Macronutrient composition of milk from captive southern pig-tailed macaques (Macaca nemestrina)

Milk composition is a fundamental aspect of mammalian reproduction. Differences in milk composition between species may reflect phylogeny, dietary ecology, lactation strategy, and infant growth patterns, but may also vary within a species due to maternal body condition. This study presents the first published data on milk macronutrient composition of southern pig-tailed macaques (Macaca nemestrina) and compares the results with data on two other Cercopithecine species. Milk samples were obtained from five dams at 10- and 14-weeks postparturition. Macronutrient composition was determined at the Smithsonian's National Zoo and Conservation Biology Institute using proven methods developed over 30 years. On average (±SEM), the milk contained 83.9 ± 0.4% water, 6.7 ± 0.4% fat, 7.6 ± 0.1% sugar, 1.8 ± 0.1% protein, and 0.22 ± 0.01% mineral content. The Ca:P ratio was 1.8; concentrations of Ca and protein were correlated. Mean gross energy was 1.02 ± 0.03 kcal/g with most of the energy coming from fat (59.6 ± 1.5%), followed by sugar (29.9 ± 1.4%) and protein (10.5 ± 0.5%). The milks at 14 weeks of infant age were higher in energy than the milks at 10 weeks, with an increase in energy from fat (p = 0.005) and decrease in energy from sugar (p = 0.018). The energy from protein did not change (p = 0.272). Compared to captive rhesus macaque (Macaca mulatta) and olive baboon (Papio anubis) milk assayed by identical methods, captive pig-tailed macaque milk was higher in energy, but after accounting for the higher milk energy there was no difference in the proportions of milk energy from protein, fat, and sugar. The captive pig-tailed dams were significantly heavier than reported values for wild pig-tailed macaques, suggesting high body condition. High body condition in captive Cercopithecines appears to result in milk higher in energy, with more energy coming from fat and less from sugar. However, variation in the proportion of milk energy from protein in captive Cercopithecine milks appears relatively constrained.

The transcriptional legacy of developmental stochasticity

Genetic and environmental variation are key contributors during organism development, but the influence of minor perturbations or noise is difficult to assess. This study focuses on the stochastic variation in allele-specific expression that persists through cell divisions in the nine-banded armadillo (Dasypus novemcinctus). We investigated the blood transcriptome of five wild monozygotic quadruplets over time to explore the influence of developmental stochasticity on gene expression. We identify an enduring signal of autosomal allelic variability that distinguishes individuals within a quadruplet despite their genetic similarity. This stochastic allelic variation, akin to X-inactivation but broader, provides insight into non-genetic influences on phenotype. The presence of stochastically canalized allelic signatures represents a novel axis for characterizing organismal variability, complementing traditional approaches based on genetic and environmental factors. We also developed a model to explain the inconsistent penetrance associated with these stochastically canalized allelic expressions. By elucidating mechanisms underlying the persistence of allele-specific expression, we enhance understanding of development's role in shaping organismal diversity.

Food preference of nine-banded armadillo (Dasypus novemcinctus, Linnaeus, 1758) under human care

This study aims to evaluate the food preference of nine banded armadillos kept in captivity, exposed to four different diets: Diet 1 (D1) - dry dog food and ground beef; Diet 2 (D2) - dry dog food, ground beef, and chicken eggs; Diet 3 (D3) - dog food, ground beef, bananas, and papaya; Diet 4 (D4) - dog food, ground beef, chicken eggs, banana, and papaya. To this end, an experiment was carried out for five weeks, the first four of which were for preliminary management and the fifth week for data collection. Frequency of consumption, total intake for each diet, and intake ratio were evaluated. The dietary preference was higher for the diets with a higher protein percentage (D1 and D2), mainly D2, which presented increased demand and intake starting on the fourth day of observation. In second day of observation, D1 presented the higher intake ratio, but D2 gradually replaced it. The diet containing the lowest protein rate (D3) was the least favored on all observation days and evaluations. In conclusion, the food preference of ex-situ armadillos seems to be related to the inclusion of greater amounts of protein, particularly that of animal origin, with eggs being the most appreciated ingredient in this study.

Marsupial and monotreme milk-a review of its nutrient and immune properties

All mammals are characterized by the ability of females to produce milk. Marsupial (metatherian) and monotreme (prototherian) young are born in a highly altricial state and rely on their mother’s milk for the first part of their life. Here we review the role and importance of milk in marsupial and monotreme development. Milk is the primary source of sustenance for young marsupials and monotremes and its composition varies at different stages of development. We applied nutritional geometry techniques to a limited number of species with values available to analyze changes in macronutrient composition of milk at different stages. Macronutrient energy composition of marsupial milk varies between species and changes concentration during the course of lactation. As well as nourishment, marsupial and monotreme milk supplies growth and immune factors. Neonates are unable to mount a specific immune response shortly after birth and therefore rely on immunoglobulins, immunological cells and other immunologically important molecules transferred through milk. Milk is also essential to the development of the maternal-young bond and is achieved through feedback systems and odor preferences in eutherian mammals. However, we have much to learn about the role of milk in marsupial and monotreme mother-young bonding. Further research is warranted in gaining a better understanding of the role of milk as a source of nutrition, developmental factors and immunity, in a broader range of marsupial species, and monotremes.

Diversity and temporal dynamics of primate milk microbiomes

Milk is inhabited by a community of bacteria and is one of the first postnatal sources of microbial exposure for mammalian young. Bacteria in breast milk may enhance immune development, improve intestinal health, and stimulate the gut-brain axis for infants. Variation in milk microbiome structure (e.g., operational taxonomic unit [OTU] diversity, community composition) may lead to different infant developmental outcomes. Milk microbiome structure may depend on evolutionary processes acting at the host species level and ecological processes occurring over lactation time, among others. We quantified milk microbiomes using 16S rRNA high-throughput sequencing for nine primate species and for six primate mothers sampled over lactation. Our data set included humans (Homo sapiens, Philippines and USA) and eight nonhuman primate species living in captivity (bonobo [Pan paniscus], chimpanzee [Pan troglodytes], western lowland gorilla [Gorilla gorilla gorilla], Bornean orangutan [Pongo pygmaeus], Sumatran orangutan [Pongo abelii], rhesus macaque [Macaca mulatta], owl monkey [Aotus nancymaae]) and in the wild (mantled howler monkey [Alouatta palliata]). For a subset of the data, we paired microbiome data with nutrient and hormone assay results to quantify the effect of milk chemistry on milk microbiomes. We detected a core primate milk microbiome of seven bacterial OTUs indicating a robust relationship between these bacteria and primate species. Milk microbiomes differed among primate species with rhesus macaques, humans and mantled howler monkeys having notably distinct milk microbiomes. Gross energy in milk from protein and fat explained some of the variations in microbiome composition among species. Microbiome composition changed in a predictable manner for three primate mothers over lactation time, suggesting that different bacterial communities may be selected for as the infant ages. Our results contribute to understanding ecological and evolutionary relationships between bacteria and primate hosts, which can have applied benefits for humans and endangered primates in our care.