Yang, W. Z., Oba, M. and McAllister, T. A. 2013. Quality and precision processing of barley grain affected intake and digestibility of dry matter in feedlot steers. Can. J. Anim. Sci. 93: 251–260. A study was conducted to determine the impact of barley quality and precision processing to account for the impact of variable kernel uniformity on ruminal pH and fermentation, and digestibility in the digestive tract of steers. Eight ruminally cannulated steers were used in a replicated 4×4 Latin square experiment. The four diets consisted of light-weight barley (LB) precision-processed with roller setting based on kernel size; heavy-weight barley (HB) precision-processed; LB and HB grain mixed equal parts then processed at a single roller setting (CON); or LB and HB precision-processed and mixed equal parts (PP). The diets consisted of 10% barley silage and 90% concentrate [dry matter (DM) basis]. Dry matter intake by steers fed LB was greater (P=0.04) than by steers fed HB. Intakes of DM and other nutrients were greater (P=0.04) for steers fed PP than for steers fed CON. There were no differences (P>0.14) in ruminal pH and fermentation among treatments. Digestibility of DM in the total digestive tract tended (P=0.06) to be less with LB than with HB. Precision processing increased digestibility of crude proteion (P=0.04) and acid detergent fibre (P=0.06) resulting in a trend (P=0.10) towards increasing organic matter digestibility as compared with CON. The results suggest that screening of blended barley into more uniform fractions and precision processing of each fraction could increase intake of digestible nutrients for feedlot cattle.

Oba, M. and Swift, M. L. 2014. SHORT COMMUNICATION: Effects of feeding Falcon or Tyto whole plant barley silage on milk production and feed efficiency. Can. J. Anim. Sci. 94: 151Á153. Eight lactating dairy cows were fed diets containing either Falcon or Tyto whole-plant barley silage (Hordeum vulgare; WPBS) in a crossover design to study effects on milk production and feed efficiency. The in vitro fibre digestibility (IVFD) of Falcon and Tyto WPBS was 61.6 and 57.2%, respectively. Cows consuming the Falcon WPBS utilized feed more efficiently compared with those consuming the Tyto WPBS (1.44 vs. 1.32 kg milk kg(1 dry matter intake) although milk yield was not affected. This research demonstrates that IVFD may be an important quality indicator of WPBS when balancing diets for high producing lactating cows.

response to processing, in vitro gas production and fermentation of western Canadian feed barley. Can. J. Anim. Sci. 94: 725Á729. Sixty feed barley samples were collected from various locations in western Canada. Samples were either ground (1 mm) or dryrolled to a processing index of 80%, and fermentability was assessed by measuring gas production (GP) and dry matter disappearances (DMD) at 0, 4, 8, 14 and 24 h of incubation using a batch culture technique. Physical and chemical composition, and GP and DMD varied substantially among samples. There were significant correlations among test weight and nutrient content of barley with GP and DMD of ground barley. The results indicate that the impact of nutrient content on in vitro DMD is more easily detected with ground than rolled barley.

COMMUNICATION: The effect of seed hardness and malting characteristics on in situ dry matter digestibility of barley grain in beef heifers. Can. J. Anim. Sci. 95: 299Á303. An in situ study was conducted to evaluate the relationship between ruminal dry matter digestibility (DMD) and seed hardness or malting characteristics of barley grain. Samples were selected for low and high values of seed hardness index (53 vs. 65; N 018), beta-glucan content in wort (122 vs. 316 ppm; N018), diastatic power (146 vs. 2038L; N 018), and friability (46 vs. 81%; N 018) in malt, and incubated in the rumen of three beef heifers for 4, 12 and 48 h. In situ DMD did not vary with beta-glucan concentration or friability. However, barley grain with low seed hardness had lower (P 00.02) in situ DMD than those with high seed hardness after 4 h of incubation. The barley samples with low diastatic power also had (P 00.02) higher DMD than with high diastatic power after 4 h, a trend (P00.07) that continued after 12 h of incubation. Seed hardness and malting characteristics may have the potential to predict DMD of barley grain in the rumen. However, observed differences in in situ DMD were relatively minor, and we did not detect a relationship between malting characteristics and in situ DMD at longer incubation times. This suggests that the identified grain physical and malt parameters may impact the rate, but not the extent of barley grain digestion in the rumen. COMMUNICATION BRE`VE: Les effets de la durete´du grain et les qualite´s maltie`res sur la digestibilite´in situ des matie`res se`ches du grain d'orge chez les ge´nisses de boucherie. Can. J. Anim. Sci. 95: 299Á303. Une e´tude in situ a e´te´effectue´e pour e´valuer la relation entre la digestibilite´dans le rumen des matie`res se`ches (DMD Á « dry matter digestibility ») et la durete´du grain ou les qualite´s maltie`res du grain d'orge. Les e´chantillons ont e´te´choisis pour des valeurs faibles ou fortes d'indice de durete´du grain (53 c. 65; N 018), de teneur en be´ta-glucane dans le mouˆt (122 c. 316 ppm; N 018), du pouvoir diastatique (146 c. 2038L; N 018), et de la friabilite´(46 c. 81%; N018) dans le malt, puis incube´s dans le rumen de trois ge´nisses de boucherie pendant 4, 12 et 48 h. La DMD in situ n'a pas varie´selon la concentration en be´ta-glucane ni la friabilite´. Par contre, les grains d'orge ayant de plus faibles durete´s avaient une plus faible (P00,02) DMD in situ que ceux de plus forte dureted u grain apre`s 4 h d'incubation. Les e´chantillons d'orge avec faible pouvoir diastatique avaient aussi une plus forte DMD (P 00,02) que ceux avec fort pouvoir diastatique apre`s 4 h, une tendance (P00,07) qui se poursuivait apre`s 12 h d'incubation. La durete´du grain et les qualite´s maltie`res ont le potentiel de pre´dire la DMD du grain d'orge dans le rumen. Par contre, les diffe´rences observe´es de DMD in situ e´taient relativement mineures et nous n'avons pas de´cele´de relation entre les qualite´s maltie`res et la DMD in situ lors de plus longues pe´riodes d'incuba...