title: Effect of lonophore supplementation on selected serum constituents of sheep consuming locoweed.
abstract: The effects of ionophore supplementation on selected serum constituents of sheep consuming locoweed were investigated. Sixteen sheep were allotted by weight to a 2x2 factorial arrangement of treatments: 1) no locoweed, no lasalocid, 2) no locoweed, 0.75 mg lasalocid/kg BW, 3) 0.5 mg swainsonine/kg BW, no lasalocid, 4) 0.5 mg swainsonine/kg BW, 0.75 mg lasalocid/kg BW. Swainsonine was provided by locoweed (Oxytropissericea), and sheep were fed a blue grama based diet at 2.5% BW for a 35 d treatment period. Diets were formulated to be isocaloric and isonitrogenous. Blood samples were collected on d 1, 7,14, 21, 31 and 35 to determine serum swainsonine concentration, alkaline phosphatase, total iron, aspartate aminotransferase, g-glutamyltransferase, and lactate dehydrogenase activity and total cholesterol, and triglyceride concentrations. No lasalocid by locoweed interaction (P > 0.4) was noted for any response variable measured. Average daily gains (P = 0.4) and orts (P = 0.7) were not affected by the treatments. No lasalocid treatment (P = 0.7) or day (P = 0.1) effect of serum swainsonine was observed. A locoweed by day interaction (P < 0.0001) of serum alkaline phosphatase was detected. Alkaline phosphatase levels were elevated (P < 0.01) for locoweed treated sheep at 24 h following initial exposure and remained elevated throughout the trail. Total iron was suppressed (P < 0.08) in locoweed fed sheep. A day effect (P < 0.02) was observed for serum iron. However, no linear, quadratic, or cubic effects of day were noted (P >0.2). A locoweed by day interaction (P < 0.0001) of serum aspartate aminotransferase and g-glutamyltransferase was detected. Aspartate aminotransferase levels were elevated (P < 0.0001) by d 7 for locoweed treated animals and remained elevated throughout the trial. g--Glutamyltransferase levels were suppressed (P < 0.0001) by day 7 for locoweed treated animals and remained suppressed throughout the trial. A locoweed by day interaction (P = 0.06) of serum cholesterol was detected. However, no linear, quadratic, or cubic effects of day were detected (P = 0.2). Lasalocid treatment had no effect on any serum constituent measured. Use of lasalocid in grazing animals should not increase the likelihood of locoweed intoxication.
authors.affiliation: Department of Animal Science, University of Nebraska, Lincoln 68583, USA.
authors.forename: K M
authors.initials: KM
authors.lastname: Whittet
authors.forename: H B
authors.initials: HB
authors.lastname: Encinias
authors.forename: J R
authors.initials: JR
authors.lastname: Strickland
authors.forename: J B
authors.initials: JB
authors.lastname: Taylor
authors.forename: J D
authors.initials: JD
authors.lastname: Graham
authors.forename: A K
authors.initials: AK
authors.lastname: Clayshulte
authors.forename: A M
authors.initials: AM
authors.lastname: Encinias
mesh_terms: D000469:Alkaline Phosphatase / Q000097:blood; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood; D002784:Cholesterol / Q000097:blood; D019587:Dietary Supplements; D007476:Ionophores / Q000008:administration & dosage*; D007501:Iron / Q000097:blood; D007770:L-Lactate Dehydrogenase / Q000097:blood; D007832:Lasalocid / Q000008:administration & dosage*; D033021:Oxytropis / Q000506:poisoning*; D010939:Plant Poisoning / Q000517:prevention & control / Q000662:veterinary; D012756:Sheep; D012757:Sheep Diseases / Q000517:prevention & control*; D017026:Swainsonine / Q000097:blood / Q000506:poisoning*; D014280:Triglycerides / Q000097:blood; D005723:gamma-Glutamyltransferase / Q000097:blood
chemical_list: D007476:Ionophores; D014280:Triglycerides; D002784:Cholesterol; D007501:Iron; D007770:L-Lactate Dehydrogenase; D005723:gamma-Glutamyltransferase; D001219:Aspartate Aminotransferases; D000469:Alkaline Phosphatase; D017026:Swainsonine; D007832:Lasalocid