Effect of soybean meal treatment with Cistus ladanifer condensed tannins in growth performance, carcass and meat quality of lambs

Effect of the dietary supplementation with sunflower oil-enriched bromoform from Asparagopsis taxiformis on lambs' growth, health, and ruminal methane production

The red seaweed Asparagopsis taxiformis has a potent antimethanogenic effect, which has been proven both in vitro and in vivo. Vegetable oil immersions of this seaweed (hereafter Bromoil) help stabilise the bromoform (CHBr3) responsible for its antimethanogenic effect. We evaluate the effects of increasing the levels of CHBr3 in lamb diets on growth performance, methane (CH4) production, animal health and meat quality. Twenty-four Merino Branco ram lambs were fed a ground complete compound feed, supplemented with 50 mL/kg DM of sunflower oil with different CHBr3 content. The treatments were defined by the CHBr3 doses in the oil: 0 mg (control - B0), 15 mg (B15), 30 mg (B30) and 45 mg (B45) of CHBr3 per kg of feed DM. The feed was prepared daily by mixing Bromoil with the compound feed. At the end of the experiment, the lambs were sacrificed, the ruminal content was collected for in vitro fermentation to evaluate CH4 production and organic matter (OM) degradability, and the rumen mucosa was sampled for histological examination. Meat samples were collected for chemical composition and CHBr3 analysis. The half-life of CHBr3 in the air-exposed feed was 3.98 h making it very difficult to establish the practiced level of CHBr3 supplementation. Lambs-fed treatments B30 and B45 decreased DM intake by up to 28%. Average daily gain was also reduced due to CHBr3 supplementation, with B45 showing results 40% lower than B0. DM feed conversion ratio was similar for all treatments. The degradability of OM, the volume of total gas and of gas without CH4 were unaffected by the experimental treatments, evaluated by the in vitro method. However, the volume of CH4 decreased by up to 75% for treatments above 30 mg/kg DM, while the yield of CH4/g OM degraded was reduced by up to 78% with treatments above 30 mg/kg DM. Meat chemical composition was not affected by Bromoil supplementation and no traces of CHBr3 were found in meat samples. During this experiment, the animals presented normal health and behaviour. However, postslaughter examination of the rumen showed distinct lesions on the ventral region of the rumen mucosa of animals supplemented with Bromoil. These lesions were more severe in the animals receiving treatments B30 and B45. This research determined that although concentrations of CHBr3 in the diet above 30 mg/kg DM helped to reduce CH4 emissions, it negatively affected the performance and rumen wall.

Effect of Technological Factors on the Extraction of Polymeric Condensed Tannins from Acacia Species

The aim of this research work was to investigate the influence of parameters such as particle size, mass/solvent ratio, temperature and spray drying on the tannin extraction process in order to develop cost-effective methods with better environmental and structural performance. The pods of Acacia nilotica ssp. tomentosa (ANT) were fractionated into three fractions, coarse fraction (C) (>2 mm), medium fraction (M) (1-2 mm), and fine fraction (F) < 1 mµ), and extracted with different water-to-pod ratios (2:1, 4:1 and 6:1) at different temperatures (30, 50 and 70 °C). The best results were scaled up using the three fractions of ANT, its bark and the bark of Acacia seyal var. seyal (ASS). Part of their extract was spray dried. The tannin content and total polyphenolic materials were evaluated using standard methods. Their adhesives were tested for their tensile strength. Tannins of ASS were characterized by 13C NMR and MALDI-TOF. The results revealed that the fine fraction (F) gave the highest percentage of tannins in both small and scaled-up experiments. The results of the tensile strength conformed to the European standard. The 13C NMR spectra of ANT and ASS showed that the bark contained condensed tannins mainly consisting of procyanidins/prodelphinidin of 70%/30% and 60%/40%, respectively. MALDI-TOF spectra confirmed the results obtained by 13C NMR and detailed the presence of flavonoid monomers and oligomers, some of which were linked to short carbohydrate monomers or dimers.

Artificial Intelligence Applied to Improve Scientific Reviews: The Antibacterial Activity of Cistus Plants as Proof of Concept

Reviews have traditionally been based on extensive searches of the available bibliography on the topic of interest. However, this approach is frequently influenced by the authors' background, leading to possible selection bias. Artificial intelligence applied to natural language processing (NLP) is a powerful tool that can be used for systematic reviews by speeding up the process and providing more objective results, but its use in scientific literature reviews is still scarce. This manuscript addresses this challenge by developing a reproducible tool that can be used to develop objective reviews on almost every topic. This tool has been used to review the antibacterial activity of Cistus genus plant extracts as proof of concept, providing a comprehensive and objective state of the art on this topic based on the analysis of 1601 research manuscripts and 136 patents. Data were processed using a publicly available Jupyter Notebook in Google Collaboratory here. NLP, when applied to the study of antibacterial activity of Cistus plants, is able to recover the main scientific manuscripts and patents related to the topic, avoiding any biases. The NLP-assisted literature review reveals that C. creticus and C. monspeliensis are the first and second most studied Cistus species respectively. Leaves and fruits are the most commonly used plant parts and methanol, followed by butanol and water, the most widely used solvents to prepare plant extracts. Furthermore, Staphylococcus. aureus followed by Bacillus. cereus are the most studied bacterial species, which are also the most susceptible bacteria in all studied assays. This new tool aims to change the actual paradigm of the review of scientific literature to make the process more efficient, reliable, and reproducible, according to Open Science standards.

The effect of varying levels of purified condensed tannins on performance, blood profile, meat quality and methane emission in male Bapedi sheep fed grass hay and pellet-based diet

This study determined the effect of purified condensed tannin inclusion levels in a diet on production, haematological indices, blood biochemical components, meat quality and methane emission by yearling indigenous male Bapedi sheep on a grass hay and sheep pellet-based diet in a 28-day trial. The diets contained similar (P > 0.05) nutrients but with different (P < 0.05) purified condensed tannin supplementation levels. A complete randomized design was used. Twenty-four yearling male Bapedi sheep were assigned to four dietary treatments having different purified condensed tannin levels of 0 (GH₈₀P₂₀PCT₀), 30 (GH₈₀P₂₀PCT₃₀), 40 (GH₈₀P₂₀PCT₄₀) and 50 (GH₈₀P₂₀PCT₅₀) g/kg DM. A quadratic type of equation was also used to determine condensed tannin supplementation levels for optimal performance and methane emission reduction by sheep. Supplementing diets with purified condensed tannins did not affect (P > 0.05) diet intake, digestibility and live weight gain of male Bapedi sheep. Supplementing diets with purified condensed tannins did not affect (P > 0.05) blood components of male Bapedi sheep. Inclusion of condensed tannins in the diets did not affect (P > 0.05) Bapedi sheep meat pH and sensory attributes. However, supplementing diets with purified condensed tannins decreased (P < 0.05) methane emission by 51 to 60%. A 49.08 g supplementation level with purified condensed tannins per kg DM diet was calculated, with the use of quadratic equations, to result in the lowest methane emission by male Bapedi sheep. The meat of male Bapedi rams on diets containing 30, 40 or 50 g of purified condensed tannins per kg DM contained higher (P < 0.05) antioxidant activities than those from rams fed a diet without purified condensed tannins. These results indicate that purified condensed tannin supplementation levels of 0, 30, 40 or 50 g/kg DM diet had no adverse effects on growth performance, blood profiles and meat sensory attributes of male Bapedi sheep. However, supplementation levels of 30, 40 or 50 g of purified condensed tannins per kg DM diet reduced methane emission by 51 to 60%, and increased sheep meat antioxidant activity values. Supplementing diets with purified condensed tannins has the potential to reduce methane production and emission by sheep. However, long-term studies are recommended to ascertain the present findings.

Dietary Coleus amboinicus Lour. decreases ruminal methanogenesis and biohydrogenation, and improves meat quality and fatty acid composition in longissimus thoracis muscle of lambs

Background

Methane production and fatty acids (FA) biohydrogenation in the rumen are two main constraints in ruminant production causing environmental burden and reducing food product quality. Rumen functions can be modulated by the biologically active compounds (BACs) of plant origins as shown in several studies e.g. reduction in methane emission, modulation of FA composition with positive impact on the ruminant products. Coleus amboinicus Lour. (CAL) contains high concentration of polyphenols that may potentially reduce methane production and modulate ruminal biohydrogenation of unsaturated FA.

This study aimed to investigate the effect of BAC of Coleus amboinicus Lour. (CAL) fed to growing lambs on ruminal methane production, biohydrogenation of unsaturated FA and meat characteristics. In this study, the in vitro experiment aiming at determining the most effective CAL dose for in vivo experiments was followed by two in vivo experiments in rumen-cannulated rams and growing lambs. Experiment 1 (RUSITEC) comprised of control and three experimental diets differing in CAL content (10%, 15%, and 20% of the total diet). The two in vivo experiments were conducted on six growing, rumen-cannulated lambs (Exp. 2) and 16 growing lambs (Exp. 3). Animals were assigned into the control (CON) and experimental (20% of CAL) groups. Several parameters were examined in vitro (pH, ammonia and VFA concentrations, protozoa, methanogens and select bacteria populations) and in vivo (methane production, digestibility, ruminal microorganism populations, meat quality, fatty acids profiles in rumen fluid and meat, transcript expression of 5 genes in meat).

Results

CAL lowered in vitro methane production by 51%. In the in vivo Exp. 3, CAL decreased methane production by 20% compared with the CON group, which corresponded to reduction of total methanogen counts by up to 28% in all experiments, notably Methanobacteriales. In Exp. 3, CAL increased or tended to increase populations of some rumen bacteria (Ruminococcus albus, Megasphaera elsdenii, Butyrivibrio proteoclasticus, and Butyrivibrio fibrisolvens). Dietary CAL suppressed the Holotricha population, but increased or tended to increase Entodiniomorpha population in vivo. An increase in the polyunsaturated fatty acid (PUFA) proportion in the rumen of lambs was noted in response to the CAL diet, which was mainly attributable to the increase in C18:3 cis-9 cis-12 cis-15 (LNA) proportion. CAL reduced the mRNA expression of four out of five genes investigated in meat (fatty acid synthase, stearoyl-CoA desaturase, lipoprotein lipase, and fatty acid desaturase 1).

Conclusions

Summarizing, polyphenols of CAL origin (20% in diet) mitigated ruminal methane production by inhibiting the methanogen communities. CAL supplementation also improved ruminal environment by modulating ruminal bacteria involved in fermentation and biohydrogenation of FA. Besides, CAL elevated the LNA concentration, which improved meat quality through increased deposition of n-3 PUFA.

• Coleus amboinicus Lour. (CAL) into sheep diet decreased CH₄ emission.

• CAL did not reduce nutrient digestibility, but inhibited the methanogen community.

• CAL increased ruminal propionate proportion and decreased acetate/propionate ratio.

• CAL elevated n-3 fatty acid concentration in ruminal fluid and meat.

• Supplementation of CAL improved some meat quality traits.

The Utilisation of Tannin Extract as a Dietary Additive in Ruminant Nutrition: A Meta-Analysis

Simple Summary

Tannin has been extensively assessed for its potential and utilisation as a ruminant feed additive in recent years and is becoming important due to its beneficial effects on modulating ruminant performance and health and mitigating methane emissions. However, evidence concerning the effect of tannin in extracted forms on ruminants appears to be inconclusive on whether it can genuinely provide either beneficial or detrimental effects for ruminants. Moreover, the effects of various sources, types of tannin extract, or appropriate levels of supplementation on ruminants remain unclear. Therefore, there is a need for a systematic evaluation concerning the effects of tannin extract on rumen fermentation, digestibility, performance, methane emissions, and metabolism of ruminants.

Abstract

The objective of this meta-analysis was to elucidate whether there are general underlying effects of dietary tannin extract supplementation on rumen fermentation, digestibility, methane production, performance, as well as N utilisation in ruminants. A total of 70 papers comprised of 348 dietary treatments (from both in vivo and in situ studies) were included in the study. The database was then statistically analysed by the mixed model methodology, in which different experiments were considered as random effects and tannin-related factors were treated as fixed effects. The results revealed that an increased level of tannin extract inclusion in the diet lowered ruminant intake, digestibility, and production performance. Furthermore, the evidence also showed that an increased level of tannin extract decreased animal N utilisation where most of rumen by-pass protein was not absorbed well in the small intestine and directly excreted in the faeces. Due to the type of tannin extract, HT is more favourable to maintain nutrient intake, digestibility, and production performance and to mitigate methane production instead of CT, particularly when supplemented at low (<1%) to moderate (~3%) levels.

Growth Performance, Meat Quality and Antioxidant Status of Sheep Supplemented with Tannins: A Meta-Analysis

The objective of this study was to evaluate the effects of dietary supplementation with tannins (TANs) on productive performance, carcass characteristics, meat quality, oxidative stability, and blood serum antioxidant capacity of sheep through a meta-analysis. Using Scopus, Web of Science, ScienceDirect, and PubMed databases, a systematic search was performed for studies published in scientific journals that investigated the effects of TANs supplementation on the variables of interest. Only studies with weaned or older sheep were included. The data analyzed were extracted from 53 peer-reviewed publications. The sheep included in the present study were between 2 and 6 months old, and between 12 and 31 kg of body weight. The effects of TANs were analyzed using random-effects statistical models to examine the standardized mean difference (SMD) between treatments with TANs and control (no TANs). Heterogeneity was explored by meta-regression and a subgroup analysis was performed for covariates that were significant. Supplementation with TANs did not affect dry matter intake, pH, color (L* and b*), Warner-Bratzler shear force, cooking loss and meat chemical composition (p > 0.05). Supplementation with TANs increased daily weight gain (SMD = 0.274, p < 0.05), total antioxidant capacity (SMD = 1.120, p < 0.001), glutathione peroxidase enzyme activity (SMD = 0.801, p < 0.001) and catalase (SMD = 0.848, p < 0.001), and decreased malondialdehyde (MDA) concentration in blood serum (SMD = -0.535, p < 0.05). Supplementation with TANs decreased feed conversion rate (SMD = -0.246, p < 0.05), and the concentration of MDA (SMD = -2.020, p < 0.001) and metmyoglobin (SMD = -0.482, p < 0.05) in meat. However, meat redness (SMD = 0.365), hot carcass yield (SMD = 0.234), cold carcass yield (SMD = 0.510), backfat thickness (SMD = 0.565) and the Longissimus dorsi muscle area (SMD = 0.413) increased in response to TANs supplementation (p < 0.05). In conclusion, the addition of tannins in sheep diets improves productive performance, antioxidant status in blood serum, oxidative stability of meat and some other characteristics related to meat and carcass quality.

Nutritional Aspects of Ecologically Relevant Phytochemicals in Ruminant Production

This review provides an update of ecologically relevant phytochemicals for ruminant production, focusing on their contribution to advancing nutrition. Phytochemicals embody a broad spectrum of chemical components that influence resource competence and biological advantage in determining plant species' distribution and density in different ecosystems. These natural compounds also often act as plant defensive chemicals against predatorial microbes, insects, and herbivores. They may modulate or exacerbate microbial transactions in the gastrointestinal tract and physiological responses in ruminant microbiomes. To harness their production-enhancing characteristics, phytochemicals have been actively researched as feed additives to manipulate ruminal fermentation and establish other phytochemoprophylactic (prevent animal diseases) and phytochemotherapeutic (treat animal diseases) roles. However, phytochemical-host interactions, the exact mechanism of action, and their effects require more profound elucidation to provide definitive recommendations for ruminant production. The majority of phytochemicals of nutritional and pharmacological interest are typically classified as flavonoids (9%), terpenoids (55%), and alkaloids (36%). Within flavonoids, polyphenolics (e.g., hydrolyzable and condensed tannins) have many benefits to ruminants, including reducing methane (CH4) emission, gastrointestinal nematode parasitism, and ruminal proteolysis. Within terpenoids, saponins and essential oils also mitigate CH4 emission, but triterpenoid saponins have rich biochemical structures with many clinical benefits in humans. The anti-methanogenic property in ruminants is variable because of the simultaneous targeting of several physiological pathways. This may explain saponin-containing forages' relative safety for long-term use and describe associated molecular interactions on all ruminant metabolism phases. Alkaloids are N-containing compounds with vast pharmacological properties currently used to treat humans, but their phytochemical usage as feed additives in ruminants has yet to be exploited as they may act as ghost compounds alongside other phytochemicals of known importance. We discussed strategic recommendations for phytochemicals to support sustainable ruminant production, such as replacements for antibiotics and anthelmintics. Topics that merit further examination are discussed and include the role of fresh forages vis-à-vis processed feeds in confined ruminant operations. Applications and benefits of phytochemicals to humankind are yet to be fully understood or utilized. Scientific explorations have provided promising results, pending thorough vetting before primetime use, such that academic and commercial interests in the technology are fully adopted.

Phytogenic Additives Can Modulate Rumen Microbiome to Mediate Fermentation Kinetics and Methanogenesis Through Exploiting Diet-Microbe Interaction

Ruminants inhabit the consortia of gut microbes that play a critical functional role in their maintenance and nourishment by enabling them to use cellulosic and non-cellulosic feed material. These gut microbes perform major physiological activities, including digestion and metabolism of dietary components, to derive energy to meet major protein (65-85%) and energy (ca 80%) requirements of the host. Owing to their contribution to digestive physiology, rumen microbes are considered one of the crucial factors affecting feed conversion efficiency in ruminants. Any change in the rumen microbiome has an imperative effect on animal physiology. Ruminal microbes are fundamentally anaerobic and produce various compounds during rumen fermentation, which are directly used by the host or other microbes. Methane (CH4) is produced by methanogens through utilizing metabolic hydrogen during rumen fermentation. Maximizing the flow of metabolic hydrogen in the rumen away from CH4 and toward volatile fatty acids (VFA) would increase the efficiency of ruminant production and decrease its environmental impact. Understanding of microbial diversity and rumen dynamics is not only crucial for the optimization of host efficiency but also required to mediate emission of greenhouse gases (GHGs) from ruminants. There are various strategies to modulate the rumen microbiome, mainly including dietary interventions and the use of different feed additives. Phytogenic feed additives, mainly plant secondary compounds, have been shown to modulate rumen microflora and change rumen fermentation dynamics leading to enhanced animal performance. Many in vitro and in vivo studies aimed to evaluate the use of plant secondary metabolites in ruminants have been conducted using different plants or their extract or essential oils. This review specifically aims to provide insights into dietary interactions of rumen microbes and their subsequent consequences on rumen fermentation. Moreover, a comprehensive overview of the modulation of rumen microbiome by using phytogenic compounds (essential oils, saponins, and tannins) for manipulating rumen dynamics to mediate CH4 emanation from livestock is presented. We have also discussed the pros and cons of each strategy along with future prospective of dietary modulation of rumen microbiome to improve the performance of ruminants while decreasing GHG emissions.

The effects of improving low dietary protein utilization on the proteome of lamb tissues

Cistus ladanifer L. is a common shrub endemic to the Mediterranean region with high levels of condensed tannins (CT). CT form complexes with dietary protein resisting microbial degradation in the rumen, which enhances dietary protein utilization in ruminant diets. The objective of this study was to evaluate the utilization of CT in the diet of lambs on the proteomes of muscle, hepatic and adipose tissues. Twenty-four Merino Branco ram lambs were randomly allocated to three treatments (n = 8): C - control (160 g crude protein (CP)) per kg DM, RP - reduced protein (120 g CP/kg DM); and RPCT - reduced protein (120 g CP/kg DM) treated with CT extract. At the end of the trial, lambs were slaughtered and the longissimus lumborum muscle, hepatic and peri-renal adipose tissues sampled. A two-way approach was used for proteomic analysis: 2D-DIGE and nanoLC-MS. In the muscle, C lambs had lower abundance proteins that partake in the glycolysis pathway than the lambs of other treatments. Control lambs had lower abundance of Fe-carrying proteins in the hepatic tissue than RP and RPCT lambs. The latter lambs had highest abundance of hepatic flavin reductase. In the adipose tissue, C lambs had lowest abundance of fatty-acid synthase. SIGNIFICANCE: soybean meal is an expensive feedstuff in which intensive animal production systems heavily rely on. It is a source of protein extensively degraded in the rumen, leading to efficiency losses on dietary protein utilization during digestion. Protection of dietary protein from extensive ruminal degradation throughout the use of plants or extracts rich in CT allow an increase in the digestive utilization of feed proteins. In addition to enhance the protein digestive utilization, dietary CT may induce other beneficial effects in ruminants such as the improvement of the antioxidant status.