Effect of high-quality pellet feed level on voluntary feed intake, nutrient digestibility and rumen fermentation in beef cattle

Abstract The aim of this study was to evaluate the effect of high-quality pellet feed on voluntary feed intake, nutrient digestibility and rumen fermentation in beef cattle. Four beef cattle aged approximately 2–3 years were randomly assigned according to a 4 × 4 Latin square design to compare the replacement of pelleted diets in concentrated diets at 4 levels: 0% of diets (T1), 20% of diets (T2), 40% of diets (T3) and 60% of diets (T4). The results of this study revealed that body weight change rate/day total edible amount, or the amount of feed that can be eaten out of concentrated feed, was not significantly different (P > 0.05) among the beef cattle fed all 4 treatments. The digestibility of dry matter, organic matter, crude protein, NDF and ADF was highest in pelleted-fed beef cattle, at 60%. However, the combination of a pelleted diet and a concentrated diet resulted in a statistically significant reduction in protozoa populations when the pelleted diet level was increased. The level of pelleted feed had no effect on the pH or rumen temperature of the beef cattle. With respect to ammonia nitrogen, the propionic acid, butyric acid and total volatile fatty acid levels increased when the beef cattle were fed more pelleted feed. especially at 60%, but the acetic acid and methane production decreased when the beef cattle were fed higher levels of pelleted feed. Purine derivative release was not significantly different. In addition to purine derivative absorption and microbial nitrogen supply, the efficiency of microbial protein synthesis was greater when beef cattle were fed high-quality pelleted feed than when they were not fed high-quality pelleted feed. The present study concluded that pellet feeding in conjunction with concentrated feed at 60% resulted in decreased methane production, protozoa population and nutrient digestibility, microbial protein synthesis, total volatile fatty acids and propionic acid.