Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2007
Publication Date: 3/1/2008
Citation: Archibeque, S.L., Freetly, H.C., Ferrell, C.L. 2008. Feeding distillers grains supplements to improve amino acid nutriture of lambs consuming moderate-quality forages. Journal of Animal Science. 86(3):691-701. Interpretive Summary: With recent increases in ethanol production, there have been increasing amounts of distillers grains available for livestock feed. Currently 75%-80% of the distillers grains produced in the United States are fed to dairy and beef cattle, primarily in confinement operations. With this increase in distillers grains inventories, alternative outlets for their use need to be explored. The current study evaluated the use of distillers grains as a supplement for sheep consuming forage. Supplementing with distillers grains was an effective method of providing additional nutrients for the productive needs of the sheep and presumably other ruminants on high forage diets, such as grazing cattle, deer, elk, etc. This was accomplished without effectively changing the excretion of nutrients into the environment.
Technical Abstract: We hypothesized that providing dried distillers grains with solubles (DDGS) would improve the N retention and use of nutrients by wethers fed a moderate quality brome hay. Additionally, we hypothesized that treatment effects on nutrient fluxes would be similar after 3, 6, or 9 wk on treatment. Chronic indwelling catheters were surgically implanted in a mesenteric artery, mesenteric vein, hepatic vein, and portal vein of 9 Suffolk × Dorset wethers (initial BW +/- SD = 57.44 +/- 6.14 kg). Wethers had ad libitum access to moderate quality bromegrass hay (8.44% CP, DM basis) and received 100 g/d of either a corn-based (Corn, n = 4) or a DDGS-based supplement (n = 5). There was no difference in DMI (P = 0.85) or DM digestibility (P = 0.46) between the 2 groups. There was a numerical increase in N intake (P = 0.14) from 18.41 to 21.46 g/d and N retained (P = 0.15) from 2.54 to 4.45 g/d when wethers were supplemented with DDGS instead of Corn. Wethers fed DDGS had a greater (P =0.008) release of alpha-amino N (AAN) from the portal drained-viscera (PDV, 37.9 mmol/h) than those fed Corn (14.1 mmol/h). Similarly, there was a shift (P = 0.004) from a net splanchnic uptake to a net release of AAN in wethers fed DDGS (9.1 mmol/h) as compared to those fed Corn (- 9.6 mmol/h). However, there was no difference in ammonia release from the PDV (P = 0.49) or hepatic release of urea N (P = 0.19) between the 2 treatments. There were very limited interactions between nutrient fluxes and the length of time after the initiation of treatments. However, there was a tendency (interaction, P = 0.07) for the PDV release of alpha-amino N to be greater 6 and 9 wk after the initiation of the treatments than after 3 wk on treatment for wethers fed DDGS, although there was no difference over time for wethers fed the Corn supplement. Additionally, there were changes in numerous nutrient fluxes between 3 and 6 wk after the initiation of treatments regardless of treatment. These data indicate that DDGS is a viable supplement to enhance the performance of ruminants consuming moderate quality forages. Additionally, these data indicate that the effects are discernible after 3 wk on treatment, with modest alterations in nutrient flux after additional time on treatment.