Effects of fescue and clover forage on serum lactate dehydrogenase and glucose 6-phosphate dehydrogenase isoenzymic profiles in steers.
We determined the effects of forage type on isoenzymes of lactate dehydrogenase (LDH) and glucose 6-phosphate dehydrogenase (G6PDH). Forty-eight crossbred steers were randomly allotted to replicated pastures consisting of fungus-infected (Neotyphodium coenophialum) fescue or fungus-free fescue each with or without ladino clover overseeding. At the end of the 180-d grazing period, serum was harvested from the steers. Steers were finished in a feedlot and slaughtered after approximately 150 d in the feedlot. Isoenzymes for LDH and G6PDH were separated using PAGE. Five LDH isoenzymes (L1-15) were typically detected. Isoenzyme L1 (most anodic) had the greatest area percent as detected by laser densitometry (72, 12, 10, 5, and 7%, respectively, for L1, L2, L3, L4, and L5). Four proteins had G6PDH activity (G1-G4) with G2 having the greatest area percent (15, 52, 27, and 14, respectively, for G1, G2, G3, and G4). Isoenzymes within a dehydrogenase were correlated (P < .05). In addition, area percentage of L1 was correlated (P < .05; r = .34) with area percentage of G2, and area percentage of L4 was correlated (P < .07; r = .73) with area percentage of G1. Area percentages of L1, L2, and L3 were affected by an interaction (P < .09) of forage types. Body weight gains for steers grazing endophyte-infected fescue were depressed (P < .05); however, steers compensated with increased (P < .05) weight gains during the finishing phase. Fungal toxins produced by Neotyphodium coenophialum may alter an animal's metabolism, growth, and development via shifts in reducing equivalents (NADH).
Rosenkrans
C F
CF
Department of Animal Sciences, University of Arkansas, Fayetteville 72701, USA.
Coffey
K P
KP
Paria
B C
BC
Tarn
C Y
CY
Johnson
Z B
ZB
Moyer
J L
JL
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000201:enzymology* / Q000382:microbiology / Q000473:pathology; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D007887:Fabaceae; D005954:Glucosephosphate Dehydrogenase / Q000097:blood*; D006999:Hypocreales / Q000472:pathogenicity; D007527:Isoenzymes / Q000097:blood; D007770:L-Lactate Dehydrogenase / Q000097:blood*; D008297:Male; D010946:Plants, Medicinal; D006109:Poaceae / Q000382:microbiology / Q000633:toxicity*; D011897:Random Allocation
D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase; D005954:Glucosephosphate Dehydrogenase