Location: Livestock Issues ResearchTitle: Supplementation of zilpaterol hydrochloride does not significantly alter the serum metabolic profile and metabolic enzyme profile of finishing heifers Author
|Sieren, Sara - University Of Nebraska|
|Jones, Steven - University Of Nebraska|
|Buntyn, Joe - University Of Nebraska|
|Carroll, Jeffery - Jeff Carroll|
|Schmidt, Ty - University Of Nebraska|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 1/3/2015
Publication Date: 3/1/2015
Citation: Sieren, S.E., Jones, S.J., Buntyn, J.O., Carroll, J.A., Sanchez, N.C., Schmidt, T.B. 2015. Supplementation of zilpaterol hydrochloride does not significantly alter the serum metabolic profile and metabolic enzyme profile of finishing heifers. Journal of Animal Science Supplement. 93 (E Supplement 2):37-38, Abstract #82.
Technical Abstract: Supplementation of zilpaterol hydrochloride (ZH; Zilmax®) to cattle has been implicated as having a negative impact on the well-being of cattle. However, there is no data to support or refute these claims. This study was designed to determine if differences exist in the serum metabolic profile and metabolic enzymes of heifers supplemented ZH. Heifers (n=20; 556±7 kg BW) were separated into two groups: Control (CON): no ZH, or 2) ZIL: supplemented ZH at 7.56 g/ton (DM basis). The trial was conducted over a 25 d period (-2 to 22 d), with three serum collection periods [-2 to 3 d (ZH supplementation started on d 0); 12 to 15 d, and 20 to 22 d (withdrawal period)]. For each d of the collection periods, two blood samples were collected for serum profile analysis (0800 and 2000 h). Serum was separated and stored at -80ºC until analyzed for blood urea nitrogen (BUN), total protein, albumin, globulin, P, K, Na, anion gap, serum total Ca (TCa), creatinine (CREAT), creatine phosphokinase (CPK), and the enzymes aspartate transaminase (AT), alkaline phosphatase (AP), gamma glutamyltransferase (GG), and sorbitol dehydrogenase (SD). Data were analyzed using the MIXED procedure with h as a repeated measure and compound symmetry covariance structure [liver enzymes AT, AP, GG, and SD were analyzed as change from baseline (-2 to 0 d)]. A treatment x time interaction was observed for BUN; concentrations were similar (P>0.13) prior to ZH supplementation, however, from 12 to 22 d post supplementation, BUN concentrations in ZIL heifers were decreased (P<0.01), compared to CON heifers. No differences (P=0.58) were observed for serum total protein, albumin, globulin, P, K, Na, anion gap. For TCa, only a treatment effect (P=0.008) was observed; CON heifers had greater concentrations of TCa, compared to ZIL (9.8 vs. 9.5 mg/dL, respectively). A treatment x time interaction (P<0.001) was observed for CREAT and CPK. Prior to ZH supplementation, CREAT and CPK concentrations were similar (P=0.18); post ZH supplementation (4 to 22 d), CREAT and CPK concentrations were greater (P<0.04) in ZIL supplemented heifers. No differences (P>0.16) were observed for the liver enzymes AT, AP, GG, and SD in terms of change from baseline concentrations. While some variation was observed between ZIL and CON heifers (primarily in terms of protein accretion), all variables of interest were within normal biological ranges for cattle.