Effects of folic acid supplementation to rations differing in the concentrate to roughage ratio on ruminal fermentation, nutrient flow at the duodenum, and on serum and milk variables of dairy cows

Abstract

The present study was undertaken to determine the effects of dietary folic acid (FOL) supplementation on ruminal fermentation, duodenal nutrient flow, serum and milk variables, and on B-vitamin concentration in serum. The study was divided into two experiments: in Exp. 1 the forage to concentrate (F:C) ratio of the diet (DM basis) was 34:66 (high concentrate, HC), while in Exp. 2 the F:C ratio was 66:34 (high forage, HF). In addition, the cows received 0 or 1 g FOL/d. In Exp. 1, two German Holstein cows equipped with cannulas in the dorsal sac of the rumen and in the proximal duodenum were dry and five were lactating (186 +/- 144 days in milk); in Exp. 2 four cows were dry and four were lactating (165 +/- 57 days in milk). In cows fed the HC diet, FOL supplementation decreased the ruminally-fermented organic matter. Thus, less energy was available for ruminal microorganisms, which resulted in a reduced microbial crude protein flow at the duodenum. Feeding the HF diet, FOL supplementation only increased the apparent ruminal digestibility of acid detergent fibre (ADF). With the HF diet, FOL had no influence on the serum levels of glucose, non-esterified fatty acids, beta-hydroxybutyrate, urea, thiamine, riboflavin, pyridoxal-5'-phosphate, pyridoxic acid, pyridoxal, pyridoxine, pyridoxamine, pantothenic acid, nicotinamide or nicotinic acid, whereas supplementing FOL to the HC diet lowered the serum glucose and riboflavin levels. In both experiments, the supplementation of FOL had no effects on milk composition. Folic acid supplementation to both diets increased the concentrations of serum 5-methyl-tetrahydrofolate. However, no beneficial effects to dairy cows were obvious. Therefore, to achieve certain results, studies with a higher number of non-fistulated cows would be necessary.

Effects of rumen-protected folic acid on ruminal fermentation, microbial enzyme activity, cellulolytic bacteria and urinary excretion of purine derivatives in growing beef steers

“…The increased ruminal NDF degradability of corn silage with PRFA supplementation was consistent with the previous study in which the fibre degradability increased by 42% with folic acid supplementation at 100 g in 20 mL medium (Hall et al, 1953). Similarly, Ragaller et al (2010) found that the addition of folic acid at 1 g/d improved the degradability of ADF based on the high forage diet. The positive results of supplementary folic acid on in situ ruminal degradability can be confirmed by the improved milk production and milk protein percentage with increasing RPFA supplementation (0, 1 or 2 g/day) from 3 weeks prepartum to 15 weeks postpartum (Li et al, 2016).…”

“…Nevertheless, Girard et al (1994) found that the quantity of protein per unit of microbial mass was not modified by the dietary supplement of folic acid. Ragaller et al (2010) also found microbial protein flow to the duodenum reduced when the cows fed the high concentrate diet (forage to concentrate ratio: 34:66) and received folic acid at 0 or 1 g/d, because the ruminally fermented organic matter decreased with folic acid supplementation and then less energy was available for ruminal microorganisms. As discussed previously, these inconsistent results could be associated with the different administration practices and quantity of folic acid given as well as dietary composition.…”

“…Supplementary folic acid promoted the growth of celluloytic bacteria (Wejdemar, 1996), increased cellulose digestion (Hall et al, 1953;Ragaller et al, 2010), improved ruminal fermentation (Hayes et al, 1966) and increased the utilization of ammonia N for microbial protein synthesis (Wejdemar, 1996;Lee et al, 2000). However, other researches found limited influence of folic acid on ruminal fermentation (Clifford et al, 1967;Chiquette et al, 1993;Girard et al, 1994Girard et al, , 2009 and the utilization of ammonia N (Girard et al, 1994(Girard et al, , 2009Ragaller et al, 2010). The inconsistent influences of supplementary folic acid on ruminal fermentation and ammonia N utilization could be associated with diets with different ingredient and chemical composition, dose, physical form and way of administration of folic acid.…”

Effects of different dietary protein levels and rumen-protected folic acid on ruminal fermentation, degradability, bacterial populations and urinary excretion of purine derivatives in beef steers

“…Wang et al (2016) found similar results with RPFA supplementation in steers. Other studies also reported that fibre degradability was increased by 42% with FA supplementation in vitro (Hall et al 1953), and in situ ruminal ADF degradability was improved by supplementary FA (Ragaller et al 2010). Similarly, improved digestibilities of NDF, ADF and CP with increasing dietary CP levels were observed in cows (Weigel et al 1997; Broderick 2003).…”

Effects of pantothenic acid and folic acid supplementation on total tract digestibility coefficient, ruminal fermentation, microbial enzyme activity, microflora and urinary purine derivatives in dairy bulls

“…2017), and FA addition increased total tract digestibility in calves (Wang et al, 2019). Ragaller et al (2010) also found that ruminal ADF degradability increased with FA addition in a high-forage diet of dairy cows.…”