tRNA^(Glu)-derived fragments from embryonic extracellular vesicles modulate bovine embryo hatching

Transfer RNA-derived small RNAs(tsRNAs)have been shown to be involved in early embryo development and repression of endogenous retroelements in embryos and stem cells.However,it is unknown whether tsRNAs also regulate embryo hatching.In this study,we mined the sequencing data of a previous experiment in which we demonstrated that the microRNA(miRNA)cargo of preimplantation embryonic extracellular vesicles(EVs)influences embryo development.We thus profiled the tsRNA cargo of EVs secreted by blastocysts and non-blastocysts.The majority of tsRNAs was identified as tRNA halves originating from the 5'ends of tRNAs.Among the 148 differentially expressed tsRNAs,the 19 nt tRNA fragment(tRF)tDR-14:32-Glu-CTC-1 was found to be significantly up-regulated in EVs derived from non-blastocysts.RT-qPCR assays confirmed its significant up-regulation in non-blastocyst embryos and their conditioned medium compared to the blastocyst group(P<0.05).Inhibition of tDR-14:32-Glu-CTC-1 by supplementing antagomirs to the conditioned medium improved embryo hatching(P<0.05).Transcriptomic analysis of embryos treated with tDR-14:32-Glu-CTC-1 antagomirs further showed differential expression of genes that are associated with embryo hatching and implantation.In summary,tDR-14:32-Glu-CTC-1 is up-regulated in non-blastocyst embryos and their secretions,and inhibition of tDR-14:32-Glu-CTC-1 promotes embryo hatching,while influencing embryo implantation-related genes and pathways.These results indicate that embryonic EVs containing specific tRFs may regulate preimplantation embryo development.

Supplementing oat hulls to the diet of suckling piglets altered their intestinal tract and colonic microbiota development

Current study evaluated the effect of a fine and coarsely ground insoluble dietary fibre source on the gastrointestinal development of suckling pigs.Oat hulls(OH)were selected as a model feedstuff,rich in cellulose,lignin,and insoluble dietary fibre.Three experimental supplemental diets were formulated:a finely ground,low fibre and nutrient dense diet served as control(CON).For the 2 high fibre diets,15%heat-treated starch in CON was exchanged with OH,either finely(OH-f)or coarsely ground(OH-c).Litters of 10 primi-and multiparous sows(mean litter size 14.6±0.84)were used.Within a litter,experimental diets were allotted to triplets of 4 piglets.From approximately 12 d of age,piglets’individual feed intakes were recorded 2 times per day when separated from their dam for 70 min.Piglets could suckle with their dam for the remainder of the day.On d 24 and 25,from the total pool of 120 piglets,seven healthy well-eating piglets per treatment were selected for post-mortem evaluation,resulting in 14 replicates per treatment.Consumption of OH-c and OH-f did not impede clinical health and production performance of piglets.The full stomach weights tended to be greater for OH-c compared to OH-f whereas CON was intermediate(P=0.083).Supplementing OH significantly increased ileal villus height and caecal dry matter concentration(P<0.05).For the colon,OH increased its length,contents weight,short-chain fatty acid concentration and reduced total bacterial count as well asγ-proteobacteria count and proportion(P<0.05).The OH-c treatment specifically increased full gastrointestinal tract weight and caecum contents weight compared to piglets fed CON and OH-f.Furthermore,OH-c reduced colonic crypt depth when compared to OH-f(P=0.018).In conclusion,supplementing OH to a diet for suckling piglets exerted subtle developmental effects on gastrointestinal morphology and colonic microbial community.These effects were largely independent from the particle size of the OH.

Does feeding more phases reduce ammonia concentrations from broiler litter?

We compared a 3-and 5-phase feeding program in terms of ammonia concentrations measured at litter level,litter composition and quality,nitrogen(N)utilization,performance,welfare,and meat deposition in broilers.A total of 744 Ross 308 male broilers was divided into 2 treatments,each with 6 replicates.The 3-phase diets were formulated to CP and digestible lysine contents of 205 and 11.5 g/kg(0 to 9 d),195 and 10.8 g/kg(9 to 24 d),and 183.3 and 10.15 g/kg(24 to 39 d),respectively.The 5-phase diets had additional phases from 17 to 24 d and 32 to 39 d with CP and digestible lysine contents of 188 and 10.4 g/kg and 177 and 9.8 g/kg,respectively.Feeding 5 phases reduced the NH3concentrations at litter level by37.95%and 20.81%at 23(P<0.05)and 37 d of age(P<0.05),respectively.There was a tendency for a lower litter total ammoniacal nitrogen concentration for the 5-phase treatment than the 3-phase treatment at 24 and 39 d of age(P<0.1 for both).Total N concentration of the litter also tended to be lower for the 5-phase treatment at 39 d of age(P<0.1).The lower NH3coincided with a lower average litter pH at 24 and 32 d of age(P<0.05 for both).Birds fed the 5-phase treatments had a lower incidence of foot lesions at 24 d of age(P<0.001).Performance as well as carcass yield could be maintained,except for FCR,which was higher for the 5-phase treatment between 17 and 24 d of age and the overall period(P<0.05 and<0.001,respectively).The impact of the 5-phase treatment regarding the utilization of N(digestibility,excretion,and retention)was less clear,however the NH3volatilized from the litter was significantly reduced.Feeding 5 phases may therefore potentially reduce the NH3emitted from broiler houses which has several environmental and health benefits.Although the 5-phase treatment resulted in a significant decrease in feed efficiency,growth performance and meat deposition were maintained.