02479naa a2200313 a 450000100080000000500110000800800410001902200140006002400420007410000230011624501400013926000090027950003270028852011290061565300400174465300250178465300210180965300200183065300220185065300230187265300380189570000170193370000180195070000190196870000160198770000180200370000200202177301240204110646262024-05-29       2024    bl uuuu     u00u1 u    #d  a1873-22167 a10.1016/j.anifeedsci.2024.1159962DOI1 aTAFERNABERRY, A.I.  aUsing faecal nitrogen as a marker to estimate intake and digestibility in sheep fed multi-species native forage.h[electronic resource]  c2024  aArticle history: Received 29 December 2023, Revised 13 May 2024, Accepted 17 May 2024, Available online 22 May 2024. -- Corresponding author: Instituto Nacional de Investigación Agropecuaria (INIA), INIA Treinta y Tres. Ruta 8 km 282, Treinta y Tres, 33000, Uruguay. E-mail address: jsavian@inia.org.uy (J. V. Savian). --  aABSTRACT.- Livestock production in southern South America heavily relies on extensive native grasslands, characterized by high plant species diversity, which makes estimating forage digestibility and intake by ruminants in this pastoral ecosystem challenging. Therefore, the aim of this study was to generate regression models to establish the relationship between total faecal nitrogen excretion (FNe) and intake, and faecal nitrogen content (FNc) and digestibility in sheep fed multispecies native forage. In a completely randomized design, 16 Corriedale sheep averaging 44.4 kg of body weight (BW) were housed in metabolism cages and received forage in amounts of 15, 20, 25 g of dry matter per kg of BW or ad libitum. During the spring of 2019 and the summer of 2020, four measurement periods were carried out. The sheep had 5 days of adaptation to the metabolic cage, 10 days to adapt to the treatments of amounts of forage offered, and 5 days for intake and digestibility measurements. The forage was harvested once a day, and then the fresh forage was offered at two different times, 8 and 17 h. © 2024 Elsevier B.V.  aÁREA DE PASTURAS Y FORRAJES - INIA  aFaecal crude protein  aFeed consumption  aInternal marker  aNatural grassland  aNitrogen excretion  aSISTEMA GANADERO EXTENSIVO - INIA1 aSAVIAN, J.V.1 aKESSLER, J.D.1 aCIAPPESONI, G.1 aJAURENA, M.1 aFERNANDEZ, G.1 aDE BARBIERI, I.  tAnimal Feed Science and Technology, 2024, 115996. https://doi.org/10.1016/j.anifeedsci.2024.115996  [Article In Press].