24. Strategies to Improve Livestock Reproduction Under the Changing Climate Scenario

A hot environment impairs production (growth, meat and milk yield and quality, egg yield, weight, and quality) as well as reproductive performance, metabolic and health status, and immune response. Reproductive inefficiency incurred due to heat stress involves changes in ovarian function and embryonic development by reducing the competence of oocyte to be fertilized and the resulting embryo. The ability of an animal to cope up with environmental stress could be improved through strategic management of reproduction by manipulation of folliculogenesis, hormonal alterations, selective breeding, and application of embryo transfer techniques. Intervention of follicular dynamics with a combination of hormones like FSH, GnRH, and progesterone and ovum pick up (OPU) may result in recovery of competent oocytes. Embryo transfer may facilitate extra advantage of bypassing the thermosensitive window of oocyte development (maturation) and early embryonic development stages. Selecting thermotolerant breeds of livestock species and their selective breeding may be good strategy for combating heat stress. However, a combination of heat stress ameliorative measures including nutritional management, shelter management, and reproductive strategies is required for getting maximum benefits.