Economic comparison between ceftiofur-treated and nontreated dairy cows with metritis.

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.

Using chitosan microparticles to treat metritis in lactating dairy cows.

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, ß-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.

Effects of homolactic bacterial inoculant on the performance of lactating dairy cows.

The objective of this experiment was to determine the effect of applying a homofermentative bacterial inoculant to corn silage on the performance of dairy cows. After harvesting, corn forage was treated with nothing (CON) or with an inoculant containing a mixture of Lactococcus lactis, Lactobacillus plantarum, and Enterococcus faecium at 1.5 × 105 cfu/g of fresh forage (MC; SiloSolve MC, Chr. Hansen A/S, Hørsholm, Denmark). After 186 d of storage in Ag-Bags (A Miller-St. Nazianz Inc., St. Nazianz, WI), silages were fed as part of a total mixed ration containing 55% concentrates, 10% alfalfa hay, and 35% CON or MC corn silage. Sixty early-lactation Holstein dairy cows (30 multiparous and 30 primiparous) housed in a freestall barn with Calan gates (American Calan Inc., Northwood, NH) were assigned to the dietary treatments from 20 to 100 d in milk. Silage inoculated with MC had a more homofermentative pattern evidenced by greater lactic acid concentration (3.83 vs. 4.48% of DM) and lower concentrations of acetic (2.34 vs. 1.68% of DM) and propionic (0.37 vs. 0.10% of DM) acids and ammonia (9.11 vs. 7.82% of N) for CON and MC, respectively. Dry matter intake (23.1 vs. 23.2 kg/d) did not differ among treatments, but the MC silage had greater apparent digestibility of DM (68.8 vs. 70.8%), which led to greater yields of milk (37.7 vs. 38.5 kg/d), fat-corrected milk (37.6 vs. 38.4 kg/d), milk fat (1.30 vs. 1.33 kg/d), and lactose (1.83 vs. 1.92 kg/d) for CON and MC cows, respectively. Milk from cows fed MC silage had higher lactose (4.86 vs. 4.93%), lower protein (2.93 vs. 2.83%), and similar contents of fat (3.47 vs. 3.44%) compared with CON cows. Feed efficiency (fat-corrected milk/dry matter intake) was not affected by treatment (1.69 vs. 1.72 for CON and MC, respectively). Inoculation of corn silage with the homofermentative inoculant increased digestibility of the total mixed ration and increased milk yield by lactating dairy cows.

Clinical response after chitosan microparticle administration and preliminary assessment of efficacy in preventing metritis in lactating dairy 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 ß-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.

Effects of oral calcium supplementation on productive and reproductive performance in Holstein cows.

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 32 d postpartum and estrous cyclicity was evaluated at 38 and 52 d 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 210 d 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 5 mo 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=94 d) 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=94 d) 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.

Effects of oral calcium supplementation on mineral and acid-base status, energy metabolites, and health of postpartum dairy cows.

Two experiments were conducted to characterize blood concentrations of minerals and acid-base status after oral dosing of Ca salts and to determine the effects of oral Ca on mineral and metabolic status and incidence diseases. The hypotheses were that administration of oral Ca as CaCl2 and CaSO4 maintains blood total Ca (tCa) concentrations ≥2.125 mM and reduces the incidence of diseases in early lactation. In experiment 1, 18 Holstein cows on the day of calving were assigned to receive a single dose of 0, 43, or 86g of Ca as an oral bolus. Blood was sampled before and after treatments to characterize acid-base status and concentrations of minerals. In experiment 2, 450 Holstein cows considered of low (LRM; normal calving) or high risk (HRM; dystocia, twins, stillbirth, retained placenta, vulvo-vaginal laceration, or a combination of these) of metritis (primiparous-LRM=84; primiparous-HRM=84; multiparous-LRM=138; multiparous-HRM=138) on the day of calving were blocked by parity and then 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). Blood was sampled before and 30 min after treatment on d 0, and 30 min after treatments on d 1 to 4, and d 7 and 10 for determination of concentrations of minerals and metabolites and blood acid-base responses. Disease incidence was evaluated for the first 30 DIM. Concentrations of ionized Ca (iCa) increased for 2h in cows supplemented with 43g of Ca and fewer than 8h in cows supplemented with 86g of Ca. The changes in iCa concentrations from pretreatment to 30 min after 86g of Ca supplemented on d 0 were 0.11±0.03 mM in multiparous cows and 0.25±0.03 mM in primiparous cows. Oral Ca reduced the incidence of subclinical hypocalcemia (SCH; tCa <2.125mM) in the first 4 d in the experiment (control=69.3%; CaS1=57.5%; CaS4=34.2%). Calcium supplementation decreased the prevalence of SCH on d 0 and 1 postpartum in all cows. Stopping oral Ca in CaS1 on d 1 postpartum, however, caused a rebound in SCH on d 2 to 4 postpartum in primiparous cows. Oral Ca increased the incidence of metritis (control=22.7%; CaS1=34.8%; CaS4=32.8%), primarily because of an increase in LRM primiparous cows (control=17.9%; CaS1=35.7%; CaS4=42.9%). Oral Ca increased morbidity in primiparous cows (control=38.1%; CaS1=61.8%; CaS4=60.3%) but had no effect on multiparous cows (control=38.2%; CaS1=35.1%; CaS4=30.1%). Large doses of oral Ca as salts of chloride and sulfate in the first days postpartum should be avoided in primiparous cows and used only in cows at risk of clinical hypocalcemia.

Combined use of progesterone inserts, ultrasongraphy, and GnRH to identify and resynchronize nonpregnant cows and heifers 21 days after timed artificial insemination.

The objective was to decrease the reinsemination interval (RI) when dairy cows and heifers are inseminated using all timed artificial insemination (TAI) programs. Holstein cows (n = 211) and heifers (n = 153) were randomly assigned to a control or 21-day Resynch (21dRES) at 13 days after TAI. Animals in 21dRES (n = 109 cows and 77 heifers) had a progesterone device inserted on Day 13 and removed on Day 20 after TAI and ovaries scanned by ultrasonography. Animals found not to have an active CL (<15 mm) or a CL that decreased 10 mm or greater from Days 13 to 20, and to have a follicle of 12 mm or greater received GnRH and TAI on Day 21. Pregnancy diagnosis was performed on Day 32. Nonpregnant control cows (n = 102) were resynchronized immediately using Ovsynch-56, and control heifers (n = 76) were resynchronized using 5-day Cosynch starting on Day 34; therefore, cows and heifers were reinseminated on Day 42. Nonpregnant 21dRES animals that had not been reinseminated on Day 21 were resynchronized concurrently with the control animals. Pregnancy per AI (PAI) for the initial TAI was similar (P = 0.80) for 21dRES and control cows (30.3% vs. 29.4%) and heifers (49.4% vs. 51.3%). Of the nonpregnant 21dRES animals, 33 of 76 cows (43.4%) and 22 of 39 heifers (56.4%) had been reinseminated on Day 21. Therefore, the RI was decreased by 9.9 days (33.3 ± 1.0 vs. 43.2 ± 1.0 days; P < 0.001) in 21dRES cows and by 12.2 days in 21dRES heifers (30.1 ± 1.3 vs. 42.3 ± 1.3 days; P < 0.001) compared with controls. The overall resynchronized PAI was similar for 21dRES cows compared with controls (31.6% vs. 25.0%; P = 0.23). The PAI was 24.2% for 21dRES cows reinseminated on Day 21 and 37.2% for 21dRES cows reinseminated on Day 42. The overall resynchronized PAI was increased for 21dRES heifers compared with controls (57.5% vs. 32.4%; P = 0.03) because 21dRES heifers reinseminated on Day 21 had similar PAI compared with controls (43.5% vs. 32.4%; P = 0.39), but PAI was increased for 21dRES heifers reinseminated on Day 42 compared with controls (76.5% vs. 32.4%; P = 0.003). Consequently, the proportion of animals pregnant from the initial and resynchronized TAI tended to be increased in 21dRES heifers (79.0% vs. 67.1%; P = 0.09). Cost per pregnancy was decreased for the 21dRES in heifers. In conclusion, 21dRES provided a useful method to decrease the RI in cows and heifers, and to increase PAI and decrease cost per pregnancy in heifers.