Diagnosis of the causes of infertility in llamas and alpacas can be tedious and requires a thorough clinical examination of the animal. This article describes the approach used by the authors to investigate causes of infertility. A review of clinical cases shows that these species have a high rate of reproductive congenital abnormalities. Other major causes of infertility include trauma, infections and birthing complications. Prebreeding reproductive evaluation is important for maximising fertility and maintaining the good health and well-being of the animal.

The in vitro production of embryos is an extremely important tool for the genetic improvement for livestock. In this review, the main obstacles to and improvements in this biotechnology in goats and sheep are presented. A recent outlook indicates that if only the blastocyst rate is considered, the overall efficiency achieved in recent studies is similar to that obtained two to three decades ago; however, the quality of embryos is increasing, and cryotolerance is extremely important for the industry.

As the international production and trade of embryos continues to grow, it is imperative to continue to evaluate emerging and re-emerging embryo pathogens. This paper highlights the growth of in vitro-produced embryo production internationally and the emerging and re-emerging pathogens that are of concern to the international trade of embryos. There are some pathogens that are of special concern because they have been shown to be associated with the embryo and pose a potential threat to the international trade of embryos.

The ovarian pool of follicles, and their enclosed oocytes, is highly sensitive to hyperthermia. This review discusses some cellular and molecular mechanisms by which heat stress compromises oocyte developmental competence, emphasising that even though the oocyte is exposed to heat stress, changes are also manifested in the developed embryo. The effect of heat stress carries over from the summer to the autumn, but there is a spontaneous recovery until the winter, indicating that the phenomenon is transient.

The production of spermatozoa and eggs from pluripotent stem cells in a culture dish is a key challenge in reproductive biology and regenerative medicine. It has been achieved in mice, but not yet in humans and other mammals. This review updates the frontline of gamete production in culture and discusses the benefits of and issues with the technology.

Previous studies have demonstrated that exposure to environmental factors can cause epigenetic modifications to germ cells, particularly sperm, to promote epigenetic and transcriptome changes in the embryo. The studies reviewed in this paper support the idea that environmentally induced epigenetic changes in germ cells affect alterations in embryo cell epigenetics and transcriptomes that have an important role in the epigenetic inheritance of pathology and phenotypic change.