Effect of plant oils and aspartate on rumen fermentation in vitro

Abstract

The effect of plant oils and aspartate (ASP) on rumen fermentation in vitro. The objective of this study was to determine the effect of plant oils (rapeseed - RO, sunflower - SO; linseed - LO; 10% wt/wt) and 8 mmol sodium aspartate on rumen fermentation of a diet (250 mg) consisting of hay, barley and sugar beet molasses (60 : 30 : 10). Rumen fluid was collected from two Slovak Merino sheep fed the same diet twice daily. Mixed ruminal micro-organisms were incubated in fermentation fluid (40 ml) containing rumen fluid and McDougall's buffer (1 : 4). Incubations were carried out in batch cultures for 72 h at 39 degrees C two times in a 3-week intervals. When compared to the control, all supplemented diets (RO, SO, LO, ASP) significantly increased the pH, the mol% of propionate (LO + 8.7%; SO + 10.12%; RO + 8.65%; ASP + 5.86%) and the acetate : propionate ratio and numerically decreased methane production (SO -32.8%; LO, RO -30.08%; ASP -21.56%). Lactate production was also significantly decreased. Addition of plant oils to aspartate-treated incubations partly inhibited the decrease of n-butyrate, lactate and the increase of pH and in vitro dry matter digestibility (IVDMD) caused by ASP treatment. The effect of combined additives (RO + ASP, SO + ASP, LO + ASP) on methane production SO + ASP (-19.23%) and mol% propionate SO + ASP (+2.66%), LO + ASP (+4.28%) was less effective. All combined additives caused a significant decrease in digestibility of the given feeds. No effect of plant oils and ASP could be observed on the parameters of rumen fermentation (mainly methane and propionate).

Effects of diet supplementation with herbal blend and sunflower seeds on fermentation parameters, microbial population, and fatty acid profile in rumen of sheep

“…According to Jalc and Ceresnakova (2002), if the addition of dietary fat interferes with normal fibre digestion in the rumen, then butyrate and acetate will always be reduced. The general recommendation is that total dietary fat should not exceed 6-7% of dietary DM, otherwise an adverse effect on rumen fermentation could be observed (Jenkins 1993).…”

Effect of oils rich in linoleic acid on <i>in vitro</i> rumen fermentation parameters of sheep, goats and dairy cows

“…Some authors have suggested that if added dietary fat interferes with normal fibre digestion in the rumen, butyrate and acetate will always be reduced (Jalč and Čerešňáková, 2002).…”

“…There are many conflicting data concerning ammonia concentrations when the diet is supplemented with fats: some of the data show no effect of supplemented fats on ammonia concentrations (Jalč et al, 2005), while other publications reported increases (Jalč et al, 2002) or decreases (Doreau et al, 1991) following such supplementations. No statistically significant changes were observed in the ammonia concentration in any of our three experiments.…”

Mitigation of ruminant methane production: current strategies, constraints and future options

“…In vitro studies conducted by Mohammed et al (2004) demonstrated that addition of fumarate increased propionate production and reduced methane output. Malate has a similar effect (Jalc and Ceresnakova 2002). In vivo studies also demonstrated the potential effects of dicarboxylic acids on methane output (Bayaru et al 2001).…”