نوع مقاله : مقاله کامل
نویسندگان
1 دانشیار، گروه علوم دامی، مجتمع آموزش عالی تربتجام، تربتجام، ایران
2 دانشیار، گروه علوم دامی، دانشکده کشاورزی، دانشگاه سراوان
چکیده
کلیدواژهها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Introduction: Plant essential oils, as natural feed additives, can improve fermentation efficiency and reduce methane production by modulating the rumen microbial population. Pulicaria gnaphalodes (PG), known for its diverse bioactive compounds, holds potential for use in ruminant nutrition.
Objective: This study was conducted with the aim of determining the chemical composition of PG essential oil and investigating the effects of its different inclusion levels on ruminal fermentation parameters, gas production, and methane yield under in vitro conditions.
Methods: The essential oil was extracted via hydro-distillation and its constituents were identified by GC/MS. In vitro fermentation was conducted using rumen fluid from three fistulated male sheep and a basal diet. Treatments consisted of five levels of the essential oil (0, 250, 500, 750, and 1000 mg per liter of incubation medium). Parameters including gas production, methane emission, protozoal count, volatile fatty acids, ammonia nitrogen, pH, nutrient degradability, and microbial indices were measured over 24 to 96 hours of incubation. Data were analyzed in a completely randomized design.
Results: The essential oil of PG primarily contained 1,8-cineole (16.50%), eudesma-4(15),7-dien-1-β-ol (13.70%), and α-terpineol (12.20%). Essential oil supplementation resulted in a significant linear decrease in methane production (from 13.25 to 8.02 mL), protozoal population (from 7.27 to 4.29 × 10⁵ cells/mL), ammonia nitrogen (from 18.01 to 13.86 mg/dL), and dry matter degradability (from 70.75 to 63.95%) (P<0.05). However, microbial biomass synthesis efficiency (from 24.90 to 30.42%) and the partitioning factor (from 2.93 to 3.16 mg of truly digested organic matter/mL of gas produced) increased significantly (P<0.05). The highest microbial biomass (55.63 mg) was observed at the 500 mg/L concentration (P<0.05).
Conclusion: PG essential oil enhanced rumen efficiency by lowering protozoa and methane. The 500 mg/L dose is optimal for improving microbial activity in fattening lambs.
کلیدواژهها [English]
)