Evaluation of panicle residue from broom sorghum as a feed ingredient in finishing diets for lambs

Abstract

Sorghum panicle residue (SPR), a by-product of Sorghum vulgare, obtained in the manufacture of brooms and wisks, has potential as a partial substitute for grain in growing-finishing diets for feedlot lambs. Accordingly, 48 Pelibuey×Katahdin lambs (initial weight=16.2±4.3 kg) were used in an 84-d growth-performance trial to evaluate its comparative feeding value. Lambs were blocked by weight and assigned within weight groupings to 12 pens (4 lambs per pen). The SPR was finely ground before it was incorporated into the diet. The basal diet contained 60% whole grain sorghum (WGS; DM basis). Dietary treatments consisted in the replacement of WGS with 0, 50, or 100% SPR. Replacement of WGS with SPR decreased (linear effect, P=0.04) average daily gain (ADG), and tended to increase (linear effect, P=0.06) dry matter intake (DMI). Replacement of WGS with SPR decreased (linear effect, P<0.01) gain efficiency (ADG : DMI), and observed dietary net energy (NE), as well as hot carcass weight, dressing percentage, kidney-pelvic-heart fat, and back fat thickness (linear effect, P⩽.05) Other carcass characteristics and wholesale cuts as a percentage of cold carcass weight were not affected by dietary treatments. It is concluded that SPR is a palatable feed ingredient for inclusion in finishing diets for feedlot lambs. The comparative NE values for SPR are 1.50 and 0.91 Mcal/kg for maintenance and gain, respectively, 75% the NE value of WGS. These NE values reflect the greater fiber content of SPR. To the extent that dietary energy density limits energy intake (and hence daily weight gain), appropriate constraints on level of SPR incorporation is warranted.

Partial replacement of broom sorghum panicle residue and tallow with whole cottonseed in growing-finishing diets for lambs

“…Effects of replacing SPR with different levels of WCS on growth performance, dietary energy and energy value of WCS are shown in Table 2. Observed NE of control diet was 0.99 of expected, and this confirms the validity of NE m value of 1.50 Mcal/kg determined previously by Estrada et al (2019) for SPR. Inclusion of WCS increased (quadratic component, P=0.03) ADG, DMI and gain efficiency.…”

“…The chemical composition of WCS and SPR are described in footnotes of Table 1. Chemical composition of WCS and SPR were consistent with values previously reported Plascencia, 1993, NRC, 2007;Estrada et al, 2019).…”

“…Sorghum panicle residue (SPR), a byproduct of Sorghum vulgare (obtained in the manufacture of brooms and wisks), is also a popular substitute for grain in growing-finishing diets for feedlot lambs (Estrada et al, 2012). However, due to its high indigestible fiber content, its energy value is considerably lower than that of conventional feed grains (1.50 and 0.91 Mcal/kg NE m and NE g , respectively; Estrada-Angulo et al, 2019).When SPR-based finishing diets are fed to lambs supplemental fat and/or WCS may be added to increase diet energy density. However, the net energy value of WCS and fat can vary depending on ingredient replaced and its inclusion level, this mainly due to associative effects with other components (e.g.…”

“…d Mineralized salt contained: Ca, 13.58%; Na, 7.80%; Cl, 12.20%; P, 2.20%; Mg, 1.00%; K, 0.70%; CoSO 4 , 0.068%; CuSO 4 , 1.04%; FeSO 4 , 3.57%; ZnO, 1.24%; MnSO 4 , 1.07%, KI 0.052%. e Based on tabular net energy (NE) values for individual feed ingredientspublished by NRC (2007) with exception of broom sorghum which were assigned 1.50 and 0.91 Mcal/kg of NE m and NE g respectively(Estrada-Angulo et al, 2019). f Dietary composition was determined by analyzing subsamples collected and composited throughout the experiment.…”

Evaluation of hybrid rye on growth performance, carcass traits, and efficiency of net energy utilization in finishing steers

“…The comparative NEm values for Rye were estimated using the replacement technique. Given that the NEm value of DRC was 2.17 Mcal/kg ( NASEM, 2016 ), the comparative NEm values for Rye were estimated as follows ( Estrada-Angulo et al, 2019 ): Rye NEm (Mcal/kg) = [(test diet paNEm − control diet paNEm)/RYE y ] + 2.17, where RYE y represents the inclusion of Rye that replaced DRC in the diet (0.1991, 0.3993, and 0.6004), respectively. The same was done for NEg, assuming DRC had an NEg value (Mcal/kg) of 1.49 ( NASEM, 2016 ).…”