- Two experiments were conducted to evaluate the use of wet brewers' grain (WBG) alone and with straw so it can be used as part of the sole ration for ruminants. In Exp. 1, WBG was ensued alone and was mixed with one of two straws, wheat or tall fescue grass seed, at 20% (20:80), 30% (30:70), and 40% (40:60) WBG (dry matter basis), respectively. Final mixtures were brought to 65% moisture content with water. Treatments were replicated three times. Treatments were thoroughly mixed, vacuum sealed, and ensued for 30 days. After ensiling, bags were opened and measured for pH. Samples were freeze dried and analyzed for: ethanol, ammoniaN, lactic acid, acetic acid, propionic acid, butyric acid, and proximate analysis. Compared to the straw silage treatments, pH was lower (P<0.01) for WBG. Wet brewers' grain was higher (P<0.01) in CP than straw silage treatments as expected. Across straw treatments, CP was lower than expected.
Ethanol production was high (P<0.05) for WBG versus straw treatments. Ammonia-N was higher (P<0.05) in WBG when compared to straw treatments. Acetic acid in WBG was higher (P<0.05) versus straw treatments. Wheat straw was lower (P<0.05) in acetic acid, lactic acid, and total acids than grass seed straw. Lactic acid in WBG versus straw treatments showed no difference (P>0.30). In Exp. 2, 30:70 WBG/straw was mixed and allowed to ensile for a minimum of 45 days. Water was added to bring moisture to a desired content of 65%. Twelve Polypay X Suffolk X Dorset wethers (49 ± 3 kg BW) were used in a random complete block design to evaluate digestibility of ensued WBG and 30% WBG to 70% Fescue grass seed straw silage. Wethers were blocked by weight and assigned randomly to one of three treatments (TRT). The TRT were CON -limit fed canola meal with ad libitum access to tall fescue grass seed straw, WBG- limit fed
ensiled WBG with ad libitum access to tall fescue grass seed straw, and SIL- ad libitum 30% WBG/70% Tall Fescue grass seed straw silage. Dry matter intake was higher for CON vs. WBG (P<0.0l) and vs. SIL (P<0.01). No difference in DM1 was detected between WBG vs. SIL (P>0.24). The CON group consumed 1.18 kg/day as compared to WBG at .84 kg/day and SIL at .96 kg/day. Straw intake was affected by consumption of supplements, CON vs. WBG (P=0.06). No differences were detected in OM, NDF and ADF disappearance (P>0.27). There was no difference (P>0.24) in comparing CON (45.62%) vs. WBG (53.88%) and CON (45.62%) vs. SIL (41.70%) for CP disappearance.
The ensuing of 30:70 WBG/straw silage for use as an alternative feedstuff proved effective for use in feeding of beef cattle or sheep.