Climate change: effects on animal reproduction.

Abstract

Abstract The amounts of greenhouse gases in the atmosphere have been increased as a result of human activity, causing rise in climatic temperature. In recent times, climate has been changing faster than ever; as a result, plants and animals are exposed to more adverse conditions and are finding it difficult to adjust in temperate and tropical regions. The existence of some animals and plants is threatened. Threat to existence is due mostly to low or no reproduction. Photoperiodic action is mediated through the hypothalamus; however, nutrition and stress affect the entire hypothalamus-pituitary and gonadal axis of both male and female systems. The effects are: aberrant gametogenesis, folliculogenesis and ovulation, reduced male and female sexual behaviour, low conception rates, increased embryo and pregnancy loss, delayed post-partum recovery, increased calving intervals, lowered perinatal vigour and increased perinatal mortality and morbidity, etc. These losses are difficult to recognize and diagnose, and the consequence is expensive maintenance of animals with reduced reproductive efficiency. Low productive-reproductive performance of animals after birth is related to the epigenetic changes in the maternal womb due to nutritional deficiency and exposure to stressors. Therefore, animal farming activities are facing, and will continue to face, a tough challenge until some steps are taken to counteract these anticipated damages. Slow adoptive animals would be endangered, as they will face more problems with successful reproduction. It needs a coordinated effort for faster identification of allelic variation of important genes and transfer of adoptive variability to existing animal population by cross-breeding or any other suitable breeding policy. This chapter describes in detail the climatic factors, the mechanisms of their effect and the way forward to counter these effects.