Manipulation of ruminal fermentation and methane production by supplementation of rain tree pod meal containing tannins and saponins in growing dairy steers

Abstract

Four rumen-fistulated dairy steers were used in a 2 × 2 factorial arrangement in a 4 × 4 Latin square design. The main factors were two roughage-to-concentrate ratios (R:C, 60:40 and 40:60) and two supplementation levels of rain tree pod meal (RPM) [0 or unsupplemented and 60 g/kg of total dry matter (DM) intake]. Chopped 30 g/kg of urea-treated rice straw was used as a roughage source. All animals received dietary according to respective R:C ratios at 25 g/kg body weight. The RPM contained condensed tannins and crude saponins at 84 and 143 g/kg of DM respectively. It was found that total volatile fatty acids (VFAs) and propionate concentrations were increased (p < 0.01), while acetate concentration, acetate-to-propionate ratio, CH4 production and protozoal numbers were decreased (p < 0.01) when steers were supplemented with RPM and 600 g/kg of concentrate. Allantoin excretion was found different by both R:C ratio and supplementation of RPM, with the highest value at R:C of 40:60 with 60 g/kg RPM (123.6 mmol/day) (p < 0.05). Allantoin absorption and microbial crude protein were increased (p < 0.05) with an increasing concentrate ratio. Moreover, efficiency of microbial protein synthesis was increased (p < 0.05) by feeding a higher ratio of concentrate (R:C 40:60) and supplementation of RPM. Based on this study, it is suggested that supplementation of RPM was beneficial for dairy cows fed on high roughage ratio, which could improved rumen fermentation by reducing fermentation gas loss, thus improving VFA profiles and thus enhancing efficiency of microbial protein synthesis.

Energy utilization, nitrogen balance and microbial protein supply in cattle fed Pennisetum purpureum and condensed tannins

“…Anantosook et al. () observed that with rations of high quality with a forage to concentrate ratio of 60:40, microbial CP synthesis and the efficiency of microbial nitrogen synthesis were greater compared to rations with a 40:60 forage to concentrate ratio.…”

“…Anantosook et al. (), with better quality rations with a ratio of 60:40 forage to concentrate and with the incorporation of 60 g/kg of Samanea saman , found that the excretion of urinary allantoin was increased by 15.29%.…”

“…Variability found in the results obtained in the present experiment may have been influenced by the low-quality of the basal ration employed for the feeding of cattle (crude protein content: 30.10 g/kg DM and dry matter digestibility: 534 g/kg). Anantosook et al (2014) observed that with rations of high quality with a forage to concentrate ratio of 60:40, microbial CP synthesis and the efficiency of microbial nitrogen synthesis were greater compared to rations with a 40:60 forage to concentrate ratio.…”

“…Several of those species contain secondary metabolites such as condensed tannins (CT), which are found in foliages, fruits and cortex; and when they are consumed by ruminants, form chemical complexes with proteins and carbohydrates, which reduce rumen degradation of those components (Ramirez‐Restrepo et al., ) and favours the passage of undegraded (‘bypass’) protein and the absorption of amino acids from the small intestine (Soltan et al., ). In addition, CT may increase microbial protein synthesis (Anantosook et al., ; Hernandez et al., ), increase nitrogen retention, reduce emissions of N 2 O from urine and reduce fermentation of fiber (Barry and Manley, ; Soltan et al., ).…”

“…Condensed tannins also have the capacity to reduce protozoa and bacterial populations in the rumen (Tavendale et al., ; Animut et al., ), thus contributing to mitigate emissions of enteric CH 4 (Bhatta et al., ; Dias‐Moreira et al., ; Rira et al., ) and to improve the efficiency of energy utilization for live weight gain (Min et al., ; Burke et al., ) and milk production (Anantosook et al., ; Dey and De, ). In spite of the potential benefits of CT, when they are incorporated in ruminant rations, the responses will depend on the quality and chemical composition of the rations to which they are incorporated, the concentrations of CT, the level of feed intake, the chemical structure and the molecular weight of CT.…”