Effect of free stall surface on daily activity patterns in dairy cows with relevance to lameness prevalence

Differences in behavior of nonlame cows, slightly lame cows, and moderately lame cows in 6 free stall barns with sand bedding (SAND) vs. 6 free stall barns with rubber-crumb geotextile mattress surfaces (MAT) were documented in Wisconsin dairy herds. All lactating cows in the 12 herds were observed and given a locomotion score based on a 4-point scale: 1 = nonlame, 2 = slightly lame, 3 = moderately lame, and 4 = severely lame. Herd least square means +/-SE for prevalence of clinical lameness (locomotion scores = 3 and 4) were 11.1 vs. 24.0 +/- 1.7% for herds using SAND vs. MAT surfaces, respectively. Subsets of 10 cows per herd with locomotion scores of 1 to 3 were observed via video cameras for 24-h periods. Cows in MAT herds spent more time standing in free stalls per day than cows in SAND herds. Differences in standing times were 0.73 h/d for cows that were not lame, 2.32 h/d for cows that were slightly lame, and 4.31 h/d for cows that were moderately lame in MAT herds compared with equivalent cows in SAND herds. In MAT herds, the increase in time spent standing in the stall in moderately lame cows was associated with a significant reduction in stall use sessions per day, which impacted daily lying time. Although cause and effect are not clear, these findings have implications for housing, comfort, and care of cows in dairy herds with different types of free stall surfaces.     

Layouts for small freestall dairy barns: effect on milk yield for cows in different parities

Freestall housing for dairy cows has many different layouts and the space allocated for cows differs considerably. The objective of the present study was to investigate possible associations between barn layout and milk yield for different parities in small dairy freestall barns. Layouts of 204 Norwegian freestall barns constructed during the period from 1995 to 2005, and with a mean herd size of 42.7 ± 15.5 cows, were obtained and merged with milk yield data and calving interval, for each parity, from the Norwegian Milk Recording System (NDHRS). The milk yield data set contained 20,221 different lactations from these 204 herds. Both simple mixed models, including the different explanatory variables one by one together with parity, calving interval, and herd as random effect, and a final mixed model, including all significant explanatory variables, were created. According to variables tested in this study, the final mixed model estimates show that only primiparous cows benefit significantly from increased free space allocation. Milk yield was generally higher in automatic milking system barns compared with that in barns with milking parlors, but not for primiparous cows. Milk yield was higher for all parities for barns using separation pens in accordance with the recommendations. Barns with 2 or more dead-end alleys had lower milk yield compared with that from layouts without dead-end alleys. Primiparous cows benefited from water troughs located for easy access and responded with increased milk yield. In 10% of the barns, the water trough capacity was less than 47% of the recommendations, and all parities benefited from a water trough capacity higher than this level. Higher parities had increased milk yield when water trough capacity was more than 80%. Feed bunk space, number of freestall rows, and the location of freestalls had no significant effect on the milk yield. The present study showed that increased space and improved access to water is beneficial to primiparous cows, whereas layouts without dead-end alleys and improved water capacity is beneficial for all cows in freestall systems.     

Udder health of cows changing from tie stalls or free stalls with conventional milking to free stalls with either conventional or automatic milking

Udder health and milk production were monitored in cows transferred from tie stalls or loose housing with conventional milking to loose housing with either automatic or conventional milking. Data were collected from 182 Finnish farms from September 1999 to February 2006. Data from the first year before and first year after the changes were compared. A total of 88 herds changed from conventional milking (CM herds) to automatic milking (AM herds), 29 of which were housed in tie stalls and 59 of which were housed in a loose housing barn before the change. Additionally, 94 CM herds milked in loose housing barns that had been housed in tie stalls before the change were included. Milk record data consisted of annual herd size, parity, breed, calving dates, test day data [date, milk yield, and cow somatic cell count (SCC)] and records for treatments of clinical mastitis. Calculations were made for energy-corrected milk yield and logarithmic SCC (logSCC), proportion of cows at risk that experienced an SCC >200,000 cells/mL for the first time (highSCC), and number of treatments of clinical mastitis within a herd. Cows in tie stalls had higher milk yield (28.5 ± 0.29 vs. 26.5 ± 0.46 kg/d) and a lower logSCC (4.86 ± 0.01 vs. 4.95 ± 0.02) than cows in loose housing barns before the change. After the change, CM herds had slightly better udder health than AM herds because the proportion of cows at risk for highSCC was larger in AM herds (3.3 vs. 2.1%). The change in milking and housing systems caused a decline of 0.8 ± 0.25 kg/d per cow in energy-corrected milk yield, a slight increase in cow logSCC (from 4.88 ± 0.01 to 4.93 ± 0.01), and an increase of 0.6% in the proportion of cows having highSCC (from 2.5 to 3.1). The impact was clearer on herds that began automatic milking. Based on the results, the increase in bulk milk SCC of herds milked automatically in Finland was probably due to reduced separation of mastitic milk in AM herds.     

Herd- and cow-level prevalence of foot lesions in Ontario dairy cattle

The objectives of this cross-sectional study were to determine herd-level and cow-level prevalence estimates for 11 foot lesions in Ontario dairy cattle. Foot lesions were recorded by 5 hoof trimmers on 13,530 cows in 204 Ontario dairy herds from March 2004 to May 2005. Significant differences existed between free-stall and tie-stall housing. In free-stall housing systems, 46.4% of cows had a foot lesion, compared with 25.7% of cows in tie-stall barns. Digital dermatitis was the most common lesion in tie stalls, occurring in 9.3% of cows and 69.7% of the herds, whereas in free-stall herds, 22.7% of cows and 96.7% of the herds were affected. The most common hoof horn lesions were hemorrhages and ulcers, at 7.7 and 4.7% in tie-stall housing and 11.0 and 9.2% in free-stall housing, respectively. Foot blocks were used to treat 2.2% of cows in free stalls and 0.3% in tie stalls. Intraclass correlation coefficients ranged from 9.5 to 17.3 for hoof horn lesions and 28.0 to 38.7 for infectious lesions. In summary, foot lesions diagnosed at the time of hoof trimming are common in Ontario, and appropriate treatment for hoof horn lesions is low.     

Risk and success factors for good udder health of early lactation primiparous dairy cows

We compared the management and housing of dairy heifers from calf to calving in herds that were very successful versus less successful in preventing mastitis in early lactation primiparous cows. This retrospective observational study included 170 Swedish dairy herds. Eligible herds were identified from the Swedish official milk recording scheme (SOMRS). Each herd had at least 60 cows per year, production data from 3 consecutive years, and at least 10 primiparous cows per year with their first milk recording 5 to 35 d after calving and their second milk recording 20 to 40 d after the first milk recording. In each herd, primiparous cows with a low (≤75,000 cells/mL) cow somatic cell count (CSCC) at both the first and second milk recording were categorized as low-low (LL); those with a high (>100,000 cells/mL) CSCC at both recordings were categorized as high-high (HH). Cows with high CSCC at the first recording and low at the second were categorized as high-low (HL). The annual proportions of LL, HL, and HH cows within each herd were calculated. Herds with an above-median proportion of LL, HL, or HH cows during the first year of a 3-yr selection period, and above the third quartile proportion of LL, HL, or HH cows, respectively, during the second and third year were identified. These herds (LL herds, n = 129; HL herds, n = 92; HH herds, n = 139) were contacted until a maximum of 60 herds per category had agreed to participate. Field technicians/veterinarians visited each herd once in the mid to late indoor season to collect data on housing and management of the heifers from birth to calving. Additional data were retrieved from the SOMRS. Associations between herd category (LL, HL, or HH) and variables collected were analyzed in 8 multivariable multinomial logistic regression submodels covering herd characteristics, milk-fed calves, heifers in early pregnancy, heifers in late pregnancy, calving and colostrum period, miscellaneous factors, summarized heifer housing data, and general health, culling, and fertility data. A final multivariable model was built from the results of the submodels and univariable analyses. The final model showed that having a standard operating procedure for colostrum feeding was more common in LL and HL herds than in HH herds; the mean bulk milk SCC and overall culling rate due to udder health was higher in HH herds than in LL and HL herds; and automatic milking was less common in LL herds than in HL and HH herds. Several herd and management variables differed between herd categories in the submodels. In conclusion, we identified several success factors for herds with good udder health among early lactation primiparous cows. This knowledge can be used to improve preventive measures in dairy herds to ensure sustainable and economic milk production.     

Calf mortality in Norwegian dairy herds

The aims of this study were to estimate mortality rates in Norwegian dairy calves and young stock up to 1 yr of age, identify risk factors for calf mortality, and evaluate the etiology of calf mortality based on postmortem analyses. The material comprised 3 data sets. The first data set included information on 289,038 offspring in 14,474 dairy herds registered in the Norwegian Dairy Herd Recording System (NDHRS) in 2005. The second included recordings on 5,382 offspring in 125 Norwegian dairy herds participating in a survey on calf health, and the third included results from postmortem analyses of 65 calves from 37 of the survey herds. The calf mortality rate during the first year of life in all herds registered in the NDHRS was 7.8%, including abortion (0.7%) and stillbirth (3.4%). The overall calf mortality rate in liveborn calves in the survey herds was 4.6%. Cows with severe calving difficulties had an odds ratio (OR) of 38.7 of stillbirth compared with cows with no calving difficulties. Twins and triplets showed an increased risk of stillbirth compared with singletons (OR = 4.2 and 46.3, respectively), as did calves born in free stalls compared with tie stalls (OR = 1.9). Respiratory disease increased the risk of death in all age groups with hazard ratios (HR) of 6.4, 6.5, 7.4, and 5.6 during the first week of life, 8 to 30 d of age, 31 to 180 d of age, and 181 to 365 d of age, respectively. Diarrhea increased the risk of death among calves younger than 180 d of age, but the influence was only significant during the first week of life and between 8 to 31 d of age (HR = 2.4 and 2.9, respectively). Calves born during the winter were more likely to die during the first week of life than calves born during the summer (OR = 1.2), and were more likely to die during the first month of life than calves born during the autumn (OR = 1.2). Calf mortality rates in all age groups increased with increasing herd size. Calves housed in a group pen from 2 wk of age were more likely to die during the first month of life than calves housed individually (HR = 1.5). Bronchopneumonia and enteritis were the most frequent postmortem diagnoses, with proportional rates of 27.7 and 15.4%, respectively.     

Chlamydophila species in dairy farms: Polymerase chain reaction prevalence, disease association, and risk factors identified in a cross-sectional study in western Germany

The prevalence of Chlamydophila spp. was determined in a cross-sectional study carried out in 2007 using 100 randomly selected dairy herds in the western part of Germany. Ten dairy cows per herd were sampled in herds with fewer than 100 cows; in bigger herds, 10% of the cows were sampled. For the detection of Chlamydophila spp., vaginal swabs from early lactating dairy cows were analyzed using an established highly sensitive genus-specific real-time PCR. In consideration of the discontinuous shedding of the pathogen, a herd was classified as positive if at least 1 animal per herd tested positive for Chlamydophila spp. By use of these methods and definitions, 61% of the dairy herds and 13.5% of the cows were detected as PCR-positive for Chlamydophila spp., which is indicative for ongoing infections. To compare herd health and herd performance between herds testing positive or negative and to identify risk factors for the presence of Chlamydophila spp., a questionnaire was designed to evaluate farm characteristics and management practices. In addition, the performance recordings of the state dairy recording organization were used for these purposes. Milk yield, number of lactations, and calving to first-service interval were lower in herds testing positive for Chlamydophila spp. compared with negative herds. For all these variables, there was no interaction between Chlamydophila status and lactation number. Replacement of animals from outside sources, use of breeding bulls, lack of separate calving pens, and low scores for cleanliness of beddings, walkways, and cows were identified as the main risk factors for Chlamydophila spp.     

Transition cow nutrition and management strategies of dairy herds in the northeastern United States: Part I—Herd description and performance characteristics

Our objective was to describe management and herd characteristics of the transition period on freestall dairy herds in the northeastern United States using an on-farm survey and prospective cohort design. Enrolled herds (n = 72) had a median of 900 milking cows (range: 345–2,900) and a rolling herd average of 12,674 kg (standard deviation ± 1,220 kg), and 87.2% (n = 82/94) of fresh pens were milked at least 3×/d. The prevalence of herds with ≥15% of sampled cows with elevated concentrations of nonesterified fatty acids prepartum (≥0.27 mmol/L, 2–14 d before parturition) and postpartum [primiparous: ≥0.60 mmol/L, multiparous: ≥0.70 mmol/L, 3–14 d in milk (DIM)], β-hydroxybutyrate postpartum (≥1.2 mmol/L, 3–14 DIM), and haptoglobin postpartum (≥1 g/L, 0–12 DIM) was 51%, 51%, 51%, and 57%, respectively. In most herds, cows were moved to a calving pen when showing signs of labor (73.6%; n = 53/72) instead of 0 to 3 d before expected calving (26.4%, n = 19/72). Cows remained in the calving or maternity pen for a median (range) time of 2 (0–24) h after parturition before moving to the next pen. Primiparous cows remained in the first pen moved to after parturition for a longer period than multiparous cows [median (range) days: 12 (1.5–25) vs. 6 (1.5–22)]. Approximately 20% of herds had routine vaccinations administered in the maternity or calving pen, first pen after parturition, or both. Almost all herds (n = 69/72) performed fresh cow health checks; however, only 53% (n = 38/72) locked up all fresh cows daily. More herds housed primiparous and multiparous cows in separate pens during the far-off dry (65.3%; n = 47/72) and high-lactation (81.9%; n = 59/72) periods compared with the close-up dry (31.9%; n = 23/72) and fresh periods (27.8%; n = 20/72). At least half of the pens observed during the far-off dry, close-up dry, and fresh periods had a stocking density <100%. Approximately one-third of pens observed during the far-off dry period had feed pushed up ≤4×/d compared with approximately 15 to 20% of pens observed during the close-up dry, fresh, and high-lactation periods. More than half of the total mixed ration samples acquired from the far-off and close-up dry period visits had greater than the recommended proportion of particles in the 19-mm screen of the Penn State Particle Separator. The results of this observational study illustrated the range of management practices used in freestall herds in this region and lay the groundwork for future hypothesis-driven studies using this sampled population.     

Associations between nondietary factors and dairy herd performance

Forty-seven dairy herds (approximately 3,129 lactating cows) from northeast of Spain that were offering exactly the same lactating ration were surveyed to determine the effect of nondietary factors on herd performance. The survey collected information on the profile of the owners (their future intentions, the number of workers, and time devoted to the enterprise), information regarding the animals (reproductive performance, incidence of pathology, culling rate, etc.), information on the facilities (number of feeders, waters, stalls, cleanliness, etc.) and information on management practices (numbers of daily milkings, feed deliveries, feed push-ups, cleaning frequency, etc.). In addition, the chemical quality of drinking water from each dairy enterprise was determined. Also, amount of feed delivered to each herd, daily total milk production, and milk quality were obtained for each herd for a period of 8 mo before the fulfillment of the survey. Mortality rate of calves tended to be lesser in herds that weaned progressively than in those that weaned abruptly. Age at first calving was negatively correlated with level of milk production (mainly due to the type of heifer rearing system used). Culling rate tended to be lower in herds that used a close-up ration than in those that did not. Using gloves and paper towels (instead of cloth towels) tended to reduce the somatic cell count in milk. Concentration of calcium in the drinking water tended to be negatively correlated with the number of days open and with the proportion of cows culled due to infertility problems. Despite that the 47 herds fed the same ration and shared a similar genetic base, average milk production per cow ranged from 20.6 to 33.8 kg/d. A positive relationship (r = 0.57) between the number of stalls per cow and milk production was found. The most important nondietary factors that affected milk production in these dairy herds were age at first calving, presence or absence of feed refusals, number of free stalls per lactating cow, and whether feed was pushed up in the feed bunk. These factors accounted for more than 50% of the observed variation, not attributable to the diet, in milk yield.     

Survey of calf and heifer housing on Pennsylvania dairy farms

Research has established a link between calf and heifer housing and calf health. To determine current calf and heifer housing practices in Pennsylvania, 329 dairy farms were surveyed. The study was designed to increase awareness on the part of dairy farmers in housing and management and to develop education programs and materials in the area of calf and heifer management. All surveys were conducted on the farm by personal interviews. Results showed 24.9% of the farms had maternity pens in a building separate from the milking herd, although half of these farms used maternity pens in conjunction with facilities of lesser quality for the health and management of the animals. The same number of farms used calf hutches as those keeping calves in dairy barns with cows. A high percentage of the farms weaned calves (moved from milk diets to dry feed diets) to recommended types of facilities that included group pens, loose housing, and group or superhutches. However, 49.5% of the facilities used for weaned calves were in conjunction with other dairy animals. Animal restraint facilities have also been identified as an area that needs more emphasis on dairy farms. Many areas of dairy replacement housing on commercial dairy farms were determined to be unsatisfactory according to recommended Pennsylvania standards.     

Modeling milk production and labor efficiency in modernized Wisconsin dairy herds

The 1999 Wisconsin Dairy Modernization Project was conducted to examine variation in milk production and labor efficiency among herds that had recently expanded. Data were obtained from a sample of Wisconsin herds that expanded between 1994 and 1998. Using rolling herd average milk production in 1998 as the dependent variable in the milk production model, milking frequency, bovine somatotropin use, sprinkler use, average linear somatic cell score, average age at first calving, average days dry, and rolling herd average milk production in 1994 predicted 69% of the variation in milk production. Milking three times daily, using bovine somatotropin, using sprinklers to cool cows, and decreasing linear somatic cell score, age at first calving, and days dry were associated with increased milk production. Each of these variables supports previous research from designed experiments with on-farm results. Variation in milk production is determined primarily by differences in management ability and management practices employed by the dairy producer. Using cows per full-time equivalent as the dependent variable in the labor efficiency model, acres per cow, number of people involved in the milking operation, milking system type, herd size, and interactions between milking system types and herd size predicted approximately 43% of the variation in labor efficiency. As expected, labor efficiency increased with larger herd sizes, fewer acres per cow, and fewer people involved in the milking process. Parallel milking parlors were associated with the highest cows per full-time equivalent followed by herringbone parlors, flat barns, and stall barns.     

Prevalence of lameness in high-producing holstein cows housed in freestall barns in Minnesota

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 ≥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.     

Herd-level risk factors associated with cow mortality in Swedish dairy herds

An increase in on-farm mortality (euthanasia and death) in dairy herds has been reported in several countries in the last decade. This does not only imply possible problems with animal welfare, but it also causes economic losses to the farmer. The objective of this study was to evaluate time trends in on-farm dairy cow mortality in Sweden and identify potential herd-level risk factors. Data were retrieved on all Swedish dairy herds enrolled in the milk recording scheme between 2002 and 2010. Herds with a herd size of <20 cows or a mortality rate (MR) of >40 dead or euthanized cows per 100 cow-years were excluded. Two different models were used: 1 multiple-year analysis, which included 6,898 herds during the period 2002 to 2010 and 1 single-year analysis including 4,252 herds for the year 2010, where other variables that were not present during the entire multiple year study were analyzed. The outcome variable was the number of euthanized and dead cows per year and season. A negative binomial regression model, adjusted for clustering within herd, was applied to both models. Fixed effects in the multiple-year analysis were breed, calving interval, herd size, milk yield, region, season, pasture period, and year. The fixed effects in the single-year analysis were breed, calving interval, conventional versus organic farming, herd size, housing system, milk yield, region, and season. The results demonstrated that MR gradually increased from 5.1 to 6.6 events per 100 cow-years during the study period. Swedish MR are consequently on par with, or even greater than, MR among dairy herds in other comparable countries. Higher mortality was associated with larger herd size, longer calving intervals, and herds that had Swedish Holstein as the predominant breed. Lower mortality was observed in herds with a higher herd average milk yield, during the fall and winter, and in organically managed herds. There were regional differences in mortality. An interaction between herd size and season was found in both models. Also, an interaction between housing system and milk yield was found in the single-year analysis. This first assessment of on-farm mortality in Swedish dairy herds confirmed that the MR has increased over the last few years. The study also identified some herd-level risk factors.     

Separate housing for one month after calving improves production and health in primiparous cows but not in multiparous cows

The hypothesis was that dairy cows housed for 1 mo after calving in a separate group with herd mates would produce more milk and would be healthier than cows integrated in a group of all lactating cows immediately after calving. The experiment was conducted with 489 cows in 6 commercial loose-housing dairy herds where cows were randomly selected for treatment (separate housing) or control. Cows selected for treatment were housed for 1 mo after calving in a separate section, and controls were housed in the remaining section of the barn for lactating cows. Data were compared for milk yield, somatic cell count, medical treatments, reproductive performance, culling, mortality, and clinical observation of scores for body condition, leg and udder hygiene, lameness, hock lesions, other cutaneous lesions, vaginal discharge, and condition of the hair coat. The analysis of the effect of separate housing showed that primiparous cows produced more milk [approximately 230 kg of energy-corrected milk from 0 to 305 d in milk (DIM)], whereas multiparous and especially parity 3+ cows produced less milk (approximately 394 kg of energy-corrected milk from 0 to 305 DIM) during the lactation. Separate housing had no effect on mortality or reproductive efficiency. In primiparous cows, the number of medical treatments for ketosis was reduced by separate housing [hazard ratio 0.33, 95% confidence interval (CI): 0.13-0.83]. Clinical evaluations showed that separate housing decreased the scores for hock lesions in cows at 0 to 30 DIM (odds ratio 0.41, CI: 0.19-0.91), whereas the scoring of leg cleanliness showed more dirty legs in separated cows at 0 to 30 DIM (odds ratio 3.61, CI: 2.01-6.47) compared with cows integrated into the herd immediately. The body condition score in separated cows was reduced from 0 to 30 DIM (score reduced by 0.16, CI: 0.07-0.25) and from 31 to 60 DIM (score reduced by 0.13, CI: 0.04-0.23) compared with cows integrated immediately. We concluded that separate housing for 1 mo after calving increased milk yield in primiparous cows but not in multiparous cows, which produced less milk. The hypothesis about fewer health problems could only be confirmed with regard to fewer primiparous cows being treated for ketosis.     

Management practices and reported antimicrobial usage on conventional and organic dairy farms

The primary objective was to compare reported antimicrobial usage between conventional and organic dairy farms. A secondary objective was to contrast selected management characteristics of conventional and organic dairy herds. A questionnaire was administered on site to selected dairy farmers located in Michigan, Minnesota, New York, and Wisconsin. Organic herds (n = 32) were smaller and produced less milk than conventional herds (n = 99). Lactating cows in organic dairies were more likely to be housed in tie stalls, whereas most conventional dairies housed cows in free stalls and milked in a parlor. Total mixed rations and purchased feeds were used on more conventional dairy farms compared with organic dairy farms. Conventional dairy producers were more likely to use advice from veterinarians for recommendations of treatment, and organic dairy producers were more likely to rely on advice from other farmers. Based on recall of antibiotic usage in the previous 60 d, 5.1, 84.9, 9.1, and 0.9% of farmers with conventional herds reported treatment of none, 1 to 10%, 11 to 25%, and >25% of milk cows, respectively. Most organic farmers (90.6%) reported no antibiotic treatments of milk cows, whereas 9.4% reported treating 1 to 10% of milk cows. Ceftiofur was the most commonly reported antibiotic for both farm types. Milk replacer containing antibiotics was reportedly used on 49.5% of conventional herds but only on one organic herd (3.1%). Antibiotics were used in heifer calves on 74.7% of conventional herds versus 21.9% of organic herds. Antibiotics to treat mastitis were used on 79.8% of conventional herds but on none of the organic herds. Most organic farms were in compliance with standards in advance of implementation of regulations.     

Mastitis control in Swedish dairy herds

The aim of this study was to investigate which preventive measures targeting mastitis are implemented in Swedish dairy herds with different housing and milking systems. Data were collected through a self-administered postal questionnaire sent to 898 dairy farmers, stratified by housing and milking system, in May 2011. The questionnaire contained general questions about the herd and the person responsible for the udder health of the cows, and specific questions about perceived udder health and the implementation of preventive measures. The response rate was 48%. The median herd size of participating herds was 80 cows, and the median herd average milk yield per cow was 9,586 kg of milk. External validity was assessed by comparing participating herds with nonresponders in respect to key performance indicators in the Swedish official milk recording system; no significant differences were found. When herds with combined systems had been removed, 400 herds with tiestalls and pipeline milking, freestalls and parlor milking, and freestalls with an automatic milking system remained. Differences between herd types were analyzed using the Kruskal-Wallis test and Fisher’s exact test. The results showed that herd types differed in their rates of implementation of different preventive measures. Freestall herds with milking parlors implemented more preventive measures related to milking hygiene and milking routines than did tiestall herds. A milking order based on the udder health status of the cows was frequently implemented in tiestall herds, but not in most herds with an automatic milking system or most freestall herds with milking parlors. Irrespective of herd type, the proportion of herds in which cows were kept standing for at least 30 min after milking was low. A substantial proportion of herds ignored the udder health status of lactating cows when grouping them, and few herds grouped dry cows according to udder health status, although this occurred more frequently in tiestall herds. A large proportion of herds, especially those with tiestalls, did not allow cows and heifers to calve in single pens that were cleaned between animal occupations. These findings can be used to tailor advice on mastitis specifically to different herd types and thus improve the efficiency of mastitis control.     

The effect of stocking density and a blind on the behavior of Holstein dairy cows in group maternity pens. Part II: Labor length,lying behavior,and social behavior

In natural settings, dairy cows separate from the herd to give birth. When kept indoors, seeking isolation before calving may be restricted and may depend on space and resources provided in maternity housing. The effect of group maternity pens on behavior around calving and labor progress is unknown. Therefore, the objective of this study was to determine the effects of stocking density and provision of a blind in group bedded pack maternity pens on lying and social behavior as well as length of labor of preparturient dairy animals. The study was conducted as a complete randomized block design with a 2 × 2 factorial arrangement of treatments including stocking density and presence or absence of a blind, resulting in a total of 4 treatments: (1) high stocking density (7.7–12.9 m² lying space/cow) with a blind, (2) low stocking density (15.4–25.8 m²) with a blind, (3) high stocking density without a blind, and (4) low stocking density without a blind. A total of 127 primiparous heifers and 247 multiparous cows were housed in mixed-parity groups from approximately 3 wk before and immediately after calving. During the 4 h before calving, lying behavior (lying time and bouts) was collected automatically using accelerometers, and social behavior (agonistic interactions, allogrooming, and attention from other cows), stage II labor duration, and frequency of position change during stage II labor were collected using video. Lying behavior was collected with accelerometers. Regardless of treatment, lying time and bouts increased as calving approached. Cows and heifers performed more lying bouts in low stocking density pens compared with high stocking density pens. Agonistic interactions and allogrooming were not different between treatments. Other cows spent more time paying attention to focal animals regardless of stocking density as calving approached, but time spent paying attention was reduced by the presence of a blind during h ?2 before calving. The hazard of calving unassisted was greater for cows and heifers in low stocking density pens with a blind compared with all other treatments. Further, animals in pens with a blind tended to change positions fewer times during stage II labor. These results suggest that providing a blind in group maternity pens may improve the calving environment for cows and heifers and, in combination with low stocking density, may reduce the amount of time spent in labor.     

Bovine claw and limb disorders related to reproductive performance and production diseases

As part of a cross-sectional study of Norwegian Red Cattle, associations of lameness, lesions at the tarsus, claw shapes, and claw lesions with reproductive performance and production diseases were examined. Fifty-five tiestall herds and 57 freestall herds were sampled by computerized systematic selection and 2,665 cows were trimmed and limb and claw disorders recorded by 13 specifically trained claw trimmers during the late winter and spring of 2002. After exclusions, 2,583 cows were included in this study. Most claw lesions were mild (score 1). Prevalence of moderate and severe lesions (score 2 + 3) did not exceed 5% for any of the lesions. Hazard ratios for independent variables were identified using Cox regression analyses incorporating herd as a random effect in a positive stable frailty model. Wounds and swellings at the tarsus were associated with more clinical mastitis [hazard ratio (HR) = 4.0] and teat injuries (HR = 2.5). Moderate and severe heel-horn erosions in first-lactation cows were associated with increased calving interval (HR = 0.60). Moderate and severe hemorrhages of the sole in first-lactation cows were associated with decreased interval from calving to first service (HR = 1.6) and moderate and severe hemorrhages of the sole were associated with more milk fever (HR = 8.6). All hemorrhages of the sole (scores = 1, 2, and 3) were associated with more reproductive hormonal treatments (HR = 2.3). All sole ulcers in first-lactation cows were associated with longer interval from calving to last service (HR = 0.59) and longer calving interval (HR = 0.61), whereas sole ulcers in older cows were associated with longer calving interval (HR = 0.62). All sole ulcers also were associated with more milk fever (HR = 4.8) in all cows. Moderate and severe sole ulcers in older cows were associated with increased interval from calving to first (HR = 0.35) and last (HR = 0.37) service. Moderate and severe white-line fissures in older cows were associated with increased return rate from previous insemination (HR = 2.4). Our study shows that claw disorders are associated with poorer reproductive performance and some production diseases.     

Calf mortality in Virginia Dairy Herd Improvement herds

Information concerning heifer calf mortality and dairy herd management practices was obtained by survey of 407 Virginia Dairy Herd Improvement herds. Dairy producers, with the assistance of Dairy Herd Improvement supervisors, accounted for mortality of all heifer calves born from October 1, 1978 to March 31, 1979. Calf mortality was compared among herd sizes, fat and milk production, cow and calf housing systems, calving locations, and calf feeding practices. Average herd size was 82 cows with 87% of herds containing fewer than 120 cows. Mortality at birth and from birth through 3 mo of age averaged 1.2 and 6.5%. Mortality at birth was correlated .10 with herd size. Losses from birth through 3 mo of age were correlated .10 with age at weaning and -.16 with rolling yearly average milk and fat production. Relationship of mortality with other herd characteristics or management practices was negligible.