Effects of increasing calcium propionate in a finishing diet on dry matter intake and glucose metabolism in steers

Authors: RATHERT-WILLIAMS, ABIGAIL - Oklahoma State University; SALISBURY, CARLEE - Oklahoma State University; Lindholm-Perry, Amanda; PEZESHKI, A - Oklahoma State University; LALMAN, DAVID - Oklahoma State University; FOOTE, ANDREW - Oklahoma State University

Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/25/2021
Publication Date: 12/6/2021
Citation: Rathert-Williams, A.R., Salisbury, C.M., Lindholm-Perry, A.K., Pezeshki, A., Lalman, D.L., Foote, A.P. 2021. Effects of increasing calcium propionate in a finishing diet on dry matter intake and glucose metabolism in steers. Journal of Animal Science. 99(12). Article skab314. https://doi.org/10.1093/jas/skab314.
DOI: https://doi.org/10.1093/jas/skab314

Interpretive Summary: Cattle fed a high concentrate diet produce a greater concentration of ruminal propionate than cattle fed a high forage diet and propionate makes up most of the substrate for liver gluconeogenesis and may improve cattle feed efficiency. The objective of this study was to increase propionate in the diet and determine whether this altered dry matter intake, glucose clearance rate, blood metabolites, insulin concentrations, and hepatic gene expression in steers. Animals fed a control diet were compared to those fed either 100 g/d or 300 g/d of calcium propionate. Animals on the control diet had higher feed intake and body weight gain than either of the groups fed calcium propionate. Animals fed 300 g/d calcium propionate had greater insulin response than the other groups and also had greater expression of SLC16A1, with a tendency for greater expression of SLC2A2. The data from this study suggests that increasing calcium propionate for steers fed a finishing ration alters glucose metabolism. Calcium propionate did not influence basal circulating blood glucose but did decrease feed intake and insulin sensitivity.

Technical Abstract: The objective of this study was to determine whether increasing propionate alters dry matter intake (DMI), glucose clearance rate, blood metabolites, insulin concentrations, and hepatic gene expression in steers fed a finishing diet. Holstein steers (n = 15; BW = 243 ± 3.6 kg) were individually fed a finishing diet ad libitum. Steers were allocated by body weight (BW) to receive: no Ca propionate (Control), 100 g/d Ca propionate (Low), or 300 g/d Ca propionate (High) in the diet. Orts were collected and weighed daily to determine DMI. Blood samples were collected on days 0, 7, and 21, and BW recorded on days 0, 14, and 28. An intravenous glucose tolerance test (IVGTT) was conducted on days 14 and 28 of the trial. Liver biopsies were collected on day 33 for gene expression analysis. Blood samples were analyzed for whole blood glucose and lactate, plasma non-esterified fatty acids (NEFAs), and insulin concentrations. Data were analyzed using a mixed model with treatment, day and their interaction included, with day and minute as a repeated measure. The control treatment had greater (P < 0.01) DMI than low and high steers. Body weight was increased in control steers on days 14 and 28 compared with the steers receiving the High treatment (P = 0.03 for the interaction). Blood glucose concentrations tended (P = 0.09) to be higher on day 21 than days 0 and 7 but was not affected by treatment (P = 0.58). Plasma NEFA concentrations were lower (P = 0.05) for control steers than other treatments, and greater (P = 0.002) on day 0 than days 7 and 21. Blood lactate concentrations were greater (P = 0.05) on day 7, than days 0 and 21, but not affected by treatment (P = 0.13). High steers had greater plasma insulin concentrations in response to the IVGTT than steers on the other treatments (P = 0.001). There was no treatment (P >/= 0.16) or day effect (P >/= 0.36) on glucose peak, plateau, or clearance rate. High steers had greater expression of solute carrier family 16 member 1 (SLC16A1; P = 0.05) and tended to have greater hepatic expression of solute carrier family 2 member 2 (SLC2A2; P = 0.07). These data indicate that increased propionate may decrease DMI and insulin sensitivity.