No abstract

. 2015. Effect of feeding strategically blended feed pellets on rumen fermentation and nutrient digestion. Can. J. Anim. Sci. 95: 243Á254. Five rumen-cannulated heifers (631931 kg) were used in a 5 )5 Latin square design to evaluate the effect of feeding blended by-product feed pellets (BP) on rumen fermentation and nutrient utilization. Four BP were formulated to be high in starch (HS) or fat (HF) and either low (LSP) or high (HSP) in soluble crude protein. The control diet consisted of 49.1% forage and 50.9% barley-based concentrate. Treatments were 50.3% forage and 49.7% BP (DM). Heifers fed HF BP had higher (P 00.05) mean pH values than those fed the control diet and tended (P00.07) to have higher mean pH than those fed the HS BP. Feeding HF BP decreased (PB0.05) rumen propionate concentration without affecting acetate or total volatile fatty acid concentration. Rumen ammonia-nitrogen (N) levels and digestibility of crude protein was highest (PB0.05) for HS, intermediate for HF, and the lowest for the control. Feeding HF BP reduced (PB0.05) gross energy digestibility and digestible energy content relative to both the control and HS diets while both BP increased (PB0.01) their extract digestibility compared with the control. There was minimal effect of pellet soluble crude protein content. Total N excretion (% of N intake) was not affected (P0.05) by treatment. These results indicate that BP had no adverse effects on rumen fermentation or apparent nutrient digestibility and did not result in issues with excess nutrient excretion. As such BP can be used as an alternative energy source in backgrounding diets to cereal grains and can help counteract volatility in feed grain prices. Cinq ge´nisses canule´es au rumen (631931 kg) ont e´te´utilise´es dans une expe´rience de carre´latin 5x5 pour e´valuer les effets de l'alimentation par granule´s de produits de´rive´s me´lange´s (BP Á « by-product feed pellets ») sur la fermentation du rumen et l'utilisation des e´le´ments nutritifs. Quatre BP ont e´te´formule´s pour avoir une forte teneur en amidon (HS Á « high starch ») ou en gras (HF Á « high fat ») et soit faible teneur en prote´ines brutes solubles (LSP Á « low soluble crude protein ») ou forte teneur en prote´ines brutes solubles (HSP Á « high soluble crude protein »). La die`te te´moin consistait de 49,1 % de fourrage et 50,9 % de concentre´a`base d'orge. Les traitements e´taient de 50,3 % de fourrage et 49,7 % BP (matie`res se`ches [DM Á « dry matter »]). Les ge´nisses ayant rec¸u les BP HF avaient des valeurs moyennes de pH plus e´leve´es (P00,05) que celles ayant rec¸u la die`te te´moin, et tendaient (P00,07) vers des valeurs moyennes de pH plus e´leve´es que celles ayant rec¸u les BP HS. L'alimentation aux BP HF a diminue´(PB0,05) la concentration de propionate dans le rumen sans avoir d'effet sur les concentrations d'ace´tate ou d'acides gras volatils totaux (VFA Á « volatile fatty acids »). Les niveaux d'ammoniac-azote (N) et de digestibilite´des prote´ines brutes (CP Á « crude proteins ») dans le rumen ...