Annual Review of Animal Biosciences最新文献

Challenges in livestock production in developing countries are often linked to a high disease prevalence and may be related to poor husbandry, feeding, and nutrition practices, as well as to inadequate access to preventive veterinary care. Structural barriers including chronic poverty, gender roles, inadequate supply chains, and limitations in surveillance infrastructure further complicate progress. Despite many challenges, the livestock sector substantially contributes to agricultural GDP, and reducing livestock disease prevalence is a goal for many countries. One Health initiatives that work across disciplines and sectors to reduce livestock diseases are underway around the world and use integrated approaches that consider the connections between humans, animals, and their shared environments. The growing recognition of the role livestock play in sustainability and livelihoods, as well as their involvement in zoonotic disease transmission and global health security, has highlighted the need for disease reduction strategies as described in this review.

The decline in human reproductive and metabolic health over the past 50 years is associated with exposure to complex mixtures of anthropogenic environmental chemicals (ECs). Real-life EC exposure has varied over time and differs across geographical locations. Health-related issues include declining sperm quality, advanced puberty onset, premature ovarian insufficiency, cancer, obesity, and metabolic syndrome. Prospective animal studies with individual and limited EC mixtures support these observations and provide a means to investigate underlying physiological and molecular mechanisms. The greatest impacts of EC exposure are through programming of the developing embryo and/or fetus, with additional placental effects reported in eutherian mammals. Single-chemical effects and mechanistic studies, including transgenerational epigenetic inheritance, have been undertaken in rodents. Important translational models of human exposure are provided by companion animals, due to a shared environment, and sheep exposed to anthropogenic chemical mixtures present in pastures treated with sewage sludge (biosolids). Future animal research should prioritize EC mixtures that extend beyond a single developmental stage and/or generation. This would provide a more representative platform to investigate genetic and underlying mechanisms that explain sexually dimorphic and individual effects that could facilitate mitigation strategies.

There are plenty of reasons to believe that parasite populations will respond to biodiversity loss, warming, pollution, and other forms of global change. But will global change enhance transmission, increasing the incidence of troublesome parasites that put people, livestock, and wildlife at risk? Or will parasite species decline in abundance-or even become extinct-suggesting trouble on the horizon for parasite biodiversity? Here, I explain why answers have thus far eluded us and suggest new lines of research that would advance the field. Data collected to date suggest that parasites can respond to global change with increases or decreases in abundance, depending on the driver and the parasite. The future will certainly bring outbreaks of some parasites, and these should be addressed to protect human and ecosystem health. But troublesome parasites should not consume all of our research effort, because this changing world contains many parasite species that are in trouble.

Dogs have played an outsized role in the field of behavioral genetics since its earliest days. Their unique evolutionary history and ubiquity in the modern world make them a potentially powerful model system for discovering how genetic changes lead to changes in behavior. Genomic technology has supercharged this potential by enabling scientists to sequence the DNA of thousands of dogs and test for correlations with behavioral traits. However, fractures in the early history of animal behavior between biological and psychological subfields may be impeding progress. In addition, canine behavioral genetics has included almost exclusively dogs from modern breeds, who represent just a small fraction of all dog diversity. By expanding the scope of dog behavior studies, and incorporating an evolutionary perspective on canine behavioral genetics, we can move beyond associations to understanding the complex interactions between genes and environment that lead to dog behavior.

Immune modulation in animal agriculture has been of research interest for several decades, yet only a few immunomodulators have received regulatory approval in the United States and around the world. In this review, we summarize market and regulatory environments impacting commercial development of immunomodulators for use in livestock and poultry. In the United States, very few immunomodulators have received regulatory approval for use in livestock by either the US Department of Agriculture Center for Veterinary Biologics or the Food and Drug Administration (FDA). To date, only one immunomodulator has received FDA approval, and an extensive body of peer-reviewed literature is available regarding the basis for its use and health benefits. We present a more thorough review of the history and impact of this immune restorative. Finally, we discuss the interaction of immunomodulators on health, metabolism, and other factors impacting the future of immune modulation in livestock.

Second-generation biofuel production, which aims to convert lignocellulose to liquid transportation fuels, could be transformative in worldwide energy portfolios. A bottleneck impeding its large-scale deployment is conversion of the target polysaccharides in lignocellulose to their unit sugars for microbial fermentation to the desired fuels. Cellulose and hemicellulose, the two major polysaccharides in lignocellulose, are complex in nature, and their interactions with pectin and lignin further increase their recalcitrance to depolymerization. This review focuses on the intricate linkages present in the feedstocks of interest and examines the potential of the enzymes evolved by microbes, in the microbe/ruminant symbiotic relationship, to depolymerize the target polysaccharides. We further provide insights to how a rational and more efficient assembly of rumen microbial enzymes can be reconstituted for lignocellulose degradation. We conclude by expounding on how gains in this area can impact the sustainability of both animal agriculture and the energy sector.

The beak, a pivotal evolutionary trait characterized by high morphological diversity and plasticity, has enabled birds to survive mass extinction events and subsequently radiate into diverse ecological niches worldwide. This remarkable ecological adaptability underscores the importance of uncovering the molecular mechanisms shaping avian beak morphology, particularly benefiting from the rapidly advancing archives of genomics and epigenomics. We review the latest advancements in understanding how genetic and epigenetic innovations control or regulate beak development and drive beak morphological adaptation and diversification over the past two decades. We conclude with several recommendations for future endeavors, expanding to more bird lineages, with a focus on beak shape and the lower beak, and conducting functional experiments. By directing research efforts toward these aspects and integrating advanced omics techniques, the complex molecular mechanisms involved in avian beak evolution and morphogenesis will be deeply interpreted.

Achieving net-zero greenhouse gas (GHG) emissions in dairy production will require >50% reduction in enteric methane (CH₄) emissions together with elimination of emissions from feed production, additional carbon sequestration, reduction in manure emissions, anaerobic digestion of manure, and decreased reliance on fossil fuel energy. Over past decades, improved production efficiency has reduced GHG intensity of milk production (i.e., emissions per unit of milk) in the United States, but this trend can continue only if cows are bred for increased efficiency. Genetic selection of low-CH₄-producing animals, diet reformulation, use of feed additives, and vaccination show tremendous potential for enteric CH₄ mitigation; however, few mitigation strategies are currently available, and added cost without increased revenue is a major barrier to implementation. Complete elimination of CH₄ emissions from dairying is likely not possible without negatively affecting milk production; thus, offsets and removals of other GHGs will be needed to achieve net-zero milk production.

Most conservation programs and laws aim to prevent extinction. However, there is a gulf between such aspirations and the current reality of escalating biodiversity loss. This review focuses on efforts to prevent extinctions in Australia, but much of this consideration is likely to apply globally. As context, we consider the reasons for trying to prevent extinction, review Australia's extinction record, and note that there are likely to be many more extinctions than formally recognized. We describe recent cases where conservation actions have prevented extinction. We note that extinction is a pathway rather than solely an endpoint, and many decisions made or not made on that pathway can determine the fate of species. We conclude that all looming extinctions can and should be prevented. This will require transformational change in legislation, increased resourcing, more consideration of poorly known species, and increased societal recognition of the need to be responsible for the care of country.

Implantation in cattle is a key developmental checkpoint for pregnancy success. It involves careful spatiotemporal changes to the transcriptional landscape of the endometrium, with the heterogeneous nature of the endometrium increasing the complexity of understanding of the mechanism involved. Implantation is impacted by the developmental competency of the embryo, use of assisted reproductive technologies, and the environment in which this process occurs. We identify the factors that most impact the implantation process in cattle and highlight how it differs with that in other placental mammals. We propose the major areas that lack evidence are the mechanism(s) by which implantation itself occurs and how different stressors alter this process. Our understanding is hindered by a lack of appropriate in vitro models; however, development of novel 3D tools and available data sets will further elucidate the implantation process. Perhaps more importantly, this will develop methods to mitigate against these stressors to improve implantation success and offspring health.