Effect of dietary lipid inclusion from by-product-based pellets on dry matter intake, ruminal fermentation, and nutrient digestion in finishing beef heifers

English. This study was designed to evaluate dry matter intake (DMI), ruminal fermentation, ruminal digesta outflow, omasal flow of N constituents, and ruminal and total-tract digestibility in response to increasing dietary lipid content derived from high-lipid by-product-based pellets for finishing beef cattle. Five ruminally cannulated heifers were used in a 5 × 5 Latin square design. Dietary treatments were iso-nitrogenous with increasing ether extract (EE) concentrations resulting in dietary concentrations of 3.5%, 4.2%, 4.7%, 5.1%, and 5.9% of dry matter. Periods were 28 d in duration with the first 19 d used for dietary adaptation and the last 9 d for sample and data collection. Dry matter intake, ruminal pH, omasal flow of N constituents, and short-chain fatty acid concentrations were not affected by increasing dietary EE content (P ≥ 0.10). Increasing dietary EE content increased outflow of EE from the rumen (P < 0.001). Apparent ruminal and total-tract digestibility of EE increased linearly (P ≤ 0.03) with increasing dietary EE levels. Results indicate that increasing dietary EE content from 3.5% up to 5.9% of DM by including high-lipid by-product-based pellets does not alter site of nutrient digestibility with no negative effects on nutrient intake, ruminal fermentation, or apparent ruminal, and total-tract digestibility.

English. canola, ether extract, omasal, site of digestion

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481-492

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