Ruminal Volatile Fatty Acid Profile Research Articles

Encapsulated pepper blend in the diet of confined Holstein bullocks: effect on ruminal volatile fatty acid profiles, growth performance, and animal health

Dairy bulls in feedlots have been a viable alternative for dairy producers to reinforce the family's income. Aspects such as balanced diets and proper management are essential for these animals to develop and allow an economic return fully. Plant extracts are performance enhancers and ruminal and intestinal health promoters. Therefore, this study aims to evaluate whether the addition of encapsulated pepper (EP) blend (Capsicum annuum, Capsicum frutescens, and Capsicum chinense - rich in capsaicin) interferes with the volatile fatty acid profile in the rumen and enhances the growth performance of Holstein bullocks in a feedlot. For the experiment, 24 whole bullocks were used, distributed into three treatments, with eight replicates per treatment (one animal as an experimental unit, kept in an individual stall): groups T0, T200, and T400, receiving 0 mg, 200 mg, and 400 mg EP/kg of concentrate, respectively. Knowing the intake of concentrate and the average body weight during the experiment, we calculated the dose in mg/kg/day of the EP; that is, the T200 animals consumed 2.45 mg EP/kg (body weight -BW)/day; and T400 consumed 4.9 mg EP/kg BW/day. The animals from T400 presented a more significant weight gain between days 15 and 45 of confinement compared to T0 (P=0.05). This same treatment (T400) had a trend of lower weight gain between days 46 and 90 (P=0.09). Likewise, the T400 group had higher feed efficiency than T0 between days 15 and 45. Furthermore, the treatments affected the white blood cell count, with the T400 bullocks showing a higher number of neutrophils and lymphocytes. Higher levels of C-reactive protein (CRP) were measured in the serum of steers from both groups that consumed pepper (P<0.01). Interaction between treatment × day was observed for the activity of glutathione enzymes (GST and GPx) and levels of lipoperoxidation (LPO) (characterized by antioxidant stimulation) associated with the reduction in serum LPO; similar antioxidant enzymes behavior was observed in the liver. In the small intestine (jejunum), the activities of antioxidant enzymes (GST and GPx) were lower in the two groups of cattle that consumed EP, and LPO was lower. The treatments affected the concentration of acetic acid in the rumen fluid, presenting lower levels in T400 compared to T200 and similar T0 (P≤0.05). There was an interaction of day vs. treatment for propionic acid, presenting a higher concentration on day 45 at T400 than T0. These results, therefore, allow us to conclude that adding 400 mg of pepper extract can be an excellent additive for weight gain at the beginning of the experiment; however, over time, this dose of additive negatively affects weight gain. Both EP doses stimulated serum and tissue antioxidant responses, reducing lipoperoxidation. However, the 400 mg EP/kg concentrate suggests a pro-inflammatory response (leukocytosis and elevated CRP), s probably related to the high dose (i.e., between 1.7 and 2.4 g/animal/day).

Effects of a novel direct-fed microbial on growth performance, carcass characteristics, nutrient digestibility, and ruminal morphology of beef feedlot steers.

The effects of a novel direct-fed microbial (DFM) on feedlot performance, carcass characteristics, digestibility, ruminal morphology, and volatile fatty acid (VFA) profile of finishing steers were evaluated. Single-source Angus-crossbred yearling steers (n = 144; initial body weight (BW) = 371 ± 19kg) were used in a randomized complete block design. Steers were blocked by initial BW and randomly assigned to treatments (12 pens/treatment; 4 steers/pen). Treatments included (A) CONTROL (no DFM, tylosin, or monensin, (B) MONTY (monensin sodium [330mg/animal-daily] and tylosin phosphate [90mg/animal-daily]), and (C) MONPRO (monensin sodium [same as previous] and Lactobacillus salivarius L28 [1 × 106 CFU/animal-daily]). Treatments were included in a steam-flaked corn-based finisher diet offered once daily using a clean-bunk management for ~149d. The digestibility assessment was performed from days 70 to 74. Ruminal fluid and rumen tissue samples were collected at the slaughter for VFA profile and papillae morphology analyses, respectively. Data were analyzed using the GLIMMIX procedure of SAS with pen serving as the experimental unit, treatment as fixed effect, and BW block as random effect. Steers offered MONPRO had on average 5.3% less (P < 0.01) dry matter intake (9.56kg/d) compared with either CONTROL (10.16kg/d) or MONTY (9.96kg/d). The carcass-adjusted final BW (613kg; P = 0.23), overall average daily gain (1.64kg/d; P = 0.23), and gain-efficiency (0.165; P = 0.61) were not affected by treatments. Steers offered CONTROL had greater (P < 0.01) marbling score and tended (P = 0.06) to have less carcasses grading Select and tended (P = 0.10) to have more carcasses grading Upper-Choice, while other carcass characteristics and liver-abscesses were not affected (P ≥ 0.23) by treatments. The digestibility of nutrients (P ≥ 0.13) and the ruminal VFA profile (P ≥ 0.12) were not affected by treatments. Steers offered MONPRO tended (P = 0.09) to have 16% greater average papillae number compared to other treatments. Yearlings offered finishing diets containing L. salivarius L28 plus monensin did not affect growth performance, digestibility, or ruminal VFA, but reduced feed intake. Carcass quality was negatively affected by treatments, while animals consuming L. salivarius L28 and monensin tended to improve ruminal morphology. Current findings in ruminal morphology and feed intake may warrant further assessment of diets containing L. salivarius L28 on beef cattle food safety aspects.

Effects of conditioner retention time during pelleting of starter feed on nutrient digestibility, ruminal fermentation, blood metabolites, and performance of Holstein female dairy calves

This study evaluated the effects of conditioner retention time during the pelleting process of starter feed on intake, nutrient digestibility, ruminal fermentation, blood metabolites, and growth performance of dairy calves. A total of 30 Holstein female dairy calves [40 ± 1.93 kg of body weight (BW)] were randomly assigned to 1 of 3 treatments: (1) pelleted starter conditioned for 0 min (CON), (2) pelleted starter conditioned for 2 min, and (3) pelleted starter conditioned for 4 min. Three pelleted starter feeds had similar nutritional composition, and the starters were blended with 3% chopped wheat straw and fed to individually housed calves from d 3 to 70 of age. All calves were fed 4 L/d of pasteurized whole milk twice daily at 0800 and 1600 h from d 3 to 50 of calf age, followed by 2 L/d of morning feeding from 51 to 56 d of age. All calves were weaned on d 56 of age and remained in the study until d 70 of age. With the increase of conditioner retention time during pellet processing for 0, 2, and 4 min, the gelatinized starch content of pelleted starter feed linearly increased from 14, 30, and 45%, respectively. Additionally, the pellet durability and hardness also linearly increased with increasing conditioner retention time during pelleting. Feeding pelleted feed prepared using different conditioner retention time did not affect feed dry matter intake, metabolizable energy intake, weaning BW, final BW, or feed efficiency during the study. We observed no differences in the total-tract apparent digestibility of organic matter, neutral detergent fiber, and crude protein around weaning (d 49 to 56 of age) and after weaning (d 63 to 70 of calf cage); however, the digestibility of dry matter and starch after weaning was increased with increasing conditioner retention time during pelleting of starter feed. No difference was found in overall average daily gain (ADG) or growth rates of hip height, withers height, and heart girth. Ruminal volatile fatty acid profile was not affected by pelleting under different conditioner retention times. The ruminal ammonia concentration tended to be lower for calves fed the 4-min diet compared with those fed the CON diet during the postweaning period. The postweaning (d 57-70 of age) ADG was greater for calves fed the 4-min diet compared with those fed the CON diet. In conclusion, the conditioning time during the pelleting process of starter feed increased the gelatinization of starch, durability, and hardness of the pellets but did not influence feed intake, feed efficiency, and skeletal growth during the first 70 d of age. Increasing conditioning time during the pelleting process improved postweaning ADG; however, the final BW of calves was similar among treatments.

PSXIV-19 Effect of alpha-lipoic acid on productive parameters and ruminal VFA profile in sheep

Abstract Alpha lipoic acid (LA) is a potent nutritional antioxidant. It is a derivate of octanoic acid containing a cyclic disulfide bond. An LA complex with lysine-lipoamide, functions as a co-factor in the mitochondrial dehydrogenase that catalyzes the oxidative decarboxylation of α-keto acids. In this reaction, LA is reduced to dihydrolipoic acid (DHLA), which interacts with reactive oxygen species, and LA can also inactivate free radicals. Another important role of DHLA is in signal transduction by activating insulin receptors, which causes glucose transporters translocation from cytoplasm to the cell surface. Due to its potential antioxidant effect at ruminal level, the aim of this study was to evaluate the effect of fed LA on productive parameters, ruminal fatty volatile fatty acid (VFA) concentration and blood glucose of sheep. Sixty-four, two-months-old, crossbred lambs were penned in groups of four, divided into four treatments: 0, 40, 80, and 120 ppm LA in diet. During 84 days, every 28 days on two consecutive days, animals were weighed (to determine average daily weight gain, DWG), blood and ruminal fluid were taken for glucose and VFA quantification, respectively. All variables were analyzed in a completely randomized design. DWG was statistically higher in those animals receiving 80 ppm (250 g) as compared to the rest (200, 188, 180 g for 120, 40, 0 ppm, respectively) (P &amp;lt; 0.0001). No differences in blood glucose or ruminal VFA were found (P &amp;gt; 0.1). LA could improve the productive performance of sheep; however, it would be necessary to study the role of LA and its effects on the ruminal microbiome and its action mechanism. Research support by Project PAPIIT-UNAM IN211518

PSI-28 Effect of supplementation with low-moisture, sugarcane molasses-based block on intake and ruminal volatile fatty acid profile on steers fed low quality forage

Abstract We evaluated the effects of supplementation of molasses based on low moisture molasses (LMB) on steers fed low quality forage in DM intake and ruminal VFA. Six rumen cannulated Nellore steers (23 months, 350 ± 10 kg) were distributed in a 3 × 3 double Latin square design. The treatments were composed of Brachiaria brizantha cv. Marandu ad libtum as an exclusive source of bulks (93.65% DM, 3.97% CP and 81.76% NDF) and supplements: complete mineral blend with urea [UR, (urea, salt, mineral-vitamin premix)], a commercial protein supplement [PS, (corn grain, soybean meal, urea, salt, and mineral- vitamin premix)] or protein block based on low-moisture cooked sugarcane molasses [LMB, (cane molasses, cottonseed meal, soybean oil, urea, salt and mineral-vitamin premix)]. Before subsequent feeding, samples of orts were collected to monitor the daily intake. After 14-d adaptation period, rumen fluid samples were collected in each experimental period at 0, 2, 4, 6, 8, 10, 12 and 14 h after feeding, to evaluate concentrations of VFA, which was determined by gas chromatography. The data were analyzed using Software R, with measures repeated in time for VFA and having as fixed effect the treatments and as animal random effect, period, Latin square and error. The intake of hay (P = 0.024), total DM (g/day, P = 0.001), NDF (P = 0.027) and supplement (P &amp;lt; 0.001) was higher for animals supplemented with PS. The total VFA and acetate ratio were not affected by the treatment (P &amp;gt; 0.05). The propionate ratio was higher for LMB (P = 0.016). The butyrate ratio (P = 0.005), valerate (P = 0.010) and A:P ratio (P = 0.017) was higher when the animals were supplemented with PS. The results indicate that the use of LMB improves propionate ratio and decrease the acetate:propionate ratio for steers fed low quality forage.

The effect of tannin extract and n-3 fatty acid source on nutrient digestibility, blood metabolites, enzyme activity, and ruminal parameters of lactating ewes

This study aimed to evaluate the effects of tannin extract and n-3 fatty acid supplementation on nutrient digestibility, ruminal parameters, blood metabolites, and enzyme activity in lactating ewes. Thirty-six lactating ewes were allocated to 6 experimental groups. The dietary treatments were as follows: 1) control, 2) diet supplemented with 2% dry matter (DM) oak leaf tannin extract, 3) diet supplemented with 2% DM grape pomace tannin extract, 4) diet supplemented with 2% DM linseed oil, 5) diet supplemented with 2% DM oak leaf tannin extract and 2% DM linseed oil, and 6) diet supplemented with 2% DM grape pomace tannin extract and 2% DM linseed oil. The results showed the significant effects of treatments on final body weight, digestibility, and some blood metabolites (P < 0.05). Therefore, the treatment groups had higher final body weight, better nutrient digestibility, and higher values of blood parameters. In conclusion, our results showed that the dietary tannin extract and the n-3 fatty acid source improved nutrient digestibility and blood metabolites, and they had a trend of improving the ruminal volatile fatty acid profile while not having any adverse effects on the animals' performance.

EVALUATION OF THE EFFECT OF FOUR ESSENTIAL OILS AS POTENTIAL ALTERNATIVES FOR MONENSIN ON RUMEN FERMENTATION CHARACTERISTICS AND NUTRIENT DEGRADABILITY

The objective of this study was to evaluate the effect of four essential oils (EOs) from guava (Psidium guajava), citronella (Cymbopogon nardus), lemongrass (Cymbopogon citratus), and geranium (Pelargonium graveolens) on gas production and rumen fermentation in vitro as a natural substitute for the ionophore antibiotic monensin. These EOs are chemically characterized by Gas Chromatography-Mass and evaluated in vitro at four different concentrations (0, 15, 30, and 45 µl per 45 ml buffered rumen fluid) regarding their effects on gas production and rumen fermentation characteristics and were compared to those of monensin. Compared to the negative control, monensin significantly depressed gas production and truly degraded dry matter (TDDM) but enhanced propionate production. All EOs except P. graveolens significantly decreased gas production with increasing concentrations. TDDM was significantly reduced with C. citratus (at 45 µl) and P. graveolens (at 30 and 45 µl). No significant change was detected in the ammonia nitrogen concentration with all assayed EOs except C. nardus and C. Citrus. Compared to monensin and the negative control, C. nardus and C. Citrus reduced the ammonia concentration at high levels. High levels of all tested EOs significantly reduced protozoa counts. The EOs of C. citratus (at 45 µl) and P. graveolens (at 30 and 45 µl) also significantly increased the acetate proportion. Moreover, the acetate to propionate ratio was significantly increasedby30 µl P. graveolens. The results of the current study concluded that the tested EOs, except P. graveolens, efficiently diminished gas production with a similar potency to monensin. Furthermore, they exceed the monensin in their ability to reduce the ammonia nitrogen concentration and protozoa count without adversely affecting volatile fatty acid levels. But, they were less effective than monensin in modifying ruminal volatile fatty acid profile especially propionate and acetate to propionate ratio. Hence, P. guajava, C. nardus, and C. citratus EOs could be a safe and promising rumen manipulator.

Dynamics of methanogenesis, ruminal fermentation and fiber digestibility in ruminants following elimination of protozoa: a meta-analysis

BackgroundRuminal microbes are vital to the conversion of lignocellulose-rich plant materials into nutrients for ruminants. Although protozoa play a key role in linking ruminal microbial networks, the contribution of protozoa to rumen fermentation remains controversial; therefore, this meta-analysis was conducted to quantitatively summarize the temporal dynamics of methanogenesis, ruminal volatile fatty acid (VFA) profiles and dietary fiber digestibility in ruminants following the elimination of protozoa (also termed defaunation). A total of 49 studies from 22 publications were evaluated.ResultsThe results revealed that defaunation reduced methane production and shifted ruminal VFA profiles to consist of more propionate and less acetate and butyrate, but with a reduced total VFA concentration and decreased dietary fiber digestibility. However, these effects were diminished linearly, at different rates, with time during the first few weeks after defaunation, and eventually reached relative stability. The acetate to propionate ratio and methane production were increased at 7 and 11 wk after defaunation, respectively.ConclusionsElimination of protozoa initially shifted the rumen fermentation toward the production of more propionate and less methane, but eventually toward the production of less propionate and more methane over time.

Ruminal methane emissions, metabolic, and microbial profile of Holstein steers fed forage and concentrate, separately or as a total mixed ration.

Few studies have examined the effects of feeding total mixed ration (TMR) versus roughage and concentrate separately (SF) on ruminant methane production. Therefore, this study compared differences in methane production, ruminal characteristics, total tract digestibility of nutrients, and rumen microbiome between the two feeding methods in Holstein steers. A total six Holstein steers of initial bodyweights 540 ± 34 kg were divided into two groups and assigned to a same experimental diet with two different feeding systems (TMR or SF) in a crossover design with 21 d periods. The experimental diet contained 73% concentrate and 27% forage and were fed twice a day. The total tract digestibility of crude protein, neutral detergent fibre, and organic matter were not affected by the two different feeding systems. Steers fed TMR emitted more methane (138.5 vs. 118.2 L/d; P < 0.05) and lost more gross energy as methane energy (4.0 vs. 3.5% gross energy intake; P = 0.005) compared to those fed SF. Steers fed TMR had greater (P < 0.05) total volatile fatty acid (VFA), ammonia-N concentrations and propionate proportion of total VFA at 1.5 h, whereas lower after that compared to steers fed SF. The greater (P < 0.05) acetate: propionate ratio at 4.5 h for steers fed TMR reflected the shift of H2 sink from propionate towards acetate synthesis. The lower (P < 0.05) isobutyrate and isovalerate proportions of total VFA observed in steers fed TMR implies decrease in net consumption of H2 for microbial protein synthesis compared to SF. There were no differences in both major bacterial and archaeal diversity between TMR and SF, unlike several minor bacterial abundances. The minor groups such as Coprococcus, Succiniclasticum, Butyrivibrio, and Succinivibrio were associated with the changes in ruminal VFA profiles or methanogenesis indirectly. Overall, these results indicate that SF reduces methane emissions from ruminants and increases propionate proportion of total VFA without affecting total tract digestion compared to TMR. There were no evidences that the response differed due to different major underlying microbial population.

Effects of bacterial direct-fed microbials on ruminal characteristics, methane emission, and milk fatty acid composition in cows fed high- or low-starch diets

This study investigated the effects of bacterial direct-fed microbials (DFM) on ruminal fermentation and microbial characteristics, methane (CH4) emission, diet digestibility, and milk fatty acid (FA) composition in dairy cows fed diets formulated to induce different ruminal volatile fatty acid (VFA) profiles. Eight ruminally cannulated dairy cows were divided into 2 groups based on parity, days in milk, milk production, and body weight. Cows in each group were fed either a high-starch (38%, HS) or a low-starch (2%, LS) diet in a 55:45 forage-to-concentrate ratio on a dry matter (DM) basis. For each diet, cows were randomly assigned to 1 of 4 treatments in a Latin square design of (1) control (CON); (2) Propionibacterium P63 (P63); (3) P63 plus Lactobacillus plantarum 115 (P63+Lp); (4) P63 plus Lactobacillus rhamnosus 32 (P63+Lr). Strains of DFM were administered at 1010 cfu/d. Methane emission (using the sulfur hexafluoride tracer technique), total-tract digestibility, dry matter intake, and milk production and composition were quantified in wk 3. Ruminal fermentation and microbial characteristics were measured in wk 4. Data were analyzed using the mixed procedure of SAS (SAS Institute Inc., Cary, NC). The 2 diets induced different ruminal VFA profiles, with a greater proportion of propionate at the expense of acetate and butyrate for the HS diet. Greater concentrations of total bacteria and selected bacterial species of methanogenic Archaea were reported for the HS diet, whereas the protozoa concentration in HS decreased. For both diets, bacterial DFM supplementation raised ruminal pH (+0.18 pH units, on average) compared with CON. Irrespective of diet, P63+Lp and P63+Lr increased ruminal cellulase activity (3.8-fold, on average) compared with CON, but this effect was not associated with variations in ruminal microbial numbers. Irrespective of diet, no effect of bacterial DFM on ruminal VFA was observed. For the LS diet, supplementing cows with P63+Lr tended to decrease CH4 emission (26.5%, on average, when expressed per kilogram of milk or 4% fat-corrected milk). Only P63 supplementation to cows fed the HS diet affected the concentration of some milk FA, such as cis isomers of 18:1 and intermediates of ruminal biohydrogenation of polyunsaturated FA. Overall, bacterial DFM could be useful to stabilize ruminal pH. Their effects on CH4 production mitigation and milk FA profile depended on DFM strain and diet and should be confirmed under a greater variation of dietary conditions.

The effects of feeding 3-nitrooxypropanol at two doses on milk production, rumen fermentation, plasma metabolites, nutrient digestibility, and methane emissions in lactating Holstein cows

The objective of this study was to determine the effects of feeding 3-nitrooxypropanol (NOP) in the total mixed ration of lactating Holstein cows on rumen fermentation, ruminal microbial population, enteric methane production, milk production, nutrient digestibility, and blood metabolites. Fifteen ruminally cannulated Holstein cows in mid to late lactation were used in a 3 × 3 Latin square design study with 28-day periods. Cows were fed a 60%-forage diet (dry matter basis) with 2500 (HIGH), 1250 (LOW) or 0 (CON) mg/day of NOP. After a 20-day diet adaptation period, dry matter intake (DMI) and milk yield were recorded daily. Rumen digesta and rumen fluid were collected on Days 21 and 28 and ruminal pH was determined on Days 23–28. Methane emissions were measured on Days 23–27 using the sulfur hexafluoride tracer gas technique. Faecal and blood samples were taken on Days 25–27. Feeding NOP at either dose did not affect DMI, milk production or bodyweight gain. Total concentration of volatile fatty acids in rumen fluid did not differ; however, there was a decrease in molar proportion of acetate and increase in molar proportion of propionate with feeding NOP in a dose-dependent manner. Microbial profile and ruminal pH were not affected by treatment. Apparent total-tract digestibility of DM (62.7% vs 58.4%; P &lt; 0.05) and neutral detergent fibre (38.0% vs 30.7%; P &lt; 0.05) were increased with the HIGH dose compared with CON. Feeding NOP reduced methane yield from 19.9 to 15.3 g/kg DMI for CON versus LOW (P &lt; 0.05) and from 19.9 to 12.6 for CON versus HIGH (P &lt; 0.05). Feeding NOP at 1250 or 2500 mg/day reduced methane yield and affected ruminal volatile fatty acid profile without compromising DMI or apparent total-tract nutrient digestibility.

Effect of Fibrous By-Products on Production and Ruminal Fermentation in Lactating Dairy Cows

Lactating dairy cows were used in experiments to determine the effects of feeding a combination of fibrous by-products to replace a portion of alfalfa hay or grain. Cows were fed a control diet, consisting of alfalfa hay, corn, soybean meal, and corn silage or one of four treatment diets. In these diets, a combination of soy hulls, corn gluten feed, and wheat midds replaced approximately 30 or 60% of alfalfa hay or 25 or 50% of corn and soybean meal. A 56-d production study used 50 mid-lactation dairy cows in a randomized complete block design. No differences in milk production or composition among treatments were measured, except for the diet in which 60% of the alfalfa hay was replaced with fibrous by-products. Cows fed this diet had a significantly lower percentage of milk fat compared with other treatments. A fermentation study used five fistulated, multiparous lactating dairy cows in a 5 x 5 Latin square design. Cows were fed one of the five experimental diets used in the production study during five consecutive 14-d periods. Rumen acetate to propionate ratio was highest for the control and 50% concentrate replacement diets (3.27) and lowest for the 60% hay replacement diet (2.78). This shift in ruminal volatile fatty acid profile corresponded to the change in milk fat percentage, measured during the production study. A mixture of fibrous by-products fed as an alternative to hay or grain ingredients could potentially decrease feed costs without a resultant decrease in milk production by mid-lactation dairy cows.

Sodium Bicarbonate and Alfalfa Hay Additions to Wheat Silage Diets Fed to Lactating Dairy Cows

Two experiments were conducted to examine dietary effects of .8% sodium bicarbonate and 1.4 kg/d of alfalfa hay on performance and rumen metabolism of lactating dairy cows fed 50% wheat silage and 50% concentrate (dry basis). In Experiment 1 with 12 midlactation Holsteins in a 4×4 Latin square design, intake, milk production, and milk composition were not affected by treatment. Dietary sodium bicarbonate and alfalfa hay did not alter blood, rumen, or fecal pH. Rumen volatile fatty acid pattern was not affected by sodium bicarbonate, but addition of hay resulted in higher molar percentage propionate and lower acetate: propionate ratios. In Experiment 2 with 32 early lactation cows (20 Holsteins and 12 Jerseys) in a complete randomized block design, supplementation of sodium bicarbonate, alfalfa hay, or both did not affect intake, milk production, or milk composition in the first 8 wk of lactation. Blood, rumen, and fecal pH were not affected by treatment. Dietary sodium bicarbonate did not alter ruminal volatile fatty acid profile, whereas addition of hay increased molar proportion acetate and decreased molar proportion butyrate. A shift in rumen fermentation was observed across treatments from wk 1 through 8 postpartum with molar proportions of acetate and butyrate increasing and molar proportion of propionate decreasing.