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Butyrate regulates urea metabolism and nitrogen use in sheep
Author(s) -
Agarwal Umang,
Somers Katelyn,
Bailey Kelly,
Hu Qiong,
Bequette Brian J
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.lb194
Subject(s) - urea , rumen , butyrate , chemistry , excretion , metabolism , zoology , biochemistry , feces , medicine , fermentation , biology , microbiology and biotechnology
Butyrate has been implicated in regulation of rumen urea transporter expression and thus urea recycling, yet direct evidence is absent. This study aimed to determine the effect of butyrate on urea recycling by infusion of butyrate into the rumen. Wether sheep (42 kg BW) fitted with rumen cannula were fed to 1.8× energy maintenance a standard diet (130 g CP/kg, 9.3 MJ ME/kg) and infused into the rumen with isoenergetic (1.2 MJ/d) and isonatremic solutions of either Na‐Acetate (control) or Na‐Butyrate for 10‐d periods in a crossover design. [ 15 N 2 ]Urea was continuously infused IV for the last 5 d, and all urine and feces were collected. Compared to no infusion, Butyrate increased (P < 0.05) rumen acetate and butyrate, whereas Acetate increased (P < 0.05) rumen acetate. Compared to Acetate, Butyrate decreased urea entry (17.2 vs 14.3 g urea‐N/d, P < 0.05) and urinary urea excretion (9.3 vs 7.7 g urea‐N/d, P = 0.11). Although transfer of urea to the gut was not different, Butyrate increased (0.6 vs 2.2 g urea‐N/d, P < 0.05) microbial capture of the urea‐N that was transferred to the gut. The results suggest that butyrate does not increase urea recycling to the gut compared to acetate. However, the reduction in urea synthesis coupled with increased capture of recycled urea‐N by gut microbes suggests that butyrate enhanced overall capture of feed and urea derived ammonia by microbes. Supported by Maryland Agricultural Experiment Station.