Abstract
This study aimed to evaluate the efficacy of yeast-fermented citric waste (YFCW) as a protein source in the concentrate diet of Brahman crossbred cattle. Citric waste, a by-product from the fruit juice industry, was fermented using Saccharomyces cerevisiae (1.0 × 10(8) CFU/g) to improve its nutritional value and digestibility. The experiment lasted for 84 days and was conducted using a 4 × 4 Latin square design, consisting of four periods of 21 days each. Four Brahman crossbred cattle were assigned to receive concentrate diets in which soybean meal was replaced with YFCW at 0, 33, 66, and 100% levels. The findings showed that while rice straw intake was unaffected (P > 0.05), increasing levels of YFCW linearly reduced concentrate intake, nutrient intake (including crude protein, NDF, and ADF), and nutrient digestibility (P < 0.05). Temperature and pH levels during rumen fermentation were within ideal ranges. However, cattle fed higher levels of YFCW (66-100%) showed a decrease in the population of protozoa and the concentration of total volatile fatty acids, particularly acetic and butyric acids. With the exception of platelet counts and specific red blood cell indices, the majority of hematological and biochemical parameters did not differ significantly between treatments. In conclusion, YFCW can be used as a protein source in beef cattle diets without adverse effects on animal health. However, replacement levels above 66% may negatively affect feed intake and nutrient digestibility. Appropriate inclusion levels should be considered to ensure sustainable ruminant production.