Adding polyethylene glycol to steer ration containing sorghum tannins increases crude protein digestibility and shifts nitrogen excretion from feces to urine

Abstract

The objectives of the experiment were to study the effects of adding polyethylene glycol (PEG) to steer ration containing high sorghum tannins on rumen fermentation, nutrient digestion, nitrogen (N) balance and plasma biochemical parameters. Eight growing steers at 16 months of age were allotted to a replicated 4 × 4 Latin square design with 4 treatments and 4 periods (19 d each). Polyethylene glycol at 0, 1.75, 3.50 and 7.00 g/kg dry matter (DM) were added to a basal ration containing 27.82% DM of sorghum grain (total tannins 3.3 g/kg DM) as the treatments. The results indicated that adding PEG quadratically increased the ruminal pH ( P = 0.049), tended to linearly increase the ruminal concentration of total volatile fatty acids ( P = 0.070), increased the molar proportion of acetate ( P = 0.016), linearly decreased the molar proportion of butyrate ( P = 0.015), and tended to increase the molar proportion of iso-valerate ( P = 0.061) and the ruminal concentration of ammonia N ( P = 0.092). Adding PEG tended to quadratically decrease the relative abundance of methanogenic archaea ( P = 0.082), linearly decreased the relative abundance of Fibrobacter succinogenes ( P = 0.008) and decreased the relative abundance of Butyrivibrio fibrisolvens ( P = 0.048) at 7.00 g/kg DM. Dietary addition with PEG increased the crude protein (CP) digestibility ( P < 0.001) and tended to increase the neutral detergent fiber digestibility ( P = 0.066) in a linear manner. Adding PEG to basal ration also increased the plasma globulin concentration ( P = 0.029) and tended to linearly increase the plasma total protein concentration ( P = 0.069). Adding PEG linearly decreased the fecal N excretion ( P < 0.001) and the fecal N-to-total N excretion ratio ( P = 0.004) and increased the urinary N-to-total N excretion ratio ( P = 0.004) and urinary urea excretion ( P = 0.010) without affecting the urinary N and total N excretions ( P > 0.05). It was concluded that adding PEG effectively improved the CP digestibility of the ration containing high sorghum tannins but increased the urinary urea excretion without improving the N retention and N retention rate in steers.

Natural polyphenol tannin-immobilized composites: rational design and versatile applications

“…185 3.2.6 Other synthetic polymers. Moreover, other synthetic polymers, such as polyamide (PAM), 17,186 polyethylene glycol (PEG), [187][188][189] polyacrylonitriles (PAN), 190 and polypyrroles (Ppy), 191 were also used as substrates for the immobilization of tannins and their derivatives.…”

Potentials of using dietary plant secondary metabolites to mitigate nitrous oxide emissions from excreta of cattle: Impacts, mechanisms and perspectives

“…(2019) Zhao et al. (2021) Xie et al. (2021) Total N, g/L 15.3 (6.7 to 26.9) 2.6 (2.4 to 2.9) 5.1 (4.0 to 6.5) 4.3 (2.5 to 5.5) 6.2 (5.8 to 6.9) ND N proportion, % UN Urea 60.4 (43.0 to 70.4) 65.4 (59.2 to 70.3) 70.4 (63.9 to 76.8) 66.0 (57.4 to 77.4) 69.2 (67.2 to 71.9) 64.7 (59.0 to 70.1) Allantoin 3.1 (1.9 to 4.5) 6.0 (4.6 to 7.4) 6.9 (5.5 to 8.1) 9.5 (5.7 to 11.2) 9.6 (7.9 to 10.5) 6.1 (5.7 to 6.6) Uric acid ND 0.9 (0.8 to 1.0) 1.1 (0.8 to 1.3) 1.4 (1.0 to 1.8) 0.9 (0.9 to 1.0) 0.2 (0.2 to 0.3) Creatinine 3.4 (2.4 to 4.9) 10.5 (10.3 to 10.7) 6.5 (4.3 to 9.2) 9.6 (5.7 to 14.7) 9.4 (8.8 to 10.0) 5.4 (5.0 to 5.8) Hippuric acid 5.0 (2.2 to 7.3) 2.7 (2.5 to 2.9) 4.2 (3.2 to 5.8) 4.2 (2.2 to 5.6) 5.1 (4.8 to 5.4) 3.2 (3.1 to 3.2) ND = not determined or not reported; UN = urinary N. 1 Data are expressed as mean values (range within brackets).…”

“…(2019) contained 4 treatment means with n = 4 per treatment; Zhao et al. (2021) contained 3 treatment means with n = 6 per treatment; Xie et al. (2021) contained 4 treatment means with n = 8 per treatment.…”

Effects of polyethylene glycol (PEG 6000) and bentonite clay incorporation in selected local browse-based diets on the performance of Small East African goats

“…A passive, unabsorbed polymer called PEG can form stable complexes with tannins to stop them from interacting to proteins (Makkar,2003). Condensed tannins bind to polyethylene glycol with a high a nity, inhibiting the formation of tannin-protein complexes (Xie et al, 2021). By lessening the deleterious effects of tannins, polyethylene glycol increases livestock intake of high tannin forages (Silanikove et al, 1997).…”

“…By lessening the deleterious effects of tannins, polyethylene glycol increases livestock intake of high tannin forages (Silanikove et al, 1997). When tannins are added to the diet, ruminants' nitrogen excretion switches from urine to feces without reducing overall nitrogen excretion (Xie et al, 2021). In this study, growing Small East African goats were fed Acacia brevispica and Berchemia discolor that had been treated with polyethylene glycol and bentonite clay.…”