Genetic Diversity and Population Structure of Mesoamerican Scarlet Macaws in an Ex Situ Breeding Population in Mexico

Given the interest in the conservation of the Mesoamerican scarlet macaw (Ara macao cyanoptera), the Xcaret Park formed an initial reproductive population about 30 years ago, which has progressively grown to a considerable population in captivity. In this work, we focus on the evaluation of the genetic diversity of the captive population, taking two groups into account: its founding (49) and the current breeding individuals (166). The genetic analysis consisted of genotyping six nuclear microsatellite loci that are characterized by their high variability. Tests for all loci revealed a Hardy–Weinberg equilibrium in four loci of the founders and in no loci of the breeding groups. The results showed that the genetic variation in the Xcaret population was relatively high (founders He = 0.715 SE = 0.074, breeding pairs He = 0.763 SE = 0.050), with an average polymorphism of 7.5 (4–10) alleles per locus in founders and 8.3 (4–14) in breeding pairs. No significant differences in the evaluated genetic diversity indexes were found between both groups. This indicates that the genetic variability in Xcaret has been maintained, probably due to the high number of pairs and the reproductive management strategy. Bayesian analysis revealed five different genetic lineages present in different proportions in the founders and in the breeding pairs, but no population structure was observed between founders and breeding individuals. The analyzed captive individuals showed levels of genetic diversity comparable to reported values from Ara macao wild populations. These data indicate that the captive population has maintained a similar genetic diversity as the metapopulation in the Mayan Forest and is an important resource for reintroduction projects, some of which began more than five years ago and are still underway.

A method for partitioning trends in genetic mean and variance to understand breeding practices

Quantifying the sources of genetic change is essential for optimising breeding programmes. However, breeding programmes are often complex because many breeding groups are subject to different breeding actions. Understanding the contribution of these groups to changes in genetic mean and variance is essential to understanding genetic change in breeding programmes. Here we extend the previously developed method for analysing the contribution of groups to changes in genetic mean to analysing changes in genetic variance. We, expectedly, show that the contribution of females and males to change in genetic variance can differ and are not independent, indicating we should not look at the contributions in isolation.

Measuring dominance certainty and assessing its impact on individual and societal health in a nonhuman primate model: a network approach

The notion of dominance is ubiquitous across the animal kingdom, wherein some species/groups such relationships are strictly hierarchical and others are not. Modern approaches for measuring dominance have emerged in recent years taking advantage of increased computational power. One such technique, named Percolation and Conductance (Perc), uses both direct and indirect information about the flow of dominance relationships to generate hierarchical rank order that makes no assumptions about the linearity of these relationships. It also provides a new metric, known as ‘dominance certainty’, which is a complimentary measure to dominance rank that assesses the degree of ambiguity of rank relationships at the individual, dyadic and group levels. In this focused review, we will (i) describe how Perc measures dominance rank while accounting for both nonlinear hierarchical structure as well as sparsity in data—here we also provide a metric of dominance certainty estimated by Perc, which can be used to compliment the information dominance rank supplies; (ii) summarize a series of studies by our research team reflecting the importance of ‘dominance certainty’ on individual and societal health in large captive rhesus macaque breeding groups; and (iii) provide some concluding remarks and suggestions for future directions for dominance hierarchy research. This article is part of the theme issue ‘The centennial of the pecking order: current state and future prospects for the study of dominance hierarchies’.

Steppe Eagle in the Republic of Kalmykia (Russia): Results of the 2021 Survey

The article presents the results of the Steppe Eagle (Aquila nipalensis) study in the Republic of Kalmykia. 135 breeding territories of eagles were examined and 155 birds were observed during summer registrations and counts. The average distribution density of the occupied breeding territories in 2021 in the main part of the area was 2.15 (1.54–2.99)/100 km², in the zone of the large number of food resources – 5.72 (4.45–7.35)/100 km². The percentage of occupied breeding territories was 71%, and 43% of the occupied territories were successful. The number of nestlings in broods ranged from 1 to 3, averaging 1.81±0.69 per successful nest (n=43) and 0.73±0.95 per occupied nest (n=105). The percentage of nests with dead clutches and nestlings was high at all surveyed plots. The main diet of eagles during the breeding period included the Little Ground Squirrel (Spermophilus pygmaeus) (44%) and several additional prey items. A preliminary assessment of habitat suitability for the Steppe Eagle in terms of food conditions was carried out using GIS methods. Based on the registration data and clarification of the breeding range borders (47086.7 km²), the number of the Steppe Eagle in Kalmykia was re-estimated at 789 (587–1059) pairs. The signs indicating a negative trend in the population intensified: the percentage of immature birds in breeding pairs was 27%, the percentage of abandoned breeding territories was 19%. There is a consolidation of breeding groups in the population nucleus with a simultaneous decrease in breeding density at the periphery. Among the negative anthropogenic factors in 2021 there were the following: mass mortality on power lines, destruction of the food potential by the locals, disturbance during breeding, probable taking away of nestlings from nests.

Contribution of adult sex ratio to trauma and reproductive output in large breeding groups of rhesus macaques (Macaca mulatta)

Maintaining stable breeding groups of rhesus macaques (Macaca mulatta) can be challenging due to the complex social dynamics and despotic nature of the species. Trauma from aggression is a common problem in rhesus colonies and can cause social disruption, strain veterinary and animal management resources, and potentially affect reproduction. Previous research has shown that increasing the number of non-natal adult males in a breeding group can improve group stability, reduce trauma, and increase reproduction. Here, we used mixed-effects regression models to examine the effects of sex ratio and other factors on trauma and reproduction at the Yerkes National Primate Research Center using a historical dataset made up of four large rhesus groups over an eleven-year period (2003–2013). As expected, sex ratio was a significant predictor for both trauma and reproduction. However, group age since formation was a stronger predictor of trauma frequency and the amount of space available was a slightly better predictor of reproduction than sex ratio or trauma. These results indicate that improving sex ratios can be a viable management strategy to reduce trauma and improve reproduction, particularly when it is difficult to manipulate the group compositions and/or their housing situations. Reducing trauma is a primary goal for rhesus breeding colonies, as it directly impacts the monkeys' health and psychological well-being. Such improvements are necessary for the ethical treatment and care of the animals themselves, but also to reduce financial burdens and maintain a healthy colony for research purposes.

91 Assessing Variability of Herd Sire Economic Value for Commercial Operations

Number of calves (n = 596) and weaning calf value (n = 574) from natural service, multi-sire breeding groups were evaluated in a crossbred research herd. Sires and dams that were F1 crosses of Angus (A) and Nellore (N) were mated annually during 60 to 90-day breeding seasons to produce spring-born calves in 2009–2015. Numbers of sires used annually varied from 5 to 9; numbers of females exposed per bull ranged from 14 to 22 across years. Bulls were pastured together throughout the year as well as breeding seasons. Sires were identified based on calf DNA genotyping. Calf number, birth date, birth weight, weaning weight, and economic value were determined per bull annually. Calf value was based on weaning weight and reported prices for respective weaning dates. Calf prices were calculated separately for steers and heifers relative to 22.7 kg (50 lb) increments for corresponding weight class and year. Mixed model analyses were conducted that included fixed categorical effects of calf birth year, type of F1 sire (A-sired vs. N-sired), sire nested within type, calf sex, and the interaction of F1 sire type with calf sex. Covariates of Julian birth date and calf weaning age were included for birth weight and weaning weight, respectively. Large differences in calf numbers and performance (P < 0.05) were observed. Weaned calves produced annually per sire ranged from 0 to 48. Average annual calf performance per sire ranged from 28.4 to 50.8 kg for birth weight and 146.5 to 249.0 kg for weaning weight. Annual economic value per sire ranged from $0 to $30,870 when considering half of each calf’s value as attributed to the sire. Commercial producers should consider potential sire variability for calf numbers, birth date distribution, and ratio of female-to-male calves in combination with calf performance for economic assessments.

PSII-B-26 Comparison of Suffolk and Texel sired lamb growth and satellite cell proliferation in the early postnatal period

Suffolk ewes (n = 26) were blocked by body condition and weight, and randomly divided into two breeding groups (n = 13/group). One group was bred to a Texel ram and the other to a Suffolk ram. Ewes were confirmed pregnant by ultrasound and went to term. Male lambs (n = 4/sire/time) were harvested on d 2, 14, and 203 of age for muscle characterization and satellite cell isolation. From d 2 to 14, body weight increased (P < 0.01) by 80%, weight of the longissimus increased by 160%, and longissimus muscle area increased by 100%. Between d 14 and 203 lamb weight and weight of the longissimus increased by 350%, while longissimus area only increased by 100%. Sire breed did not alter lamb weight or weight of the longissimus (P > 0.10). Longissimus muscle area tended (P < 0.10) to be increased for Texel sired lambs when compared to Suffolk sired lambs. The total number of satellite cells isolated were not different by sire breed but did differ by animal age (P < 0.01). Satellite cell populations per gram of tissue increased between d 2 and 14 and decreased from d 14 to 203. Due to the large changes in growth from d2 to 14, satellite cell proliferation was examined at d 2 of age. Satellite cell proliferation capacity was altered by sire breed at d 2 of age potentially contributing to the increased longissimus muscle area. Advancing animal age and development alters satellite cell population numbers and potentially supports a high capacity for growth.

PSXV-12 What 30 years of accumulated pregnancy data taught us about the Bos indicus influence on reproductive performance of beef cattle

Bos taurus X Bos indicus crossbreeding is commonly used in tropical and subtropical regions to enhance beef production. The effect of Bos indicus genetics on pregnancy to AI (P/AI) and AI + natural service (P/AI+NS) is understudied. We measured the indicus effect from a 30-year dataset of the University of Florida multibreed herd (MBH; n= 7105 animals). The MBH is composed of six breed groups, according to the following proportion of Brahman: 0–19%, 20–34%, 37% (Brangus), 40–59%, 60%-78% and 79%-100%. Estrus of all animals was synchronized using mainly the SelectSynch+CIDR protocol, followed by three-day AI based on heat or timed-AI (TAI) for non-heat animals. After TAI, animals were bred by NS. Breeding seasons lasted 91±18d. Pregnancy was diagnosed by rectal palpation and/or ultrasonography 30d after AI and 30d after removal of bulls. P/AI was affected negatively (P < 0.001) by the proportion of Brahman, regardless of parity, but P/AI+NS was similar across breeding groups (Table 1). By logistic regression, each 1/32nd increment of Brahman influence reduced odds of P/AI by 0.5% (0/32nd = 51.4% to 32/32nd = 35.3%). The variables of body condition score (BCS), days post-partum (DPP) and body weight at the beginning of synchronization protocol did not explain the negative effect of indicus genetics on P/AI. However, indicus genetics were associated negatively with the proportion of animals AIed in heat (P < 0.001). AI in heat resulted in twice as great (P < 0.001) P/AI (65.4%; n = 984) than no-heat TAI (30.9%; n = 829). In conclusion, indicus genetics did not influence overall pregnancy rates at the end of a 90d breeding season. Nevertheless, indicus influence dampened estrus responses to protocols based solely on GnRH-PGF and progestin/progesterone, resulting on suboptimal P/AI (< 40%).

Some Indicators of Nonspecific Immunity of Various Breeding Groups of Carp in Different Periods of the Annual Cycle

A comparative study of some parameters of nonspecific immunity in the Angelinskii rubella-resistant variant of the scaly and mirror groups of carp in the prespawning and late feeding periods was carried out. The level of the antimicrobial properties of the C-reactive protein, nonspecific immune complexes in the blood serum, and phagocytic activity of neutrophils were studied. The study showed interbreed and inter-seasonal differences in some indicators. It is concluded that the higher level of bacteriostatic activity of blood serum in the rubella-resistant variant, compared with other groups of carp, provides a low percentage of immunodeficient individuals and resistance to pathogens of infectious diseases.

Exceptional variation in the appearance of Common Murre eggs reveals their potential as identity signals

We studied the ground colors and maculations of 161 Common Murre (Uria aalge) eggs laid by 43 females in 3 small breeding groups on the cliffs of Skomer Island, Wales, in 2016–2018. Both the colors and maculations varied much more among than within females, providing quantitative evidence for the egg traits that might facilitate the parents’ ability to identify their own eggs on the crowded breeding ledges where the density is typically ~20 eggs m–2. Ground colors had a trimodal distribution of hue values (whitish to pale brown, pale blue, or vivid blue-green) and maculations ranged from none to complex squiggles and blotches. The eggs laid by each female in different years were similar to one another, and replacement eggs laid by females within years were also more similar to their first egg than to other eggs in the same breeding group. Egg appearance did not differ among the 3 breeding groups that we studied. Our findings thus support anecdotal observations that, within and between years, female Common Murres lay eggs that have similar ground colors and maculations. We do not, however, find evidence that there is much difference among the eggs laid in different parts of a colony.