Berthiaume, R., Lafrenie`re, C., Girard, C., Campbell, C. P., Pivotto, L. M. and Mandell, I. B. 2015. Effects of forage silage species on yearling growth performance, carcass and meat quality, and nutrient composition in a forage based beef production system. Can. J. Anim. Sci. 95: 173Á187. Forty weaned, crossbred beef calves (predominantly Angus and Simmental) were forage-finished using all-silage diets (red cloverÁtimothy versus tall fescue) to examine forage species' effects on growth performance, carcass traits, meat quality, and nutrient composition. Weaned calves (257 d of age) were forage-finished using red cloverÁtimothy or tall fescue silage and harvested at approximately 1 yr of age. During carcass processing, one side from each carcass was covered with a polyliner to examine if reducing rates of chilling could compensate for limited fat cover expected from low dietary energy contents fed, and limited time on feed. Longissimus thoracis, semimembranosus, and semitendinosus steaks were aged 10, 14, and 21 d to examine effects on WarnerÁBratzler shear force values while fatty acid and vitamin B 12 composition were determined on 10-d-aged steaks. Average daily gain, feed efficiency, hot carcass weights, and longissimus muscle area were greater (P B0.03) when cattle were fed red cloverÁtimothy versus tall fescue silage, most likely due to the higher protein content of red cloverÁtimothy silage. Shear force was greater (PB0.002) in steaks from all muscles evaluated from cattle fed tall fescue versus red cloverÁtimothy silage. In comparison to 10-d-aged steaks, 14 d of ageing were needed to reduce (P B0.001) shear force for longissimus steaks, while 21 d of ageing were needed to reduce (PB0.001) shear force for semitendinosus steaks. Use of a polyliner decreased (P 00.0001) the rate of temperature decline at selected carcass sites, but did not reduce shear force values. The percent of n-3 fatty acids and polyunsaturated fatty acid/saturated fatty acid ratio were greater (PB0.04) in longissimus from cattle fed red cloverÁ timothy versus feeding tall fescue silage. Feeding red cloverÁtimothy silage improved growth performance, carcass, shear force, and fatty acid composition traits versus feeding tall fescue silage.

Alfonso-Á vila, Á . R., Charbonneau, E., Lafrenie`re, C. and Berthiaume, R. 2015. Effect of glycerol in combination with alfalfa on in vitro gas production and microbial protein synthesis. Can. J. Anim. Sci. 95: 577Á588. This study sought to determine the effect of added glycerol on microbial protein synthesis, ruminal degradation and utilization of alfalfa at different concentrations of nonstructural carbohydrates (NSC), using in vitro gas production. The 2 )3 factorial plus one treatment consisted of oven-dried alfalfa with two NSC levels [high: 17.9 (HNSC) or low: 7.4% dry matter (DM) (LNSC)] and three glycerol treatments [control without glycerol, 15% crude glycerol (CG) and 15% pure glycerol (PG)], the additional treatment was LNSC'exogenous sugars (LNSC'ES: LNSC with 5% sucrose'5% starch). Five pre-planned contrasts were evaluated from the seven treatments: (1) HNSC vs. LNSC alfalfa; (2) with glycerol vs. without; (3) interaction of alfalfa and glycerol; (4) CG vs. PG, and; (5) LNSC'ES vs. HNSC. Gas production over 24 h was higher for HNSC than LNSC (202 vs. 179 mL g(1 DM) and with glycerol than without glycerol (202.2 vs. 168 mL g (1 DM). A decrease in the acetate:propionate ratio was observed for HNSC compared with LNSC (2.87 vs. 3.27) and for the addition of glycerol vs. no glycerol (2.78 vs. 3.65). Reduced microbial mass (185.5 vs. 240.5 mg g(1 DM) was observed for CG compared with PG. The LNSC'ES treatment had lower microbial protein synthesis and propionic acid production in relation to HNSC. No significant interaction was observed between the effect of NSC content of alfalfa and glycerol utilization. When effects were studied separately, results indicate that increasing NSC in alfalfa stimulates the synthesis of microbial protein. Also, the addition of glycerol promotes the synthesis of glucose precursors. Finally, the type of glycerol has an impact on results obtained suggesting caution when extrapolating results for PG to CG.