Feeding value of wet tomato pomace ensiled with wheat straw and wheat grain for Awassi sheep

Abstract

In this study, two experiments were conducted to preserve tomato pomace (TP) by ensiling it with different levels of wheat straw (WS) and wheat grain (WG) to improve feeding value, digestibility, and acceptability of this source. Experiment I was arranged in a 3 × 4 factorial in which WS level (10, 15, and 20%) and WG (ground) level (0, 2, 4, and 6%) added to TP as wet basis and ensiled in 1 L jars. Effects of WS and WG addition on nutrient composition, pH value, Fleig points, and in vitro dry matter digestibility (IVDMD) of TP silages were investigated. In experiment II, three experimental silages were chosen among the twelve silages in experiment I for apparent digestion trial. These were 10% WS (I), 15% WS + 2% WG (II), and 15% WS + 4% WG (III) added TP wet basis and ensiled in 250 L barrels. In experiment I, when the level of WS increased, organic matter (OM), crude protein (CP), and IVDMD of TP silages decreased ( P < 0.05). In contrast, 4 and 6% WG addition increased OM, CP, and IVDMD of TP silage ( P < 0.05). While increasing the WS level increased neutral detergent fiber (NDF) and acid detergent fiber (ADF) content of TP silages, WG reduced NDF and ADF contents ( P < 0.05). Also, silage qualities of all TP silages were in very good quality according to the Fleig Point Scale. In experiment II, dry matter (DM), OM, CP, ADF, and NDF digestibility of silage I (10% WS) and silage III (15% WS + 4% WG) were found similar ( P > 0.05), but silage II (15% WS + 2% WS) had a lower DM, OM, CP, ADF, and NDF digestibility ( P < 0.05). Silage DMI was not affected by WS and WG addition to TP ( P > 0.05). As a result, ensiling TP with 10% WS can be a source of good quality roughage for sheep during the insufficiency periods of roughages.