Effect of Sodium Laurate on Ruminal Fermentation and Utilization of Ruminal Ammonia Nitrogen for Milk Protein Synthesis in Dairy Cows

Abstract

A crossover design trial with 4 ruminally and duodenally cannulated lactating dairy cows was conducted to study the effect of sodium laurate on ruminal fermentation, nutrient digestibility, and milk yield and composition. The daily dose of sodium laurate (0, control or 240 g/cow, LA) was divided in 2 equal portions and introduced directly into the rumen through the cannula before feedings. Ruminal samples (29 in 114 h) were analyzed for fermentation variables and protozoal counts. Sodium laurate had no effect on ruminal pH and total and individual volatile fatty acids concentrations. Ruminal ammonia concentration, ammonia N pool size, and the irreversible loss of ammonia N were unaffected by treatment. Compared to control, protozoal counts were reduced by 91% by LA. Carboxymethylcellulase and xylanase activities of ruminal fluid were decreased (by 40 and 36%, respectively), and amylase activity was not affected by LA compared with control. Flow of microbial N to the duodenum was reduced by LA. Dry matter intake and apparent total tract digestibility of dry matter, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber were not different between the 2 treatments. Milk yield, fat-corrected milk yield, milk fat and protein concentrations and yields, and milk urea N content were not affected by treatment. Sodium laurate did not affect transfer of ruminal ammonia-15N into bacterial or milk protein. In conclusion, LA at approximately 0.3% of the rumen weight reduced ruminal protozoal population and had a negative effect on fibrolytic activities of ruminal fluid and microbial protein flow to the intestine. Treatment had no other significant effects on ruminal fermentation, total tract digestibility, or transfer of ruminal ammonia-15N into milk protein.

Effect of supplemental Bacillus cultures on rumen fermentation and milk yield in Chinese Holstein cows

“…Fraction and ratio of amino acids in bacteria are beneficial for ruminants (Storm and Ørskov, 1983), which can provide 35–65% metabolizable protein. Microbial protein synthesized in the rumen supplies the majority of absorbable amino acids in the small intestine, because rumen microbes form a large proportion of their cell protein from ammonia N (Hristov et al., 2004).…”

Effects of lauric acid on physical, chemical and microbial characteristics in the rumen of steers on a high grain diet

“…This is in goodagreement with the results of previous in vitro (Dong et al . 1997) and in vivo (Hristov et al . 2004a; Jordan et al .…”

“…Although lauric acid sodium salt is recognized a potent protozoa inhibitor (Hristov et al . 2004a), the protozoa number was not affected by lauric acid feeding in the present study (Table 4).…”

“…2006). However, there was no significant effect on propionate in the in vivo studies with sodium laurate (Hristov et al . 2004a) and coconut oil (Jordan et al .…”

“…Moreover, coconut oil or lauric acid reduces the level of rumen protozoa (Newbold & Chamberlain 1988; Matsumoto et al . 1991; Hristov et al . 2004a; Jordan et al .…”