In vitro fermentation with inoculated goat rumen to evaluate the degradation of diets supplemented with three levels of protected palmitic acid

Abstract

Abstract Few studies evaluate the impact of a lipid-rich diet with palmitic acid (PA) in ruminal fermentation. The objective was to evaluate the in vitro bath culture of the protected PA on the ruminal fermentative variables. Four diets were used: a) without protected PA (nPA), b) inclusion of protected PA at three levels: PA3 = 3%, PA6 = 6%, and PA9 = 9% dry matter (DM). The results indicated that protected PA decreased gas production (p ≤ 0.05). DM and organic matter (OM) degradation after 72h of incubation linearly decreased (p ≤ 0.05) with a high level of protected PA. Neutral and acid detergent fiber degradation had no significant differences between treatments (p > 0.05). PA concentration in ruminal fluid had a linear effect with an increase from PA3 to PA9. Propionate had a quadratic effect (p ≤ 0.05) from nPA to PA3, and total volatile fatty acids had a linear decrease (p ≤ 0.05) from nPA to PA9. In conclusion, supplements with protected PA at 3 and 6% increased PA availability, and the results indicate good benefits of protected PA on fermentative variables. The doses of 3 and 6% of protected PA are recommended for use and evaluation in lactating goats.