Study the effect of inclusion of feed flavonoid substances on animal performance and ruminal fermentation in calves

The thesis includes the effect of Bioflavex®, an orange plant extract rich in flavonoids, on rumen fermentation and meat quality. Several experiments were performed, in the “in vivo” trials (Exp. 1,2 and 3) under acidosis conditions the plant extract blend, ameliorated pH decrease and improved the acetic/propionic ratio and relative abundance of lactate-consuming microorganism (M. elsdenii). The “in vitro” trials (Exp. 4 and 5) confirmed the “in vivo” findings and it was demonstrated that the effect of flavonoids blend relies in its main components, Naringine, Neohesperidine moreover the flavonoids blend reduced gas and methane production through a significant reduction in abundances of methanogenic archaeas. Finally, in the sixth “in vivo” experiment, the effect of Bioflavex® on carcass quality and fat color and stability of 32 young Friesian bulls was negligible.En la memoria se analizó el efecto de un extracto cítrico rico en flavonoides, Bioflavex® sobre la fermentación ruminal y la calidad de la carne. En los experimentos “in vivo” (Exp. 1,2 y 5) y en condiciones de acidosis ruminal la presencia de Bioflavex® tamponó los descenso del pH, mejoró la tasa acético/propionico y la abundancia de especies bacterianas consumidoras de lactato. En los ensayos “in vitro” (Exp.4 i 5) se validaron los ensayos “in vivo” pero además se demostró como el efecto de Bioflavex® derivaba de la de sus componentes principales Naringina y Neohesperidina. Además, la presencia de flavonoides redujo la producción de gas y metano deprimiendo las concentración de arqueas metanogénicas. Finalmente, en el sexto ensayo, “in vivo”, (Exp. 6) el efecto de la mezcla comercial de flavonoides sobre la calidad de la canal, color y estabilidad de la grasa de 32 terneros frisones tuvo una mínima relevancia.A la tesis s’analitza l’efecte d’un extracte vegetal ric en flavonoides, Bioflavex® sobre la fermentació ruminal i la qualitat de la carn. A les probes “in vivo” (Exp. 1,2 i 3) i en condicions d’acidosis ruminal la presencia de Bioflavex® redueix els nivells d’acidosis, millora la taxa acètic/propiònic i la abundància de especies consumidores de lactat. Al assajos “in vitro” (Exp. 4 i 5) es validaren els resultats obtinguts “in vivo” però a més és demostrà com l’activitat de la mescla Bioflavex® derivava de la de llurs components principals Naringina i Neohesperidina. A més, la presencia de flavonoides reduí la producció de gas i la de metà al deprimir els títols de de arquees meta gèniques. Finalment, en un sisè assaig, “in vivo” l’efecte de la barreja comercial sobre la qualitat de la canal, color i estabilitat de la grassa en 32 vedells Frisons va tenir una escassa rellevància

The Impact of Genetics on Gut Microbiota of Growing and Fattening Pigs under Moderate N Restriction

Characterization of intestinal microbiota is of great interest due to its relevant impact on growth, feed efficiency and pig carcass quality. Microbial composition shifts along the gut, but it also depends on the host (i.e., age, genetic background), diet composition and environmental conditions. To simultaneously study the effects of producing type (PT), production phase (PP) and dietary crude protein (CP) content on microbial populations, 20 Duroc pigs and 16 crossbred pigs (F2), belonging to growing and fattening phases, were used. Half of the pigs of each PT were fed a moderate CP restriction (2%). After sacrifice, contents of ileum, cecum and distal colon were collected for sequencing procedure. Fattening pigs presented higher microbial richness than growing pigs because of higher maturity and stability of the community. The F2 pigs showed higher bacterial alpha diversity and microbial network complexity (cecum and colon), especially in the fattening phase, while Duroc pigs tended to have higher Firmicutes/Bacteroidetes ratio in cecum segment. Lactobacillus was the predominant genus, and along with Streptococcus and Clostridium, their relative abundance decreased throughout the intestine. Although low CP diet did not alter the microbial diversity, it increased interaction network complexity. These results have revealed that the moderate CP restriction had lower impact on intestinal microbiota than PP and PT of pigs.This research was a part of the Feed-a-Gene project and received funding from the European Union’s H2020 program under National Institutes of Health (grant number 633531), as well as Spanish National funding by the Spanish Ministry of Economy and Competitiveness (AGL2017-89289- R). L. Sarri is the recipient of a research training grant from the Generalitat de Catalunya-European Social Funds (2019 FI_B 00416)

Methanogenesis in animals with foregut and hindgut fermentation: a review

Methane is the main greenhouse gas contributor to global warming in the livestock sector; it is generated by anaerobic fermentation in the different sections of the gut, and differs significantly among species. Methane is only produced by a certain type of microorganisms called methanogens. The species composition of methanogenic archaea population is largely affected by the diet, geographical location, host and the section of the gut. Consequently, methane production, either measured as total grams emitted per day or per body weight mass, differs greatly between animal species. The main difference between methanogenic activity in different gut sections and animal species is the substrate fermented and the metabolic pathway to complete anaerobic fermentation of plant material. The three main substrates used by methanogens are CO2, acetate and compounds containing methyl groups. The three dominant orders of methanogens in gut environments are Methanomicrobiales, Methanobacteriales and Methanosarcinales. They normally are present in low numbers (below 3 % of total microbiome). This review will describe the main metabolic pathways and methanogens involved in CH4 production in the gut of different host animal, species, as well as discuss general trends that influence such emissions, such as geographical distribution, feed composition, section of the gut, host age and diurnal/season variation. Finally, the review will describe animal species (large and small domestic ruminants, wild ruminants, camelids, pigs, rabbits, horses, macropods, termites and humans) specificities in the methanogens diversity and their effects on methane emission.This work was supported by FEDER/Ministerio de Ciencia, Innovación yUniversidades - Agencia Estatal de Investigación (grant number AGL2017-89289) and European Union's H2020 program under National Institutes ofHealth (Feed-a-Gene, grant number 633531)