ARS | Publication request: PROPIONIBACTERIUM ACIDIPROPIONICI P169 AND GLUCOGENIC PRECURSORS TO IMPROVE RUMEN PARAMETERS ASSOCIATED WITH LOW QUALITY FORAGE

Submitted to: Western Section of Animal Science Proceedings
Publication Type: Proceedings
Publication Acceptance Date: March 15, 2010
Publication Date: July 15, 2010
Citation: Sanchez, P.H., Tracey, L.N., Browne-Silva, J., Petersen, M.K., Lodge-Ivey, S.L. 2010. Propionibacterium acidipropionici p169 and glucogenic precursors to improve rumen parameters associated with low quality forage. Western Section of Animal Science Proceedings 61:67-71.

Interpretive Summary: Cattle grazing dormant western rangelands tend to have a high ruminal acetate to propionate ratio (A:P) and may have low tissue clearance of acetate. Two studies were conducted to evaluate the effects of P. acidipropionici, P169 (P169) on VFA production, forage digestibility, and rumen bacterial ecology. In Exp. 1, in vitro effect of P169 on IVDMD and VFA production was evaluated in a 2 x 2 factorial arrangement of treatments. Factors were substrate (dormant warm-season grass extrusa or 50:50 Sudan:corn, DM basis) and P169 (with or without). In Exp. 2, twelve 2-yr old, pregnant Brangus heifers (BW = 416 ± 85 kg) were assigned to 1 of 3 treatments (n = 4). All cattle were fed a basal ration consisting of Old World Blue stem hay at 1.5% BW 10 d prior to initiation of treatment and for the duration of the experiment. Treatments were 1) protein supplement (36% CP, 35% UIP of CP, DM basis, fed at 454 g/hd per d; CON), 2) CON plus P169 (6×1010 cfu/hd, twice per d; P169), 3) calcium-propionate supplement fed at 454 g/hd per d (36% CP, 53 % UIP of CP + 80 g calcium propionate; PROP). Ruminal fluid was collected and analyzed for VFA, ammonia, pH and community DNA was extracted for denaturing gradient gel electrophoresis (DGGE). Glucogenic potential of treatment was evaluated with an acetate tolerance test on d 49. In Exp. 1, IVDMD, total VFA, acetate, propionate, and A:P increased (P < 0 .001) in both extrusa and 50:50 with P169 addition. In Exp. 2, the only effect of P169 on rumen parameters was a 4.3% increase in propionate (P < 0.02) over CON. Calciumpropionate supplement increased propionate and decreased A:P by 7.8% and 5.9% respectively (P < 0.004) over CON. Similarity of bacterial populations between treatments was evaluated with construction of a DGGE dendrogram using the Dice coefficient and samples were 73.9 ± 6.38% similar. Acetate half-life did not differ by treatment (P = 0.49). These data indicate that addition of propionateproducing bacteria to low quality forage diets could be as beneficial as supplementing with a propionic salt.

Technical Abstract: Cattle grazing dormant western rangelands tend to have a high ruminal acetate to propionate ratio (A:P) and may have low tissue clearance of acetate. Two studies were conducted to evaluate the effects of P. acidipropionici, P169 (P169) on VFA production, forage digestibility, and rumen bacterial ecology. In Exp. 1, in vitro effect of P169 on IVDMD and VFA production was evaluated in a 2 x 2 factorial arrangement of treatments. Factors were substrate (dormant warm-season grass extrusa or 50:50 Sudan:corn, DM basis) and P169 (with or without). In Exp. 2, twelve 2-yr old, pregnant Brangus heifers (BW = 416 ± 85 kg) were assigned to 1 of 3 treatments (n = 4). All cattle were fed a basal ration consisting of Old World Blue stem hay at 1.5% BW 10 d prior to initiation of treatment and for the duration of the experiment. Treatments were 1) protein supplement (36% CP, 35% UIP of CP, DM basis, fed at 454 g/hd per d; CON), 2) CON plus P169 (6×1010 cfu/hd, twice per d; P169), 3) calcium-propionate supplement fed at 454 g/hd per d (36% CP, 53 % UIP of CP + 80 g calcium propionate; PROP). Ruminal fluid was collected and analyzed for VFA, ammonia, pH and community DNA was extracted for denaturing gradient gel electrophoresis (DGGE). Glucogenic potential of treatment was evaluated with an acetate tolerance test on d 49. In Exp. 1, IVDMD, total VFA, acetate, propionate, and A:P increased (P < 0 .001) in both extrusa and 50:50 with P169 addition. In Exp. 2, the only effect of P169 on rumen parameters was a 4.3% increase in propionate (P < 0.02) over CON. Calciumpropionate supplement increased propionate and decreased A:P by 7.8% and 5.9% respectively (P < 0.004) over CON. Similarity of bacterial populations between treatments was evaluated with construction of a DGGE dendrogram using the Dice coefficient and samples were 73.9 ± 6.38% similar. Acetate half-life did not differ by treatment (P = 0.49). These data indicate that addition of propionateproducing bacteria to low quality forage diets could be as beneficial as supplementing with a propionic salt.