Khanam, A. | Search bioRxiv

bioRxiv2023

Relationship between luteal size and plasma progesterone concentration in pregnant and non-pregnant Indian crossbred dairy cows

The relationship between luteal size and plasma progesterone concentration in purebred cows has been investigated previously. However, there is limited information on this topic in Indian crossbred cows. This study aimed to evaluate the relationship between luteal size parameters (diameter and area) and plasma progesterone concentration in healthy pregnant and non-pregnant Indian crossbred cows. Fifty healthy lactating crossbred cows were artificially inseminated after estrus detection and retrospectively classified into pregnant (n=29) and non-pregnant (n=21) based on the results of ultrasonographic pregnancy diagnosis. Data on luteal diameter, luteal area, and plasma progesterone concentration collected on Days 7, 14, and 20 in non-pregnant cows and on Days 7, 14, 20, 25, 30, 35, 40, and 60 in pregnant cows were analyzed. Spearmans correlation test was used to evaluate the association between the corpus luteum size parameters and the plasma progesterone concentration. Luteal area was positively correlated with plasma progesterone concentration in both pregnant ({rho}=0.48, P<0.001) and non-pregnant ({rho}=0.43, P=0.001) cows. Luteal diameter had a relatively weaker correlation with plasma progesterone concentration in both pregnant ({rho}=0.45, P<0.001) and non-pregnant ({rho}=0.24, P=0.058) cows. These results suggest that luteal area is a better indicator of CL function than luteal diameter in healthy Indian crossbred cows.

physiology↗

bioRxiv2022

Metagenomic analysis unravels novel taxonomic differences in the uterine microbiome between healthy mares and mares with endometritis

The application of high throughput technologies has enabled unravelling of unique differences between healthy mares and mares with endometritis at transcriptomic and proteomic levels. However, differences in the uterine microbiome are yet to be investigated. The present study was aimed at evaluating the differences in uterine microbiome between healthy mares and mares with endometritis. Low-volume lavage (LVL) samples were collected from the uterus of 30 mares classified into healthy (n=15) and endometritis (n=15) based on their reproductive history, intrauterine fluid accumulation, gross appearance of LVL samples, endometrial cytology, and bacterial culture. The samples were subjected to metagenomic analysis using 16S rRNA sequencing. Notable differences in the uterine microbiome were observed between healthy mares and mares with endometritis at various taxonomic levels. In healthy mares, the most abundant phylum, class, order, and family were Firmicutes, Bacilli, Bacillales, and Paenibacillaceae, respectively. In contrast, the most abundant corresponding taxonomic levels in mares with endometritis were Proteobacteria, Gammaproteobacteria, Enterobacterales, and Enterobacteriaceae, respectively. At the genus level, Brevibacillus and Paenibacillus were more abundant in healthy mares, whereas Escherichia, Salmonella, and Klebsiella were more abundant in mares with endometritis. In healthy mares, Brevibacillus brevis was the most abundant species, followed by Brevibacillus choshinensis and Paenibacillus sp JDR-2. However, in mares with endometritis, Escherichia coli was the most abundant species, followed by Salmonella enterica and Klebsiella pneumoniae. These results indicate novel differences in the uterine microbiome between healthy mares and mares with endometritis. The findings can potentially help formulate new approaches to prevent or treat equine endometritis.

genomics↗