Abstract #35
Section: ADSA Production PhD Oral Competition (Graduate)
Session: ADSA Production PhD Oral Competition (Graduate)
Format: Oral
Day/Time: Monday 11:45 AM–12:00 PM
Location: Room 301 D
Session: ADSA Production PhD Oral Competition (Graduate)
Format: Oral
Day/Time: Monday 11:45 AM–12:00 PM
Location: Room 301 D
# 35
Bioavailability of rumen-protected histidine, lysine and methionine assessed by fecal amino acid excretion.
Susanna E. Räisänen*1, Cristian M. M. R. Martins2, Krum Nedelkov3, Joonpyo Oh1, Michael T. Harper1, Xianjiang Chen4, Claudia Parys5, Robert A. Patton6, Makoto Miura7, Alexander N. Hristov1, 1The Pennsylvania State University, University Park, PA, 2University of São Paulo, Pirassununga, Brazil, 3Trakia University, Stara Zagora, Bulgaria, 4Lanzhou University, Lanzhou, Gansu, China, 5Evonik Nutrition & Care GmbH, Hanau-Wolfgang, Germany, 6Nittany Dairy Nutrition Inc, Mifflinburg, PA, 7Animal Nutrition Group, Research Institute for Bioscience Products & Fine Chemicals, Ajinomoto Co. Inc, Kawasaki, Japan.
Key Words: rumen-protected amino acid, bioavailability, dairy cattle
Bioavailability of rumen-protected histidine, lysine and methionine assessed by fecal amino acid excretion.
Susanna E. Räisänen*1, Cristian M. M. R. Martins2, Krum Nedelkov3, Joonpyo Oh1, Michael T. Harper1, Xianjiang Chen4, Claudia Parys5, Robert A. Patton6, Makoto Miura7, Alexander N. Hristov1, 1The Pennsylvania State University, University Park, PA, 2University of São Paulo, Pirassununga, Brazil, 3Trakia University, Stara Zagora, Bulgaria, 4Lanzhou University, Lanzhou, Gansu, China, 5Evonik Nutrition & Care GmbH, Hanau-Wolfgang, Germany, 6Nittany Dairy Nutrition Inc, Mifflinburg, PA, 7Animal Nutrition Group, Research Institute for Bioscience Products & Fine Chemicals, Ajinomoto Co. Inc, Kawasaki, Japan.
The objective of this experiment was to assess bioavailability of rumen-protected His, Lys and Met products (RPAA). Eight Holstein cows (96 ± 21 DIM, 39.4 ± 7.0 kg/d milk yield), 4 of which rumen-cannulated, were used in a replicated 4 × 4 Latin square design experiment with four 25-d experimental periods. RPAA were fed daily to supply 20, 25, and 35 g/d of digestible (d)His, dLys and dMet, based on manufacturer’s specification and dietary AA deficiencies. Treatments were combinations of RPAA products: MetA+LysA+HisA, MetB+LysB+HisB, MetC+LysC and MetD+LysC. Total fecal collection and blood sampling were performed during the last 3 d of each experimental period. Data were analyzed using the MIXED procedure of SAS with square, square(period), treatment and treatment × square in the model; cow(square) was random effect. Rumen by-pass AA (RBP, %) in each RPAA was determined in situ with the cannulated cows. RBP ranged (P < 0.001) from 29.3 to 98.0% for RPMet, from 33.3 to 84.7% for RPLys and was higher for HisA (89.7%) than for HisB (59.9%). Digestibility of AA from RPAA (%) was calculated as: (RBP AA, g – fecal AA excretion, g) ÷ RBP AA, g × 100, and bioavailability (BA, %) as: RBP, % × AA digestibility, % ÷ 100. Digestibility of Met from RPMet products varied from 86.1 to 97.8% (P < 0.001) and from 50.1 to 85.6% for RPLys (P < 0.001); dHis was not different for the 2 RPHis (85.6 and 88.5%; P = 0.12). BA of Met in RPMet varied (P < 0.001) from 25.8 to 95.3%, of Lys from 16.7 to 72.4%, and was 76.8 and 52.9% for HisA and HisB, respectively. Plasma Met concentration was higher for MetD (44.9 µM; P < 0.001) compared with the other 3 RPMet (averaging 25.5 µM). Plasma Lys concentration did not differ among RPLys (averaging 82.4 µM, P = 0.47). Plasma His concentration was greater (P = 0.002) for HisA (73.9 µM) than for HisB (55.5 µM), reflecting the considerably greater dHis supply by HisA. This study showed that rumen degradability and bioavailability of AA from RPAA vary considerably and fecal AA output in relation to the amount of rumen by-pass AA can be used to estimate bioavailability of RPAA.
Key Words: rumen-protected amino acid, bioavailability, dairy cattle
