Nutrient digestion and performance by lambs and steers fed thermochemically treated crop residues

Abstract

Five studies were conducted to determine nutrient digestibility and performance of lambs and steers fed thermochemically treated crop residues and distillers dried grains with solubles (DDGS) as a corn replacement pellet (CRP; 75% residue:25% DDGS, DM basis). Fifteen Hampshire, Suffolk, or Dorset wethers (BW 33.3 +/- 5.0 kg) were utilized to evaluate nutrient digestibility of the unprocessed native (NAT) and CRP [Exp. 1: wheat straw (WS); Exp. 2: corn stover (CS); Exp. 3: switchgrass (SWG) and corn fiber:wheat chaff (CFWC)] when limit fed (Exp. 1 and 2: 1.8% of BW daily; Exp. 3: 2.5% of BW daily) compared with a 60% corn diet. In Exp. 4, 56 individually fed Dorset-cross wether lambs (BW 32.0 +/- 1.4 kg) were utilized to compare performance and digestibility of WS, wheat chaff (WC), corn fiber (CF), a 3:1 blend of corn fiber:wheat straw (CFWS), a 3:1 blend of CFWC, and SWG-CRP fed for ad libitum intake compared with a 45% corn diet. In Exp. 5, 32 individually fed Holstein steers (BW 185.2 +/- 0.9 kg) were used to evaluate performance and digestibility of diets containing corn, WS-CRP, CFWC-CRP, or NAT-WS fed for ad libitum intake. Crop residues were processed with 5% calcium oxide (DM basis) and 35% water in a double-shaft enclosed mixer (Readco Kurimoto Continuous Processor, York, PA) and subsequently pelleted with DDGS to form CRP. Feeding lambs WS-CRP (Exp. 1) or CS-CRP (Exp. 2) increased digestion of DM, NDF, and ADF compared with NAT (P < 0.05). In Exp. 3, feeding CFWC-CRP increased total tract NDF digestibility and ADF digestibility (P < 0.05). Experiment 4 final BW were greatest for control lambs and least for lambs fed CFWS-CRP or SWG-CRP. Body weight gains for lambs fed CRP averaged 15.9% less than control (P < 0.05). Lambs fed CRP diets had greater (P < 0.05) NDF and ADF intake and output. In Exp. 5, steers fed the corn or 2 CRP diets gained similarly and faster (P < 0.05) than those fed the NAT-WS diet. Steers fed the control corn diet were more efficient (P < 0.05) than steers fed other treatments. Steers fed the corn diet, CFWC-CRP, and WS-CRP had greater (P < 0.01) DM digestibility than NAT. The results confirm benefits for nutrient digestion and subsequent animal performance when crop residues are thermochemically processed. Processed crop residues may be fed in combination with DDGS to partially replace corn in ruminant diets.

Digestibility and performance of steers fed low-quality crop residues treated with calcium oxide to partially replace corn in distillers grains finishing diets1

“…However, we did not observe any difference in DM or OM digestibility between the treated diets and CON. Differences between the results in the present study and those of Sewell et al (2008) could be related to the amount of corn replaced and the fact that both corn and roughage were replaced in this work.…”

“…They concluded the addition of roughage in diets containing WDGS appears to have effects similar to those observed in grain-based diets. Sewell et al (2008) fed lambs treated (processed in a manner similar to that described above with 5% CaO, DM basis) pellets composed of wheat straw or corn stover at 30% of diet DM. They noted improvements in diet DM and NDF digestibilities of 9.7% and 48.3%, respectively, for treated wheat straw compared with the native form.…”

Effects of replacing wild rye, corn silage, or corn grain with CaO-treated corn stover and dried distillers grains with solubles in lactating cow diets on performance, digestibility, and profitability

“…In the present study, the DM digestibility was higher for the RWR treatment than the other treatments, and no difference was observed between the RCS, RCG, and CON treatments. Differences between the results in the present study and those of Sewell et al (2009) could be related to differences in animals used, diet composition, and the type and amount of feed replaced.…”

“…Effects of T-CS with by-product inclusion have also been studied previously. Sewell et al (2009) combined T-CS (processing similar to the method described above with 5% CaO, DM basis) with DDGS to create a CG replacement pellet for lambs. They found that the DM, NDF, and ADF digestibility were improved for T-CS compared with the native form.…”

Effects of grind size when alkaline treating corn residue and impact of ratio of alkaline-treated residue and distillers grains on performance of finishing cattle1

“…typically making up at least 50% of the diet (DM basis). Sewell et al (2008) fed Holstein steers (n = 32) a diet that replaced all of the DRC with pellets that contained 25% (DM basis) dried distillers grains plus solubles (DDGS) and CaO-treated (5% DM basis) wheat straw or corn bran (in varying proportions) that made up the majority of the pellet composition. In that study, no difference in ADG was observed but replacing all of the DRC increased DMI, which lead to 11.9% (corn fiber:wheat chaff blend) and 25.8% (wheat straw) reductions in G:F compared with a CON diet that contained 50% DRC, 25% DDGS, and 15% corn silage (DM basis).…”