The objectives of the present study were to describe, in detail, behavior associated with standing estrus (STE) in lactating dairy cows and behavioral changes during complete estrous cycles. Estrus signs were monitored by continuous video recording of 20 Holstein-Friesian (HF) cows housed on an outdoor wood-chip pad during 1 estrous cycle (22 d). Other social behavior was recorded during STE and, for comparison, during 1 selected day when none of the cows were in estrus. Standing stationary when mounted was defined as the primary estrus sign. Anogenital sniff, chin rest, attempt to mount, and mount were defined as secondary estrus signs. Ovarian cyclicity was confirmed by progesterone measurements. This study reports short mean duration of STE (7.1±1.44h) and estrus (mount period; 12.9±1.84h) of the 13 cows expressing these signs. All mounting activities involved at least one cow in, or within 4h of, STE. The most frequent sign during STE was anogenital sniff initiated, followed by chin rest received, chin rest initiated, chase up initiated, anogenital sniff received, mount initiated, head butt, mount received, attempt to mount initiated, push away received, play rub, attempt to mount received, follow initiated, threat received, flehmen, avoid, bellow, and social lick received. Standing and mounting activity in HF cows was inconsistent during estrus, indicating that other signs could be of greater use. The frequency of secondary estrus signs initiated and received increased gradually during the last 12h before STE, revealing significant differences between periods from 4 to 6 and 1 to 3h before STE. A considerable increase in receptive behavior (secondary estrus signs received) was identified between 1 to 3h prior to STE and STE. Both frequent initiated and received behaviors were associated with STE. A significant decrease in the frequency of secondary estrus signs initiated and received occurred 3h after STE. Cows in STE simultaneously predominantly chose the other standing cow as mate and expressed secondary estrus signs more frequently. Based on the results of this study, we suggest that chase up could be regarded as a reliable indicator of estrus and that the changes in proceptive (initiated) and receptive (received) behavior could be used as predictors of different stages in estrus. Knowledge of these behavioral signs may improve heat detection rates and the ability to predict the optimum breeding time for dairy cows.

Relationships among body condition score (BCS), milk constituents, and resumption of postpartum luteal function were studied in 162 lactations of first- and second-parity Norwegian dairy cows. Milk components included acetone, lactose, fat, protein, urea, and ratios of fat to protein and fat to lactose. Milk progesterone concentrations were used to determine intervals from calving to first luteal response (> 5 ng/ml). Intervals to first luteal response were divided into categories of early (< or = 24 d) or late (> 24 d) responses. Higher BCS were observed during wk 4 and 5 postpartum among both first- and second-parity cows with early compared with delayed luteal responses. Second-parity cows with early onset of luteal function also had higher BCS from wk 6 through 12, whereas first-parity cows with early onset of luteal function had higher BCS from wk 13 through 15. Higher acetone levels from wk 2 through 4 postpartum were associated with late luteal response in second-parity cows. Greater milk lactose content during wk 1, 2, 3, 6, 7, and 8 postpartum and higher fat fractions during wk 4 postpartum were related to early luteal response in second-parity cows. Relationships between milk constituents and onset of luteal function were less evident and occurred later postpartum among first-parity cows than among second-parity cows. Measures of weekly milk composites obtained during the early postpartum period and BCS were closely associated with postpartum resumption of luteal function. Acetone and lactose values in milk from the first 4 wk postpartum predicted postpartum luteal function in second-parity cows at a sensitivity of 0.84 and specificity of 0.86.

Thirty-one stabile murine monoclonal antibody (MAb) producing cell lines to progesterone were generated by using a short and a long immunization protocol. Long-term immunization with high doses of 11alpha-hydroxyprogesterone-hemisuccinate-bovine serum albumin (11alpha-OH-P-HS-BSA) antigen led to very good antibody response in Balb/c mice. The donor mouse produced antiserum with a high titre of 1/250,000. Eleven MAbs were selected for further characterization since they showed high sensitivities (<35 pg/well to inhibit 50% of the tracer) in bridge homologous enzyme immunoassay (EIA). The results were compared to the donor mouse polyclonal antiserum. The MAbs and the donor mouse antiserum were generally found to be highly specific, when tested with 30 different steroids. Employing MAb 9C11, with affinity constant, Ka, to 11alpha-OHP-HS of 1.1 X 10 10 M-1, a bridge heterologous microtitre plate EIA for milk progesterone was developed, using the second-antibody coating technique and horseradish peroxidase (HRP) as an enzyme label. The assay is simple and convenient to use, as it permits direct addition of undiluted milk samples, at the same time maintaining high sensitivity, high precision, and a wide range of optical density (OD) values. The major advantage of the assay developed, compared to previously published direct addition milk progesterone immunoassays, is that progesterone concentrations, measured by the EIA, were not influenced by changing milk fat concentrations, even when milk samples containing up to 10% of milk fat were used for analysis.

The aim of the study was to test the effect of two treatments in cases of acute puerperal metritis (APM) and clinical metritis (CM).