Background:The greatest impact on profitability of a commercial beef operation is reproduction.However,in beef heifers,little is known about the vaginal and fecal microbiota with respect to their relationship with fer...Background:The greatest impact on profitability of a commercial beef operation is reproduction.However,in beef heifers,little is known about the vaginal and fecal microbiota with respect to their relationship with fertility.To this end,we followed heifers through gestation to examine the dynamics of vaginal and fecal microbial composition throughout pregnancy.Results:Heifers were exposed to an estrus synchronization protocol,observed over a 12-day period,artificially inseminated 12 h to 18 h after observed estrus,and subsequently exposed to bulls for a 50-day breeding season.Vaginal samples were taken at pre-breeding(n=72),during the first(n=72),and second trimester(n=72)for all individuals,and third trimester for individuals with confirmed pregnancies(n=56).Fecal samples were taken at prebreeding(n=32)and during the first trimester(n=32),including bred and open individuals.Next generation sequencing of the V4 region of the 16 S rRNA gene via the Illumina Mi Seq platform was applied to all samples.Shannon indices and the number of observed bacterial features were the same in fecal samples.However,significant differences in vaginal microbiome diversity between gestation stages were observed.No differences in beta-diversity were detected in vaginal or fecal samples regarding pregnancy status,but such differences were seen with fecal microbiome over time.Random Forest was developed to identify predictors of pregnancy status in vaginal(e.g.,Histophilus,Clostridiaceae,Campylobacter)and fecal(e.g.,Bacteroidales,Dorea)samples.Conclusions:Our study shows that bovine vaginal and fecal microbiome could be used as biomarkers of bovine reproduction.Further experiments are needed to validate these biomarkers and to examine their roles in a female’s ability to establish pregnancy.展开更多
This study evaluated Anti-Mullerian hormone (AMH) and/or follicle counts as predictors of subsequent superovulatory response and embryo production in 79 beef cows. Before superovulation, 3 to 5 mm follicles presented ...This study evaluated Anti-Mullerian hormone (AMH) and/or follicle counts as predictors of subsequent superovulatory response and embryo production in 79 beef cows. Before superovulation, 3 to 5 mm follicles presented on the ovaries of donor cows were counted, and blood was collected for measure of serum AMH. Across cows, serum AMH ranged from 0.013 to 0.898 ng/mL, with a mean of 0.293 ng/mL. The distribution of both AMH concentrations and follicle counts were divided into quartiles (AMH Q1 through Q4, with Q1 the lowest and Q4 the highest) for analysis. Donor cows in AMH Q4 had a greater (P < 0.001) number of 3 to 5 mm follicles at the start of superovulation than did donors in either Q1 or Q2. At embryo collection, cows in AMH Q3 and 4 had more (P < 0.001) palpable corpora lutea (CL) than cows in AMH Q1. The mean number of embryos recovered from donor cows in AMH Q4 was greater (P < 0.001) than those recovered from cows in either AMH Q1 or 2, but similar to that of AMH Q3. Analysis indicated that AMH was positively correlated (P < 0.001) with mean follicles (r = 0.458), CL (r = 0.452) and embryos recovered (r = 0.430). Donor cows with higher follicle counts (F Q3 and 4) at the start of superovulation had more (P < 0.001) palpable CL at embryo collection than donor cows in F Q1 or 2. More (P < 0.001) embryos were recovered from cows with the highest follicle counts (F Q4) as compared with cows having lower (F Q1 and 2) follicle counts. Results confirm that relative AMH concentration was positively correlated with number of small antral follicles in the ovaries of cows;both AMH measure and antral follicle counts might be used to predict subsequent superovulatory response in beef cows.展开更多
Cattle in some parts of the world graze pastures that consist of tall fescue that may contain ergot alkaloid contamination. Those ergot alkaloids are associated with reduced reproductive rates in cattle. Our objective...Cattle in some parts of the world graze pastures that consist of tall fescue that may contain ergot alkaloid contamination. Those ergot alkaloids are associated with reduced reproductive rates in cattle. Our objective was to determine if ergot alkaloids [dihydroergotamine (DHET), ergonovine (EN), and ergotamine (ET)] directly affect bovine sperm characteristics. Spermatozoa were collected from mature Angus (n = 2) and Balancer (n = 4) bulls. Within bull, treatments were structured as a 3 × 5 factorial with three alkaloids (DHET, EN, and ET) and five concentrations of each alkaloid (0, 33, 66, 100, or 200 μM). Spermatozoa (25 × 106) were incubated (39?C) in 1 mL of modified sperm medium. Sperm motility characteristics were evaluated using CASA (Hamiliton Thorne IVOS, Beverly, MA) at 0, 3, and 6 h after initial alkaloid exposure. Initial sperm motility was (69% ± 1.1%) and declined (P = 0.01) to (35% ± 2.6%) at 6 h. Sperm motility decreased (P P < 0.05) both characteristics. Our results demonstrate that ergot alkaloids (ET and DHET) can directly alter bovine sperm motility and morphology, which adds to our understanding of how ergot alkaloids may hinder cattle reproductive rates.展开更多
基金supported by the China Scholarship Council(CSC)Scholarship.
文摘Background:The greatest impact on profitability of a commercial beef operation is reproduction.However,in beef heifers,little is known about the vaginal and fecal microbiota with respect to their relationship with fertility.To this end,we followed heifers through gestation to examine the dynamics of vaginal and fecal microbial composition throughout pregnancy.Results:Heifers were exposed to an estrus synchronization protocol,observed over a 12-day period,artificially inseminated 12 h to 18 h after observed estrus,and subsequently exposed to bulls for a 50-day breeding season.Vaginal samples were taken at pre-breeding(n=72),during the first(n=72),and second trimester(n=72)for all individuals,and third trimester for individuals with confirmed pregnancies(n=56).Fecal samples were taken at prebreeding(n=32)and during the first trimester(n=32),including bred and open individuals.Next generation sequencing of the V4 region of the 16 S rRNA gene via the Illumina Mi Seq platform was applied to all samples.Shannon indices and the number of observed bacterial features were the same in fecal samples.However,significant differences in vaginal microbiome diversity between gestation stages were observed.No differences in beta-diversity were detected in vaginal or fecal samples regarding pregnancy status,but such differences were seen with fecal microbiome over time.Random Forest was developed to identify predictors of pregnancy status in vaginal(e.g.,Histophilus,Clostridiaceae,Campylobacter)and fecal(e.g.,Bacteroidales,Dorea)samples.Conclusions:Our study shows that bovine vaginal and fecal microbiome could be used as biomarkers of bovine reproduction.Further experiments are needed to validate these biomarkers and to examine their roles in a female’s ability to establish pregnancy.
文摘This study evaluated Anti-Mullerian hormone (AMH) and/or follicle counts as predictors of subsequent superovulatory response and embryo production in 79 beef cows. Before superovulation, 3 to 5 mm follicles presented on the ovaries of donor cows were counted, and blood was collected for measure of serum AMH. Across cows, serum AMH ranged from 0.013 to 0.898 ng/mL, with a mean of 0.293 ng/mL. The distribution of both AMH concentrations and follicle counts were divided into quartiles (AMH Q1 through Q4, with Q1 the lowest and Q4 the highest) for analysis. Donor cows in AMH Q4 had a greater (P < 0.001) number of 3 to 5 mm follicles at the start of superovulation than did donors in either Q1 or Q2. At embryo collection, cows in AMH Q3 and 4 had more (P < 0.001) palpable corpora lutea (CL) than cows in AMH Q1. The mean number of embryos recovered from donor cows in AMH Q4 was greater (P < 0.001) than those recovered from cows in either AMH Q1 or 2, but similar to that of AMH Q3. Analysis indicated that AMH was positively correlated (P < 0.001) with mean follicles (r = 0.458), CL (r = 0.452) and embryos recovered (r = 0.430). Donor cows with higher follicle counts (F Q3 and 4) at the start of superovulation had more (P < 0.001) palpable CL at embryo collection than donor cows in F Q1 or 2. More (P < 0.001) embryos were recovered from cows with the highest follicle counts (F Q4) as compared with cows having lower (F Q1 and 2) follicle counts. Results confirm that relative AMH concentration was positively correlated with number of small antral follicles in the ovaries of cows;both AMH measure and antral follicle counts might be used to predict subsequent superovulatory response in beef cows.
文摘Cattle in some parts of the world graze pastures that consist of tall fescue that may contain ergot alkaloid contamination. Those ergot alkaloids are associated with reduced reproductive rates in cattle. Our objective was to determine if ergot alkaloids [dihydroergotamine (DHET), ergonovine (EN), and ergotamine (ET)] directly affect bovine sperm characteristics. Spermatozoa were collected from mature Angus (n = 2) and Balancer (n = 4) bulls. Within bull, treatments were structured as a 3 × 5 factorial with three alkaloids (DHET, EN, and ET) and five concentrations of each alkaloid (0, 33, 66, 100, or 200 μM). Spermatozoa (25 × 106) were incubated (39?C) in 1 mL of modified sperm medium. Sperm motility characteristics were evaluated using CASA (Hamiliton Thorne IVOS, Beverly, MA) at 0, 3, and 6 h after initial alkaloid exposure. Initial sperm motility was (69% ± 1.1%) and declined (P = 0.01) to (35% ± 2.6%) at 6 h. Sperm motility decreased (P P < 0.05) both characteristics. Our results demonstrate that ergot alkaloids (ET and DHET) can directly alter bovine sperm motility and morphology, which adds to our understanding of how ergot alkaloids may hinder cattle reproductive rates.
