Prediction of energy contents and potential nutrient supply of raisin byproducts for ruminants using National Research Council feeding system and in vitro gas production method.

Article history Received: 30 May, 2015 Revised: 5 Jul, 2015 Accepted: 6 Jul, 2015 Abstract Using local agro-industrial by-products can help to fill feed shortages in ruminant feeding in semi-arid climate condition. The objective of current study was to determine the nutritive value of several sun dried grapevine (raisin) by-products (RBPs) for ruminants using National Research Council feeding system (NRC) and in vitro gas production method. Several RBPs of sun dried treated grapevine cluster (Vitis vinifera L. cv. Sultana), were 1) some outer layer of flesh and skin and pedicle of berries (RBP1); 2) rejected raisins mostly un-ripped berries with their pedicles (RBP2) and 3) peduncles and rachises with their lateral branches of clusters (RBP3). Using NRC 1996 and 2001 feeding system, RBP1 and RBP2 had higher predicted metabolizable energy (ME; 11.48 and 9.45 vs. 5.99 MJ/kg DM; P<0.05) and net energy for lactation at the level of production intake (NElp; 4.90 and 5.52 respectively vs. 2.68 MJ/kg DM; P<0.05) compared with RBP3. The RBP2 had higher in vitro cumulative gas production at 24 h of incubation, estimated NEl, ME and organic matter digestibility compared with RBP1 and RBP3 (P<0.01). Current results indicate that the RBPs could be considered as alternative feeds in ruminants feeding during dry periods.