Veterinary and hygienic methods of directed reproduction in formation of healthy herds of cows

Our work provided for the study of the impact of directed reproduction of cows on the formation of highly productive healthy herds in the basic farms of the Republic of Kazakhstan. For accelerated replacement of herd and increase of number of highly productive cows in large farms for milk production one uses sexed semen at the first and the second insemination of primiparous cows obtained from highly productive mothers. The efficiency obtained from using this technique is 65-95% of individuals of the desired sex. Insemination was carried out by recto-cervical method using a tool AlphaVision frozen-thawed sexed semen divided by sex. The highest results of the fruitfulness of insemination with sexed semen in Agricultural production cooperative “Breeding Plant Almaty”, Individual entrepreneur “Karimov” and Kakpatas Kordai were obtained in the autumn-winter period and ranged from 58.1 to 65.2%, with an insemination index of 1.58-1.72. Economic efficiency when using the technology of artificial insemination of calves with sexed semen amounted to 10,040.2 tenge. When using sexed semen, an average of 92% of calves were obtained from bovine. Less insemination costs, the profit from calf production amounted to 76,109.2 tenge.

An intergenerational androgenic mechanism of female intrasexual competition in the cooperatively breeding meerkat

Female intrasexual competition can be intense in cooperatively breeding species, with some dominant breeders (matriarchs) limiting reproduction in subordinates via aggression, eviction or infanticide. In males, such tendencies bidirectionally link to testosterone, but in females, there has been little systematic investigation of androgen-mediated behaviour within and across generations. In 22 clans of wild meerkats (Suricata suricatta), we show that matriarchs 1) express peak androgen concentrations during late gestation, 2) when displaying peak feeding competition, dominance behaviour, and evictions, and 3) relative to subordinates, produce offspring that are more aggressive in early development. Late-gestation antiandrogen treatment of matriarchs 4) specifically reduces dominance behaviour, is associated with infrequent evictions, decreases social centrality within the clan, 5) increases aggression in cohabiting subordinate dams, and 6) reduces offspring aggression. These effects implicate androgen-mediated aggression in the operation of female sexual selection, and intergenerational transmission of masculinised phenotypes in the evolution of meerkat cooperative breeding.

Cooperative breeding and the emergence of multilevel societies in birds

Multilevel societies (MLSs), where social levels are hierarchically nested within each other, are considered one of the most complex forms of animal societies. Although thought to mainly occur in mammals, it is suggested that MLSs could be under-detected in birds. Here we propose that the emergence of MLSs could be common in cooperatively breeding birds, as both systems are favoured by similar ecological and social drivers. We first investigate this proposition by systematically comparing evidence for multilevel social structure in cooperative and non-cooperative birds in Australia and New Zealand, global hotspots for cooperative breeding. We then analyse non-breeding social networks of cooperatively breeding superb fairy-wrens (Malurus cyaneus) to reveal their structured multilevel society, with three hierarchical social levels that are stable across years. Our results confirm recent predictions that MLSs are likely to be widespread in birds and suggest that these societies could be particularly common in cooperatively breeding birds.

Prolactin and the regulation of parental care and helping behavior in cooperatively breeding white-browed sparrow weaver societies

In many cooperatively breeding societies non-breeding individuals help to rear the offspring of breeders. The physiological mechanisms that regulate such cooperative helping behavior are poorly understood, but may have been co-opted, during the evolution of cooperative breeding, from pre-existing mechanisms that regulated parental care. Key among these may be a role for prolactin. Here we investigate whether natural variation in circulating prolactin levels predicts both parental and helper contributions to nestling provisioning in cooperatively breeding white-browed sparrow weavers, Plocepasser mahali. In sparrow weaver groups, a single dominant pair monopolize reproduction and non-breeding subordinates help with nestling feeding. We show that: (i) among parents, dominant females feed nestlings at higher rates, make longer provisioning visits and have higher prolactin levels than dominant males; and (ii) among subordinates, engaged in cooperative helping behavior, those within their natal groups feed nestlings at higher rates and have higher prolactin levels than immigrants. Moreover, continuous variation in prolactin levels positively predicts nestling-provisioning rates and mean provisioning visit durations when all bird classes are combined. These relationships are principally driven by differences among bird classes in both circulating prolactin levels and provisioning traits; the more limited within-class variation in prolactin and provisioning traits were not evidently correlated, highlighting a likely role for additional mechanisms in the fine-scale regulation of care. Our findings broadly support the hypothesis that parental care and cooperative helping behavior are regulated by a common underlying mechanism and highlight the need for experimentation to now establish the causality of any role for prolactin.

Grandparental Investment

This chapter assesses the alloparental role that grandparents play in the human cooperative breeding system. Grandparenthood is an intriguing phenomenon and a fascinating chapter in the extraordinary human life-history story. Grandparental investment is well-defined as an adaptive strategy that enhances inclusive fitness. Although there is great diversity in grandparenting practices across human cultures, the evidence clearly demonstrates that grandparents help, and that that help is beneficial to the whole fitness unit. By applying an evolutionary ecological framework to understanding how differential grandparental solicitude emerges, and by understanding that these differences depend on genetic, ecological, and social factors, predictable patterns of investment can be derived.

Dynamic finite-element simulations reveal early origin of complex human birth pattern

Human infants are born neurologically immature, but whether this originates from conflicting selection pressures between bipedal locomotion and encephalization as suggested by the obstetrical dilemma remains controversial. Australopithecines are ideal for investigating this trade-off as they have a bipedally adapted pelvis, yet relatively small brains. Our finite-element birth simulations based on different pelvic reconstructions and a range of fetal head sizes indicate that australopithecines already possessed a human-like rotational birth pattern. Since only newborn head sizes smaller than those predicted for non-human primates leave adequate space for soft tissue between the bony pelvis and fetal skull, our data imply that australopithecines had secondarily altricial newborns and likely evolved cooperative breeding to care for their helpless infants. These prerequisites for advanced cognitive development therefore seem to have been corollary to skeletal adaptations to bipedal locomotion that preceded the appearance of the genus Homo and the increase in encephalization.