The objectives of this experiment were to determine the speed at which cows that had their estrous cycle presynchronized with a GnRH or PGF(2α) injection are reinseminated and become pregnant. Furthermore, this experiment aimed to determine whether treatment with a controlled internal drug-releasing (CIDR) insert during the timed artificial insemination (AI) protocol improves pregnancy per AI (P/AI) of cows that had their estrous cycle presynchronized with GnRH or PGF(2α). Lactating cows from 2 herds were assigned to 1 of 2 presynchronization treatments at 32 ± 4 d after AI: GGPG (n=452)--GnRH injection at enrollment (d 0), 7d before the start of the timed AI protocol, and P11GPG (n=466)--PGF(2α) injection on d 3, 11 d before the start of the timed AI protocol. Cows observed in estrus at any interval after enrollment were reinseminated on the same day. Cows not observed in estrus by d 7 were paired by presynchronization treatment and assigned to receive or not receive a CIDR insert during the timed AI protocol (CIDR = 240, no CIDR = 317). Timed AI protocols were the Ovsynch56 at site A and the Cosynch48 at site B. A subsample of cows from site A had their ovaries scanned by ultrasound at enrollment and on the day of the first GnRH and PGF(2α) injections of the timed AI protocol and had blood sampled at each injection of the timed AI protocol for determination of progesterone concentration. Cows were examined for pregnancy 32 ± 4 and 67 ± 4 d after reinsemination. Cows in the P11GPG treatment had a faster reinsemination rate [adjusted hazard ratio = 1.24 (95% CI = 1.07, 1.45)] and were less likely to be submitted to the timed AI protocol (40.3 vs. 89.8%) and to be reinseminated at a fixed time (38.6 vs. 83.9%). The interval from enrollment to reinsemination was shorter for cows in the P11GPG group (13.0 ± 0.4 vs. 15.0 ± 0.2d). Presynchronization treatment did not affect P/AI 32 ± 4 d (GGPG = 42.3%, P11GPG = 39.3%) and 67 ± 4 d (GGPG = 37.0%, P11GPG = 35.4%) after reinsemination. Pregnancy rate from d 0 to 7 (GGPG = 3.6%, P11GPG = 17.7%) and from d 8 to 14 (GGPG = 1.6%, P11GPG = 5.7%) were greater for cows in the P11GPG treatment. Treatment with the CIDR insert during the timed AI protocol did not affect P/AI 32 ± 4 d (CIDR = 41.7%, no CIDR = 41.4%) and 67 ± 4 d (CIDR = 36.5%, no CIDR = 35.3%) after reinsemination. A greater percentage of cows in the GGPG treatment had progesterone concentration ≥ 1 ng/mL on the day of the first GnRH injection of the timed AI protocol (83.8 vs. 51.5%), but a greater percentage of cows in the P11GPG treatment ovulated in response to the first GnRH injection of the timed AI protocol (66.1 vs. 46.8%). We conclude that the P/AI of cows that had their estrous cycle presynchronized with GnRH or PGF(2α) was not different, but in herds with adequate estrous detection efficiency and accuracy, presynchronization with PGF(2α) may reduce the interval to the establishment of pregnancy.

The objectives of the current experiment were to determine the effect of 2 prepartum grouping strategies on the health, metabolic, reproductive, and productive parameters of dairy cows. Jersey cows enrolled in the experiment at 253±3 d of gestation (d 0=calving) were balanced for parity and projected 305-d mature equivalent and assigned to 1 of 2 treatments. Cows assigned to the traditional (TRD; n=6 replicates with a total of 308 cows) treatment were moved to the study pen as a group of 44 cows and weekly thereafter groups of 2 to 15 cows were moved to the study pen to reestablish stocking density. Cows assigned to the all-in-all-out (AIAO; n=6 replicates with a total of 259 cows) treatment were moved to the study pen in groups of 44 cows, but no new cows entered the AIAO pen until the end of the replicate. At the end of each replicate, a new TRD and AIAO group started but pens were switched. Cows were milked thrice daily and monthly milk yield, fat and protein contents, and somatic cell count data were recorded up to 305 d postpartum. Plasma nonesterified fatty acid concentration was measured weekly from d -18±3 to 24±3 and plasma β-hydroxybutyrate was measured weekly from d 3±3 to 24±3. Cows were examined on d 1, 4±1, 7±1, 10±1, and 13±1 for diagnosis of uterine diseases and had their ovaries scanned by ultrasound on d 39±3 and 53±3 to determine resumption of ovarian cycles. Average stocking density was reduced for the AIAO (71.9%) treatment compared with the TRD (86.9%) treatment. Treatment did not affect the incidences of retained fetal membranes (TRD=10.9, AIAO=11.6%), metritis (TRD=16.7, AIAO=19.8%), and acute metritis (TRD=1.7, AIAO=3.6%). Concentrations of nonesterified fatty acids (TRD=80.4±8.2, AIAO=62.9±8.5 µmol/L) and β-hydroxybutyrate (TRD=454.4±10.9, AIAO=446.1±11.1 µmol/L) were not different between treatments. Percentages of cows that resumed ovarian cycles by d 39±3 (TRD=70.8, AIAO=63.1%) and 53±3 (TRD=90.1, AIAO=90.2%) were not different between treatments. Similarly, treatment had no effect on rate of removal from the herd {TRD=referent, AIAO [(adjusted hazard ratio (95% confidence interval)]=0.85 (0.63, 1.15)} or rate of pregnancy [TRD=referent, AIAO=1.07 (0.88, 1.30)]. Finally, treatment did not affect energy-corrected milk yield (TRD=34.4±0.6, AIAO=34.3±0.7 kg/d). In conditions of adequate feed bunk space, the AIAO treatment did not improve health, metabolic, reproductive, or productive parameters compared with the TRD treatment.

Objectives were to evaluate the effects of a stable prepartum grouping strategy on innate immune parameters, antibody concentration, and cortisol and haptoglobin concentrations of Jersey cows. Cows (253±3 d of gestation) were paired by gestation length and assigned randomly to the stable (all-in-all-out; AIAO) or traditional (TRD) treatment. In the AIAO treatment, groups of 44 cows were moved into a pen where they remained for 5 wk, whereas in the TRD treatment, approximately 10 cows were moved into a pen weekly to maintain stocking density (44 cows for 48 headlocks). Pens were identical in size and design and each pen received each treatment a total of 3 times (6 replicates; AIAO, n=259; TRD, n=308). A subgroup of cows (n=34/treatment) was selected on wk 1 of each replicate from which blood was sampled weekly from d -14 to 14 (d 0=calving) to determine polymorphonuclear leukocyte (PMNL) phagocytosis, oxidative burst, and expression of CD18 and L-selectin, hemogram, cortisol and glucose concentrations, and haptoglobin concentration. Another subgroup of cows (n=40/treatment) selected on wk 1 of each replicate was treated with chicken egg ovalbumin on d -21, -7, and 7 and had blood sampled weekly from d -21 to 21 for determination of immunoglobulin G anti-ovalbumin. All cows (n=149) had blood sampled weekly for nonesterified fatty acid (NEFA) and β-hydroxybutyrate (BHBA) concentrations from d -21 to 21. Treatment did not affect percentage of PMNL positive for phagocytosis and oxidative burst (AIAO=64.3±2.9 vs. TRD=64.3±2.9%) and intensity of phagocytosis [AIAO=2,910.82±405.99 vs. TRD=2,981.52±406.87 geometric mean fluorescence intensity (GMFI)] and oxidative burst (AIAO=7,667.99±678.29 vs. TRD=7,742.70±682.91 GMFI). Similarly, treatment did not affect the percentage of PMNL expressing CD18 (AIAO=96.3±0.7 vs. TRD=97.8±0.7%) and L-selectin (AIAO=44.1±2.8 vs. TRD=45.1±2.8%) or the intensity of expression of CD18 (AIAO=3,496.2±396.5 vs. TRD=3,598.5±396.9 GMFI) and L-selectin (AIAO=949.8±22.0 vs. TRD=940.4±22.3 GMFI). Concentration of immunoglobulin G anti-ovalbumin was not affected by treatment (AIAO=0.98±0.05 vs. TRD=0.98±0.05 OD). The percentage of leukocytes classified as granulocyte (AIAO=38.9±1.5 vs. TRD 38.2±1.5%) and the granulocyte:lymphocyte ratio (AIAO=0.75±0.04 vs. TRD=0.75±0.04) were not affected by treatment. Concentrations of cortisol (AIAO=14.95±1.73 vs. TRD=18.07±1.73 ng/mL), glucose (AIAO=57.6±1.5 vs. TRD=60.0±1.5 ng/mL), and haptoglobin (AIAO=3.09±0.48 vs. TRD=3.51±0.49 OD) were not affected by treatment. According to the current experiment, a stable prepartum grouping strategy does not improve innate immune parameters or antibody concentration compared with weekly prepartum regrouping.

The objectives of the current experiment were to evaluate the effects of intrauterine infusion of Escherichia coli lipopolysaccharide (LPS) in cows diagnosed with purulent vaginal discharge (PVD) on intrauterine cell population, resolution of PVD, uterine health, and reproductive performance. Jersey cows (n = 3,084) were examined using the Metricheck device to diagnose PVD at 35 ± 6 d postpartum. Purulent vaginal discharge was defined as the presence of purulent (≥50% pus) discharge detectable in the vagina. Of the 310 cows positive for PVD, 267 cows were enrolled in the current experiment. To ensure proper timing of treatment and collection of samples, only 9 PVD-positive cows were treated per day. Selected cows were balanced at 35 ± 6 d postpartum for lactation number, body condition score, and milk yield and were randomly assigned to receive an intrauterine infusion of 20 mL of phosphate-buffered saline (PBS; control, n = 87), 20 mL of PBS with 150 µg LPS (LPS150, n = 91), or 20 mL of PBS with 300 µg of LPS (LPS300, n = 89). Uterine cytology was performed immediately before treatment and 1, 2, and 7 d after treatment to evaluate the effect of LPS treatment on intrauterine cell population. Cows were examined with the Metricheck device at 7 and 28 d after treatment to evaluate the effects of treatment on resolution of PVD. Reproductive status was recorded up to 200 d postpartum. Cows diagnosed with PVD had greater incidence of twinning, dystocia, retained placenta, and metritis after calving than cows without PVD. Count of polymorphonuclear leukocytes (PMNL) in uterine cytology 1, 2, and 7 d after intrauterine infusion was not statistically different among treatments. From d 0 to 1, however, PMNL count in uterine cytology of PBS cows increased by 5%, whereas the PMNL count in uterine cytology of LPS150 and LPS300 cows increased by 54 and 48%, respectively. Treatment did not affect the likelihood of cows being diagnosed with PVD 7 and 28 d after intrauterine infusion. Cows without PVD and LPS150 cows were more likely to be pregnant after the first postpartum AI than PBS cows. After the second postpartum AI, cows without PVD were more likely to be pregnant than PBS and LPS300 cows. Hazard of pregnancy up to 200 d postpartum was decreased for PBS and LPS300 cows compared with cows without PVD, and it tended to be decreased for LPS150 cows compared with cows without PVD. Intrauterine treatment with 150 µg of E. coli LPS of cows diagnosed with PVD improved likelihood of pregnancy after the first postpartum AI, but further research is needed to elucidate the mechanism by which LPS treatment improved fertility.

The objectives of the current experiment were to investigate the effects of intrauterine treatment of cows with purulent vaginal discharge (PVD) using lipopolysaccharide (LPS) from Escherichia coli on uterine mRNA expression of genes related to inflammatory responses, peripheral polymorphonuclear leukocyte (PMN) function, hematological parameters, and blood concentrations of cortisol, haptoglobin, and progesterone (P4). Jersey cows (n = 3,084) were examined for PVD at 35 ± 6 d postpartum using the Metricheck device (Simcro, Hamilton, New Zealand). At examination, 310 cows had PVD (10.1%), but to ensure proper collection and processing of samples, 267 cows were used in this experiment. Cows were balanced for lactation number, body condition score, and milk yield, and randomly assigned to the control treatment [intrauterine infusion of 20 mL of phosphate-buffered saline (PBS); n = 87] or to receive intrauterine infusion of 20 mL of PBS containing 150 µg (LPS150; n = 91) or 300 µg (LPS300; n = 89) of E. coli LPS. Uteri were biopsied in a subgroup of cows at 6 h after infusion and in another subgroup of cows at 24 h after infusion. Peripheral PMN expression of adhesion molecules (L-selectin and MAC-1) and phagocytosis and oxidative burst were evaluated at 0, 2, and 6 h after infusion. Blood sampled 0, 2, 6, 24, 48, and 168 h after infusion was used for complete hemogram and to determine concentrations of cortisol, haptoglobin, and P4. Treatment did not affect uterine mRNA expression of adhesion molecules [endothelial leukocyte adhesion molecule (E-selectin), intracellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1)], cytokines (tumor necrosis factor-α, IL-1β, IL-6, IL-8, and IL-10), and toll-like receptor-4. Treatment did not affect PMN expression of L-selectin, but intensity of expression of MAC-1 was higher for LPS150 cows than PBS cows, and tended to be higher in LPS150 than LPS300 cows. Furthermore, a greater percentage of PMN from LPS300 cows were positive for phagocytosis and oxidative burst compared with PBS and LPS150 cows. No effects were observed of treatment on hematological parameters and concentrations of cortisol, haptoglobin, and P4. These observations suggest that intrauterine infusion of E. coli LPS moderately stimulates peripheral PMN function, but further research is needed to better understand the immunomodulatory effects of LPS in the uterus of cows with PVD.