Horses with two different metabolic tendencies are referred to as
“easy keepers” (EK) or “hard keepers” (HK). These tendencies
are anecdotal and often related to the Henneke Body Condition Scoring
system. EK tends to be over-conditioned (BCS ≥ 6) and HK need extra
feed to maintain a BCS of 5. “Medium keepers” (MK) can maintain a
BCS of 5 easily. This lab group has developed the Equine Keeper
Status Scale (EKSS) and the objective of this work is to compare the
microbiome composition of the three keeper statuses between owner
reported keeper statuses (ORKS) and EKSS assignments. Fresh fecal
samples from 73 horses were collected for 16S rRNA profiling. ORKS
were obtained by a verbal estimate of their horse’s keeper status
in regard to their metabolic tendencies with no influence of the
research team (ORKS: EK, n=20; MK, n=26; HK, n = 27). Feed weights
and BCS scores of each horse were collected and digestible energy
intakes were estimated by FeedXL software (input variables of the
EKSS) and EKSS assignments were determined at a later time (EK, n=31;
MK, n = 22; HK, n=20). QIIME2 (Quantitative Insights Into
Microbial Ecology, v. 2020.8) R was used for data processing and
analysis. α diversity Shannon-Weaver measures between ORKS groups
were not found (P = 0.34) but were found after EKSS evaluation
(P = 0.06) and Tukey’s pairwise tests found the difference
between EK and MK to be the most different (P < 0.05). β
diversity weighted Unifrac measures of ORKS found group centroids
were different (P = 0.07) but it wasn’t due to ORKS (P
= 0.58); while EKSS evaluation found different centroids due to EKSS
(P = 0.02, P = 0.03, respectively). Spearman
correlation testing identified bacteria correlated with every keeper
status except ORKS MK which is likely due to the inconsistencies of
ORKS. Differential abundance testing performed with ANCOM identified
4 phyla differences (Planctomycetes, Euryarchaeota, Spirochaetes,
Proteobacteria) between EKSS groups but not between ORKS.
Planctomycetes thrive in low nutrient environments and are most
abundant in EK. HK appears to have optimized starch fermentation
characteristics due to higher abundances of the methane producers
(Euryarcheaota), and denitrifying (Spirochaetes), and N oxidizers
(Proteobacteria). The EKSS removes the objectivity and reliance on
ORKS and with the more clearly defined EKSS keeper groups we
demonstrate we are able to identify structural differences in the
microbiomes of EK and HK horses and how it relates to metabolism.
p { margin-bottom: 0.1in; direction: ltr; line-height: 115%; text-align: left; orphans: 2; widows: 2; background: transparent }p.western { font-family: "Times New Roman", serif }p.cjk { font-family: "Times New Roman" }p.ctl { font-family: "Times New Roman" }
…Read more
Less…