Evaluation of ruminal methane and ammonia formation and microbiota composition as affected by supplements based on mixtures of tannins and essential oils using Rusitec

BACKGROUND

Dietary supplements based on tannin extracts or essential oil compounds (EOC) have been repeatedly reported as a promising feeding strategy to reduce the environmental impact of ruminant husbandry. A previous batch culture screening of various supplements identified selected mixtures with an enhanced potential to mitigate ruminal methane and ammonia formation. Among these, Q-2 (named after quebracho extract and EOC blend 2, composed of carvacrol, thymol, and eugenol) and C-10 (chestnut extract and EOC blend 10, consisting of oregano and thyme essential oils and limonene) have been investigated in detail in the present study with the semi-continuous rumen simulation technique (Rusitec) in three independent runs. For this purpose, Q-2 and C-10, dosed according to the previous study, were compared with a non-supplemented diet (negative control, NC) and with one supplemented with the commercial EOC-based Agolin® Ruminant (positive control, PC).

RESULTS

From d 5 to 10 of fermentation incubation liquid was collected and analysed for pH, ammonia, protozoa count, and gas composition. Feed residues were collected for the determination of ruminal degradability. On d 10, samples of incubation liquid were also characterised for bacterial, archaeal and fungal communities by high-throughput sequencing of 16S rRNA and 26S ribosomal large subunit gene amplicons. Regardless of the duration of the fermentation period, Q-2 and C-10 were similarly efficient as PC in mitigating either ammonia (-37% by Q-2, -34% by PC) or methane formation (-12% by C-10, -12% by PC). The PC was also responsible for lower feed degradability and bacterial and fungal richness, whereas Q-2 and C-10 effects, particularly on microbiome diversities, were limited compared to NC.

CONCLUSIONS

All additives showed the potential to mitigate methane or ammonia formation, or both, in vitro over a period of 10 d. However, several differences occurred between PC and Q-2/C-10, indicating different mechanisms of action. The pronounced defaunation caused by PC and its suggested consequences apparently determined at least part of the mitigant effects. Although the depressive effect on NDF degradability caused by Q-2 and C-10 might partially explain their mitigation properties, their mechanisms of action remain mostly to be elucidated.

Dietary supplementation with natural antioxidants: assessment of growth performance and meat quality in broiler chickens

Exposure to air and light lowers the meat quality of chickens, which is mainly determined by the color alteration and accumulation of detrimental products from lipid oxidation. This study tests the effects of 2 supplements rich in polyphenols, Oxilem (OX) and OxiGem (OG), on broiler Ross 308 performance and meat quality in comparison to a control group (C). A total of 105 one-day-old Ross 308 male chicks were allocated to 21 pens and randomly assigned to 1 of the 3 treatments. The trial lasted 42 d. Individual live weight and feed intake per pen were recorded. Proximate analysis, color, cholesterol content and cholesterol oxidation products (COPs), fatty acids (FAs), volatile aldehydes profile, and secondary oxidation products of meat FAs were determined, with analyses for detecting oxidative alterations conducted on breast burgers preserved for 7 d at 4°C. Birds fed OG grew 7 g/d more than those receiving OX, reaching a higher final weight. After slaughtering, meat from the OX group had a higher yellow index compared to C. After 7 d of air and light exposure, the influence on the color parameters of the OG and OX burgers was significantly less pronounced than that of C. Secondary oxidation products of the FAs of the burgers were not significantly affected by the diet regimens. In addition, OX and OG burgers exhibited lower amounts of volatile aldehydes, triol and COPs. These results confirm the effectiveness of OX and OG supplementation against lipid oxidation at the inclusion level used in this trial.

Linseed supplementation in the diet of fattening pigs: Effect on the fatty acid profile of different pork cuts

Linseed supplementation improves the fatty acid (FA) profile of meat, primarily by increasing α-linolenic acid (ALA). Pork is one of the most consumed meats, though the high level of saturated FA, therefore, a change of the FA profile is needed to improve the health properties. The aim of this work was to study the influence of extruded linseed supplementation on the FA profile in 5 different pork cuts, increasing their nutraceutical properties. Sixty pigs were divided into two groups, which were fed two different diets: control (C) and experimental (L, 8% supplementation with extruded flaxseed). Five cuts were sampled: backfat (Bf), bacon (B), Boston shoulder (Bs), ham lean part (Hl) and ham fatty part (Hf). The L diet reduced fat content in Hf (-6%) and B (-11%), while the other cuts did not show differences. Moreover, L group showed a higher level of n-3 PUFA (approx. 9-fold), with a significant reduction in the n-6/n-3 from 20 to 2.5. In cuts rich in fat (Bf, B and Hf) of L group, the level of n-3 PUFA was higher than the thresholds set by EU to obtain the claim "Source of omega-3 fatty acids". In contrast, the lean cuts (Hl and Bs) did not exceed the threshold of n-3 PUFA required to obtain the claim, as consequence of the low level of fat. The results demonstrated that a diet with 8% extruded linseed enhanced the nutraceutical quality of pork meat.

Consumer attitudes toward dairy products from sheep and goats: A cross-continental perspective

This study aimed to assess consumer knowledge, attitudes, and perceptions toward dairy products from sheep and goats. A web-based survey was conducted in Latin America (Mexico and Chile), Europe (Italy, Spain, Greece, and Denmark), and Asia (Bangladesh). From March to June 2021, adult participants answered an online survey available in 5 languages. In total, 1,879 surveys were completed. Categorical and ordinal data were analyzed as frequencies and percentages. To determine the relationship between the variables for purchasing and consumption behaviors of respondents who declared that they consume dairy products, a multiple correspondence analysis was carried out. Most completed surveys were from Mexico and Italy (30% and 33.7%, respectively). Most respondents were between 18 and 29 yr old, female, highly educated, and employed. The majority of respondents (70.8%) declared that they consume dairy products from small ruminants. Consumers preferred products from both sheep and goats (49.4%); however, it was observed that in Mexico, Denmark, and Bangladesh, more than 50% preferred goat dairy products. The most-consumed products were mature and fresh cheeses. Mature cheese was the most-preferred product in Chile; in Mexico, Italy, Greece, and Denmark, it was fresh cheese. Unlike the rest of the countries, in Bangladesh, dairy product consumption from small ruminants was observed by more than 30% of respondents. In Mexico, a higher percentage of people do not consume sheep or goat dairy products because they are unfamiliar with them. In Mexico, Chile, and Bangladesh, limited market availability was also a variable responsible for nonconsumption. In European and Asian countries, sheep and goat dairy products are not consumed because consumers dislike them, in addition to a greater awareness of sustainability and climate change issues. The multiple correspondence analysis defined 5 dimensions. Dimension 1 was associated with the geographic location of the respondent (country and continent), the type of milk (sheep or goat), and the consideration of well-being and health as characteristics associated with the consumption of dairy products from small ruminants. Dimension 2 was associated with the respondent's country of origin and the frequency of consumption. Dimension 3 was associated with gender, education, and employment status. Dimension 4 was associated with the respondent's age, the association of the "healthy" concept of sheep and goat dairy products, and the consideration of the nutritional benefits of dairy as responsible for considering them healthy. Dimension 5 was associated with a "strong smell and taste" of sheep and goat dairy products. This study showed that consumer attitudes toward dairy products from sheep and goats vary between continents. In conclusion, results showed consumer interest in animal welfare and environmental impact issues related to small ruminant farming as well as a general attraction to local products. It seems that these factors contribute to consumers' perception of the quality of dairy products, so the industry and select farmers should carefully consider incorporating them into their supply chain.

Effect of tannins from tropical plants on methane production from ruminants: A systematic review

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A negative relationship was observed between the level of tannin inclusion and CH₄ emission.

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The effect of CH₄ mitigation is increasing as the level of tannin inclusion is higher.

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Sub-group analysis revealed differences of tannins supplementation response according to CH₄ emission measurements techniques.

Methane (CH₄) is a greenhouse gas generated during the feed fermentation processes in the rumen. However, numerous studies have been conducted to determine the capacity of plant secondary metabolites to enhance ruminal fermentation and decrease CH₄ production, especially those plants rich in tannins. This review conducted a descriptive analysis and meta-analysis of the use of tannin-rich plants in tropical regions to mitigate CH₄ production from livestock. The aim of this study was to analyse the effect of tannins supplementation in tropical plants on CH₄ production in ruminants using a meta-analytic approach and the effect on microbial population. Sources of heterogeneity were explored using a meta-regression analysis. Final database was integrated by a total of 14 trials. The ‘meta’ package in R statistical software was used to conduct the meta-analyses. The covariates defined a priori in the current meta-regression were inclusion level, species (sheep, beef cattle, dairy cattle, and cross-bred heifers) and plant. Results showed that supplementation with tropical plants with tannin contents have the greatest effects on CH₄ mitigation . A negative relationship was observed between the level of inclusion and CH₄ emission (−0.09), which means that the effect of CH₄ mitigation is increasing as the level of tannin inclusion is higher. Therefore, less CH₄ production will be obtained when supplementing tropical plants in the diet with a high dose of tannins.

Histochemical Characterisation and Gene Expression Analysis of Skeletal Muscles from Maremmana and Aubrac Steers Reared on Grazing and Feedlot Systems

Simple Summary

Muscle fibre types and sizes are important factors affecting muscle growth potential and meat quality. Their variability depends on some factors like muscle type, animal breed, physical activity, and they could be going through morphological or metabolic modifications, throughout animal life. Two muscles from Maremmana, an autochthonous breed from Tuscany (Italy), was compared to those from Aubrac, a breed from the Massif Central (France), under histochemical and gene expression points of view. Both these breeds were poorly studied, and the results identified Maremmana muscles were more oxidative in comparison to Aubrac. Moreover, steers of each breed were proportionally divided and reared on grazing or feedlot systems. Conversely to what was expected, the voluntary physical activity on pasture, another aspect poorly studied, influenced neither histochemical characteristics nor the gene expression.

Abstract

This study aimed to characterise the fibre composition of Triceps brachii (TB) and Semimembranosus (SM) muscles from 20 Maremmana (MA) and 20 Aubrac (AU) steers, and the effect of grazing activity in comparison with feedlot system. The histochemical method was performed with the m-ATPase method with an acid pre-incubation, thus allowing to distinguish type I, IIA, and IIB fibres. Additionally, on total RNA extracted from SM muscle, the expressions of atp1a1, mt-atp6, and capn1 genes were evaluated, in order to find potential associations with muscle fibre histochemical characteristics. In SM muscle, the MA steers had the greater frequency of oxidative fibres (type I and IIA) and the higher atp1a1 expression, in comparison to AU steers. Conversely, AU steers had a greater frequency of type IIB fibres, and the higher capn1 expression. A similar histochemical pattern was observed in TB muscle. The grazing activity was probably insufficient to determine differences both for fibre proportion and size, and gene expressions, except for mt-atp6 expression that was surprisingly highest in feedlot MA in comparison to other steers. These findings further the knowledge of muscle properties belonging to these breeds, and the effect of voluntary physical activity since few studies were available in this regard.

[Anatomical and cytohistological changes caused by aqueous extracts of Tamus communis L. leaves]

Aqueous extracts of Tamus communis leaves induce root tip swelling of Medicago seedlings and disrupt the mitotic process of Allium root tips. The cells of the swollen roots of Medicago treated seedlings are much wider an shorter than the homologous control cells. In the treated roots of Allium prophases prevail and some cells contain vacuolated nuclei or micronuclei.

[Effect of aqueous extracts of Tamus communis L. leaves on the germination of seeds of various species]

The different influence of germination and growth inhibitors in aqueous extracts, at the same concentration, of Tamus communis L. leaves, on germinating seeds and seedlings of nigra L., Lactuca sativa L., Medicago sativa L., has been shown. This action, very marked at the experimental concentrations, is not toxic, as the seeds and seedlings, if immersed in deionized water after treatments, recover their germination and growth. This recovery occurs however differently in the plants investigated.