The objective of this study was to estimate the cost of metritis in dairy herds. Data from 11,733 dairy cows from 16 different farms located in 4 different regions of the United States were compiled for up to 305 d in milk, and 11,581 cows (2,907 with and 8,674 without metritis) were used for this study. Metritis was defined as fetid, watery, red-brownish vaginal discharge that occurs ≤21 d in milk. Continuous outcomes such as 305-d milk production, milk sales ($/cow), cow sales ($/cow), metritis treatment costs ($/cow), replacement costs ($/cow), reproduction costs ($/cow), feeding costs ($/cow), and gross profit per cow ($/cow) were analyzed using mixed effect models using the MIXED procedure of SAS (SAS Institute Inc., Cary, NC). Gross profit was also compared using the Kruskal-Wallis test. Dichotomous outcomes such as pregnant and culling by 305 d in milk were analyzed using the GLIMMIX procedure of SAS. Time to pregnancy and culling were analyzed using the PHREG procedure of SAS. Models included the fixed effects of metritis, parity, and the interaction between metritis and parity, and farm as the random effect. Variables were considered significant when P ≤ 0.05. Metritis cost was calculated by subtracting the gross profit of cows with metritis from the gross profit of cows without metritis. A stochastic analysis was performed with 10,000 iterations using the observed results from each group. Milk yield and proportion of cows pregnant were lesser for cows with metritis than for cows without metritis, whereas the proportion of cows leaving the herd was greater for cows with metritis than for cows without metritis. Milk sales, feeding costs, residual cow value, and gross profit were lesser for cows with metritis than for cows without metritis. Cow sales and replacement costs were greater for cows with metritis than for cows without metritis. The mean cost of metritis from the study herds was $511 and the median was $398. The stochastic analysis showed that the mean cost of a case of metritis was $513, with 95% of the scenarios ranging from $240 to $884, and that milk price, treatment cost, replacement cost, and feed cost explained 59%, 19%, 12%, and 7%, respectively, of the total variation in cash flow differences. In conclusion, metritis caused large economic losses to dairy herds by decreasing milk production, reproduction, and survival in the herd.

The objective was to investigate the economic effect of treating dairy cows with metritis using ceftiofur-free acid or leaving them untreated at the time of diagnosis. Cows with a fetid, watery, red-brownish vaginal discharge were diagnosed with metritis (d 0). Data from 875 dairy cows (506 primiparous and 369 multiparous) from 1 herd in northern Florida that had been part of a larger study evaluating different treatments for metritis were used for the economic analysis. Holstein cows with metritis had been randomly assigned to: Ceftiofur (CEF, n = 239) = subcutaneous injection of 6.6 mg/kg of ceftiofur crystalline-free acid in the base of the ear at d 0 and d 3; Untreated (UNT, n = 233) = no treatment applied at metritis diagnosis. Both groups could receive escape therapy if condition worsened. A group of nonmetritic healthy cows (NMET; n = 403) from the same cohort was randomly selected for comparison. Continuous outcomes such as 300-d milk production (kg/cow), milk sales ($/cow), cow sales ($/cow), treatment cost by 60 days in milk ($/cow), reproduction cost ($/cow), replacement cost ($/cow), feeding cost ($/cow), and gross profit per cow ($/cow) were analyzed using the ANOVA (MIXED procedure of SAS version 9.4). Dichotomous outcomes such as pregnancy and culling by 300 d were analyzed using logistic regression (GLIMMIX procedure of SAS). Models included the fixed effects of treatment, parity, and the interaction between treatment and parity. A stochastic analysis was performed with 10,000 iterations using the observed results from each group. The CEF treatment resulted in greater treatment cost by 60 DIM than UNT ($112 vs. $37), but resulted in a greater proportion of pregnant cows (71 vs. 61%) and decreased culling by 300 DIM (29 vs. 39%) compared with UNT. Gross profit was lesser for UNT than NMET ($2,969 vs. $3,426), and CEF was intermediate ($3,219). The stochastic analysis showed that the mean difference in gross profit between UNT and NMET was -$457; saleable milk (49%) and replacement cost (24%) accounted for most of the variation. The mean difference in gross profit between CEF and NMET group was -$207; saleable milk (82%) and initial metritis treatment cost (9%) accounted for most of the variation. The mean difference in gross profit between the UNT and the CEF group was -$250; replacement cost (41%) and cow sales (31%) accounted for most of the variation. In summary, metritis caused large economic losses when left untreated, and CEF reduced those losses by improving fertility, reducing culling and replacement cost, and reducing milk yield losses.

Our objectives were to compare the effects of ceftiofur crystalline free acid (CCFA) and ampicillin trihydrate (AMP) treatments of cows diagnosed with metritis on uterine health, behavior, reproductive, and productive responses. A controlled randomized clinical trial was designed. Metritis was defined as vaginal discharge (VD) = 5 (fetid, watery, red/brown) within 21 d in milk (DIM) and rectal temperature (RT) <39.5°C, whereas VD = 5 and RT ≥39.5°C was defined as puerperal metritis. On the day of diagnosis (d 0), cows were paired by parity and severity of metritis (metritis vs. puerperal metritis) and assigned randomly to the AMP and CCFA treatments. Cows enrolled in the AMP (n = 308) treatment were moved to a nonsalable-milk pen, where they were treated once daily for 5 d, and were moved back to their original pen 72 h after the last treatment (d 7). Cows enrolled in the CCFA (n = 310) treatment remained in their original pen and received 2 treatments of CCFA, 72 h apart. Rectal temperature was measured daily from d 0 to 6 and on d 11. Vaginal discharge was evaluated on d 4, 6, and 11 to assess cure. Cure was defined as the absence of treatment with additional antimicrobial before experiment d 11, VD <5, and RT <39.5°C. Cows were examined at 28 ± 3 DIM for purulent VD (PVD) and at 35 ± 3 DIM for cytological endometritis. Pregnancy was diagnosed at 40 ± 3 and 60 ± 7 d after first and second artificial inseminations. Cure of metritis did not differ between treatments on d 11 (AMP = 64.6 ± 3.1, CCFA = 63.5 ± 3.1%). Cows treated with AMP had greater RT from experiment d 1 to 6 compared with cows treated with CCFA (AMP = 39.1 ± 0.02, CCFA = 39.0 ± 0.02°C). Cows in the AMP treatment had greater prevalence of PVD at 28 ± 3 DIM (AMP = 82.6 ± 2.3, CCFA = 74.4 ± 2.7%) and tended to have greater prevalence of cytological endometritis at 35 ± 3 DIM (AMP = 77.8 ± 6.2 vs. CCFA = 61.7 ± 7.5%) than CCFA-treated cows. Treatment did not affect the hazard of pregnancy among multiparous cows; however, among primiparous cows, CCFA treatment reduced the hazard of pregnancy and increased the median days to pregnancy (AMP = 145 vs. CCFA = 169 d). Finally, average daily milk yield up to 14 wk postpartum was not affected by treatment (AMP = 38.0 ± 0.4, CCFA = 37.5 ± 0.4 kg). We conclude from the current experiment that CCFA was more effective in reducing RT and improving uterine health of metritic cows; however, the improved hazard of pregnancy of primiparous cows treated with AMP is important and warrants further investigation.

The main objective of this study was to evaluate the efficacy of intrauterine administration of chitosan microparticles (CM) in curing metritis in dairy cows. A secondary objective was to evaluate the effects of metritis treatments on milk yield, survival, and reproductive performance. Cows with a fetid, watery, red-brownish vaginal discharge were diagnosed with metritis. Holstein cows (n = 826) with metritis from 3 dairies located in northern Florida were blocked by parity (primiparous or multiparous) and, within each block, randomly assigned to one of 3 treatments: CM (n = 276) = intrauterine infusion of 24 g of CM dissolved in 40 mL of sterile distilled water at the time of metritis diagnosis (d 0), 2 (d 2), and 4 (d 4) d later; ceftiofur (CEF; n = 275) = subcutaneous injection of 6.6 mg/kg ceftiofur crystalline-free acid in the base of the ear at d 0 and d 3; Control (CON; n = 275) = no treatment applied at metritis diagnosis. All groups could receive escape therapy if condition worsened. Cure was considered when vaginal discharge became mucoid and not fetid. A group of nonmetritic (NMET; n = 2,436) cows was used for comparison. Data were analyzed by generalized linear mixed and Cox's proportional hazard models. Cows in CM and CON had lesser risk of metritis cure on d 12 than cows in CEF (58.6 ± 5.0 vs. 61.9 ± 4.9% vs. 77.9 ± 3.9, respectively). The proportion of cows culled within 60 days in milk (DIM) was greater for cows in CM than for cows in CEF and CON (21.5 ± 2.7 vs. 9.7 ± 1.9 vs. 11.3 ± 2.0%, respectively). Treatment did not affect rectal temperature or plasma nonesterified fatty acids, β-hydroxybutyrate, and haptoglobin concentrations. Milk yield in the first 60 DIM differed for all treatments, and it was lowest for CM (35.8 ± 0.3 kg/d), followed by CON (36.8 ± 0.3 kg/d) and CEF (37.9 ± 0.3 kg/d). The hazard of pregnancy up to 300 DIM was lesser for CM than CEF (hazard ratio = 0.62; 95% CI: 0.50-0.76), for CM than CON (hazard ratio = 0.77; 95% CI: 0.62-0.95) and for CON than CEF (hazard ratio = 0.80; 95% CI: 0.65-0.99). Culling was greater, and milk yield and fertility were lesser for CEF than NMET. In summary, CM did not improve the cure of metritis, and was detrimental to milk yield, survival, and fertility compared with CON. In contrast, CEF increased the cure of metritis, milk yield, and fertility compared with CM and CON. Finally, the negative effects of metritis on milk yield culling and fertility could not be completely reversed by CEF.

Third-generation cephalosporins, such as ceftiofur, are commonly used to treat metritis in dairy cows. Chitosan microparticles has been shown to have a broad spectrum of activity in vitro and to be effective against uterine pathogens in vivo ; therefore, they have been hailed as a possible alternative to traditional antibiotics. Nonetheless, in the present study, we saw that chitosan microparticle treatment slowed the progression of the uterine microbiome of cows with metritis toward a healthy state, whereas ceftiofur treatment hastened the progression toward a healthy state. Given the lack of an effective alternative to traditional antibiotics and an increased concern about antimicrobial resistance, a greater effort should be devoted to the prevention of metritis in dairy cows.

The main objective of this study was to determine the association of dry matter intake as percentage of body weight (DMI%BW) and energy balance (EB) prepartum (-21 d relative to parturition) and postpartum (28 d) with ketosis (n = 189) and clinical mastitis (n = 79). For this, DMI%BW and EB were the independent variables and ketosis and clinical mastitis were the dependent variables. A secondary objective was to evaluate prepartum DMI%BW and EB as predictors of ketosis and clinical mastitis. For this, ketosis and clinical mastitis were the independent variables and DMI%BW and EB were the dependent variables. Data from 476 cows from 9 experiments were compiled. Clinical mastitis was diagnosed if milk from 1 or more quarters was abnormal in color, viscosity, or consistency, with or without accompanying heat, pain, redness, or swelling of the quarter or generalized illness, during the first 28 d postpartum. Ketosis was defined as the presence of acetoacetate in urine that resulted in any color change [5 mg/dL (trace) or higher] in the urine test strip (Ketostix, Bayer, Leverkusen, Germany). Cows that developed ketosis had lesser DMI%BW and lesser EB on d -5, -3, -2, and -1 than cows without ketosis. Each 0.1-percentage point decrease in the average DMI%BW and each 1-Mcal decrease in the average of EB in the last 3 d prepartum increased the odds of having ketosis by 8 and 5%, respectively. Cut-offs for DMI%BW and EB during the last 3 d prepartum to predict ketosis were established and were ≤1.5%/d and ≤1.1 Mcal/d, respectively. Cows that developed ketosis had lesser postpartum DMI%BW and EB and greater energy-corrected milk (ECM) than cows without ketosis. Cows that developed clinical mastitis had lesser DMI%BW but similar prepartum EB compared with cows without clinical mastitis. Each 0.1-percentage point decrease in the average DMI%BW and each 1-Mcal decrease in the average EB in the last 3 d prepartum increased the odds of having clinical mastitis by 10 and 8%, respectively. The average DMI%BW and EB during the last 3 d prepartum produced significant cut-offs to predict clinical mastitis postpartum, which were ≤1.2%/d and ≤1.0 Mcal/d, respectively. Cows that developed clinical mastitis had lesser postpartum DMI%BW from d 3 to 15 and on d 17; greater EB on d 18, from d 21 to 23, and on d 26; and lesser ECM. The main limitation in this study is that the time-order of disease relative to DMI%BW and ECM is inconsistent such that postpartum outcomes were measured before and after disease, which was diagnosed at variable intervals after calving. In summary, measures of prepartum DMI were associated with and were predictors of ketosis and clinical mastitis postpartum, although the effect sizes were small.

The main objective of this study was to determine the association of dry matter intake as percentage of body weight (DMI%BW) and energy balance (EB) prepartum (-21 d relative to parturition) and postpartum (28 d) with calving disorders (CDZ; dystocia, twins, and stillbirths; n = 101) and metritis (n = 114). For this, DMI%BW and EB were the independent variables and CDZ and metritis were the dependent variables. A secondary objective was to evaluate prepartum DMI%BW and EB as predictors of CDZ and metritis. For this, CDZ and metritis were the independent variables and DMI%BW and EB were the dependent variables. Data from 476 cows from 9 experiments were compiled. Cows that developed CDZ had lesser postpartum DMI%BW from d 3 to 12 and lesser energy-corrected milk (ECM) than cows that did not develop CDZ. Dry matter intake as percentage of BW and EB prepartum did not affect the odds of CDZ. Cows with metritis had lesser prepartum DMI%BW and EB. Each 0.1-percentage point decrease in the average DMI%BW and each 1-Mcal decrease in the average EB in the last 3 d prepartum increased the odds of having metritis by 8%. The average DMI%BW and EB during the last 3 d prepartum produced significant cut-offs to predict metritis postpartum, which were ≤1.6%/d and ≤2.5 Mcal/d, respectively. Cows that developed metritis had lesser overall postpartum DMI%BW and ECM and lesser EB from d 2 to 5 and from d 7 to 11 than cows that did not develop metritis. The main limitation in this study is that the time-order of disease relative to DMI%BW and ECM is inconsistent such that postpartum outcomes were measured before and after disease, which was diagnosed at variable intervals after calving. In summary, prepartum DMI%BW and EB were associated with and were predictors of metritis although the effect sizes were small for metritis, and calving disorders and metritis were associated with decreased DMI%BW and ECM postpartum.

The objective was to evaluate the association between changes in daily rumination time (dRT) and early stages of disease during early lactation and to assess the performance of two proposed disease detection indices. This cohort study included 210 multiparous Holstein cows at the University of Florida Dairy Unit. Cows were affixed with a neck collar containing rumination loggers providing rumination time. The occurrence of health disorders (mastitis, metritis, clinical hypocalcemia, depression/dehydration/fever (DDF), digestive conditions, lameness and clinical ketosis) was assessed until 60 days in milk. Two indices were developed to explore the association between dRT and disease: (i) Cow index (CIx), based on changes in dRT in the affected cow during the days before the diagnosis of health disorders; (ii) Mates index (MIx), index based on deviations in dRT relative to previous days and healthy pen mate cohorts. Subsequently, an alert model was proposed for each index (ACIx and AMIx) considering the reference alert cut-off values as the differences between average index values in healthy and sick cows for each specific disease. The sensitivity (SE) of ACIx detecting disease ranged from 42% (digestive conditions and DDF) to 80% (clinical hypocalcemia) with 84% specificity (SP). The SE of AMIx ranged from 46% (digestive conditions and DDF) to 100% (clinical hypocalcemia) with 85% SP. Consistent reductions in rumination activity, both within cow and relative to healthy mate cohorts, were observed for each health disorder at the day of diagnosis. However, the ability of the proposed algorithms for detecting each specific disease was variable.

The transition period in dairy cows is characterized by a drop in dry matter intake, leading to lipid mobilization in the form of nonesterified fatty acids [NEFA) and an increase in ketone bodies such as beta-hydroxybutyrate. Concentrations of NEFA > 0.3 mEq/L during 14 to 2 days prepartum can predict diseases like displaced abomasum, clinical ketosis, metritis, and retained placenta (RP). These diseases reduce milk yield, impair reproductive performance, and increase culling, hence incurring economic losses. The association between DMI prepartum and disease incidence postpartum has not been extensively studied. The primary objectives of this study were to determine the association between prepartum dry matter intake (DMI), DMI as percentage of body weight (DMI%BW), and net energy balance (NEB) (-21 days) and postpartum diseases or disorders; calving problems (dystocia, twins, stillbirth), RP, metritis, mastitis, metabolic problems (hypocalcemia, ketosis), digestive problems (indigestion, displaced abomasum), lameness, and disease (Dz) (no disease, 1 disease, >2 diseases). A secondary objective was to use DMI, DMI%BW and NEB prepartum to predict Dz postpartum.

Subclinical hypocalcemia occurs frequently in multiparous dairy cattle during early lactation. Calcium supplements are widely used in an attempt to mitigate the substantial negative effects of subclinical hypocalcemia on health and production. Cows with subclinical hypocalcemia spend less time ruminating than normocalcemic cows. The objective of this study was to determine whether oral supplementation of calcium at calving and 12 h after calving was associated with changes in rumination or activity patterns in multiparous Holstein cows. Our hypothesis was that cows supplemented with oral calcium at calving would spend more time ruminating and have altered activity compared with unsupplemented cows during early lactation.

Several observational studies have produced different levels of strength of evidence indicating that mastitis can be a predisposing factor for pregnancy loss (PL) in dairy cows. In some of those studies, clinical mastitis before or after AI, subclinical mastitis before AI, and clinical mastitis during early lactation in combination with low BCS increased the risk of subsequent PL. Some studies, however, failed to identify a relationship between PL and clinical or subclinical mastitis after AI in dairy cows. To our knowledge, no studies have simultaneously examined the relationships between PL and exposures to clinical, subclinical, or clinical and subclinical mastitis during different exposure periods (for instance, before breeding and during gestation) in dairy cows. The objective of the study reported here was to examine the association between PL and previous exposure to clinical or subclinical mastitis before breeding or during gestation in primiparous Holstein cows.

The objectives were to evaluate the clinical response to intrauterine administration of chitosan microparticles (CM) and to assess efficacy for preventing metritis in dairy cows. Holstein cows (n=104; 40 primiparous and 64 multiparous) at increased risk for metritis (cows that had abortion, dystocia, twins, stillbirth, or retained placenta) were randomly assigned to 1 of 2 treatments at 1d in milk (DIM; 24h postpartum): CM group (n=52), daily intrauterine infusion of 8g of CM dissolved in 40mL of sterile water for 5d; control (CON) group (n=52), daily intrauterine infusion of 40mL of sterile water for 5d. Clinical response was assessed by evaluation of parameters associated with inflammation (rectal temperature and plasma haptoglobin concentration) and metabolism [plasma nonesterified fatty acid (NEFA) and β-hydroxybutyrate (BHB) concentrations] up to 14 DIM, and daily milk yield up to 30 DIM. Uterine discharge pH was evaluated at 4, 7, 10, and 14 DIM as an indicator of bacterial load and acid byproduct production. The cumulative incidence of metritis was evaluated up to 4, 7, 10, and 14 DIM. Continuous and dichotomous outcomes were evaluated with mixed linear and logistic regression analysis, respectively. Treatment with CM did not affect rectal temperature (39.17±0.04 vs. 39.14±0.04°C), haptoglobin (1.10±0.05 vs. 1.07±0.05mg/mL), NEFA (0.64±0.04 vs. 0.63±0.04mmol/L), BHB (0.61±0.03 vs. 0.57±0.03mmol/L), or milk yield (30.3±0.92 vs. 30.1±0.97kg/d) compared with CON. An interaction between treatment and time showed that NEFA concentrations were lower for CM than CON at 10 DIM (0.46±0.06 vs. 0.64±0.06mmol/L). Treatment with CM resulted in greater uterine discharge pH than CON (6.91±0.03 vs. 6.83±0.02). Cows that developed metritis had increased concentrations of haptoglobin and BHB, and decreased uterine discharge pH and milk yield. Treatment with CM resulted in decreased incidence of metritis up to 7 DIM compared with CON (46.2 vs. 65.4%); however, no differences were found at 4 (11.5 vs. 17.3%), 10 (61.5 vs. 73.1%), and 14 DIM (63.5 vs. 73.1%) for CM versus CON, respectively. In conclusion, CM did not alter clinical parameters of cows at risk for metritis, and may merit further investigation for prevention of metritis. However, the duration of treatment may have to be extended to effectively reduce the incidence of metritis during the high-risk period.

Our objective was to evaluate the effect of season of calving, associated with variable levels of heat stress, on the dynamics of rumination during the prepartum period and early lactation of cows that were healthy or affected by peripartal health disorders. Three weeks before the estimated due date, 210 multiparous Holstein cows at the University of Florida Dairy Unit were affixed with a neck collar containing rumination loggers, providing rumination time (RT) in 2-h periods. One blood sample was collected in a subpopulation of cows (n=76) at 12 to 48h postcalving to assess metabolic status by determining serum calcium, nonesterified fatty acid, and β-hydroxybutyrate concentrations. The occurrence of peripartal health disorders (dystocia, clinical ketosis, clinical hypocalcemia, metritis, and mastitis) was assessed by University of Florida veterinarians and trained farm personnel. We analyzed the dynamics of daily RT over ± 14d relative to parturition in cows that were healthy or affected by specific health disorders by season of calving [hot season, June to September (n=77); cool season, November to April (n=118)] using repeated measures analysis and comparison of least squares means at different time points relative to calving. Rumination was consistently reduced on the day of calving in both healthy and sick cows in both the hot and cool seasons. Only hot-season calvings had shorter average daily RT prepartum and postpartum in cows affected by severe negative energy balance and subclinical ketosis. Dystocia during the hot season was associated with shorter daily RT prepartum; for cool-season calvings, cows with dystocia had reduced RT postpartum. We also observed reduced RT in cows with ketosis prepartum and postpartum in both the hot and cool seasons. Daily RT was reduced postpartum in cows with hypocalcemia and mastitis that calved during the cool season, and it was shorter in cows with metritis in both the hot and cool seasons. Our results indicated that the effect of heat stress on changes in rumination patterns around calving for sick cows depends on the specific health disorder or metabolic condition.

The objectives of this experiment were to determine the effects of oral Ca supplementation on milk yield, body condition, pregnancy per artificial insemination (P/AI), and days to pregnancy in Holstein cows considered to be of low (LRM; no calving assistance, live singleton without retained placenta) or high (HRM; at least one of the following: dystocia, twins, stillbirth, retained placenta, or vulvo-vaginal laceration) risk of developing metritis. The hypotheses were that oral Ca supplementation during the early postpartum period would reduce the loss of body condition and improve lactation performance and reproduction. Four hundred fifty Holstein cows were blocked by parity as primiparous cows (n=174) or multiparous cows (n=276). Within parity, a cow considered at HRM was matched with a cow of LRM and the pair was randomly assigned to control (no Ca supplementation), 86g of Ca on d 0 and 1 postpartum (CaS1), or 86g of Ca on d 0 and 1 postpartum followed by 43g/d on d 2 to 4 postpartum (CaS4). Body condition was scored at calving and 32d postpartum and estrous cyclicity was evaluated at 38 and 52d postpartum. Milk yield was recorded daily. Multiparous cows were classified as above or below the mean 305-d mature equivalent milk yield based on production in the previous lactation. Reproductive performance was evaluated for the first 210d postpartum. Body condition did not differ among treatments, and cows lost on average 0.44 units of body condition in the first month of lactation. Calcium supplementation did not affect milk yield in the first 5mo postpartum. For multiparous cows, Ca supplementation was beneficial to milk yield in the first 30 DIM in cows of greater production potential, but detrimental to multiparous cows with below average production potential. Calcium supplementation to primiparous cows reduced P/AI at first (control=55.8, CaS1=31.5, CaS4=37.0%) and all artificial inseminations (control=48.5, CaS1=34.6, CaS4=38.5%); however, Ca supplementation to multiparous cows improved P/AI at the first (control=32.1, CaS1=38.6, CaS4=41.3%) and all artificial inseminations (control=28.1, CaS1=35.3, CaS4=40.5%). These responses in P/AI to Ca supplementation resulted in extended median days to pregnancy (control=75, CaS1=100, CaS4=94d) and smaller proportion of pregnant cows (control=89.3, CaS1=83.9, CaS4=83.9%) in primiparous cows, but shorter days to pregnancy (control=115, CaS1=94, CaS4=94d) and increased proportion of pregnant cows in multiparous cows (control=67.0, CaS1=77.2, CaS4=74.3%). Risk of metritis depressed most measures of reproduction evaluated in the experiment. Results indicate that responses to oral Ca supplementation are conditional on parity and production potential of cows. Oral Ca supplementation was detrimental to reproduction in primiparous cows. On the other hand, Ca supplementation benefited reproduction in multiparous cows and milk yield in the cohort of multiparous cows of greater production potential.

The objective was to evaluate the potential of milk fat to protein (FP) and milk fat to lactose (FL) ratios for detection of clinical disease before evident clinical signs. Milk component data from 198 Holstein cows were recorded until 60 days in milk (DIM), using the AfiLab® milk analysis system at the University of Florida (UF) Dairy Unit. Milk components were recorded as an average of AM and PM milkings. Occurrence of health disorders (mastitis [MAS], metritis [MET], clinical hypocalcemia [HYC], digestive disorders [DIG], lameness [LAM], and ketosis [KET]) were assessed by UF veterinarians and farm personnel. Two indices were developed: (i) Cow index (CI) = measurement on the day of diagnosis (d 0) minus –3 to –5 d average relative to d 0, divided by the –3 to –5 d average; and (ii) mates index (MI) = (–3 to –5 d average minus pen mates –3 to –5 d average value)/pen mates d 0 value. Cow alert value (CAV) and mates alert value (MAV) were set when the respective index value was less than –0.1 or more than +0.1.The correlation between FP and FL was intermediate for both sick and healthy cows (r = 0.50 and 0.56, respectively). The odds (95% CI) of MAS multiplied by 1.16 (1.01–1.34) and 1.36 (1.26–1.47), for each decimal unit increment in FP and FL, respectively. For each decimal unit increment in FP and FL, the odds of MET multiplied by 1.38 (1.25–1.54) and 1.36 (1.25–1.47), respectively; the odds of KET multiplied by 1.43 (1.31–1.57) and 1.34 (1.24–1.44); the odds of HYC multiplied by 0.40 (0.22–0.73) and 1.39 (1.14–1.69); and the odds of DIG multiplied by 1.31 (1.22–1.39) and 1.35 (1.24–1.47). The odds of LAM were only significant for changes in FL [1.28 (1.12–1.45)]. Sensitivity and specificity calculations (Table 1) suggested that changes in both FP and FL may be used as indicators of disease; MAS and KET were better detected using FL, whereas FP was more effective for HYC detection. Overall, MAV was more effective than CAV on disease detection.

The objective was to evaluate the effect of housing type on health and performance of preweaned dairy calves. One hundred calves, Holsteins (HO) or Holstein-Jersey crosses (HJ), were randomly assigned to a Calf-Tel (L. T. Hampel Corp., Germantown, WI) polyethylene hutch exposed to direct sun light (n=25 for both HO and HJ) or a wire hutch with a plywood shade located under trees (n=24 and 26 for HO and HJ, respectively). Calf rectal temperature, respiratory rate, health scores, and weaning weight were compared by housing type. Rectal temperatures were higher in calves in Calf-Tel hutches compared with calves in wire hutches at 1500h, at 40.1±0.28 and 39.1±0.22°C, respectively. Similarly, respiratory rates were higher in calves in Calf-Tel hutches compared with calves in wire hutches at 1500h, at 90±15 and 65±10 breaths per minute, respectively. Frequencies of calves presenting abnormal ear scores did not differ between calves in Calf-Tel or wire hutches. Abnormal eye scores were less likely to occur for calves in the wire hutches. Frequencies of calves with signs of respiratory disease, such as nasal discharge and coughing, were higher in the wire hutches compared with the Calf-Tel hutches. No differences were noted in the incidence and time of first diarrhea event in calves between hutch types. Calves in wire hutches had 5.47 greater odds of receiving veterinary treatment compared with calves in the Calf-Tel hutches. Weaning weights were not different for calves in Calf-Tel or in wire hutches. The lower frequency of calves with abnormal health scores and receiving veterinary treatment in Calf-Tel hutches and the lack of difference in weight gain suggests that this housing system adapted well to the specific environmental conditions of this study.

Pregnancy-associated glycoproteins (PAG) are produced by the ruminant placenta and secreted into the maternal circulation throughout pregnancy. The extent to which circulating PAG concentrations predict pregnancy outcomes was examined herein. Also, associations between circulating PAG concentrations and various production parameters and clinical diseases were evaluated. Lactating primiparous and multiparous Holstein cows (n=345) were bred via timed artificial insemination using a standard Ovsynch protocol. Pregnancy was diagnosed by transrectal ultrasonography at d 32, 46, and 74 of gestation. Blood was harvested at d 32 to determine plasma concentrations of PAG and progesterone. Cows pregnant at d 32 that subsequently lost their pregnancy at d 46 and 74 had reduced PAG concentrations. Both artificial insemination service number and parity were associated with plasma PAG concentrations. Concentration of PAG in plasma was greater for cows pregnant from their second or later breeding than those pregnant from the first breeding postpartum, and was increased for primiparous compared with multiparous. In addition, cows with greater milk yield had increased plasma PAG concentrations. No association was detected between body condition score and plasma PAG concentrations. Cows that experienced clinical metritis, metabolic problems, or left displacement abomasum in the early postpartum period preceding breeding had greater plasma PAG concentrations than cows not experiencing these clinical diseases. Also, cows with multiple clinical diseases had increased odds of pregnancy loss when compared with cows not experiencing clinical diseases. Odds ratio testing detected a tendency in the relationship between reduced milk yield and increased pregnancy loss. Collectively, these associations illustrate one feature of the early developing placenta that may predict pregnancy outcomes in dairy cattle. It is unclear if plasma PAG are actively involved with mediating pregnancy outcomes, but modifications in circulating PAG concentrations due to pregnancy loss, milk yield, parity, and clinical disease implicate placental PAG production or PAG release as being responsive to various physiological stimuli.