LAUSR

Effects of using ground woody plants in Rambouillet wether lamb feedlot diets on growth performance, blood serum, and rumen parameters were evaluated. A randomized design study was used with 2 feeding periods (70% concentrate diet from d 0 to 27 [Period 1] and 86% concentrate diet from d 28 to 57 [Period 2]); the concentrate portion of the diets mainly consisted of dried distiller's grains with solubles and sorghum grain. Lambs were individually fed 6 diets that differed only by roughage source ( = 8 animals/treatment; 32.9 ± 3.2 kg initial BW): either cottonseed hulls (CSH; control) or ground wood consisting of redberry juniper (RED), blueberry juniper (BLUE), one-seeded juniper (ONE), or eastern red cedar (ERC) spp. or honey mesquite (MESQ; ). Using ground wood vs. CSH as the roughage source did not affect ( > 0.12) BW. There tended to be a treatment × day interaction ( = 0.07) for lamb DMI, attributed to Period 1 when DMI was greater ( < 0.05) for lambs fed CSH vs. RED, ONE, ERC, or MESQ during the first 14 d and greater ( < 0.05) during d 14 to 28 vs. lambs fed ERC. Overall, ADG was less for lambs fed ERC ( < 0.10) or MESQ ( < 0.05) vs. lambs fed CSH, but G:F was similar ( > 0.10) among all lambs. Dietary treatments did not affect ( > 0.15) ruminal pH, but treatment × day interactions ( < 0.05) were observed for rumen fluid ammonia N or molar proportions of propionate and butyrate; few differences were observed within day. However, overall, lambs fed RED or MESQ had greater ( < 0.05) total rumen VFA than lambs fed CSH. A treatment × day interaction ( = 0.04) was observed for the acetate:propionate ratio, but no differences ( > 0.10) were observed within day. Treatment × day interactions ( < 0.05) were observed for blood serum glucose, γ-glutamyl transferase, the albumin:globulin ratio, total bilirubin, β-hydroxybutyrate, P, Cl, and Mg, with most results being less for lambs fed the wood-based diets than for lambs fed the CSH diets. Results suggested that even though lamb DMI was reduced during the growing period when diets contained 30% ground woody products (RED, ONE, ERC, and MESQ), animal health and rumen fluid parameters were not negatively affected by ground woody plants.