Author
Sanchez, Nicole | |
Carroll, Jeffery - Jeff Carroll | |
Broadway, Paul | |
HUGHES, HEATHER - West Texas A & M University | |
ROBERTS, SHELBY - West Texas A & M University | |
RICHESON, JOHN - West Texas A & M University | |
SCHMIDT, TY - West Texas A & M University | |
VANN, RHONDA - West Texas A & M University |
Submitted to: Jacobs Journal of Physiology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 1/6/2017 Publication Date: 6/15/2017 Citation: Sanchez, N.C., Carroll, J.A., Broadway, P.R., Hughes, H.D., Roberts, S.L., Richeson, J.T., Schmidt, T.B., Vann, R.C. 2017. Cattle temperament alters the metabolic response to a feed restriction challenge in beef steers. Jacobs Journal of Physiology. 3(1):016. Interpretive Summary: Recent studies have demonstrated metabolic differences between calm and temperamental cattle. Specifically, temperamental cattle exhibit greater concentrations of non-esterified fatty acids, decreased blood urea nitrogen, and decreased insulin sensitivity compared to Calm cattle. It is hypothesized that these differences may influence the manner in which temperamental cattle respond to feed restriction. Therefore, the objective of this study was to determine whether cattle temperament would influence the metabolic responses to a feed restriction challenge in cattle. Data from this study demonstrate that calm and temperamental steers have different metabolic responses to feed restriction and gradual feed reintroduction. Specifically, Temperamental steers had increased non-esterified fatty acids and glucose, yet decreased blood urea nitrogen, insulin, and insulin sensitivity compared to calm steers. These data further implicate metabolic differences as the primary factor associated with differences observed in immune function and performance traits between calm and temperamental cattle, and accentuate the need for different management strategies for feeding these cattle. Technical Abstract: Recent studies have demonstrated metabolic differences between calm and temperamental cattle. Specifically, Temperamental cattle exhibit greater concentrations of non-esterified fatty acids (NEFAs), decreased blood urea nitrogen (BUN), and decreased insulin sensitivity compared to Calm cattle. It is hypothesized that these differences may influence the manner in which Temperamental cattle respond to feed restriction (FR). Therefore, the objective of this study was to determine whether cattle temperament would influence the metabolic responses to a FR challenge in cattle. Angus-cross steers (16 Calm and 15 Temperamental; 216 +/- 6 kg body weight) were selected based on Temperament Score measured at weaning. On day 1 of the study, steers were moved indoors into individual stanchions to allow measurement of individual feed intake. Feed and water was provided ad libitum from day 1- 5 in order to determine ad libitum feed intake. On day 6, steers were fitted with indwelling rectal temperature probes and jugular catheters, and were returned to individual stalls. Beginning at 08 am on day 8, feed was removed for a 72-h period (days 8 - 10). Feed was then provided at 25%, 50%, 75%, and 100% of ad libitum on days 11, 12, 13, and 14, respectively. Blood samples were collected every 6 hours from 0 to 156 hours during the FR challenge. Serum was isolated and analyzed for cortisol, glucose, insulin, NEFA, and BUN concentrations. All variables changed over time (P < 0.01). For the duration of the study, Temperamental steers maintained greater (P < 0.01) NEFA and decreased (P < 0.01) BUN and insulin sensitivity (calculated using RQUICKI) compared to Calm steers. Additionally, Temperamental steers maintained greater (P = 0.001) glucose and decreased (P = 0.001) insulin than Calm steers. These data suggest that Temperamental and Calm cattle have metabolically different responses to FR, and further implicate metabolic differences as the primary factor associated with differences observed in immune function and performance traits between temperamental and calm cattle. These differences accentuate the need for different management strategies for feeding temperamental versus calm cattle. |