Nguyen Binh Truong1,2*, Tran Trung Tuan1,2
1Department of Animal Science, Faculty of Agriculture and Natural Resources, An Giang University, Vietnam
2Vietnam National University, Ho Chi Minh City, Vietnam
*Corresponding author’s email: nbtruong@agu.edu.vn
Received: 22 September 2025 / Revised: 24 December 2025 / Accepted: 17 January 2026 / Published Online: 30 January 2026
Abstract
This study aims at finding out the combined Tra fish oil (TrO) and energy feed sources in the dietary combinations on feed intake, nutrient degradability, and greenhouse gas emissions of Charolais crossbred cattle. The in vitro gas experiment (Ex1) was arranged in a complete randomized design with two factors and four replications. Factor 1 was carbohydrate source (Es): cassava chip (Ca) and Maize (Ma), and factor 2 was Tra fish oil (TrO): with and without Tra fish oil. The in vivo digestion (Ex2) was arranged in a group of Latin square design with three factors. Factors 1 and 2 were similar to those in Ex1, but factor 3 was of cattle age periods, such as 13-16, 17-20, and 21-24 months. Results of Ex1 showed that the organic matter degradability was significantly distinct (P<0.05) at Es and TrO. Still, the interaction between Es and TrO was not variable (P>0.05) at 72 h incubation. Results of Ex2 showed that the methane emission (MJ/Kg DDM) was not divergent (P>0.05) between the Ma (169 MJ) and Ca (171 MJ). TrO (160 MJ) had lower methane emissions than NoTrO (181 MJ) by about 11.6%. The 13-16 months had higher methane emissions than 17-20 and 21-24 months (219, 161, and 131 MJ, respectively). Therefore, the Ma had better digestibility than the Ca on the beef cattle diet. Charolais crossbred cattle at 21-24 months had better intake, digestibility, and the lowest methane emission than 17-20 and 13-16 months’ age periods. In addition, supplementing the diet of the Tra fish oil could reduce methane in crossbred beef cattle.
Keywords: Climate change, Local feed, Lipid, Nutrition, Combinations, Ruminants
