Sunflower cake versus soybean meal and alfalfa for nitrogen utilization when crude protein and non-fiber carbohydrate levels are equivalent.

The reported efficiency of N usage by sunflower cake (SFC) was inferior to that of soybean meal (SBM) in a study in which the non-fiber carbohydrate (NFC) content was lower in the SFC diet. Here, we adjusted crude protein (CP) and NFC levels to near-equivalence among three diets containing SFC or SBM for four non-lactating Holstein cows. Alfalfa hay was also added to the comparison. The results demonstrated that the total digestible nutrient contents were not significantly different among the diets. Intake N, fecal N, absorbed N, urinary N, and retained N did not differ significantly among the diets. The efficiency of N usage in the body (retained N/absorbed N) did not differ significantly among the diets. No between-diet difference was observed in the protein- and energy-related ruminal and blood properties, including the estimated microbial protein synthesis in the rumen. These results suggest that regardless of the quality and balance of amino acids in a feed, the efficiency of N usage can be improved by a supply of digestible carbohydrates, which leads to an increase in ruminal microbial protein.

Digestive, fermentative, and physical properties of pineapple residue as a feed for cattle.

The intake, digestion, and ruminal fermentation properties; the antioxidative activity; and the physical effectiveness of pineapple residue (PR) from the cut-fruit industry as a feed for cattle were investigated. Four nonlactating Holstein cows were fed a basal diet and diets with 1.4- and 3.6-kg dry matter (DM)/day of PR (low-PR and high-PR diets, respectively). The DM digestibility and total digestible nutrients were 71% and 70%, respectively. Ruminal pH, volatile fatty acids, and ammonia-N did not differ among the diets. The numbers of total viable, amylolytic, cellulolytic, and methanogenic bacteria and protozoa, and microbial protein synthesis in the rumen also did not differ significantly. Blood triglyceride, nonesterified fatty acids, urea nitrogen, and aspartate transaminase were lower in the high-PR diet. Feeding PR did not affect blood malondialdehyde, although PR has a higher antioxidative value than other commonly used feeds. The particle distribution of PR satisfied the recommended range for haylage. The chewing time for ingestion and rumination did not change with PR content, and the roughage value index of PR was 57-min/kg DM. These results suggest that PR has good intake and digestion properties and satisfactory physical effectiveness. Even a high-PR-content feed unlikely induces the risk of ruminal acidosis.