Impact of global warming on the productive and reproductive efficiency of goats

Global warming is the rise in the average temperature of Earth's atmosphere and oceans. Climate change has had an enormous impact on domestic animal production system. Thermal stress is the most prominent impact of global warming in goat production resulting in a range of physiological, metabolic and production disorders. Negative energy balance due to poor food quality and heat stress cause endocrinal disturbances: increased frequency of LH-waves (anovulatory cycles), increased diameter of dominant follicle (lower concentration of oestradiol)) and increased system or intrafollicular level of insulin–like growth factor-I (IGF-I). Glucocorticoids inhibit the release of gonadotrope hormones, which reduces fertility probably due to ovulation failure and reduced growth and maturation of follicles. A high temperature several days prior to and after mating was found to reduce conception rate, since heat stress may negatively affect oocytes, spermatozoa and embryos. Increased ambient temperature also affects animal health, reproduction and nutrition, resulting in poor reproductive performance, low product quality and quantity, or the possible outbreak of new diseases. The indirect impact of global warming is manifested in the reduced production of fodder used to feed animals due to long-term droughts or floods. In addition to decreased quantity of animal feed, the quality of fodder grown during droughts or floods is also questionable. As a result of feeding with poor quality feed and insufficient quantities, numerous metabolic and endocrine disorders occur that can significantly affect fertility and sexual performance in goats. Globalno zatopljenje je porast prosječne temperature Zemljine atmosfere i oceana. Klimatske promjene imaju ogroman utjecaj na sustav uzgoja domaćih životinja. Toplinski stres je najizrazitiji utjecaj globalnog zatopljenja na uzgoj koza koji rezultira različitim fiziološkim, metaboličkim i proizvodnim poremećajima. Negativna energetska ravnoteža zbog loše kvalitete hrane i toplinski stres prouzroče endokrine poremećaje: povećanu učestalost LH-valova (anovulatorni ciklusi), povećani promjer dominantnog folikula (nižu koncentraciju estradiola) te povećanu sustavnu ili intrafolikularnu razinu faktora rasta sličnog inzulinu-I (IGF-I). Glukokortikoidi inhibiraju oslobađanje gonadotropnih hormona koji smanjuju plodnost vjerojatno zbog izostanka ovulacije, usporenog rasta i sazrijevanja folikula. Utvrđeno je da visoka temperatura nekoliko dana pri