Effects of a bacterial probiotic on ruminal pH and volatile fatty acids during subacute ruminal acidosis (SARA) in cattle

Nutrient digestibility, ruminal fermentation, and blood metabolites of growing cattle-fed fermented cassava pulp with added flavoring agents

Objective

This study aimed to assess the effect of adding flavoring agents to fermented cassava pulp (FCPU) on nutrient utilization, ruminal fermentation characteristics, and blood metabolites in growing cattle.

Materials and Methods

A duplicated 3 × 3 Latin square design was randomly assigned to six growing beef cattle. Treatments were: 1) untreated FCPU (control), 2) 0.05% w/v vanilla-flavored FCPU, and 3) 0.05% w/v amyl acetate-flavored FCPU.

Results

The results showed that flavoring agents did not affect dry matter intake (DMI) or digestibility of nutrients. Rumen pH and ammonia nitrogen concentrations did not change all treatments postfeeding. Flavoring added to FCPU after feeding did not affect total volatile fatty acid (VFA) or VFA percentage. However, propionic acid levels tended to be lower in the vanilla-flavored FCPU group than those in the unflavored FCPU group at 0 h postfeeding (p < 0.01). Growing bulls fed vanilla-flavored FCPU tended to have greater fungal zoospores in the rumen than those fed amyl acetate-flavored FCPU (p < 0.1) at 2 h after feeding. Dietary treatments did not affect blood glucose and urea nitrogen concentrations (p > 0.05). However, blood triglyceride concentration was greater for cattle fed a control diet than other treatments at 0 h postfeeding (p < 0.05) and tended to be higher than those fed vanilla-flavored FCPU at 2 h afterfeeding (p < 0.1).

Conclusion

It was suggested that adding vanilla or amyl acetate flavor to the FCPU showed no adverse effects on ruminal fermentation, blood metabolites, or nutritional digestibility; however, it did not increase DMI.

In vitro ruminal fermentation and cow-to-mouse fecal transplantations verify the inter-relationship of microbiome and metabolome biomarkers: potential to promote health in dairy cows

Introduction

There are differences in the gut microbiome and metabolome when the host undergoes different physical or pathological conditions. However, the inter-relationship of microbiome and metabolome biomarkers to potentially promote the health of dairy cows needs to be studied. Further, the development of next-generation probiotics for dairy cattle health promotion has not been demonstrated.

Objective

In the present study, we identified the microbiome and metabolome biomarkers associated with healthy cows.

Methods

We analyzed the relationships of the ruminal microorganism profile and metabolites between healthy and mastitis lactating dairy cows. The roles of bacterial biomarker were further verified by in vitro fermentation and cow-to-mouse fecal microbiota transplantation (FMT).

Results

Two species, Ruminococcus flavefaciens and Bifidobacterium longum subsp. longum, and six rumen metabolites were positively correlated with healthy cows by Spearman's correlation analysis. Through in vitro ruminal fermentation, inoculating R. flavefaciens and B. longum subsp. longum showed the upregulation of the levels of putrescine, xanthurenic acid, and pyridoxal in the mastitis ruminal fluid, which confirmed the inter-relationships between these microbiota and metabolites associated with healthy cows. Further, we verified the role of R. flavefaciens and B. longum subsp. longum in promoting health by FMT. The administration of R. flavefaciens and B. longum subsp. longum reduced the death rate and recovered the bodyweight loss of germ-free mice caused by FMT mastitis feces.

Discussion

We provided evidence that the bacterial biomarkers alter downstream metabolites. This could indirectly indicate that the two bacterial biomarkers have the potential to be used as next-generation probiotics for dairy cattle, although it needs more evidence to support our hypothesis. Two species, R. flavefaciens and B. longum subsp. longum, with three metabolites, putrescine, xanthurenic acid, and pyridoxal, identified in the ruminal fluid, may point to a new health-promoting and disease-preventing approach for dairy cattle.

Effect of coated cysteamine hydrochloride and probiotics supplemented alone or in combination on feed intake, nutrients digestibility, ruminal fermentation, and blood metabolites of Kamphaeng Saen beef heifers

This study aimed to determine the effects of coated cysteamine hydrochloride (CSH) and probiotics (PB) supplemented alone or in combination on feed intake, digestibility, ruminal fermentation, and blood metabolites of heifer beef cattle. Sixteen heifers (body weight = 210 ± 41 kg; age = 9 ± 2 months) were assigned according to a randomized complete block design in a 2 × 2 factorial arrangement. All animals were fed the basal diet, which contained an 82:17 concentrate-to-forage ratio, and the forage source was rice straw. The treatments were as follows: (1) 0% PB + 0 g/d CSH, (2) 0.1% PB + 0 g/d CSH, (3) 0% PB + 20 g/d CSH, and (4) 0.1% PB + 20 g/d CSH. The main effect of CSH supplementation has been found to improve feed intake (P < 0.05). There were no treatment interactions with nutrient digestibility or rumen fermentation parameters. Supplementation of CSH did not affect any of the variables evaluated, while probiotics supplementation increased DM digestibility due to the increases in CP and fiber fraction digestibility. Compared to controls and CSH, at 16 h post-feeding, heifers receiving probiotics tended (P = 0.07) to show 17% greater ruminal NH3-N concentration, but this effect was not evident at 2 h post-feeding. However, the main effects of probiotic supplementation showed a tendency to increase the number of total bacteria and fungal zoospores in the rumen at 2 h post-feeding. The blood triglyceride (BTG) concentration of heifers fed a diet supplemented with 20 g/d CSH and 0.1% probiotics was found to be greater than those fed CSH alone (P < 0.1) at 16 h post-feeding, and then, there were greater BTG concentrations than other treatments (P < 0.05) at 2 h post-feeding. In conclusion, the combination of CSH and PB did not potentiate the effects of probiotics on digestibility and rumen fermentation and had minimal effects on blood parameters.

Impact of Probiotics on Dairy Production Efficiency

There has been growing interest on probiotics to enhance weight gain and disease resistance in young calves and to improve the milk yield in lactating animals by reducing the negative energy balance during the peak lactation period. While it has been well established that probiotics modulate the microbial community composition in the gastrointestinal tract, and a probiotic-mediated homeostasis in the rumen could improve feed conversation competence, volatile fatty acid production and nitrogen flow that enhances the milk composition as well as milk production, detailed changes on the molecular and metabolic level prompted by probiotic feed additives are still not understood. Moreover, as living biotherapeutic agents, probiotics have the potential to directly change the gene expression profile of animals by activating the signalling cascade in the host cells. Various direct and indirect components of probiotic approaches to improve the productivity of dairy animals are discussed in this review.

Probiotics: Symbiotic Relationship with the Animal Host

Simple Summary

Intestinal health directly influences the profitability of animal production, and so growth-promoting antibiotics have been used in the feed or drinking water to reduce the impact of enteric diseases and improve production parameters. However, these have generated long-term bacterial resistance. In the search for natural alternatives to antibiotics, various probiotic strains have been developed to improve intestinal health and biological indicators in farm animals, which is important to provide the consumer with safe food. This review describes the main probiotic bacteria and yeasts, their in vitro properties and their impact on the antioxidant capacity and intestinal environment of animals. Furthermore, this review outlines the role of probiotics in apparently healthy ruminants, pigs and poultry, including animals with digestive diseases.

Abstract

Antibiotic growth-promoters in animal feeding are known to generate bacterial resistance on commercial farms and have proven deleterious effects on human health. This review addresses the effects of probiotics and their symbiotic relationship with the animal host as a viable alternative for producing healthy meat, eggs, and milk at present and in the future. Probiotics can tolerate the conditions of the gastrointestinal tract, such as the gastric acid, pH and bile salts, to exert beneficial effects on the host. They (probiotics) may also have a beneficial effect on productivity, health and wellbeing in different parameters of animal performance. Probiotics stimulate the native microbiota (microbes that are present in their place of origin) and production of short-chain fatty acids, with proven effects such as antimicrobial, hypocholesterolemic and immunomodulatory effects, resulting in better intestinal health, nutrient absorption capacity and productive responses in ruminant and non-ruminant animals. These beneficial effects of probiotics are specific to each microbial strain; therefore, the isolation and identification of beneficial microorganisms, as well as in vitro and in vivo testing in different categories of farm animals, will guarantee their efficacy, replicability and sustainability in the current production systems.

Pectus excavatum em uma ninhada de Buldogue Francês: relato de caso

O pectus excavatum é considerado uma patologia da parede torácica, onde há convexidade no aspecto ventral do esterno, o que gera complicações secundárias, como alongamento ventrodorsal do tórax e aumento da pressão intratorácica, entre outras. No presente caso, o corpo de um cachorro Buldogue Francês nasceu com sinais prévios de decaimento e baixo consumo de leito materno, além de uma avaliação médica forense. De acordo com a avaliação patológica, foi encontrada uma fenda no peito esternal relacionada às esternas caudais próximas à cartilagem xifóide, conteúdo espumoso na cartilagem epiglótica da laringe e sinais graves de enfisema nos lobos caudal, craniano e médio pulmonar. Na avaliação cardiológica, foi observada assimetria morfológica invaginante no septo interventricular na mesma área em que a fenda esternal ocorre, por sua vez, na avaliação radiográfica, evidencia uma depressão dorsal do terço caudal do esterno com alterações consideráveis na silhueta cardíaca. Na Colômbia não há relatos de ninhadas completas que apresentem esta alteração, portanto, pretende-se que este seja o primeiro relatório anatomopatológico e de imagem que descreva a patologia em caninos.

The Recent Trend in the Use of Multistrain Probiotics in Livestock Production: An Overview

It has been established that introducing feed additives to livestock, either nutritional or non-nutritional, is beneficial in manipulating the microbial ecosystem to maintain a balance in the gut microbes and thereby improving nutrient utilization, productivity, and health status of animals. Probiotic use has gained popularity in the livestock industry, especially since antimicrobial growth promoter's use has been restricted due to the challenge of antibiotic resistance in both animals and consumers of animal products. Their usage has been linked to intestinal microbial balance and improved performance in administered animals. Even though monostrain probiotics could be beneficial, multistrain probiotics containing two or more species or strains have gained considerable attention. Combining different strains has presumably achieved several health benefits over single strains due to individual isolates' addition and positive synergistic adhesion effects on animal health and performance. However, there has been inconsistency in the effects of the probiotic complexes in literature. This review discusses multistrain probiotics, summarizes selected literature on their effects on ruminants, poultry, and swine productivity and the various modes by which they function.

Systematic review and meta-analysis of probiotic use on inflammatory biomarkers and disease prevention in cattle

The aim of this study was to appraise the available evidence on the effectiveness of probiotic treatment on mature cattle immunity, inflammation, and disease prevention. A systematic review with meta-analysis was conducted to analyse studies that were eligible to answer the following research question: "in cattle of at least 6-months of age, is the use of probiotics associated with immunomodulatory and inflammatory responses, and clinical disease outcomes?" Our literature search yielded 25 studies that fit the inclusion criteria. From these studies, only 19 were suitable for inclusion in the meta-analysis due to data limitations and differences in study population characteristics. Included studies were assessed for bias using a risk assessment tool adapted from the Cochrane Collaboration's tool for assessing risk of bias in randomised trials. GRADE guidelines were used to assess the quality of the body of evidence at the outcome level. The meta-analysis was performed using Review Manager and R. The overall quality of evidence at the outcome level was assessed as being very low. On average, the treatment effect on immunoglobulin G (IgG), serum amyloid A (SAA), haptoglobin (Hp) and β-hydroxybutyrate (BoHB) for cows receiving probiotics did not differ from control cows. Exposure to probiotics was not associated with reduced risk of reproductive disorders (pooled RR = 1.02 95 % CI = 0.81-1.27, P = 0.88). There is insufficient evidence to support any significant positive effects of probiotics on cattle immunity and disease prevention. This lack of consistent evidence could be due to dissimilarities in the design of the included studies such as differences in dosage, dose schedule, diet composition and/or physiological state of the host at the time of treatment.

Influence of three microbial feed additives of Megasphaera elsdenii, Saccharomyces cerevisiae and Lactobacillus sp. on ruminal methane and carbon dioxide production, and biofermentation kinetics

AIMS

This study was performed to investigate the effects of Megasphaera elsdenii (Me), Saccharomyces cerevisiae (SC) and lactic acid bacteria (FP-Lactobacillus fermentum plus Lactobacillus plantarum) alone or in combination on biogas production and ruminal biofermentation parameter in a heterofermenter system.

METHODS AND RESULTS

Eight treatments were evaluated; (i) control (without additive; CON); (ii) Me; (iii) SC; (iv) FP; (v) Me plus SC (MSC); (vi) Me plus FP (MFP); (vii) SC plus FP (SCFP) and (viii) Me plus SC plus FP (MSCFP). Doses of FP, Me and SC were 1·5 × 10⁸ (CFU per ml), 1·5 × 10⁸ (CFU per ml) and 1·4 × 10⁷ (CFU 0·002^-1  g), respectively. Biogas production in all time increased (P < 0·05) by MSCFP than CON additive. The proportional methane (CH₄ ) decreased (P < 0·05) in MSCFP and FP, while carbon dioxide (CO₂ ) was decreased (P < 0·05) by SC compared MSCFP and MSC. The proportional CO₂ decreased (P < 0·05) by MSCFP and FP additive. The mean concentration of NH₃ -N was not affected by treatments. Concentration of total volatile fatty acids and the percent of acetate and propionate was not affected by treatments. The highest (P < 0·05) percent of butyrate and valerate were observed in MSCFP additive. The experiment showed that microbial additives of FP, SCFP and MSCFP reduced proportional CH₄ and CO₂ .

CONCLUSIONS

Microbial additives of MFP and MSCFP had a sustainable positive efficiency on pH and volatile fatty acids and mitigate CH₄ and CO₂ .

SIGNIFICANCE AND IMPACT OF THE STUDY

The use of microbial additives control on the ruminal pH (MFP) and improve VFA such as butyrate (MSC, MSCFP) and valerate (MSCFP) and reduce the greenhouse gases production showed a reduced risk of ruminal acidosis.

Influence of probiotics on biofilm formation and diversity of bacteria colonising crop sorghum ensiled with unsalable vegetables

The objective of this study was to characterise in situ digestion kinetics and bacterial colonisation of crop sorghum ensiled with unsalable carrot or pumpkin at 0, 20 or 40% dry matter (DM). Silages with or without the application of a commercial probiotic were incubated in situ for 0, 3, 6, 9, 24 and 48 h. Calculation of in situ digestion kinetics was conducted for DM, organic matter and neutral detergent fibre (aNDF). The V4 region of the 16S rRNA gene was sequenced to determine the composition and diversity of bacteria colonising the silage. Organic matter and DM digestion kinetics indicated that greater vegetable inclusion increased (P < 0.05) the soluble fraction and effective degradability. Bacterial richness at 48 h incubation was greater (P = 0.02) in 20% carrot and 40% pumpkin treatments, compared with the control. An effect of level × probiotic was observed with increased Shannon diversity (P = 0.01) for 40% carrot and 20% pumpkin probiotic treatments, respectively. Primary colonising bacteria were members of the Prevotella genus, dominating after 3 and 6 h of incubation. The abundance of Prevotella increased by 4.1% at 3 h (P < 0.01) and by 4.7% at 9 h incubation with probiotics, compared with the control. Secondary biofilm colonisers included members of Treponema, Saccharofermentans, Fibrobacter, Ruminobacter and Anaerosporobacter genera, dominant from 9 h incubation onward. This study demonstrated that including unsalable vegetables at 20 or 40% DM increases the soluble fraction and effective degradability of sorghum silage during in situ digestion and increases diversity of bacteria colonising ensiled vegetables within the rumen. KEY POINTS: • Ensiling unsalable vegetables is a viable strategy to reduce food waste. • Ensiled vegetables increased in situ soluble fraction and effective degradability. • Bacterial richness at 48 h incubation improved with 20% carrot or 40% pumpkin. • Diversity of colonising rumen bacteria increased with carrot or pumpkin inclusion.

Alterations in fermentation parameters during and after induction of a subacute rumen acidosis in the rumen simulation technique

Subacute rumen acidosis (SARA) is a common problem in dairy cattle. High-concentrate rations lead to an accumulation of short-chain fatty acids (SCFA) in the rumen and a subsequent decrease in ruminal pH. As SARA impairs animal welfare and productivity, numerous in vivo studies are focusing on evaluation of prevention strategies. In vitro models can support this research and reduce animal numbers and experimental costs. We used different diets and buffer compositions to induce SARA in the rumen simulation technique (Rusitec) and investigated the recovery process. The experiment consisted of an equilibration period (7 days), a first control period, a SARA period and a second control period (5 days each). During the SARA period, SARA was induced by infusing SARA1 or SARA2 buffer with reduced bicarbonate (20 mmol/L and 25 mmol/L) and phosphate (both 10 mmol/L) contents compared to a modified McDougall's buffer (bicarbonate 97.9 mmol/L, phosphates 20 mmol/L). Additionally, we compared three feeding strategies, which differed in the concentrate-to-roughage ratio (30:70, 70:30, changing ratio: 30% concentrate in control periods and 70% concentrate in SARA period). During the SARA period, the pH decreased to a constant value below the SARA thresholds of pH 5.8 and 5.6, whereas lactate concentrations remained low. The total SCFA production rate declined 3 days after SARA induction, and the molar proportion of acetate decreased. The decrease in pH and SCFA production was more pronounced for SARA1 buffer. The high-concentrate diet reduced the molar proportion of acetate and increased NH₃ -N concentrations. During the second control period, most parameters recovered. In conclusion, SARA conditions were successfully induced in the Rusitec. However, we observed a higher influence of buffer composition than of concentrate proportions on most biochemical parameters. Nearly all changes were reversible. This model can be applied to test acidosis prevention strategies prior to animal experiments.

Could probiotics be the panacea alternative to the use of antimicrobials in livestock diets?

Probiotics are most frequently derived from the natural microbiota of healthy animals. These bacteria and their metabolic products are viewed as nutritional tools for promoting animal health and productivity, disease prevention and therapy, and food safety in an era defined by increasingly widespread antimicrobial resistance in bacterial pathogens. In contemporary livestock production, antimicrobial usage is indispensable for animal welfare, and employed to enhance growth and feed efficiency. Given the importance of antimicrobials in both human and veterinary medicine, their effective replacement with direct-fed microbials or probiotics could help reduce antimicrobial use, perhaps restoring or extending the usefulness of these precious drugs against serious infections. Thus, probiotic research in livestock is rapidly evolving, aspiring to produce local and systemic health benefits on par with antimicrobials. Although many studies have clearly demonstrated the potential of probiotics to positively affect animal health and inhibit pathogens, experimental evidence suggests that probiotics' successes are modest, conditional, strain-dependent, and transient. Here, we explore current understanding, trends, and emerging applications of probiotic research and usage in major livestock species, and highlight successes in animal health and performance.

Effects of an increased concentrate diet on rumen pH and the bacterial community in Japanese Black beef cattle at different fattening stages

This study evaluated the effects of increasing the proportion of concentrate in the diet on the rumen pH and bacterial community in Japanese Black beef cattle at different fattening stages. Six rumen-cannulated beef cattle were studied in the middle (Mid group, n=3, age 21–22 months) and late (Late group, n=3, age 31 months) fattening stages. The cattle were fed rice straw with control (CON period) or high-concentrate (HC period) diets for 14 consecutive days in each period. Rumen pH was measured continuously and the rumen fluids were collected on the last day of each period. The 24-hr mean and minimum rumen pH in the Mid group were significantly (P<0.05) lower during the HC period compared with the CON period, whereas those in the Late group were continuously low during both periods. In the Late group, the ruminal volatile fatty acid and lactic acid concentrations were significantly (P<0.05) higher during the HC period. During the HC period, the proportions of Prevotella and Caloramator were significantly (P<0.05) higher and lower, respectively, in the Mid group. From these findings, significant changes in the rumen pH and bacterial community induced by dietary changes were mainly observed in the Mid group. Therefore, the ruminal fermentative function in response to a higher concentrate diet might adapt differently in Japanese Black beef cattle at the two different fattening stages.

Effects and immune responses of probiotic treatment in ruminants

Gut microbial colonization and establishment are vital to ruminant health and production. This review article focuses on current knowledge and methods used to understand and manipulate the gut microbial community in ruminant animals, with a special focus on probiotics treatment. This review highlights the most promising of studies in this area, including gut microbial colonization and establishment, effect of gastrointestinal tract microbial community on host mucosal innate immune function, impact of feeding strategies on gut microbial community, current probiotic treatments in ruminants, methods to manipulate the gut microbiota and associated antimicrobial compounds, and models and cell lines used in understanding the host immune response to probiotic treatments. As a lot of work in this area was done in humans and mice, this review article also includes up-to-date knowledge from relevant studies in human and mouse models. This review is a useful resource for scientists working in the areas of ruminant nutrition and health, and to researchers investigating the microbial ecology and its relation to animal health.