An Australasian perspective on the role of reproductive technologies in world food production

Perspective: science and the future of livestock industries

Since the 1990s, livestock industries have been forced to respond to major pressures from society, particularly with respect to methane emissions and animal welfare. These challenges are exacerbated by the inevitability of global heating and the effects it will have on livestock productivity. The same challenges also led to questions about the value of animal-sourced foods for feeding the world. The industries and the research communities supporting them are meeting those challenges. For example, we can now envisage solutions to the ruminant methane problem and those solutions will also improve the efficiency of meat and milk production. Animal welfare is a complex mix of health, nutrition and management. With respect to health, the 'One Health' concept is offering better perspectives, and major diseases, such as helminth infection, compounded by resistance against medication, are being resolved through genetic selection. With respect to nutrition and stress, 'fetal programming' and the epigenetic mechanisms involved offer novel possibilities for improving productivity. Stress needs to be minimized, including stress caused by extreme weather events, and solutions are emerging through technology that reveals when animals are stressed, and through an understanding of the genes that control susceptibility to stress. Indeed, discoveries in the molecular biology of physiological processes will greatly accelerate genetic progress by contributing to genomic solutions. Overall, the global context is clear - animal-sourced food is an important contributor to the future of humanity, but the responses of livestock industries must involve local actions that are relevant to geographical and socio-economic constraints.

Frontiers in sheep reproduction - making use of natural responses to environmental challenges to manage productivity

This review addresses advances, directions and opportunities for research on sheep reproduction in the context of the global challenges of food security and climate change, and demand for 'clean, green and ethical' (CGE) animal management. The foundation of CGE management is an understanding of the physiological processes through which the reproductive system responds to changes in the animal's environment. These days, to the main environmental factors (photoperiod, nutrition, pheromones), we need to add stress from extreme weather events. With respect to nutrition in rams, we now have a deeper understanding of the responses of the brain centres that control gonadotrophin secretion (the kisspeptin system). At testis level, we have found that nutrition affects non-coding RNAs in Sertoli cells and germ cells, thus affecting the balance between cell proliferation and apoptosis. This proliferation-apoptosis balance is also affected during prenatal development, when undernutrition or stress in pregnant ewes seems to elicit epigenetic changes in developing gonads that could affect offspring fertility in adult life. With respect to nutrition in ewes, metabolic signals act directly on ovarian follicles, and thus change ovulation rate, but the variety of signals now includes the adipokines. An early concern was that nutritional supplements that increase ovulation rate would also increase embryo mortality but we now know that embryo survival is improved under field conditions. Finally, we had always thought that the efficiency gains from early puberty in lambs could only be achieved by accelerating fat accumulation, but we now know that faster muscle growth will achieve the same goal, offering two advantages in meat production systems. With respect to pheromones ('ram effect'), we have a deeper understanding of the brain responses (kisspeptin system) but, most importantly, a realization that the response of ewes to the ram signal involves cell division in memory centres. Many opportunities remain.

Interactions between Nutrition and the “Ram Effect” in the Control of Ovarian Function in the Merino Ewe

Simple Summary

Clean, green, and ethical management of sheep flocks involves the use of socio-sexual stimuli (the “ram effect”) to coordinate nutritional inputs into reproductive success. However, the value of the “ram effect” is limited by three factors: (i) the proportion of the ewe flock that ovulates; (ii) ovulation rate in ewes that respond to the ram stimulus; and (iii) luteal failure after the first ram-induced ovulation, leading to short luteal phases. We tested whether these problems could be overcome by using a brief nutritional supplement (500 g lupin grain per head daily for 6 days) to stimulate ovarian activity. Lupin supplementation before ram introduction did not improve the percentage of the ewe flock that ovulates or reduce the frequency of short cycles (so will not improve the synchrony of lambing). However, lupin supplementation after ram introduction should be used to increase prolificacy.

Abstract

We tested whether short-term nutritional supplementation (500 g lupin grain per head daily) would affect the response of ewes to the ram effect. Experiment 1 (end of non-breeding season): ewes were supplemented for either Days −6 to −1 relative to ram introduction (n = 24) or for 12 days after ram introduction (Days 11 to 22 of the ram-induced cycle; n = 29). Controls (n = 30) were not supplemented. Across all groups, 94–100% of ewes ovulated. Supplementation before ram introduction did not affect ovulation rate at the ram-induced ovulation but increased it during the ram-induced cycle (Control 1.37; supplemented 1.66; p < 0.05). Experiment 2 (the middle of non-breeding season): the supplement was fed for Days −5 to −1 relative to ram introduction. Again, supplementation did not increase number ovulating (Control 16/29; Supplemented 10/29) but it did increase ovulation rate at the ram-induced ovulation (Control 1.31; Supplemented 1.68; p < 0.05). In neither experiment did supplementation affect the frequency of short cycles. Supplementation before ram introduction did not improve the percentage of ewes ovulating or reduce the frequency of short cycles (so will not improve the synchrony of lambing). However, supplementation after ram introduction can increase prolificacy.

State-of-the-Art and Prospective of Nanotechnologies for Smart Reproductive Management of Farm Animals

Many biotechnological assisted reproductive techniques (ART) are currently used to control the reproductive processes of farm animals. Nowadays, smart ART that considers technique efficiency, animal welfare, cost efficiency and environmental health are developed. Recently, the nanotechnology revolution has pervaded all scientific fields including the reproduction of farm animals, facilitating certain improvements in this field. Nanotechnology could be used to improve and overcome many technical obstacles that face different ART. For example, semen purification and semen preservation processes have been developed using different nanomaterials and techniques, to obtain semen doses with high sperm quality. Additionally, nanodrugs delivery could be applied to fabricate several sex hormones (steroids or gonadotrophins) used in the manipulation of the reproductive cycle. Nanofabricated hormones have new specific biological properties, increasing their bioavailability. Applying nanodrugs delivery techniques allow a reduction in hormone dose and improves hormone kinetics in animal body, because of protection from natural biological barriers (e.g., enzymatic degradation). Additionally, biodegradable nanomaterials could be used to fabricate hormone-loaded devices that are made from non-degradable materials, such as silicon and polyvinyl chloride-based matrixes, which negatively impact environmental health. This review discusses the role of nanotechnology in developing some ART outcomes applied in the livestock sector, meeting the concept of smart production.

Ethical issues in the development and implementation of nutrition-related public health policies and interventions: A scoping review

Background

The limited integration of ethics in nutrition-related public health policies and interventions is one major concern for those who have the task of implementing them. Ethical challenges that are overlooked during the development of such interventions could raise serious ethical issues during their implementation and even after. As a result, these decision makers need technical support and ethical guidance for adaptation of interventions to local (cultural, social, economic, etc.) contexts.

Aim

The goal of this scoping review is to delineate and “map” the range of ethical issues in nutrition-related public health interventions, as well as the range of the various fields in which they may arise.

Methods

A scoping review of empirical research and conceptual literature was conducted following the framework of Arksey and O’Malley. Searches using PubMed with Medical Subject Headings (MeSH) categories and Advanced Search Builder as well as in the Global Health Library were performed. The final sample consists of 169 publications.

Results

The ethics of public health prevention or treatment of obesity and non-communicable diseases is the most explicitly and frequently discussed subject. In comparison, ethical issues raised by public health interventions in the fields of undernutrition, breastfeeding, vitamin/mineral supplementation and food fortification, food security, food sustainability and food safety are addressed in a lower proportion of the sample. The results illustrate the various natures, types, and scopes of existing public health nutrition-related interventions, and the various ethical issues that may be raised by these interventions, in addition to the numerous and different contexts in which they may be implemented.

Discussion

The ethical issues faced in the development and implementation of nutrition-related public health interventions are varied and cannot be equated with, nor generalized about, when dealing with specific activities in this field. More importantly, these ethical issues cannot be managed without a careful consideration for the complexity of contexts in which nutrition-related interventions are expected to be implemented. These interventions engage a variety of actors with diverse perspectives and interests. We discuss these challenges and also comment on the importance of considering ethical impacts in the monitoring and evaluation of such interventions.

Conclusion

General ethical frameworks or recommendations–although useful–cannot be expected to provide policy makers, implementators and other public health personnel with sufficient practical ethical guidance as they cannot consider and anticipate the particularities of all specific nutrition-related public health interventions and the complexity of the contexts in which they are implemented. Further research is needed in order to develop more targeted ethical frameworks.

Nanomedicine and mammalian sperm: Lessons from the porcine model

Biomedical nanotechnology allows us to engineer versatile nanosized platforms that are comparable in size to biological molecules and intracellular organelles. These platforms can be loaded with large amounts of biological cargo, administered systemically and act at a distance, target specific cell populations, undergo intracellular internalization via endogenous uptake mechanisms, and act as contrast agents or release cargo for therapeutic purposes. Over recent years, nanomaterials have been increasingly viewed as favorable candidates for intragamete delivery. Particularly in the case of sperm, nanomaterial-based approaches have been shown to improve the efficacy of existing techniques such as sperm-mediated gene transfer, loading sperm with exogenous proteins, and tagging sperm for subsequent sex- or function-based sorting. In this short review, we provide an outline of the current state of nanotechnology for biomedical applications in reproductive biology and present highlights from a series of our studies evaluating the use of specialized silica nanoparticles in boar sperm as a potential delivery vehicle into mammalian gametes. The encouraging data obtained already from the porcine model in our laboratory have formed the basis for ethical approval of similar experiments in human sperm, thereby bringing us a step closer toward the potential use of this novel technology in the clinical environment.