Effect of olive and date palm by-products on rumen methanogenic community in Barki sheep

Abstract

<abstract> <p>Rumen methanogens prevent the accumulation of fermentation gases in the rumen and generate methane that increases global warming and represents a loss in animals' gross energy. Non-traditional feed resources such as the by-products of date palm (<italic>Phoenix dactylifera</italic>) and olive (<italic>Olea europaea</italic>) trees have received attention to be used in animal feeding. This study evaluated the impact of non-traditional feed resources including olive cake (OC), discarded dates (DD), and date palm frond (DPF) in sheep diet on rumen fermentation, diversity and relative abundance of rumen methanogens. Nine adult rams were assigned to three equal groups and fed three diets: traditional concentrates mixture (S1); non-traditional concentrate mixture (S2) based on DD and OC; and (S3) composed of the same S2 concentrate supplemented with DPF as a roughage part. The results showed that rumen pH was higher with S3 diet than the other two diets. However, the S1 diet showed the highest values of total volatile fatty acids (TVFA) and rumen ammonia. In addition, the proportions of acetic and butyric acids were increased, whereas propionic acid declined in S2 and S3 compared to the S1 diet. Rumen methanogens were dominated by <italic>Methanobrevibacter</italic> that showed a numeric decline by including DD, OC, and DPF in the animal diets. Principal component analysis (PCA) based on rumen fermentation parameters and relative abundances of methanogens genera showed three distinct clusters. Also, positive and negative correlations were revealed between methanogens genera and rumen metabolites. This study expands the knowledge regarding the effect of agricultural byproducts on rumen fermentation and the methanogenic community.</p> </abstract>

Composition of the rumen archaeal community of growing camels fed different concentrates levels

“…Therefore understanding the effect of different animal diet on the rumen methanogens in different animal species progresses the global efforts to cut methane emission and improve of livestock sector. Concentrate level impact the ber to starch ratio, consequently, it impacted the animal feed intake, volatile fatty acids, and the relative abundance of the dominant methanogenic genera, which in the same line with the ndings of previous studies on feedlot bulls and sheep (Popova et al 2011;Rabee et al 2022). However, no available data on the effect of concentrates level on the methanogenic community in dromedary camels.…”

“…Zhang et al (2017), on the other hand, investigated the effect of forage-to-concentrate ratios on rumen methanogen changes in Holstein heifers and discovered that the methanogenic community was dominated by the genus Methanobrevibacter and the relative abundances of rumen methanogenic genera were not signi cantly affected by dietary concentrate levels. Rabee et al (2022) showed a small decrease in the relative abundance of the genus Methanobrevibacter in sheep diets as a result of the substitution of concentrate feed combination with date palm byproducts and olive cake. According to Vaidya et al (2020), silage type (grass or maize silage) was positively linked with the abundance of the species Methanobrevibacter and Methanosphaera.…”

“…Askar et al (2023) reported the effect of concentrate supplement levels on the rumen bacterial community in growing camels. In addition, the effect of concentrate level and diet composition on rumen methanogens in other ruminants has been well-documented (Zhang et al, 2017;Vaidya et al, 2020;Rabee et al, 2022). However, the effect of concentrate level in the diet on the community of rumen methanogens in growing camels has not yet been reported.…”

Rumen fermentation and microbiota in Shami goats fed on condensed tannins or herbal mixture

“…Additionally, rumen archaea uses fermentation gases such as hydrogen (H 2 ) and carbon dioxide (CO 2 ) besides methyl group derived from acetic acid, and format to generate methane (CH 4 ) [ 5 ]. Methane represents a 2–12% loss of the gross energy feed intake of host animal and it is one of the main reasons for climate change [ 5 , 6 ]. Rumen methanogens interact with H 2 producers and utilizers; therefore, modifying rumen microbial ecosystem is a main target for studies that aim to improve animal efficiency and decrease methane emission [ 5 , 7 ].…”

Influence of olive cake dietary supplementation on fecal microbiota of dairy cows

“…Recent evidence suggests that the use of olive by-products did not negatively impact nutrients utilization, microbiota composition, and rumen fermentation variables, such as pH, ammonia and volatile fatty acids (VFA) concentrations ( Ruiz et al, 2004 ; Estaún et al, 2014 ; Pallara et al, 2014 ; Tzamaloukas et al, 2021 ). Differently by influencing the ruminal fermentation and the rumen pH, the increase of the content of linoleic acid, in both milk and meat, as well as change in the aromatic and microbiological profiles of milk are reported ( Chiofalo V. et al, 2020 ; Liotta et al, 2020 ; Foti et al, 2021 ; Tzamaloukas et al, 2021 ; Rabee et al, 2022 ). In fact, the high polyphenol content could modulate the rumen microbiota biodiversity and, consequently, affect the rumen metabolism, decreasing dietary protein degradation and fatty acid biohydrogenation by means of targeting specific groups of microorganisms ( Mannelli et al, 2018 ; Biondi et al, 2019 ; Milani et al, 2020 ).…”