Long-term effects of early-life rumen microbiota modulation on dairy cow production performance and methane emissions

Abstract

Rumen microbiota modulation during the pre-weaning period has been suggested as means to affect animal performance later in life. In this follow-up study, we examined the post-weaning rumen microbiota development differences in monozygotic twin-heifers that were inoculated (T-group) or not inoculated (C-group) (n = 4 each) with fresh adult rumen liquid during their pre-weaning period. We also assessed the treatment effect on production parameters and methane emissions of cows during their 1st lactation period. The rumen microbiota was determined by the 16S rRNA gene, 18S rRNA gene, and ITS1 amplicon sequencing. Animal weight gain and rumen fermentation parameters were monitored from 2 to 12 months of age. The weight gain was not affected by treatment, but butyrate proportion was higher in T-group in month 3 (p = 0.04). Apart from archaea (p = 0.084), the richness of bacteria (p < 0.0001) and ciliate protozoa increased until month 7 (p = 0.004) and anaerobic fungi until month 11 (p = 0.005). The microbiota structure, measured as Bray–Curtis distances, continued to develop until months 3, 6, 7, and 10, in archaea, ciliate protozoa, bacteria, and anaerobic fungi, respectively (for all: p = 0.001). Treatment or age × treatment interaction had a significant (p < 0.05) effect on 18 bacterial, 2 archaeal, and 6 ciliate protozoan taxonomic groups, with differences occurring mostly before month 4 in bacteria, and month 3 in archaea and ciliate protozoa. Treatment stimulated earlier maturation of prokaryote community in T-group before month 4 and earlier maturation of ciliate protozoa at month 2 (Random Forest: 0.75 month for bacteria and 1.5 month for protozoa). No treatment effect on the maturity of anaerobic fungi was observed. The milk production and quality, feed efficiency, and methane emissions were monitored during cow’s 1st lactation. The T-group had lower variation in energy-corrected milk yield (p < 0.001), tended to differ in pattern of residual energy intake over time (p = 0.069), and had numerically lower somatic cell count throughout their 1st lactation period (p = 0.081), but no differences between the groups in methane emissions (g/d, g/kg DMI, or g/kg milk) were observed. Our results demonstrated that the orally administered microbial inoculant induced transient changes in early rumen microbiome maturation. In addition, the treatment may influence the later production performance, although the mechanisms that mediate these effects need to be further explored.

Fecal microbiota colonization dynamics in dairy heifers associated with early-life rumen microbiota modulation and gut health

“…Starting from the 2nd week after birth to the end of the pre-weaning period, one calf from each pair was given an oral dose of adult cow rumen liquid. The results demonstrated that the inoculum stimulated earlier maturation of rumen bacterial ecosystem in treated calves before and after weaning, with additional positive effect observed on the growth in young animals ( Huuki et al, 2022a , b ). Later, the same animals were followed up during their first lactation period, where differences between the groups were observed in residual energy intake and milk yield at different phases of lactation among others ( Huuki et al, 2022b ).…”

“…The results demonstrated that the inoculum stimulated earlier maturation of rumen bacterial ecosystem in treated calves before and after weaning, with additional positive effect observed on the growth in young animals ( Huuki et al, 2022a , b ). Later, the same animals were followed up during their first lactation period, where differences between the groups were observed in residual energy intake and milk yield at different phases of lactation among others ( Huuki et al, 2022b ). As the colonization routes of the rumen and hindgut are interconnected, our next objective was to elucidate if early-life rumen microbiota modulation also affected the colonization and development of the colonic microbiota or had beneficial effect on gut health in young animals.…”

“…The bull calves were removed from the experiment after weaning. Management and feeding of heifers during the post-weaning period are described in detail by Huuki et al (2022b) .…”

“…The quantities of bacteria, archaea, and anaerobic fungi were estimated with qPCR by quantifying rRNA/ITS1 gene copy numbers of each taxonomic group in 1 ng of extracted DNA. The quantitation was performed as described by Huuki et al (2022b) .…”

Life at the borderlands: microbiomes of interfaces critical to One Health

“…Ciliate and flagellate protozoa appear later in the development, around 15 days after birth, and are transferred from animal to animal through saliva (Li et al 2023 ). Therefore, the first weeks of a ruminant’s life provide a window of opportunity to influence microbial colonization in the rumen to support better feed utilization, decrease methane production and optimize overall health (Yáñez-Ruiz et al 2015 , Huuki et al 2022 ).…”