Effects of intrauterine infusion of Escherichia coli lipopolysaccharide on uterine mRNA gene expression and peripheral polymorphonuclear leukocytes in Jersey cows diagnosed with purulent vaginal discharge.

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-1ß, 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.

Effects of intrauterine infusion of Escherichia coli lipopolysaccharide on uterine health, resolution of purulent vaginal discharge, and reproductive performance of lactating dairy cows.

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.

Social stressors and their effects on immunity and health of periparturient dairy cows.

Management practices during the periparturient period have been the focus of much research recently because during this period immune function, metabolism, and health of cows are severely challenged. Responses to stress are often classified as behavioral, immunological, neuroendocrine, and autonomic. In production systems, understanding all facets of stress response is important to correctly predict the consequences of stressors to the health and performance of animals and to prevent costly managerial changes that have minimal effect on animal well-being and performance. Common social stressors faced by periparturient animals are regrouping, overstocking, and for nulliparous animals, commingling with parous animals. In conventional dairies, feeding strategies during the periparturient period often require several group changes during the most challenging period of an animal's life. Traditional weekly regrouping of prepartum cows increases competitive behavior at the feed bunk but it does not affect immune and metabolic responses, health and production, as long as stocking density is not overwhelming, and nulliparous and parous animals are housed separately. Stocking density of prepartum animals may be overlooked because these are nonproductive animals. Severe overstocking (200% of feeding space) of commingled nulliparous and parous pregnant animals produces neuroendocrine and metabolic changes. On the other hand, when prepartum nulliparous and parous animals are housed separately, stocking densities of up to 120% do not seem to affect innate and adaptive immunity, metabolic responses, milk yield, and reproductive performance, despite increasing negative behavior among cows. In recent experiments, when animals were ranked based on feed bunk displacement, dominant animals were more likely to be diagnosed with metritis than subordinate animals. Importantly, dominant animals with large number of interactions with pen mates (displacement at the feed bunk) were considerably more likely to be diagnosed with uterine diseases (retained placenta and metritis) and to be removed from the herd within 60d postpartum. Much has been learned about behavioral responses of cows to stressful conditions, but our understanding of neuroendocrine and immune responses to such conditions is somewhat limited. A multidisciplinary approach to research that encompasses several responses to stress and biological functions is critical.

Short communication: Plasma progesterone concentration and ovarian dynamics of lactating Jersey cows treated with 1 or 2 intravaginal progesterone inserts.

The objectives of the current experiment were to determine circulating progesterone concentrations and ovarian follicle development of lactating Jersey cows treated with 1 or 2 controlled internal drug release (CIDR) insert containing 1.38 g of progesterone during proestrus. Cows were enrolled in the experiment at 34 ± 3 d in milk and were paired by parity, body condition score, body weight, and milk yield. Estrous cycles were presynchronized with an injection of GnRH concurrent with a new CIDR insert (study d -7) and 2 injections of PGF2α given 5 and 6 d after the GnRH injection (study d -2 and -1, respectively). Cows assigned to the 1CIDR treatment (n=30) or 2CIDR treatment (n=30) received 1 and 2 CIDR inserts, respectively, from study d 0 through 7. Control cows (n=10) did not receive further treatment. On study d -2 and daily from study d 0 through 7, ovaries were examined by transrectal ultrasound and blood samples were collected for determination of progesterone. On study d 7, CIDR inserts were removed after ultrasound exam and blood sample collection. Progesterone concentration from study d 0 through 7 was greatest for 2CIDR cows (2.17 ± 0.09 ng/mL), followed by 1CIDR cows (1.37 ± 0.10 ng/mL) and control cows (0.62 ± 0.21 ng/mL). The interaction between treatment and study day affected progesterone concentration from study d 0 through 7. The average increase in progesterone concentration from study d 1 through 7 was 0.80 ng/mL for 1CIDR and 1.72 ng/mL for 2CIDR cows compared with control cows. The percentage of cows that ovulated between study d 0 and 7 was greatest for control cows (80%), but it did not differ between 1CIDR (12%) and 2CIDR (3.7%) cows. Growth of class III follicles (10-17 mm) identified on study d 0 was affected by treatment because 1CIDR cows had larger class III follicles than 2CIDR cows on study d 5, 6 and 7. A larger proportion of control cows developed a new follicular wave between study d 0 and 7 (control=60.0%, 1CIDR=12.0%, 2CIDR=7.4%). Treatment of lactating Jersey cows with 1 and 2 CIDR inserts resulted in a 1 and 2 fold increase, respectively, in circulating progesterone concentration. Growth class III follicles from cows treated with 2 CIDR inserts was reduced compared with untreated cows and cows treated with 1 CIDR insert.

Characterization of peripartum rumination and activity of cows diagnosed with metabolic and uterine diseases.

The objectives of the current experiment were to characterize the correlation among total serum Ca, nonesterified fatty acids (NEFA), ß-hydroxybutyrate (BHBA), and haptoglobin concentrations and daily rumination time (DRT) and activity of periparturient cows and to determine the association between periparturient events and peripartum DRT and activity. Holstein animals (nulliparous = 77, parous = 219) were enrolled in the experiment approximately 21 d before expected calving date. Cows were fitted with individual Heat Rumination Long Distance collars (HRLD, SCR Engineers Ltd., Netanya, Israel) from enrollment until approximately 21 ± 3 d postpartum. Blood samples collected weekly from enrollment to 21 d postpartum were used to determine concentrations of NEFA, BHBA, and haptoglobin. Blood samples collected within 72 h after calving were used to determine total serum Ca concentration. Subclinical ketosis was characterized by BHBA > 1,000 µmol/L in any sample, and subclinical hypocalcemia was characterized by Ca < 8.55 ng/dL within 72 h after calving. Cows were examined 1, 7 ± 3, and 14 ± 3 d postpartum for diagnosis of retained fetal membrane and metritis. Total Ca (r = 0.15), NEFA (r = -0.27), and haptoglobin (r = -0.18) concentrations were weakly correlated with DRT. Concentration of BHBA (r = -0.14) was weakly correlated with activity. Postpartum DRT was reduced among cows that delivered twins compared with cows that delivered singletons (437.9 ± 4.8 vs. 385.9 ± 17.1 min/d). Prepartum (465.8 ± 4.1 vs 430.8 ± 14.9 arbitrary units) and postpartum (536.5 ± 5.5 vs. 480.3 ± 19.4 arbitrary units) activity were reduced among cows that delivered twins compared with cows that delivered singletons. Delivery of stillborn calves was associated with reduced DRT prepartum (478.0 ± 5.9 vs. 417.0 ± 23.4 min/d) and postpartum (437.2 ± 4.8 vs. 386.5 ± 19.3 min/d). On the other hand, cows delivering stillborn calves had increased activity prepartum compared with cows delivering live calves (499.3 ± 16.2 vs. 461.3 ± 4.1 arbitrary unit). Occurrence of retained fetal membrane tended to and was associated with reduced prepartum (444.3 ± 11.0 vs. 466.5 ± 4.3 arbitrary unit) and postpartum (488.2 ± 14.5 vs. 538.8 ± 5.7 arbitrary unit) activity, respectively. Cows diagnosed with metritis had reduced postpartum DRT (415.9 ± 10.1 vs. 441.0 ± 5.2 min/d) and activity (512.5 ± 11.5 vs. 539.2 ± 6.0 arbitrary unit). Postpartum activity was reduced among cows that were diagnosed with subclinical ketosis (502.20 ± 16.5 vs. 536.6 ± 6.2 arbitrary unit). Although differences in DRT and activity between populations of cows that developed periparturient diseases and healthy cows were observed, further experiments are necessary to determine how DRT and activity data may be used to precociously diagnose individuals that will develop such periparturient diseases.

Association between Prepartum Feeding Behavior and Periparturient Health Disorders in Dairy Cows.

The objective of this study was to investigate the relationship between prepartum feeding behavior, measured as time spent feeding per day, and periparturient health disorders, milk yield, milk composition, and milk somatic cell count in Jersey cows. Pregnant Jersey cows were marked with unique alphanumeric symbols and were moved into a prepartum group 4 weeks prior to their expected calving date. At enrollment, cows with a body condition score <2 or >4 or a locomotion score >3 were not included. Time spent feeding was measured using 10-min video scan sampling for 24-h periods of 2-4 days per week of the study. A total of 925 cows were eligible for analysis. Parity was based on lactation number at the time of enrollment and classified as nulliparous (cows pregnant with their first calf), primiparous (cows pregnant with their second calf), and multiparous (lactation ≥2). Multiparous cows with two or more health disorders spent approximately 10% less time feeding prepartum than cows that did not have any health disorders. Multiparous cows subsequently diagnosed with metritis had a tendency to spend 5% less time feeding prepartum than healthy counterparts. Primiparous cows with retained placenta had a 10% reduction in feeding time compared to healthy primiparous cows. Monitoring time spent feeding prepartum by primiparous and multiparous cows, even on a limited number of days, appeared to be beneficial in predicting cows at risk for periparturient health disorders. Real-time daily feeding behavior monitoring technologies that can be used by dairy farms are now available, which might prove to be even more helpful in identifying cows at risk for periparturient cow health disorders as more data points can be recorded for each cow and compared to her own behavior or that of specific cohorts.