A cross-sectional study was conducted to estimate the prevalence of clinical lameness in high-producing Holstein cows housed in 50 freestall barns in Minnesota during summer. Locomotion and body condition scoring were performed on a total of 5,626 cows in 53 high-production groups. Cow records were collected from the nearest Dairy Herd Improvement Association test date, and herd characteristics were collected at the time of the visit. The mean prevalence of clinical lameness (proportion of cows with locomotion score >or=3 on a 1-to-5 scale, where 1 = normal and 5 = severely lame), and its association with lactation number, month of lactation, body condition score, and type of stall surface were evaluated. The mean prevalence of clinical lameness was 24.6%, which was 3.1 times greater, on average, than the prevalence estimated by the herd managers on each farm. The prevalence of lameness in first-lactation cows was 12.8% and prevalence increased on average at a rate of 8 percentage units per lactation. There was no association between the mean prevalence of clinical lameness and month of lactation (for months 1 to 10). Underconditioned cows had a higher prevalence of clinical lameness than normal or overconditioned cows. The prevalence of lameness was lower in freestall herds with sand stalls (17.1%) than in freestall herds with mattress stall surfaces (27.9%). Data indicate that the best 10th percentile of dairy farms had a mean prevalence of lameness of 5.4% with only 1.47% of cows with locomotion score = 4 and no cows with locomotion score = 5.

The compost bedded pack dairy barn is an alternative housing system for lactating cows that has received increased attention in the last 2 yr. No descriptive data were available about this housing system. Therefore, a study of 12 compost dairy barns in Minnesota was conducted between late June 2005 and September 2005. The objectives of this study were to describe the housing system, identify management practices used in these herds, observe cow welfare, analyze herd performance and udder health prior to and following the change in housing system, and measure producer satisfaction with the system. Producers were interviewed on various aspects related to the housing system and herd management, samples of milk were collected, and cows were scored for locomotion, body condition, hygiene, and hock lesions. In addition, historical bulk tank information and Dairy Herd Improvement Association data were collected when available. At the time of the visit, the Dairy Herd Improvement Association somatic cell count (SCC) was 325,000 +/- 172,000 cells/mL, rolling herd average was 10,457 +/- 1,138 kg per cow, and herd size was 73 +/- 35.5 lactating cows. The body condition score was 3.04 +/- 0.11, the cow hygiene score was 2.66 +/- 0.19, and 7.8% of all cows were clinically lame (locomotion score > or = 3 on a 1 to 5 scale). No hock lesions were present on 74.9% of the cows; 24.1% of cows had a mild lesion (hair loss), and 1.0% had a severe lesion (swollen hock). Historical analysis of the bulk tank SCC showed that 3 out of the 7 herds analyzed had a significant reduction in bulk tank SCC when compared with the previous housing system. Mastitis infection rates decreased significantly by 12% on 6 of the 9 farms analyzed. Reproductive performance significantly improved for 4 out of the 7 herds analyzed, with 25.9 and 34.5% improvement in heat detection rates and pregnancy rates, respectively. The main reasons producers reported for building this type of housing system were for improved cow comfort, cow health and longevity, and ease of completing daily chores. The largest concern was the cost and availability of bedding, especially as additional compost barns are built. Overall, all producers were satisfied with their decision to build a compost barn.

The objectives of the current experiment were to characterize the correlation among total serum Ca, nonesterified fatty acids (NEFA), β-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.

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Results suggest that the hygiene scoring system was repeatable, accurate, and easy to use. However, only hygiene scores for the udder and hind limbs and the udder-hind limb composite score were significantly associated with SCS.