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In this era of rapid climate change, heat stress has emerged as a major problem for sheep farming. The quantity and quality of sheep production, as well as the welfare, are all shown to be negatively impacted by heat stress. Reduced cellular immune function in sheep exposed to high temperatures increases susceptibility to various diseases, although the underlying mechanisms are unclear. The imbalance between oxidants and antioxidants, known as oxidative stress, negatively impacts animal health due to heat stress-induced impairments in immune responses, increased production of reactive oxygen species, and/or a lack of antioxidants. Heat stress in livestock has negative effects on both the cell-mediated and humoral immune responses. However, the negative effects of heat stress on immune response in sheep can vary by breed. This review discusses how heat stress affects sheep's immunity. An overview of some molecular markers related to immunity, such as interleukin (ILs), Toll-like receptors (TLRs), and also the heat stress protein (HSPs) in sheep, is also discussed. Finally, recent research on the effects of antioxidant supplementation and other promising nutritional strategies for reducing heat stress and improving animal health is presented. [ABSTRACT FROM AUTHOR]

The Merino breed of sheep is one of the oldest breeds still in existence. All around the world, purebred and mixed populations of the Merino and Merino-derived sheep breeds can be found. This is a result of their wide distribution and increasing popularity. They constitute a huge genetic resource that has been applied historically to create numerous new breeds. The current Hungarian Merino sheep breed has evolved over many years as a result of crossbreeding with different breeds. Consequently, the objective of this study is to compare the genomic inbreeding coefficient (FROH) and patterns of runs of homozygosity (ROH) between the Hungarian Merino and other closely related Merino breeds. Following Rambouillet, Hungarian Merino had the second highest number of ROH class of 1-6 mbs. The Spanish Merinos Cordoba had the most ROH class of > 48Mbs, while the Hungarian Merino had none. The FROH of Hungarian Merinos was comparable to that of other studied breeds, while Spanish Merinos Cordoba had the highest. This study confirms that Hungarian Merino has several intermediate ancestors, and its breeding management is comparable to other Merino breeds and may also indicate greater genetic diversity within the breed. The results can therefore be used to improve genomic management of Hungarian Merino sheep breed. [ABSTRACT FROM AUTHOR]

Copyright of Animal Breeding & Feeding / Állattenyésztés és Takarmányozás is the property of Herman Otto Intezet Nonprofit Kft. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Animal Breeding & Feeding / Állattenyésztés és Takarmányozás is the property of Herman Otto Intezet Nonprofit Kft. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)