Nutrient Digestibility, Microbial Fermentation, and Response in Bacterial Composition to Methionine Dipeptide: An In Vitro Study

It is well known that the methionine dipeptide (MD) could enhance the dairy cows milking performance. However, there is still a knowledge gap of the effects of MD on the rumen fermentation characteristics, microbiota composition, and digestibility. This experiment was conducted to determine the effect of different nitrogen sources with a total mixed ration on in vitro nutrient digestibility, fermentation characteristics, and bacterial composition. The treatments included 5 mg urea (UR), 25.08 mg methionine (Met), 23.57 mg MD, and no additive (CON) in fermentation culture medium composed of buffer solution, filtrated Holstein dairy cow rumen fluid, and substrate (1 g total mixed ration). Nutrient digestibility was measured after 24 h and 48 h fermentation, and fermentation parameters and microbial composition were measured after 48 h fermentation. Digestibility of dry matter, crude protein, neutral detergent fiber (NDF), and acid detergent fiber (ADF) in the MD group at 48 h were significantly higher than in the CON and UR groups. The total volatile fatty acid concentration was higher in the MD group than in the other groups. In addition, 16S rRNA microbial sequencing results showed MD significantly improved the relative abundances of Succinivibrio, Anaerotruncus, and Treponema_2, whereas there was no significant difference between Met and UR groups. Spearman’s correlation analysis showed the relative abundance of Succinivibrio and Anaerotruncus were positively correlated with gas production, NDF digestibility, ADF digestibility, and acetate, propionate, butyrate, and total volatile fatty acid concentrations. Overall, our results suggested that the microbiota in the fermentation system could be affected by additional nitrogen supplementation and MD could effectively enhance the nutrient utilization in dairy cows.

Effect Of Dietary Concentrate And Bypass Fat Supplements On In Vitro Rumen Fermentation, Digestibility And Rumen Microbial Population In Buffaloes

Background: The effect of Brachiaria decumbens supplemented with concentrate and bypass fat ratio 100, 70:30, 70:15:15 (w/w) on nutritional composition, in vitro rumen fermentation and microbial population in Murrah cross and Swamp buffaloes were investigated. Incubation were conducted using rumen fluid obtained from the breed of each buffalo which were fed the same based diet (100% Brachiaria decumbens). For the in vitro fermentation characteristic after 48h incubation, total gas production, pH, total volatile fatty acid (TVFA), apparent rumen degradable carbohydrate (ARDC), methane (CH4) and ammonia (NH 3) were determined. The molecular technique also was used to quantify rumen total bacteria, total protozoa, total methanogens, Fibrobacter succinogens and Ruminococcus albus.Results: The results revealed Diet C showed significantly highest in dry matter, crude fat, metabolized energy and optimum in crude protein and carbohydrate value while lower in crude fiber as compared to Diet B and Diet A (P<0.05). In both breed were showed parameters of gas production, total volatile fatty acid (TVFA) and its proportion, and total microbial population were increased parallelly with the increase of 30% concentrate levels in Diet B, while Diet C was moderate with the presence of 4% bypass fat and 26% of concentrate (P<0.05). The methane concentration as well the total methanogens population increased significantly (P<0.05) in Diet B when compared among other diets, but no significant difference was found when comparing between buffalo species. Meanwhile, pH value was slightly decreased with the dietary supplementation in both breeds, but the population of cellulolytic bacteria was not affected.Conclusions: This study showed that dietary concentrate and bypass fat supplementation had improved nutritional composition, in vitro fermentation characteristics by increasing VFA concentration, altering total microbial population, and potentially used as new diet for buffaloes in Malaysia.

Effects of wild or mutated inoculants on rye silage and its rumen fermentation indices

Objective: This study was conducted to confirm the effects of new inoculants producing-antifungal or esterase substances on rye silage and its rumen fermentation indices by comparing wild with mutated types.Methods: Rye harvested at dough stage was ensiled into 3 L mini bucket silo (1 kg) for 90 d in triplicate following: distilled water at 20 μL/g (CON); <i>Lactobacillus brevis</i> 100D8 (AT) and its inactivation of antifungal genes (AT-m) at 1.2×10⁵ cfu/g, respectively; and <i>Leuconostoc holzapfelii</i> 5H4 (FD) and its inactivation of esterase genes (FD-est) at 1.0×10⁵ cfu/g, respectively. After silo opened, silage was sub-sampled for the analysis of ensiling quality and its rumen fermentation indices.Results: Among the wild type inoculants (CON vs AT vs FD), FD inoculant had higher (p<0.05) <i>in vitro</i> digestibilities of dry matter and neutral detergent fiber, the total degradable fraction, and total volatile fatty acid in rumen, while AT inoculant had higher (p<0.05) lactate, acetate, and lactic acid bacteria in silage. Silage pH and the potentially degradable fraction in rumen increased (p<0.05) by inactivation of antifungal activity (AT vs AT-m), but lactate, acetate, and lactic acid bacteria of silage decreased (p<0.05). In silage, acetate increased (p<0.05) by inactivation of esterase activity (FD vs FD-est) with decreases (p<0.05) of pH, ammonia-N, lactate, and yeast. Moreover, inactivation of esterase activity clearly decreased (p<0.05) <i>in vitro</i> digestibilities of dry matter and neutral detergent fiber, the total degradable fraction, and total volatile fatty acid in the rumen.Conclusion: This study concluded that FD inoculant confirmed esterase activity on rye silage harvested at dough stage, while AT inoculant could not be confirmed with antifungal activity due to the absence of mold in all silages.

USING SAGO PITH AS ADHESIVE SUBSTANCE IN VITRO DIGESTIBILITY OF COMPLETE RATION BISCUIT

The objective of the study was to determine in-vitro digestibility of complete ration biscuit using sago pith as adhesive substance. The experiment was arranged in Complete Randomized Design with 5 treatments and 5 replications. The treatments were P1 (50% mini elephant grass+ 20% leucaena + 30% sago pith + 0% rice bran), P2 (50% mini elephant grass+ 20% leucaena + 25% sago pith + 5% rice bran), P3 (50% mini elephant grass+ 20% leucaena + 20% sago pith +10% rice bran ) and P4 (50% mini elephant grass+ 20% leucaena + 15% sago pith + 15% rice bran). Variables measured were digestibility of dry (DM) and organic matter (OM), NH3 level, total volatile fatty acid (VFA), and rumen pH. The results show that the treatment has no significant effect on vitro digestibility of dry and organic matter. In vitro -digestibility is ranging from 90.7 – 91.4% and 87.5 – 88.4 % for DM and OM, respectively. In-vitro test on complete ration biscuit which consists of sago pith, rice bran, mini elephant grass and leucaena leucocephala has no significant (P>0.05) on NH3 level, total volatile fatty acid and rumen pH. In conclusion, sago pith can be potentially used as adhesive substance in formulating complete ration biscuit.

Determining the nutritive value of some commercial pulse screenings using in sacco and in vitro methods

The present study aimed at determining in sacco and in vitro the nutritive value of lentil screenings (LS), common vetch screenings (CVS) and bitter vetch screenings (BVS). For this purpose, three experiments (Exp.) were conducted. Ruminal degradation characteristics of the screenings were determined in Exp. 1 by the nylon bag technique using three ruminally fistulated rams. Gas production kinetics, and ruminal degradability and fermentation indices of the screenings were determined using 144 and 24-h incubations, respectively in Exp. 2. In Exp. 3, a basal growing ration for lambs (control) was supplemented by 175 or 350 g/kg of either LS, CVS or BVS (LS175, LS350, CVS175, CVS350, BVS175 and BVS350 respectively), and ruminal degradability and fermentation of the rations were evaluated in vitro. Soluble and potentially degradable fractions of protein were 0.321 and 0.719, 0.362 and 0.688, and 0.333 and 0.707, for LS, BVS and CVS respectively. Metabolisable energy was 11.1, 11.6 and 12.1 MJ/kg DM for LS, BVS and CVS respectively. The screenings had comparable gas production profiles, ruminal digestibility and total volatile fatty acid concentration. However, CVS and BVS had a higher propionate and a lower acetate:propionate ratio than LS (P &lt; 0.05). Including BVS and LS in the mixed ration increased total volatile fatty acid at both inclusion levels, but only BVS enhanced propionate proportion and lowered the acetate:propionate ratio (P &lt; 0.05). These results revealed that these screenings have a good nutritional value and can be used in ruminant diets without adversely affecting the rumen fermentation.

Rumen Fermentation Characteristics in Pre- and Post-Weaning Calves upon Feeding with Mulberry Leaf Flavonoids and Candida tropicalis Individually or in Combination as a Supplement

Although flavonoids or yeast have been used as feed additives to improve the production efficiency and health of adult cattle, little information is available on their effects on rumen fermentation in calves. The objective of this study was to investigate the effects of feed supplementation with mulberry leaf flavonoids and Candida tropicalis on performance, blood parameters, and rumen fermentation characteristics during pre-weaning and post-weaning periods. Forty-eight Holstein calves were used in a four-groups trial and were supplemented with (1) no yeast or flavonoids (CON), (2) active dry yeast (ADY; C. tropicalis, 5.0 × 109 CFU/d), (3) flavonoids (FLA; 3 g/d), or (4) yeast and flavonoids (YF; C. tropicalis, 5.0 × 109 CFU/d; flavonoids, 3 g/d). The feeding strategy was as follows: milk replacer was offered at 12% of body weight in two meals per calf each day at age 21 d, and a gradual weaning process was adopted at age 50 to 56 days. Data of daily feed intake, body weight, and serum and rumen fermentation parameters were obtained at 28, 42, 56, and 80 d ages, respectively. A significant time effect and interaction between treatment and time was found for average daily gain, feed efficiency, total volatile fatty acid concentration, and proportion of propionate in calves (p < 0.05). Average daily gain and feed efficiency increased during post-weaning and overall periods for calves in FLA and YF groups compared with CON and ADY groups (p < 0.05). A reduction of fecal scores with supplementation was found in FLA and YF groups (p < 0.05). Rumen fluid pH and ammonia nitrogen concentration remained constant across the groups, whereas total volatile fatty acid concentration and molar proportion of propionate significantly increased during the pre-weaning and overall periods in FLA and YF groups (p < 0.05). Calves in YF group had the highest serum concentrations of IgG and IgA during the overall period (p < 0.05). Additionally, serum β-hydroxybutyric acid concentration was higher in ADY and FLA groups during the post-weaning period (p < 0.05). Supplementation with C. tropicalis showed little effect on increasing growth performance and health compared with flavonoids alone. Meanwhile, the combination of C. tropicalis and flavonoids was not synergistic with respect to improving health and rumen fermentation compared with use of flavonoids alone in pre- and post-weaning calves (p > 0.05).

KECERNAAN DAN FERMENTABILITAS SUBSTRAT KOMBINASI MINERAL– FUNGI DALAM RUMEN

This study aims to determine the digestibility and fermentability of mineral-fungal combinations. The benefit of this study was to obtain data from the digestibility and fermentability of mineral-fungi combinations. The study was carried out in vitro with a completely randomized factorial 2 × 4 design with 3 replications. The variables observed were dry matter digestibility, organic matter digestibility, total VFA production (total volatile fatty acid), and NH3. The data obtained were then analyzed using variance test (ANOVA), if there was an influence on the variables measured, it will be followed by the Tukey’s Studentized Range test. The results showed that the combination of minerals gave a significant effect (P <0.05) and there was an interaction between mineral-fungi (P <0.05) in the digestibility of organic matter and VFA. The highest result was combination mineral with S. cerevisiae and as individual was combination Cu-Sc and Se-Sc. Keywords: Digestibility, Fermentability, Fungi, Mineral, Rumen.

Extending the Applications of the ADM1 to Predict Performance of the Induced Bed Reactor (IBR) Co-Digesting Municipal Sludge with Bakery Waste

The goal of this research was to examine the stability of the induced bed reactor (IBR) digesting municipal sludge (MS) mixed with bakery waste (BW) by experiment and modeling. It was necessary to modify the Anaerobic Digestion Model number1(ADM1) to accurately predict the performance of the IBR for this mixed waste. The total mixed influent COD was 50 g/L with hydraulic retention times that varied from 27 to 6 days at mesophilic temperatures. The reactor reached the steady state at each HRT with no sign of inhibition or failure, however, the COD removal efficiency of the digester decreased from 92% to 72% with decreasing HRT. The modified ADM1 outputs agreed well with the measured stability indicators (pH, total volatile fatty acid (TVFA), Q (gas production), percent CH₄ at the longer retention times of 27, and 20 days. The model overestimated the pH, and methane percentage and underestimated the TVFA when the HRT was shorter (12, 9 and 6 days). However, the model predicted well the trends of the observed data and the overall stability process of the digester until 6 d HRT. This research provided an alternative for the disposal of industrial bakery waste and also pointed out the ability of the IBR to manage high waste loads stably, while providing high energy production.