared by a rhesus foster mother and rhesus monkeys reared by Japanese monkey mothers received the same preference test. The Japanese monkey infant preferred to see pictures of rhesus monkeys. However, rhesus infants did not show clear species preferences. These results suggest that infants of both Japanese and rhesus monkeys have a native tendency to prefer to see physical characteristics of rhesus monkeys over Japanese monkeys.     

Normal hematological indices, blood chemistry and histology and ultrastructure of pancreatic islets in the wild Indian bonnet monkeys (Macaca radiata radiata)

The present study is aimed at determining some haematological and biochemical parameters in the wild Indian bonnet monkeys as also the microscopic and ultrastructural characteristics of their pancreatic islets. Adult wild Indian bonnet monkeys (Macaca radiata radiata) of both sexes weighing between 2.5 and 4 kg were used in these experiments. Their platelet, reticulocyte and total leukocyte counts and the blood concentrations of hemoglobin and plasma proteins and the serum concentrations of aspartate amino transferase, alanine amino transferase and calcium are similar to the values reported for M. mulatta. Plasma glucose is lower when compared with reported values of M. mulatta and M. fascicularis. Insulin levels are comparable with those of M. mulatta and M. nigra. Histology of islets is similar to that of humans. Ovoid cell collections of islet cells are scattered throughout the pancreas. Ultrastructure of A, B and D cells is similar to humans. These findings suggest that this relatively underutilized macaques may be a suitable model for biomedical research.