Impacts of Climate Change on Livestock Production: A Review

Abstract

This review was conducted to assess the effect of climate change on livestock production. The climate change especially global warming may highly influence production performance of farm animals throughout the world. Among the environmental variable that affect animals heat stress seems to be the intriguing factor making animal production challenging in many geographical locations in the world. changes in climatic factors such as temperature, precipitation and the frequency and severity of extreme events like droughts directly affected livestock yields. All animals have a range of ambient environmental temperature termed as thermo neutral zone and temperature above or below this thermo neutral range of the animal create stress condition in animals. A thermal environment is a major factor that affects milk production in dairy cow especially on animals of high genetic merit. Milk yield decline by 0.2kgper unit increase thermal humidity index (THI) when it exceeded 72.The increase in milk yield increase sensitivity of animals to thermal stress and decline the threshold temperature at which milk losses occur. The mid lactating dairy cows were the most heat sensitive compared to their early and late lactating counterparts. In addition mid lactating dairy cows showed a higher decline in milk production (-38%) when the animals were exposed to heat. Animals can adapt the hot environment, however the response mechanism are helpful for survival but are detrimental to productive and reproductive performances. Reproduction is normally luxurious phenomenon and appropriate when the animal is in right homeostasis. Heat stress due to high ambient temperature accompanied with excess humidity cause infertility in most of the farm species and adverse effect on reproductive performance of farm animals. Climate change has a direct impact on the growth of palatable grass species and the regeneration of fodder species in pasture and forest fodder is decreasing because of less rainfall leading to a shortage in diversity and quality of livestock fodder. This has led to a decrease in livestock population which has further affected production of milk, milk products and meat. The drought also affected livestock by drying wetlands, pasture land, water resources, streams and decreasing availability of drinking water for livestock. Temperature increase led to outbreak of new born diseases and scarcity of fodder led to change in livestock pattern Changes in rainfall and temperature regimes may affect both the distribution and abundance of disease causing vectors, as can changes in the frequency of extreme events. Higher temperature resulting from climate change may increase the rate of development of certain pathogen or parasites that have one or more life cycle stages outside their animal host. This may shorten generation times and possible increase the total number of generations per year leading to higher pathogen or parasite population size. Therefore to adapt climate change farmers from developing countries implement different adaptation strategies such as breeding locally adapted livestock species, diversifying livestock types, proper resource management practices and alternative feed production technologies.