Effects of dry-rolled or steam-flaked corn finishing diets with or without twenty-five percent dried distillers grains on ruminal fermentation and apparent total tract digestion.
A metabolism study was conducted to evaluate ruminal fermentation and apparent total tract digestibilities of cattle finishing diets. Holstein steers (n = 16, 351 kg of BW) with ruminal cannulas were fed diets consisting of 0 or 25% dried corn distillers grains (DDG), using dry-rolled corn (DRC) or steam-flaked corn (SFC) as the principal energy source (2 x 2 factorial arrangement). The study was conducted in 2 periods, with 4 steers per treatment in each period. Periods consisted of a 12-d adaptation phase and a 3-d collection phase. Compared with DRC, feeding SFC decreased intakes of DM, OM, starch, NDF, and ether extract (P < 0.01), and steers fed SFC excreted less DM, OM, starch, NDF, and ether extract (P < 0.01). Compared with SFC, feeding DRC decreased ruminal concentrations of acetate, butyrate, isobutyrate, and isovalerate, and decreased the acetate-to-propionate ratio (P < 0.01). Compared with SFC, DRC decreased ruminal propionate, valerate, and lactate concentrations (P < 0.01). When compared with cattle fed SFC, ruminal pH of cattle fed DRC was less at 0 h and greater at 6 h postfeeding (P < 0.01). Ruminal ammonia concentrations were greater for DRC vs. SFC at h 0, 6, 10, 12, 14, 16, 18, 20, and 22 postfeeding (P < 0.05). Feeding DDG decreased consumption of starch and ether extract, but increased NDF intake (P < 0.01). Fecal excretion of ether extract was increased by adding DDG compared with diets without DDG (P < 0.05), resulting in less apparent total tract digestibility of ether extract for cattle fed DDG (P < 0.01). Ruminal lactate concentrations were increased with addition of DDG compared with diets without DDG (P = 0.01). Ruminal ammonia concentrations were less for steers fed 25 vs. 0% DDG at 2, 4, 6, 8, and 10 h postfeeding (P < 0.05). We conclude, based on these results, that ruminal fermentation and apparent total tract digestibility of DDG are affected by grain processing.
May
M L
ML
Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506, USA.
Quinn
M J
MJ
Reinhardt
C D
CD
Murray
L
L
Gibson
M L
ML
Karges
K K
KK
Drouillard
J S
JS
D000821:Animal Feed; D000818:Animals; D002087:Butyrates / Q000032:analysis; D002417:Cattle / Q000502:physiology*; D004063:Digestion / Q000502:physiology*; D002523:Edible Grain; D005243:Feces; D005285:Fermentation / Q000502:physiology*; D005511:Food Handling; D005750:Gastric Juice / Q000737:chemistry; D045782:Hemiterpenes; D058610:Isobutyrates; D019344:Lactic Acid / Q000032:analysis; D008297:Male; D010421:Pentanoic Acids / Q000032:analysis; D014631:Valerates / Q000032:analysis; D003313:Zea mays
D002087:Butyrates; D045782:Hemiterpenes; D058610:Isobutyrates; D010421:Pentanoic Acids; D014631:Valerates; C008216:isovaleric acid; D019344:Lactic Acid; C020380:isobutyric acid