Effects of increasing levels of corn or beet pulp on utilization of low-quality crested wheatgrass hay by lambs and in vitro dry matter disappearance of forages.

Two trials were conducted to evaluate the effects of corn or dried beet pulp on intake and digestibility of forage by lambs and on IVDMD. In Trial 1, 16 lambs (average BW = 41 +/- .9 kg) were used in a randomized complete block design with eight lambs per block. Lambs were fed a crested wheatgrass hay (7.5% CP) and received either no supplement (NS), a protein supplement (PS), or protein supplements with various levels of corn or beet pulp. Corn supplements supplied 1.75 (PCL), 3.5 (PMC), and 5.25 (PHC) g of corn/kg of BW, whereas beet pulp supplements supplied 2.1 (PLBP), 4.2 (PMBP), and 6.3 (PHBP) g of beet pulp/kg of BW. All supplemented lambs received .128 g of CP/kg of BW. Hay DMI decreased linearly (P < .03) as the level of corn and beet pulp increased in the supplement. Total DMI decreased linearly (P = .013) as the level of corn increased; however, beet pulp did not affect total DMI (P > .71). Supplemental corn increased (P = .03) apparent diet DM digestibility (DMD), whereas supplemental beet pulp did not affect (P > .32) diet DMD. Lambs whose diet was supplemented with beet pulp had greater (P = .010) estimated hay DMD than lambs whose diet was supplemented with corn. In Trial 2, 48-h IVDMD was determined on each of three forages mixed with either corn or beet pulp. The crude protein content of the three forages was 4.9, 9.4, and 12.2% for low-, medium-, and high-quality forages, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)