02564naa a2200265 a 450000100080000000500110000800800410001902200140006002400360007410000170011024500860012726000090021350004990022252012590072165300220198065300240200265300200202665300250204665300140207165300380208570000210212370000200214470000210216477301130218510646252024-05-29       2024    bl uuuu     u00u1 u    #d  a0049-47477 a10.1007/s11250-024-04018-72DOI1 aFERREIRA, J.  aCompilations and updates on residual feed intake in sheep.h[electronic resource]  c2024  aArticle history: Received 30 August 2023; Accepted 9 May 2024; Published online 21 May 2024. -- Correspondence: Ferreira, J.; Centro de Pesquisa e Desenvolvimento de Zootecnia Diversificada, Instituto de Zootecnia (IZ), Rua Heitor Penteado, 56, SP, Nova Odessa, Brazil; email:jjosielborges@hotmail.com  ; da Costa, R.L.D.; Centro de Pesquisa e Desenvolvimento de Zootecnia Diversificada, Instituto de Zootecnia (IZ), Rua Heitor Penteado, 56, SP, Nova Odessa, Brazil; email:rldcosta@sp.gov.br --  aABSTRACT.- The increasing global demand for food and the strong effect of climate change have forced animal science to advance regarding new methods of selection in search of more efficient animals in production systems. Feed consumption represents more than 70% of the costs of sheep farms, and more efficient animals can increase the farmers? profitability. One of the main measures of feed efficiency is estimated residual feed intake (RFI), created in 1963 by Robert Koch for estimation in cattle and later adapted for sheep. Animals with negative RFI values (RFI-) are more efficient than animals with positive values (RFI+), with influence on the variables of performance, carcass quality and production of enteric gases. The RFI is the most common and accepted metric of the feed efficiency trait for genetic selection, since it is independent of growth traits, unlike the feed conversion ratio. The purpose of this review article was to present updated literature information on the relationship of RFI estimates with performance measures, molecular markers, greenhouse gas production and feed efficiency, the technical aspects and physiological basis of metabolic in sheep. © The Author(s), under exclusive licence to Springer Nature B.V. 2024.  aAnimal efficiency  aGenetic improvement  aMeat production  aPhenotypic selection  aRuminants  aSISTEMA GANADERO EXTENSIVO - INIA1 aCHAY-CANUL, A.J.1 aDE BARBIERI, I.1 aDA COSTA, R.L.D.  tTropical Animal Health and Production, 2024, volume 56 (5): 172.  https://doi.org/10.1007/s11250-024-04018-7