02820naa a2200289 a 450000100080000000500110000800800410001902400330006010000190009324501300011226000090024250004080025152015660065965300090222565300150223465300140224965300200226365300130228370000170229670000160231370000140232970000180234370000130236170000170237470000170239177301220240810614272020-09-28       2020    bl uuuu     u00u1 u    #d7 a10.15232/aas.2020-020022DOI1 aCLARIGET, J.M.  aEucalyptus barkbA new source of fiber from the wood pulp industry for feeding to beef feedlot cattle.h[electronic resource]  c2020  aArticle history: Received 28 February 2020, Accepted 26 June 2020, Available online 28 September 2020. ACKNOWLEDGMENTS: This research was supported by the Instituto Nacional de Investigación Agropecuaria (INIA), Uruguay (grant numbers N-19407, 2016) and the MARFRIG Group industry. The authors wish to thank to the agricultural technicians Christian Solari and Gabriel Fernandez for their. cooperation.  aABSTRACT: Objective: Our objectives were to compare the effects of feeding eucalyptus bark or eucalyptus wood chips, both by-products from the pulp industry, on voluntary feed intake, animal performance, and physiological variables of heifers finished on high-concentrate diets. Materials and Methods: Forty-eight British-breed heifers (Angus, Hereford, and their crosses) that were 22 to 24 mo of age and had an initial BW of 355 ± 8 kg were used. Four heifers were allocated to each of the 12 pens (experimental units). The experiment was a randomized complete block design with 2 treatments and 6 replications each. The 2 different fiber sources (wood chips or bark) were included in the fattening diet in the same proportion (8.9% DM basis). The rest of the ingredients in the diet were the same. The final diet was offered 3 times per day, and heifers were fed for 84 d. Results and Discussion: Fiber source (wood chips vs. bark) did not affect ADG or G:F (P > 0.10). However, DMI (P < 0.01), DP (P = 0.04), and hot carcass weight (P = 0.06) were greater in heifers fed with bark compared with those fed with wood chips. Heifers from the bark treatment spent less time (P = 0.02) chewing than heifers from the wood chips treatment. Implications and Applications: In conclusion, bark could be used as a source of fiber for finishing cattle in high-concentrate diets at the same levels as wood chips. This finding is relevant for the feedlot industry because eucalyptus bark has no industrial uses and would represent a cheaper fiber source than wood chips.  aBEEF  aEUCALYPTUS  aFATTENING  aFEED EFFICIENCY  aROUGHAGE1 aLA MANNA, A.1 aLUZARDO, S.1 aPEREZ, E.1 aFERNANDEZ, E.1 aROIG, G.1 aAZNÁREZ, V.1 aBANCHERO, G.  tApplied Animal Science, Volume 36, Issue 5, October 2020, Pages 592-599. DOI: https://doi.org/10.15232/aas.2020-02002