Effect of postruminal infusion of fructose on hepatic steatosis

Wednesday, July 23, 2014
Exhibit Hall AB (Kansas City Convention Center)
Katie E Boesche , Purdue University, West Lafayette, IN
James E Sibray , Purdue University, West Lafayette, IN
Stephanie L Koser , Purdue University, West Lafayette, IN
Shawn S Donkin , Purdue University, West Lafayette, IN
Abstract Text:

Periparturient dairy cattle are prone to metabolic disease and frequently experience hepatic steatosis. A more complete understanding of the development and impact of hepatic steatosis has been hampered by the lack of a predictable and convenient steatosis induction model. Intensive fructose consumption in both rats and humans rapidly results in hepatic steatosis and insulin resistance, but the impacts of fructose on hepatic steatosis in dairy cattle are unknown. The objective of this study was to examine the effects of postruminal fructose supply on accumulation of liver triglycerides (TG) and other parameters of fatty liver disease in lactating dairy cattle. Eighteen multiparous late-lactation (241.7 ± 28.5 d in milk) Holstein cattle were assigned to either control (CON), postruminal fructose infusion (INF), or a pair-fed (PAIR) group. INF cows were previously fitted with rumen cannulae and received 1,000 g/d D-fructose for 7 d as a 16.67% w/v fructose solution delivered postruminally. Fructose dose averaged 1.47 g ± 0.11 / kg body weight (BW) and was delivered over a 23 h period. Amount of feed offered to PAIR group was matched to the previous 24 h intake of INF cows to account for any potential impact of fructose infusion on voluntary feed intake. CON group was fed ad libitum. There were no differences (P > 0.1) between groups in BW or body condition score before or after the infusion period. Milk production decreased (26.2, 23.1, 23.3 ± 0.79 kg for CON, INF, PAIR, respectively; P < 0.05) in both INF and PAIR groups during infusion period and was accompanied by decreased feed intake (23.5, 20.1, 19.4 ± 1.21 kg/d dry matter intake; P < 0.05). Plasma TG levels were not significantly different (P > 0.1) before, during, or after fructose infusion, but were numerically lower in INF, compared to PAIR, after infusion. Liver TG levels did not differ (P > 0.1) by group before or after infusion. Plasma fructose levels tended to remain high (602.9, 485.8 ± 44.60 µM for INF, PAIR, respectively; P < 0.1) in INF group after infusion period. Plasma glucose levels did not differ (P > 0.1) by group, nor did serum nonesterified fatty acid levels (P > 0.1). Data do not support the use of 7 d postruminal infusion of D-fructose at 1000 g/d as a model to study hepatic steatosis in lactating dairy cattle. 

Keywords: fructose, hepatic steatosis, postruminal infusion