Rumen Protozoa Research Articles

Investigating the chemical composition, digestion and fermentation of Alternanthera sessilis red plant and its effect on the performance of fattening lambs.

The present experiment was conducted to evaluate the nutritional value of red Alternanthera sessilis for fattening lambs when they were replaced with alfalfa forage. Forty growing lambs with an average weight of 21.12kg and an age of 5 months were randomly assigned to four experimental treatments. Growth performance, nutrient digestibility, rumen fermentation parameters, protozoa population, blood parameters, and composition of carcass components were evaluated. The results of this experiment showed that the use of Alternanthera sessilis in the diet significantly reduced feed intake, increased the average daily weight gain, and improved the feed conversion ratio compared to the control treatment (P < 0.05). The digestibility of dry matter and protein was significantly increased (P < 0.05), while the digestibility of neutral detergent fiber, acid detergent fiber, and organic matter showed a numerical increase. Diets containing different levels of the Alternanthera sessilis plant did not affect pH, but the increase in the amount of this plant in the diet led to an increase ammonia nitrogen concentration and rumen protozoa population (P < 0.05). The addition of Alternanthera sessilis to the diet significantly reduced the concentration of blood glucose and cholesterol and increased the concentration of blood urea nitrogen (P < 0.05). Except for the weight of the thigh and neck, the effect of experimental treatments on other carcass components was not significant. Overall, the results of this experiment showed that using the Alternanthera sessilis plant in the rations of fattened lambs as a substitute for alfalfa forage not only had no negative effect on the studied parameters but also improved them in some cases. Therefore, Alternanthera sessilis can be used in rations of fattened lambs as a substitute for part of alfalfa forage.

Methane emission, nitrogen excretion, and energy partitioning in Hanwoo steers fed a typical TMR diet supplemented with Pharbitis nil seeds.

Two in vivo experiments were conducted to evaluate the potential of Pharbitis nil seeds (PA) as an anti-methanogenic additive to ruminant feed. In experiment 1, six Hanwoo steers (459.0 ± 25.8 kg) were fed either a total mixed ration (TMR; 32-d period) or TMR supplemented with PA at 5% dry matter (DM) intake (TMR-PA; 45-d period) for two consecutive periods. Fecal and urine outputs were measured in an apparent digestibility trial in both periods. Methane (CH4) yield and heat energy (HE) were measured using respiratory chambers equipped with gas analyzers. In experiment 2, five rumen cannulated Holstein steers (744 ± 35 kg) were fed the same TMR or TMR-PA diets for 40 days; rumen samples were collected at 0, 1.5, and 3 h after feeding on the last day of the feeding period. In experiment 1, although there were no differences (p > 0.05) in nutrients or gross energy intake (GEI) between the groups, an increase (p < 0.05) in the apparent digestibility of DM (9.1%) and neutral detergent fiber (22.9%) was observed in the TMR-PA fed Hanwoo steers. Pronounced decreases (p < 0.05) in CH4 (g/Kg DM; 17.1%) and urinary N excretion (% N intake; 7.6%) were observed in the TMR-PA group, leading to a 14.7% increase in metabolizable energy intake (% GEI). However, only a numerical increase (p > 0.05) in retained energy was observed due to the increase in HE loss. In experiment 2, a drastic decrease (p < 0.05) in rumen ammonia concentration (56.3%) associated with an increased (p = 0.091) rumen short-chain fatty acid concentration 1.5 h after feeding were observed in TMR-PA fed Holstein steers. A 26.6% increase (p < 0.05) in the propionate proportion during the treatment period clearly reflected a shift in the ruminal H2 sink after 3 h of feeding. A 40% reduction (p = 0.067) in the relative abundance of rumen protozoa Entodinium caudatum was also observed. It was concluded that PA could be a natural feed additive for CH4 and N emission abatement.

Improved and easy method for long-term in vitro culture of rumen ciliates Dasytricha ruminantium

The rumen ciliates are a diverse group of protozoa residing in the rumen of ruminant animals. They are primarily found in the orders Entodiniomorphida and Vestibuliferida, playing crucial roles in the digestion and breakdown of feed within the host's rumen, closely intertwined with the host's nutrient absorption. In vitro monocultures of representatives of rumen ciliates are important to better study them. So far, Entodinium caudatum and Epidinium caudatum, representatives of the order Entodiniomorphida, have been successfully cultivated as a monoculture in vitro. However, for the order Vestibuliferida, no representative species has been established a stable monoculture in vitro up to date, which hampers to study their physiology and metabolism. Therefore, we have developed a simple method for the in vitro cultivation of Dasytricha ruminantium, a representative rumen ciliate in the order Vestibuliferida. Utilizing an optimized culture medium with easily obtainable components, and the cultivation process is simple. This will facilitate further research in metabolism and other studies requiring large pure live materials.1.Filtration and separation for enriching D. ruminantium.2.A culture medium (DRM) suitable for the growth of D. ruminantium, with easily obtainable components.3.Simple cultivation process, facilitating the obtainment of a large number of monocultured D. ruminantium.

Rumen protozoa are a hub for diverse hydrogenotrophic functions.

Ciliate protozoa are an integral part of the rumen microbial community involved in a variety of metabolic processes. These processes are thought to be in part the outcome of interactions with their associated prokaryotic community. For example, methane production is enhanced through interspecies hydrogen transfer between protozoa and archaea. We hypothesize that ciliate protozoa are host to a stable prokaryotic community dictated by specific functions they carry. Here, we modify the microbial community by varying the forage-to-concentrate ratios and show that, despite major changes in the prokaryotic community, several taxa remain stably associated with ciliate protozoa. By quantifying genes belonging to various known reduction pathways in the rumen, we find that the bacterial community associated with protozoa is enriched in genes belonging to hydrogen utilization pathways and that these genes correspond to the same taxonomic affiliations seen enriched in protozoa. Our results show that ciliate protozoa in the rumen may serve as a hub for various hydrogenotrophic functions and a better understanding of the processes driven by different protozoa may unveil the potential role of ciliates in shaping rumen metabolism.

Effect of mushroom crop residue on growth performance, carcass traits, nutrient digestibility, nitrogen balance, ingestive behavior, ruminal and blood parameters of lambs

Using agricultural wastes as substrates of mushroom cultivation can minimize environmental pollution and provide a high-quality substrate that might be used for animal feeding after cultivation, which is beneficial for ruminants. Three experiments were conducted to evaluate the nutritional value of cultivated mushroom residue in lamb diets. Seven inoculation times (0, 5, 10, 15, 20, 25, and 30 days of cultivation) of mushroom substrates by Pleurotus ostreatus were evaluated in a completely randomized design with five replications to characterize the mushroom crop substrate. Within 30 days of cultivation, the mushroom crop residue (MCR) was sun-dried and tested on the lambs’ diet. The first experiment involved 40 uncastrated crossbred lambs (Santa Ines × Dorper), with a mean body weight (BW) of 27.8 ± 2.37 kg (mean ± SD), which were randomly assigned to five groups of six lambs each. They received five levels of MCR replacing Tifton-85 hay: 0, 25, 50, 75, and 100 % on dry matter basis (DM) to evaluate performance, carcass traits, ingestive behavior, and blood parameters. In the second experiment, 25 lambs (40.0 ± 3.0 kg BW) were distributed in metabolic cages in a completely randomized design with the same five treatments of experiment 1 (MRC replacing Tifton-85 hay) and six replications to determine nutrient digestibility and nitrogen balance. To evaluate ruminal parameters, a third experiment was conducted with five Santa Ines × Dorper crossbreed rumen-cannulated sheep weighing 42.0 ± 4.0 kg, which were distributed in a 5 × 5 Latin square. After 30 days of cultivation of the fungus Pleurotus ostreatus, there was a reduction in the MCR contents of DM, ether extract (EE), and non-fiber carbohydrates (NFC). In contrast, ash, crude protein (CP), neutral detergent fiber expressed exclusive of residual ash (aNDF), acid detergent fiber (ADF), and in vitro DM digestibility coefficient (IVDMD) increased (P ≤ 0.05) over the cultivation time. The intake of DM, CP, aNDF and NFC quadratically increased (P ≤ 0.05) with the addition of dehydrated MCR in the lambs’ diet. The effective consumed CP composition and the digestibility coefficient of DM, CP, and aNDF decreased linearly (P ≤ 0.05) due dehydrated MCR addition in the lambs’ diet. The time spent eating and idling, and the rumination efficiency rates (g DM and NDF/h) increased linearly (P ≤ 0.05) with the replacement of Tifton-85 hay by the dehydrated MCR. The time spent on rumination and chewing, the nº of boli chewed, and the DM intake efficiency rate reduced linearly (P ≤ 0.05). There was a linear (P ≤ 0.05) increase in N-intake, N-fecal, and N-retention and linear reduction (P ≤ 0.05) in N-urinary excretion and rumen protozoa count due to the inclusion of MCR in the lambs’ diet. Growth performance, carcass traits, rumen pH, ammonia nitrogen (NH3-N), and blood parameters were not changed by the replacement of hay with MCR. Dehydrated mushroom crop residue inclusion at 75 % of total DM replacing Tifton-85 hay in lambs’ diet is recommended because it improves rumination efficiency, and N-retention without any negative effect on rumen pH, blood metabolites, and carcass traits.

Effect of nicotinic acid supplementation on digestion, metabolism, microbiome, and production in late-lactation Holstein cows

The purpose of this experiment was to determine if nicotinic acid (NA) effects on dairy cows and rumen microbial characteristics are forage type dependent (corn silage, CS; grass silage, GS). Four late lactation (days in milk = 225 +/- 12 d) Holstein cows were used in a 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. The main effects were a CS (66.10% CS) based diet or a GS (79.59%) based diet with or without 12 g/d NA. Each experimental period lasted for 28 d. Milk production and milk components, blood metabolites, apparent total-tract nutrient digestibilities, minutes rumen pH were below 5.8 as an indicator of ruminal acidosis, and body temperature changes were analyzed as indicators of heat stress. Nicotinic acid supplementation did not improve apparent total-tract nutrient digestibility. Feeding a GS-based diet improved NDF and hemicellulose digestibility. Feeding a CS-based diet increased the apparent total-tract digestibility of fat, and minutes rumen pH below 5.8 for a greater proportion of the time. The CS-based diet also improved milk yield, milk fat and protein yields, and energy-corrected milk yield; however, somatic cell count and BHB were also increased. Supplementing NA tended to decrease nonesterified fatty acids, especially when combined with GS where DMI was low. There was a trend for the total protozoa population to increase when GS and NA were fed but decreased when CS and NA were fed. Nicotinic acid tended to decrease rumen protozoal populations of Dasytricha, but increased populations of Ophryoscolex and Diplodiniinae with GS diets and decreased with CS diets. Entodiniinae were increased with CS but NA had no effect. Body temperature was increased when a CS-based diet was fed when compared with a GS-based diet. More research is needed to determine how NA can affect rumen microbial protein synthesis and what kind of diets will provide the optimum effect.

Study of Fauna and Ecology of Species Belonging to Entodynimorpha in the Regions of Nakhchivan Autonomous Republic

Rumen Protozoa are strictly anaerobic and highly specialized ciliates and can live only in the rumen and similar habitats. These Ciliata play an important role in feed utilization and indicate the environmental impact (methane emissions and nitrogen excretion) of ruminant production. Digestion of feed in ruminants depends on the life activity of microorganisms. Without their help, ruminants could not assimilate cellulose with simple non-protein compounds. These microorganisms located in rumen decompose the organic substances in the feed and form volatile fatty acids, ammonia, amino acids, which animals use for their development and reproduction. In the rumen of domesticated cattle and sheep, rumen cilia constitute 20-50% of the total microbial biomass. Rumen Ciliata develop symbiotic relationships with their animal hosts and both symbiotic and predator-prey relationships with other members of the rumen microbiota. The lack of axenic cultures of rumen Ciliata has forced researchers to use other methods to determine the metabolism and functions of rumen Protozoa, such as comparing rumen fermentation and microbial profiles of faunal and non-ciliated cattle or sheep or using in vitro cultures.

Bacteriolytic activity of ruminal protozoa is affected by rate and type of common essential oils: Effect of thyme oil

Over the past two decades, research into the effects of essential oils (EOs) on rumen microorganisms as an alternative to antibiotics has intensified. Yet, there are few investigations on rumen protozoa. To evaluate if EOs have antiprotozoal efficacy against rumen protozoa, the present investigation was conducted. Using the potentiality of rumen protozoa to digest 14C-labeled bacteria, the influence of EOs on in vitro protozoal activity was determined. For the study, orange peel, cinnamon, laurel, oleaster, garlic, and thyme essential oils were selected. Control (without essential oil), 500 mg/kg, 1000 mg/kg, and 5000 mg/kg dosages were used. Except for garlic oil, all essential oils showed a notable effect on antiprotozoal activity. The highest antiprotozoal impact was reported at 500 mg/kg and 1000 mg/kg doses of thyme oil, with respective reductions of 89.1% and 84.8% in bacteria degraded by protozoa. Cinnamon and oleaster oils had the strongest antiprotozoal efficacy at a concentration of 5000 mg/kg. At 5000 mg/kg doses of oleaster and cinnamon oils, the quantity of 14C-labeled bacteria degraded by protozoa was reduced by 96% compared to the group that served as the control. In conclusion, orange peel, cinnamon, laurel, oleaster, and thyme oils demonstrated remarkable in vitro antiprotozoal activity; however, more comprehensive research is required to analyse the effects of the EOs used in this study on rumen living groups such as protozoa, bacteria, and yeast and on rumen dynamics.

Rumen ciliates (Ciliophora, Trichostomatia) in Brazilian domestic cattle feeding on diets with crescent urea levels

Since their discovery, rumen ciliates of domestic cattle have been reported from various geographic locations. However, until now there is only one taxonomic inventory of ciliates associated with Brazilian cattle. The present study aimed to assess the community composition, relative abundance, richness, and density of rumen ciliates in Brazilian cattle, whose feeding diets were supplemented with crescent urea levels. Across all treatments analyzed, one subclass, two orders, three families, 11 genera, and 31 species of ciliates were identified. The ciliate community composition and species richness varied among the four treatments used. However, the total ciliate density was not affected by the experimental diets. We described a new entodiniid morphotype, Entodinium caudatum m. orbonuclearis, and recorded Oligoisotricha bubali for the second time in Brazil.

A Review of Potential Feed Additives Intended for Carbon Footprint Reduction through Methane Abatement in Dairy Cattle.

Eight rumen additives were chosen for an enteric methane-mitigating comparison study including garlic oil (GO), nitrate, Ascophyllum nodosum (AN), Asparagopsis (ASP), Lactobacillus plantarum (LAB), chitosan (CHI), essential oils (EOs) and 3-nitrooxypropanol (3-NOP). Dose-dependent analysis was carried out on selected feed additives using a meta-analysis approach to determine effectiveness in live subjects or potential efficacy in live animal trials with particular attention given to enteric gas, volatile fatty acid concentrations, and rumen microbial counts. All meta-analysis involving additives GO, nitrates, LAB, CHI, EOs, and 3-NOP revealed a reduction in methane production, while individual studies for AN and ASP displayed ruminal bacterial community improvement and a reduction in enteric CH4. Rumen protozoal depression was observed with GO and AN supplementation as well as an increase in propionate production with GO, LAB, ASP, CHI, and 3-NOP rumen fluid inoculation. GO, AN, ASP, and LAB demonstrated mechanisms in vitro as feed additives to improve rumen function and act as enteric methane mitigators. Enzyme inhibitor 3-NOP displays the greatest in vivo CH4 mitigating capabilities compared to essential oil commercial products. Furthermore, this meta-analysis study revealed that in vitro studies in general displayed a greater level of methane mitigation with these compounds than was seen in vivo, emphasising the importance of in vivo trials for final verification of use. While in vitro gas production systems predict in vivo methane production and fermentation trends with reasonable accuracy, it is necessary to confirm feed additive rumen influence in vivo before practical application.

The effects of rosemary essential oil supplementation on growth performance, rumen flora and antioxidant blood parameters in growing Merino lambs

Thirty-two male growing Merino lambs (78 ± 5 days of age) were used in a 45-day randomized complete block desing to determine the effects of rosemary essential oil (REO) on the growth performance, rumen fermentation, rumen protozoa population, plasma antioxidant enzyme parameters and fecal microbiology. The control group was fed a diet consisting of concentrate and alfalfa hay. The lambs in control group did not receive REO whereas each lamb in experimental groups supplemented with 250 mg/d (R250), 500 mg/d (R500) and 750 mg/d (R750) REO throughout the study. There weren’t statistically differences (P&gt;0.05) in average initial weight, average final weight, live weight gain, average daily gain, daily feed intake, daily dry matter intake and feed conversion ratio between the control and experimental groups. There were also no differences (P&gt;0.05) in the rumen pH, fecal pH, NH3N and rumen volatile fatty acid (VFA) profile of the control and experimental groups. At the end of the study, although the plasma superoxide dismutase (SOD) value increased significantly (P&lt;0.05) in the experimental groups (R500 and R750), glutathione peroxidase (GPX) and catalase values did not differ between REO groups and control. In addition, the fecal microorganism profile did not differ statistically (P&gt;0.05) between the control and experimental groups. The results of this study show that the addition of REO to Merino lamb rations is more effective on antioxidant parameters than on performance parameters and can be used as a natural antioxidant product

Enhancing rumen microbial diversity and its impact on energy and protein metabolism in forage-fed goats.

This study explores if promoting a complex rumen microbiota represents an advantage or a handicap in the current dairy production systems in which ruminants are artificially reared in absence of contact with adult animals and fed preserved monophyte forage. In order to promote a different rumen microbial diversity, a total of 36 newborn goat kids were artificially reared, divided in 4 groups and daily inoculated during 10 weeks with autoclaved rumen fluid (AUT), fresh rumen fluid from adult goats adapted to forage (RFF) or concentrate (RFC) diets, or absence of inoculation (CTL). At 6 months of age all animals were shifted to an oats hay diet to determine their ability to digest a low quality forage. Early life inoculation with fresh rumen fluid promoted an increase in the rumen overall microbial diversity which was detected later in life. As a result, at 6 months of age RFF and RFC animals had higher bacterial (+50 OTUs) and methanogens diversity (+4 OTUs) and the presence of a complex rumen protozoal community (+32 OTUs), whereas CTL animals remained protozoa-free. This superior rumen diversity and presence of rumen protozoa had beneficial effects on the energy metabolism allowing a faster adaptation to the forage diet, a higher forage digestion (+21% NDF digestibility) and an energetically favourable shift of the rumen fermentation pattern from acetate to butyrate (+92%) and propionate (+19%) production. These effects were associated with the presence of certain rumen bacterial taxa and a diverse protozoal community. On the contrary, the presence of rumen protozoa (mostly Entodinium) had a negative impact on the N metabolism leading to a higher bacterial protein breakdown in the rumen and lower microbial protein flow to the host based on purine derivatives urinary excretion (-17% to -54%). The inoculation with autoclaved rumen fluid, as source of fermentation products but not viable microbes, had smaller effects than using fresh inoculum. These findings suggest that enhancing rumen microbial diversity represents a desirable attribute when ruminants are fed forages in which the N supply does not represent a limiting factor for the rumen microbiota.

Morphometric and Molecular Analysis of Five-Spine Epidinium Morphotypes Taken from the Rumen of European Bison, Bison bonasus.

An important feature of ruminal ciliates is their phenotypic plasticity, which makes their identification difficult. The common manifestation of the phenotypic plasticity in rumen ciliates is a change in their cell size and caudal spination. We analyzed various morphotypes of Epidinium with five caudal processes (spines) taken from the rumen of European bison (Bison bonasus). In the study, the cluster analysis and K-means analysis of morphometric data could not distinguish very similar morphotypes of Epidinium with five caudal processes. However, the morphotype of E. parvicaudatum prevailed (70%). The DNA of four individual E. parvicaudatum was isolated successfully from formaldehyde-preserved samples. The partial 18S rDNA gene sequences (about 350-400 bp) were identical to Epidinium sequences in GenBank (E. caudatum, a one-spine morphotype, and E. cattanei, a five-spine morphotype). It can be assumed that these short sequences cannot distinguish the differences between the Epidinium morphospecies. Complete gene sequences from various hosts and various molecular markers are necessary to reveal the validity of the Epidinium five-spine species. In conclusion, classical morphology should be supplemented with molecular data when more morphotypes of the rumen ciliate species are present in samples.

Starter protein content and supplemental soybean oil or hydrogenated palm fatty acids in Holstein dairy calves: growth performance, protozoa population, and nitrogen utilization efficiency

The study hypothesized that a 24% protein starter diet supplemented with inert fat (palm fatty acids; PLFs) instead of triglyceride-rich soybean oil (SBO) would promote the growth of dairy calves. The effects of different protein contents (20 vs 24% CP) and fat sources (SBO vs PLF at 2.5% DM) on growth, digestibility, blood metabolites, rumen protozoa and urinary nitrogen in dairy calves were investigated. A total of 52 female dairy calves (mean age 3 days and BW 40.7 kg) were allocated to the following treatments in a completely randomized design: (1) 20% CP starter diet supplemented with SBO (20CP-SBO), (2) 20% CP starter diet supplemented with PLF (20CP-PLF), (3) 24% CP starter diet supplemented with SBO (24CP-SBO), and (4) 24% CP starter diet supplemented with PLF (24CP-PLF). Calves were weaned on day 53, and the study ended on day 73. The 24CP diets enhanced starter feed intake, average daily gain (ADG), withers height, hip width, organic matter (OM) digestibility, and preweaning blood glucose compared to the 20CP diets. In contrast, SBO supplementation reduced feed intake, ADG, withers height, OM and CP digestibility, and pre- and postweaning blood glucose and beta-hydroxybutyrate levels, while increasing preweaning aspartate aminotransferase, compared to PLF. SBO supplementation led to lower urinary excretion of purine derivatives and microbial protein synthesis postweaning, and a reduction in protozoa population both pre- and postweaning. Calves fed PLF had higher starter intake than those fed SBO, regardless of the diet being 20CP or 24CP. Calves fed the 24CP-PLF diet had the highest ADG, while calves fed the 20CP-SBO diet had the lowest ADG. Calves fed the 20CP-SBO diet had lower feed efficiency than calves fed the other diets during the preweaning period and throughout the experimental period. Calves fed the 24CP-PLF diet had higher hip heights at weaning and on day 73 than calves fed the other diets. Calves fed the 20CP-SBO diet had lower neutral detergent fiber digestibility than calves fed the other diets. Calves fed the 24CP-SBO diet had higher postweaning blood urea nitrogen concentration than calves fed the other diets. Feeding the 20CP-SBO diet to dairy calves decreased urinary allantoin excretion and rumen microbial protein synthesis but increased urinary nitrogen excretion during the preweaning period. Our results suggest that PLF is more suitable than SBO in calf diets, especially when calves fed 24% CP, possibly due to improved nutrient digestibility.

The use of condensed tannin in lambs' diet alters the rumen protozoa population without affecting growth performance

The aim of this study was to evaluate the effect of different doses of Black Wattle (Acacia mearnsii) condensed tannin on performance, dry matter intake, blood parameters, and identification and quantification of the rumen protozoa population at fasting and after feeding of feedlot lambs. Sixteen Santa Ines intact ram lambs and sixteen Santa Ines ewe lambs were distributed and randomly assigned to 1 of 4 dietary treatments with different doses of condensed tannin (0 %, 1 %, 2 %, and 3 %) in the concentrate, on a feedlot system. No significant treatment effect (P > 0.05) was observed for growth performance, dry matter intake, and blood parameters. No significant effects of treatment (P > 0.05), phase (fasting and after feeding) (P > 0.05), and interaction between treatment and phase (P > 0.05) were observed for total and differential protozoa percentage. However, differences were observed for total and differential protozoa count. A quadratic effect (P = 0.03) was observed for total counts of Diplodiniinae in the rumen fluid of animals fed 3 % of condensed tannin. A phase effect was observed for counts of Isotricha spp, Entodinium spp. Diplodiniinae, and total protozoa count with higher numbers observed at fasting when compared to after feeding. Results of this research suggest that up to 3 % of black wattle condensed tannin in the diet of lambs does not affect dry matter intake, animal performance, and blood parameters.

Effect of supplementing bacterial probiotics on microbial protein synthesis, blood indices and rumen ciliate protozoa population of lactating crossbred cattle in Nepal

In recent times, the dairy industry in Nepal has been recognized as a burgeoning agro-industry, successfully meeting the domestic demand for fluid milk. Nevertheless, further efforts are necessary to achieve self-sufficiency in dairy products. To enhance milk production, alongside breed improvement and health management initiatives, nutritional interventions have been identified as crucial. In this context, a study was conducted in Rampur, Chitwan, focusing on the supplementation of diverse strains of bacterial probiotics in lactating crossbred cattle to evaluate their effects on microbial protein synthesis, animal health assessed through blood indices, and changes in rumen fauna. The findings of the study revealed that the inclusion of bacterial probiotics resulted in notable improvements in the overall excretion of purine derivatives. Specifically, the individual excretion of allantoin, xanthine, and hypoxanthine significantly increased (p&lt;0.01) in the group supplemented with Lactobacillus acidophilus, while uric acid levels remained unchanged. Consequently, microbial nitrogen supply and absorption also showed a significant increase within the same group. However, blood hematological and biochemical parameters remained unaffected across all treatment groups. Moreover, the supplementation did not induce any notable changes in the individual or overall population of rumen ciliate protozoa. The study underscores that the use of L. acidophilus can enhance the overall protein economy of the rumen, thus potentially reducing production costs by substituting expensive sources of dietary protein for lactating crossbred dairy cows.

Effect of Chitosan on Ruminal Fermentation and Microbial Communities, Methane Emissions, and Productive Performance of Dairy Cattle.

This study aimed to expand the knowledge about the activity and mode of action of CHI on methanogenesis and rumen microbial populations in vivo. A total of 16 lactating dairy cows were distributed in two groups, one of them receiving 135 mg CHI/kg body weight daily. The effect on productive performance, milk composition, fermentation efficiency, methane emissions, microbial protein synthesis, and ruminal microbial communities was determined. Supplementation with CHI did not affect rumen microbial diversity but increased the relative abundance (RA) of the bacteria Anaeroplasma and decreased those of rumen ciliates and protozoa resulting in a shift towards a lower acetic to propionic ratio. However, no effect on milk yield or methane intensity was observed. In conclusion, supplementing 135 mg CHI/kg body weight increased the RA of Anaeroplasma and decreased those of rumen ciliates and protozoa, both being related to fiber degradation in the rumen in different ways and resulted in a shift of ruminal fermentation towards more propionate proportions, without affecting CH4 emissions, milk yield, or milk composition. Further research with higher doses would be necessary to assess the potential use of this additive as a methane inhibitor.

Review on Effect of the Rumen Protozoa on the Productivity Performance of Some Ruminant

One of three groups of microorganisms that can be found in the rumen of ruminants is the ciliate protozoa. Isotrichid and Entodiniomorphid are the two categories into which ciliate protozoa can be separated in the rumen. This mini-review briefly describes the role of protozoa in ruminant metabolism and fiber digestion, as well as the influence on animal performance. The role of the rumen is carried out by diverse groups of microorganisms residing within it, including protozoa. Rumen protozoa are responsible for digesting approximately 19% to 28% of the total fibrous material in the rumen. These microorganisms within the rumen have the capability to acclimate to an anaerobic environment through a fermentation process that occurs in the absence of oxygen. Forages that contain cellulose can be transformed by rumen protozoa into easily absorbed chemicals and energy. For a variety of reasons, protozoa are beneficial to their hosts. Metabolic process is the first, while fiber digestion is the second. The amounts of fermentation products including methane, ammonia, lactate, propionate, butyrate, and others are maintained in large part by protozoa. When ciliate protozoa are eliminated from the rumen, the amount of microbial protein produced can rise by up to 30% while methane production can fall by up to 11%. The purpose of this review is to elucidate the involvement of rumen protozoa in the degradation of forage within the rumen, as well as their potential to enhance ruminant growth, reduce methane emissions, and positively contribute to the fermentation process in herbivores.

Effects of melatonin on rumen microorganisms and methane production in dairy cow: results from in vitro and in vivo studies

BackgroundMethane (CH4) is a major greenhouse gas, and ruminants are one of the sources of CH4 which is produced by the rumen microbiota. Modification of the rumen microbiota compositions will impact the CH4 production. In this study, the effects of melatonin on methane production in cows were investigated both in the in vitro and in vivo studies.ResultsMelatonin treatment significantly reduced methane production in both studies. The cows treated with melatonin reduced methane emission from their respiration by approximately 50%. The potential mechanisms are multiple. First, melatonin lowers the volatile fatty acids (VFAs) production in rumen and reduces the raw material for CH4 synthesis. Second, melatonin not only reduces the abundance of Methanobacterium which are responsible for generating methane but also inhibits the populations of protozoa to break the symbiotic relationship between Methanobacterium and protozoa in rumen to further lowers the CH4 production. The reduced VFA production is not associated with food intake, and it seems also not to jeopardize the nutritional status of the cows. This was reflected by the increased milk lipid and protein contents in melatonin treated compared to the control cows. It is likely that the energy used to synthesize methane is saved to compensate the reduced VFA production.ConclusionThis study enlightens the potential mechanisms by which melatonin reduces rumen methane production in dairy cows. Considering the greenhouse effects of methane on global warming, these findings provide valuable information using different approaches to achieve low carbon dairy farming to reduce the methane emission.6uXNnBCVHjJWi7WJQ32EAMVideo

Effects of rearing mode on gastro-intestinal microbiota and development, immunocompetence, sanitary status and growth performance of lambs from birth to two months of age

BackgroundArtificial rearing system, commonly used in prolific sheep breeds, is associated to increased mortality and morbidity rates before weaning, which might be linked to perturbations in digestive tract maturation, including microbiota colonization. This study evaluated the effect of rearing mode (mothered or artificially reared) on the establishment of the rumen and intestinal microbiome of lambs from birth to weaning. We also measured immunological and zootechnical parameters to assess lambs’ growth and health. GIT anatomy as well as rumen and intestinal epithelium gene expression were also analysed on weaned animals to assess possible long-term effects of the rearing practice.ResultsTotal VFA concentrations were higher in mothered lambs at 2 months of age, while artificially-reared lambs had lower average daily gain, a more degraded sanitary status and lower serum IgG concentration in the early growth phase. Metataxonomic analysis revealed higher richness of bacterial and eukaryote populations in mothered vs. artificially-reared lambs in both Rumen and Feces. Beta diversity analysis indicated an evolution of rumen and fecal bacterial communities in mothered lambs with age, not observed in artificially-reared lambs. Important functional microorganisms such as the cellulolytic bacterium Fibrobacter succinogenes and rumen protozoa did not establish correctly before weaning in artificially-reared lambs. Enterobacteriaceae and Escherichia coli were dominant in the fecal microbiota of mothered lambs, but main E. coli virulence genes were not found differential between the two groups, suggesting they are commensal bacteria which could exert a protective effect against pathogens. The fecal microbiota of artificially-reared lambs had a high proportion of lactic acid bacteria taxa. No difference was observed in mucosa gene expression in the two lamb groups after weaning.ConclusionsThe rearing mode influences gastrointestinal microbiota and health-associated parameters in offspring in early life: rumen maturation was impaired in artificially-reared lambs which also presented altered sanitary status and higher risk of gut dysbiosis. The first month of age is thus a critical period where the gastrointestinal tract environment and microbiota are particularly unstable and special care should be taken in the management of artificially fed newborn ruminants.