Uterine microbial profiles in healthy postpartum dairy cows do not vary with sampling techniques or phases of estrous cycle.

In this study, we aimed to compare uterine microbial profiles in postpartum dairy cows, determined by bacteriological culture and next-generation sequencing, using three uterine sampling techniques (swab, cytobrush, and lavage) and induced phases of the estrous cycle (estrus and diestrus). Fifteen healthy postpartum dairy cows at 53 ± 5 days postpartum were enrolled in the study. Uterine samples were collected during a fixed-time artificial insemination protocol.

Dynamics of pre- and post-insemination progesterone profiles and insemination outcomes determined by an in-line milk analysis system in primiparous and multiparous Canadian Holstein cows.

The objective was to evaluate in-line milk progesterone (mP4) data to determine dynamics of pre- and post-insemination mP4 profiles and their associations with parity and outcomes of artificial insemination (AI) in Holstein cows. Milk progesterone (ng/mL) was quantified at pre-determined time points before and after AI through an automated in-line milk analysis system (Herd Navigator™, DeLaval International, Tumba, Sweden). Only AI (∼d0; n = 605) preceded by an mP4-decline (at least two samples of mP4 ≥5 ng/mL followed by at least one sample <5 ng/mL; d-2) were evaluated.

Relationships among early postpartum luteal activity, parity, and insemination outcomes based on in-line milk progesterone profiles in Canadian Holstein cows.

The objectives of this retrospective study were to use in-line milk progesterone (mP4) data to investigate relationships of (1) commencement of luteal activity (CLA), and (2) luteal phase (LP) length and frequency preceding first postpartum AI, with parity and AI outcomes in Canadian Holstein cows. Starting 21 ± 1 days postpartum (DPP), levels of mP4 were assessed every 2.2 ± 2.

Effects of prepartum oilseed supplements on subclinical endometritis, pro- and anti-inflammatory cytokine transcripts in endometrial cells and postpartum ovarian function in dairy cows.

Postpartum uterine infections affect ovarian function and delay ovulation in cattle. As dietary fats can affect immune cell function, we investigated the influence of prepartum diets on postpartum uterine inflammatory status (UIS) as assessed 25±1 days postpartum by endometrial cytology (normal: ≤8% polymorphonuclear cells (PMN) vs subclinical endometritis (SCE): >8% PMN) and associations between SCE, pro- and anti-inflammatory cytokine gene expression and ovarian function. During the last 5 weeks of gestation, dairy cows received a diet supplemented with 8% rolled sunflower (n=10) or canola seed (n=9) or no oilseed (n=9).

Uterine Microbiota Progression from Calving until Establishment of Metritis in Dairy Cows.

The objective of this study was to evaluate the progression of the uterine microbiota from calving until establishment of metritis. Uterine swabs (n = 72) collected at 0, 2, and 6 ± 2 days postpartum (dpp) from 12 metritic and 12 healthy cows were used for metagenomic sequencing of the 16S rRNA gene on the Illumina MiSeq platform. A heat map showed that uterine microbiota was established at calving.

Low-dose natural prostaglandin F2α (dinoprost) at timed insemination improves conception rate in dairy cattle.

The primary objective was to determine if low doses of PGF2α (dinoprost) given intramuscularly (im) concurrent with timed artificial insemination (TAI) would improve conception rates in dairy cattle. A secondary objective was to determine if body condition score (BCS) and parity would influence conception rates, either independently or in interaction with PGF2α treatment. In experiment I, 307 lactating Holstein cows were randomly assigned to receive either 5-mg PGF2α im (PGF2α treated, n = 154) or 0-mg PGF2α (control, n = 153) at TAI (Day 0).