Abstract #T373
Section: Ruminant Nutrition
Session: Ruminant Nutrition: Beef II
Format: Poster
Day/Time: Tuesday 7:30 AM–9:30 AM
Location: Gatlin Ballroom
Session: Ruminant Nutrition: Beef II
Format: Poster
Day/Time: Tuesday 7:30 AM–9:30 AM
Location: Gatlin Ballroom
# T373
Effects of starch content on in vitro ruminal fermentation of ground and dry-rolled barley grain.
Uchenna Y. Anele1, Basim Refat1,4, Mary-Lou Swift2, Yanli Zhao1,3, Tim McAllister1, Wenzhu Yang*1, 1Agriculture and Agri-Food Canada, Research Centre, Lethbridge, AB, Canada, 2Alberta Agriculture & Rural Development, Lethbridge, AB, Canada, 3Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, China, 4Zagazig University, Zagazig, Egypt.
Key Words: barley starch content, in vitro fermentation, grain processing
Effects of starch content on in vitro ruminal fermentation of ground and dry-rolled barley grain.
Uchenna Y. Anele1, Basim Refat1,4, Mary-Lou Swift2, Yanli Zhao1,3, Tim McAllister1, Wenzhu Yang*1, 1Agriculture and Agri-Food Canada, Research Centre, Lethbridge, AB, Canada, 2Alberta Agriculture & Rural Development, Lethbridge, AB, Canada, 3Inner Mongolia Agricultural University, Hohhot, Inner Mongolia, China, 4Zagazig University, Zagazig, Egypt.
Rapid digestion of barley starch in the rumen is hypothesized that starch content of barley grain can influence both rates of gas production (GP) and dry matter disappearance (DMD). Rumen fermentation of ground and dry-rolled barley grain differing in starch content was evaluated using a batch culture technique. The study was arranged in a 2 starch contents (low vs. high) × 2 processing (ground vs. dry-rolled) factorial design. Barley samples were collected monthly from 10 different feedlots in southern Alberta during one year. Samples were ranked according to the starch content into low (<60%) and high (>60% of DM). Ten barley samples with 5 low (57.1 ± 1.7%) and 5 high (66.0 ± 0.7% of DM) starch were either ground 2 mm or dry-rolled with processing index (PI) of 75%. Gas production and DMD were estimated at 3, 6, 12 and 24 h of incubation using rumen fluid from 3 fistulated beef heifers fed diet containing 70% barley silage and 30% barley grain (DM basis). Cumulative GP (mL/g DM) was fitted to a model GP = B(1−e−c(t−lag)). Starch content × processing interaction was not significant for in vitro GP kinetics. Rate of GP (%/h) was greater (P < 0.01) in both high starch (18.3) and ground (20.6) versus, respectively, low starch (16.1) and rolled (13.9) barley samples. Similarly, both high starch (40.0) and ground (44.9) samples had greater (P < 0.01) absolute initial GP during the first hour of incubation compared with, respectively, low starch (34.6) and rolled (29.7) barley. Data from DMD at different times of incubation were fitted to a model DMD = a + b(1–e–c(t–L)). Starch content × processing interactions were noted for the b fraction (P < 0.03) and rate of DMD (P < 0.01). Consistently, both high starch and ground barley had greater (P < 0.05) a, b and c of DM versus low starch and dry-rolled barley. However, the a, b, and c of starch did not differ between low and high starch barley. Ground barley had greater (P < 0.01) c (ground vs. rolled; 8.9 vs 6.1%) compared with rolled barley. The results indicated that starch content of barley had significant effect on in vitro rate of GP and the rate of DMD; processing (ground vs. dry-rolled) increased the extent and rate of DMD and starch.
Key Words: barley starch content, in vitro fermentation, grain processing
