Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: 3/28/2008
Publication Date: 7/7/2008
Citation: Wilcox, C.S., Schutz, M.M., Donkin, S.S., Eicher, S.D. 2008. Temporary glycosuria alters molasses consumption in Holstein calves [abstract]. Journal of Dairy Science. 91, E-Suppl. 1:401.
Technical Abstract: Phlorizin temporarily blocks renal absorption of glucose from the urine causing glysuria. This causes increased demand for glucose in order to maintain normal physiologic blood glucose levels. This study was conducted to determine the effect of experimentally increased glucose demand on the level of molasses consumption by dairy calves. To ensure pre-ruminant status, all calves were maintained on milk replacer (fed at 10% of body weight) and given free access to water. In a complete randomized design with 2 treatments, 3-wk-old calves (n = 6/treatment) received 0.365 g of phlorizin by s.c. injection (3 ml) or 3 ml of s.c. saline. During a 7 d adjustment period and 24 h after treatment, all calves were allowed free access to molasses. Hourly urinary output, urinary glucose concentration, and molasses consumption were measured. Mean molasses consumption for the 24 h after treatment was 0.72 g (P = 0.07) for the control group (n = 6) and 1.42 g (P = 0.01) for the phlorizin treated group. Urinary output for the 8 h test period was 1.13 kg for the control group and 1.67 kg for the phlorizin treated calves. Mean urinary glucose peaked at 60 mg/dL 4 h after treatment for calves given phlorizin while the concentration for the control group fluctuated between 0 and 5 mg/dL. Phlorizin treatment significantly increased urinary excretion (P = 0.026), urinary glucose concentration (P = 0.001) and molasses consumption in 3-week-old Holstein calves. Results of our study showed that alterations in glucose metabolism, specifically increased urinary glucose losses, lead to increased voluntary sucrose intake. Additional investigations are needed to confirm the relationship of stress with voluntary sucrose intake and to extend the utility of this feeding behavior response as an experimental model.