Transition dairy cow health is associated with first postpartum ovulation risk, metabolic status, milk production, rumination, and physical activity.

Our objective was to determine the association of health status during the first 60 d in milk (DIM) and first postpartum ovulation risk, physical activities recorded by an activity monitor, and metabolic and milk measures in Holstein cows. Late-gestation heifers and close-up dry cows in 1 herd fitted with CowManager SensOors (Agis, Harmelen, the Netherlands) were enrolled in the study 3 wk before expected parturition to assess ear skin temperature and daily rumination, eating, inactivity, and activity times. Blood samples were collected at calving (d 0), and on d 3, 7, and 14 to assess concentrations of free fatty acids, ß-hydroxybutyrate (BHB), calcium, glucose, and haptoglobin. In addition, weekly measures were conducted for body condition, body weight, and progesterone through 63 ± 3 DIM when ovulation was synchronized (GnRH-1 - 7 d - PGF2α - 24 h - PGF2α - 32 h - GnRH-2 - 16 h - artificial insemination). Disease diagnosed in 68 of 160 cows (42.5%) was distributed equally between primiparous (48.5%) and multiparous (51.5%) cows. Cows were classified as diseased when any case of metritis, digestive disorders, ketosis, hypocalcemia, calving problems, mastitis, or lameness occurred during the first 60 DIM. Odds of early ovulation by median postpartum d 33 was 1.92 times greater in healthy than diseased cows. Incidence of individual diseases included metritis (18.8%), digestive disorders (17.5%), ketosis (BHB >10 mg/dL; 11.9%), hypocalcemia (Ca <2.2 mmol/L; 10.6%), calving problems (6.3%), mastitis (3.1%), and lameness (3.1%). Odds of early ovulation were 2.48, 2.65, and 5.72 times greater in healthy cows compared with cows diagnosed with metritis, digestive disorders, or ketosis, respectively. Diseased compared with healthy cows had greater concentrations of free fatty acids, BHB, haptoglobin, greater rectal temperature, and lesser concentration of serum calcium on d 0, 3, 7, and 14 than healthy cows. Plasma glucose was not affected by health status, but was lesser in concentration on d 3, 7, and 14 compared with day of calving. Weekly (calving through 9 wk) body condition scores tended to be and weekly body weights were greater in healthy compared with diseased cows. Activity measures differed by health status during prepartum (d -14 through -1) and postpartum (d 0 through 20) periods except for eating time. Healthy cows spent less time being inactive during both periods compared with diseased cows and had greater postpartum rumination times than diseased cows. Mean daily milk yield during the first 14 wk in milk was greater in healthy than diseased cows by 2.1 ± 0.8 kg. We conclude that disease negatively affects early postpartum ovulation risk and is associated with measurable changes in periparturient physical activity and postpartum metabolic profiles.

Physiological, health, lactation, and reproductive traits of cooled dairy cows classified as having high or low core body temperature during the dry period1.

Primary objectives of this study were to compare concentrations of pregnancy-associated glycoprotein (PAG) before calving, prolactin (PRL) after calving, and energy balance indicators before and after calving in cooled cows classified as having high (HT) or low (LT) core body temperature (CBT) during the dry period. Secondary objectives were to investigate associations between dry-period CBT and likelihood of cows developing health disorders, and compare health, productive and reproductive traits of HT and LT cows. Dry Holstein cows (n = 260) with 250 to 260 d of gestation from three herds were enrolled in the study during summer. Cows were provided evaporative cooling during the dry and lactating period. The vaginal temperature was recorded in 5-min intervals during 7 consecutive days and cows were classified as HT or LT. Blood samples were collected weekly from enrollment until 14 ± 3 d in milk (DIM). Additional blood samples were collected within 12 h postpartum from a subgroup of cows (n = 25) to determine PRL concentration. Cows were monitored for health disorders, productive, and reproductive performance until 13 wk of the subsequent lactation. High temperature cows had shorter (P < 0.01) gestation length (273.9 ± 0.9 vs. 278.2 ± 0.9 d) and greater (P < 0.01) incidence of twinning (19.7 vs. 4.2%) than LT cows. Cows classified as HT had greater (P = 0.02) PAG concentration (134.1 ± 4.9 vs. 117.4 ± 4.9 ng/mL), but postpartum PRL concentration did not (P = 0.55) differ between HT and LT cows. Primiparous HT cows had greater (P = 0.05) prepartum nonesterified fatty acids concentration (135, 95% CI = 102 to 178 vs. 104, 95% CI = 75 to 144 mmol/dL) than primiparous LT cows, but no differences (P = 0.72) were observed between CBT group in multiparous cows. The concentration of ß-hydroxybutyrate was greater (P = 0.04) for LT compared with HT cows at 7 ± 3 DIM. The quadratic effect of CBT tended (P = 0.09) to be associated with risk of health disorders within 60 DIM. Milk yield tended (P = 0.10) to be greater for LT compared with HT cows (49.3 ± 1.9 vs. 46.2 ± 1.6 kg). Pregnancy per AI at first service did not (P = 0.64) differ between HT and LT cows. In conclusion, HT cows have distinct concentrations of PAG in late gestation and energy balance indicators during the transition period. In addition, CBT assessment during the dry period may be a useful tool to identify cows expected to have impaired health and milk yield in the subsequent lactation.

Animal factors associated with core body temperature of nonlactating dairy cows during summer.

The primary objectives of the current study were to investigate animal factors associated with core body temperature (CBT) and to determine the time of the day in which CBT assessment best describes the magnitude of hyperthermia throughout the day of heat-stressed dry cows. The secondary objective was to develop a predictive model for CBT of dry cows. Nonlactating Holstein cows (n = 105) with 250 to 260 d of gestation from 2 commercial dairies were enrolled in the study during summer. During 4 consecutive days, CBT from all cows was recorded in 5-min intervals and average CBT was calculated for each cow. In addition, mean, maximum, minimum, and standard deviation of daily CBT were calculated and using these measures cows were categorized as having high temperature (HT) or low temperature (LT) based on the median values. Cows carrying twins had greater (P < 0.01) CBT than cows bearing singletons (39.07 ± 0.07 vs. 38.84 ± 0.03 °C). Average CBT decreased (P < 0.01) 0.015 ± 0.004 °C for each 1-d increase in gestation length. Cows in Dairy A tended (P = 0.09) to have lower CBT than cows in Dairy B (38.91 ± 0.04 vs. 39.00 ± 0.06 °C). Season of birth, lactation number, body condition score category, previous projected 305-d mature equivalent milk yield, days in milk at dry-off, days after dry-off at enrollment, days of gestation at enrollment, and calf sex were not associated (P > 0.12) with CBT. Principal component analyses showed that 71% of the variance of CBT was explained by the first principal component alone, which was correlated with mean CBT (r = 0.99). Among all time points assessed, CBT recorded at 2215 h had the highest correlation with the first principal component (r = 0.93). The best agreement for classifying cows as HT or LT was between mean daily CBT and assessment at 2215 h (k = 0.73). The model that resulted in best predictivity (0.56) of average CBT included the following variables: dairy, gestation length, and twinning. In conclusion, findings from the present study suggest that CBT assessed between 250 and 260 d of gestation is negatively associated with gestation length and cows bearing twins have greater CBT than singletons. Our results indicate that the best time of the day to evaluate severity of heat stress in dry cows is 2215 h. Predictive models for CBT of dry cows should include dairy, twinning, and gestation length.

Association between body condition score change during the dry period and postpartum health and performance.

The objectives of the current study were to determine the association between body condition score change during the dry period (ΔBCS) and postpartum health and reproductive and productive performance of Holstein cows. Data from 16,104 lactations from 9,950 parous cows from 2 dairies located in the San Joaquin Valley of California were used. Within dairy, cows were scored for body condition at dry off and parturition by the same herd workers, who were trained by veterinarians from the Veterinary Medicine Teaching and Research Center of the University of California Davis. Cows were classified as having excessive loss of BCS (ΔBCS ≤-0.75; n = 1,604), moderate loss of BCS (ΔBCS = -0.5 to -0.25; n = 6,430), no change in BCS (ΔBCS = 0; n = 4,819), and gained BCS (ΔBCS ≥0.25; n = 3,251). Data regarding morbidity, mortality, and reproductive and productive performance were recorded until 305 d postpartum or until cows were dried off or left the herd. Loss of BCS during the dry period was associated with greater incidence of uterine disease and indigestion. Additionally, loss of BCS during the dry period was associated with greater likelihood of treatment with antimicrobials, anti-inflammatories, and supportive therapy. Loss of BCS during the dry period was associated with reduced likelihood of pregnancy after the first and second postpartum inseminations. Cows that gained BCS during the dry period had greater yield of milk, fat, and protein and had reduced somatic cell linear score in the subsequent lactation. In the current study, loss of BCS during the dry period was a predisposing factor associated with health disorders and reduced productive and reproductive performance in Holstein cows.

Associations between activity of arginase or matrix metalloproteinase-8 (MMP-8) and metritis in periparturient dairy cattle.

Metritis, a uterine disease caused by bacterial infection, is highly prevalent in dairy cattle after parturition. Uterine disease has negative effects on milk production and reproductive efficiency. Finding markers or indicators that can predict cows at greater risk for uterine disease could be beneficial to mitigating these deleterious effects. This study investigates the immune-derived enzymes arginase and matrix metalloproteinase-8 (MMP-8) as potential markers for development of metritis in dairy cows. In a retrospective matched case-control study, 53 lactating Holstein cows diagnosed with metritis were matched and paired to 53 lactating Holstein control cows. In addition to examining cows for diagnosis of metritis on d 4, 7, 10, and 14 after parturition, occurrence of retained fetal membranes, gender of the calf, and the event of a stillbirth were recorded. Blood samples were collected 7 ± 3 d before calving, on the day of calving, and 7 ± 3 d after calving and were assayed for activity of arginase and MMP-8. Associations between metritis and activity of arginase or MMP-8 were determined by conditional logistic regression at each individual sampling time point. An interaction between activity of arginase, before and on the day of parturition, and retained fetal membranes tended (P ≤ 0.13) to be associated with metritis. After parturition, activity of arginase and the interaction between activity of arginase and retained fetal membranes were not (P ≥ 0.22) associated with metritis. Activity of MMP-8 was not (P ≥ 0.20) associated with metritis in the periparturient period. Retained fetal membranes were associated with the odds of developing metritis. Activity of arginase before and at the time of parturition might be a potential marker for occurrence of metritis, especially in cows that develop retained fetal membranes. MMP-8 does not seem to be a potential indicator for metritis.

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.

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 resynchronization strategies for lactating Holstein cows on pattern of reinsemination, fertility, and economic outcome.

The objectives were to evaluate the pattern of re-insemination, pregnancy outcomes to re-insemination in estrus and at fixed time, and economic outcomes of lactating Holstein cows submitted to three resynchronization protocols. Cows were enrolled in the Experiment at 32 ± 3 d after pre-enrollment Artificial Insemination (AI), 7 d before pregnancy diagnosis, and randomly assigned to three resynchronization protocols. All cows diagnosed not pregnant at 39 ± 3 d after pre-enrollment AI were submitted to the Cosynch72 (Day 0 GnRH, Day 7 prostaglandin F(2α), and Day 10 GnRH and fixed time AI). Cows assigned to the control treatment received no further treatment, cows assigned to the GGPG treatment received a GnRH injection on Day -7, and cows assigned to the CIDR treatment received a controlled internal drug release (CIDR) insert containing 1.38 g of progesterone from Days 0-7. Cows observed in estrus were re-inseminated on the same day. Pregnancy was diagnosed at 39 ± 3 and 67 ± 3 d after re-insemination. Costs of the resynchronization protocols were calculated for individual cows enrolled in the study and pregnancies generated were given a value of $275. The GGPG treatment resulted in the slowest (P ≤ 0.06) rate of re-insemination. Overall pregnancy per AI (P/AI) at 39 ± 3 (P = 0.50) and 67 ± 3 (P = 0.49) d after re-insemination were not affected by treatment. Although cost of the control protocol was (P < 0.01) the smallest, return per cow resynchronized was (P < 0.01) greater for GGPG and CIDR protocols. We concluded that presynchronizing the estrous cycle of cows with GnRH or treating cows with a CIDR insert during resynchronization altered the pattern of re-insemination and improved the economic return of resynchronized cows.

Ovarian responses and embryo survival in recipient lactating Holstein cows treated with equine chorionic gonadotropin.

The objectives of Experiment 1 were to determine a dose of eCG that would increase total luteal volume and plasma progesterone (P4) concentration on estrous cycle Day 7 in cows. The objectives of Experiment 2 were to determine the effects of treating embryo recipient lactating Holstein cows with eCG on pregnancy per embryo transfer (P/ET). In Experiment 1, lactating dairy cows at 63 ± 3 d postpartum (DIM) received no treatment (control, n = 10), or 600 (eCG6, n = 19), or 800 (eCG8, n = 19) IU of eCG 2 d after the start of the ovulation-synchronization protocol, Day -8 (Day -10 GnRH, Day -3 PGF(2α), Day 0 GnRH). Blood was sampled on Days -10, -8, -3, 0, 7, and 14 for P4 concentration. Ovaries were examined by ultrasound on Days -10, -3, 0, and 7. In Experiment 2, lactating dairy cows were paired according to parity and previous insemination (0 or > 1 insemination) and assigned to receive 800 IU of eCG (eCG8, n = 152) 2 d after the start of the ovulation-synchronization protocol (Day -10 GnRH, Day -3 PGF(2α), Day 0 GnRH) or to receive no treatment (control, n = 162). Blood was sampled on Days -10, -3, 0, 7, and 14 for determination of P4 concentration. Ovaries were examined by ultrasound on Days -10, -3, and 7, and cows with a CL > 20 mm in diameter on Day 7 received an embryo. In Experiment 1, P4 concentration on Day 7 was higher (P < 0.05) for eCG8 cows (2.3 ± 0.3 ng/mL) compared with control (1.2 ± 0.3 ng/mL) and eCG6 (1.1 ± 0.3 ng/mL) cows. In Experiment 2, eCG8 primiparous cows had more (P < 0.01) follicles > 10 mm on Day -3 compared with control primiparous cows (2.5 ± 0.9 vs 1.7 ± 0.5 mm), but multiparous control and eCG8 cows did not differ. A larger (P = 0.03) percentage of control cows received an embryo (87.5 vs 79.1%) compared with eCG8 cows. Among cows that received an embryo, total luteal volume on Day 7 was affected (P = 0.05) by treatment (eCG8 = 8.3 ± 0.4 cm(3), control = 6.2 ± 0.4 cm(3)), but P4 concentration on Day 7 did not differ significantly between treatments. The percentage of cows pregnant 53 d after ET (overall, 24.2%) was not significantly different between control and eCG8 cows. In the current study, no differences in P/ET were observed between control and eCG8 cows and treatment with eCG increased the percentage of cows with asynchronous estrous cycle.

Reduced progesterone concentration during growth of the first follicular wave affects embryo quality but has no effect on embryo survival post transfer in lactating dairy cows.

Fertility of lactating dairy cows is associated with reduced progesterone (P(4)) concentration compared with nonlactating animals. The objective of the current study was to determine whether P(4) during growth of the first follicular wave (FFW) affects embryo quality. Lactating Holstein cows at 33±3 days post partum were allocated to one of three treatments. Cows in the FFW and FFW with P(4) (FFWP) treatments started the superstimulation protocol on day 1 of the estrous cycle and second follicular wave (SFW) cows started the superstimulation protocol on estrous cycle day 7. Cows were superstimulated with 400  mg of NIH-FSH-P1 (FSH) given twice daily for 5 days, two prostaglandin F(2α) (PGF(2α)) injections given with the ninth and tenth injections of FSH, GNRH given 48  h after the first PGF(2α) injection, and timed insemination 12 and 24  h after the GNRH injection. Cows in the FFWP treatment received two intravaginal P(4) inserts during the superstimulation. Embryos were recovered 6.5 days after artificial insemination and excellent/good and fair embryos were frozen and transferred. Blood was sampled daily from estrous cycle day 0 until insemination from donor cows. During the superstimulation protocol, P(4) was (P<0.01) greatest for SFW cows followed by FFWP and FFW cows respectively. The percentage of embryos-oocytes from SFW and FFWP cows classified as excellent/good and fair embryos was (P=0.02) greater than those of FFW cows. Pregnancy per embryo transfer was not (P≥0.73) affected by embryo donor treatment. Reduced embryo quality of cows induced to ovulate the follicles from the first follicular wave is a consequence of reduced P(4) during follicle growth.