Tiestall Farms Research Articles

Associations of the Swiss national reporting system's antimicrobial use data and management practices in dairy cows on tiestall farms

Antimicrobial use (AMU) in Switzerland is above target and requires reduction, especially in dairy cattle. Measuring AMU is pivotal to identifying starting points for AMU reduction, and so are studies investigating its potential drivers in dairy farms worldwide. However, although AMU in dairy farms is high, studies estimating AMU specifically in tiestall farms are scarce. Tiestalls are a common housing system and their prevalence among dairy farms accounts to approximatively 73%, 41%, and 40% in Canada, the United States, and Switzerland, respectively. The objectives of this cross-sectional, retrospective observational study were to estimate AMU using the newly established Swiss national reporting system for AMU in livestock and to identify associated factors on Swiss tiestall dairy farms. We calculated the treatment incidence (TI) by using the European Medicines Agency methodology and their defined daily dose (DDD) and defined course dose (DCD) standards. Data on factors potentially associated with AMU were obtained through personal interviews with farm managers on 221 farms. Retrospectively, during a 1-year period, data on a total of 7,619 treatments were extracted from the national database. Associations between management factors and TI were analyzed using a generalized linear model with gamma distribution. The mean (± SD) overall TI was 5.46 DDD/cow-year (± 4.10 DDD/cow-year). Intramammary treatment during lactation accounted for highest TI (3.24 ± 3.16 DDD/cow-year), whereas dry-cow therapy accounted for lowest TI (0.44 ± 0.49 DCD/cow-year). We found that 5 of the investigated management factors were significantly associated with TI. Organic production (estimate = -2.16; 95% CI = -3.62 to -0.70) and herd size (estimate = -0.81; 95% CI = -1.23 to -0.39) were negatively associated with TI. Specific cow breeds (Brown Swiss estimate = 1.56; 95% CI = 0.45-2.68) and Holstein Friesian (estimate = 1.42; 95% CI = 0.03-2.82; reference: other breeds) and the use of hygienic powders on the lying area (estimate = 1.10; 95% CI = 0.04-2.17) were positively associated with TI. Overall, the Swiss national reporting system is a valuable tool for AMU estimation. Several herd characteristics and management factors were associated with AMU in tiestall farms. Further studies focusing on factors associated with AMU and which are amenable to intervention will help improve stewardship programs and subsequently reduce AMU in dairy cows.

Bioaerosols in Eastern Canadian Dairy Barns Using Tie- and Free-Stall Housing

Highlights Building characteristics (ventilation and animal density) seem to have an important effect on air quality. Concentration in the air seems to be influenced by amounts in the bedding for certain air quality indicators. Dust concentrations were below OSHA threshold, while some barns exceeded DECOS threshold for endotoxins. This study gives new data into the biological components in the air of dairy barns (bacteria, molds, endotoxins, etc.) Free-stall or tie-stall housing may not be linked with poorer air quality. Abstract. Alternative farming methods make it possible to satisfy public demands for animal welfare while preserving production efficiency, with free housing in dairy farms being an example. The increased movement of cows may have a negative impact on air quality and the presence of etiological agents, increasing the prevalence of lung disease in workers. Free-stall farms, however, are more spacious and modern than tie-stall farms. This study characterizes air quality in free-stall and tie-stall farms (dust, total bacteria, Penicillium/Aspergillus, archaea, and endotoxins). It also focuses on detecting airborne etiological agents and indicators of fecal contamination, as well as assessing the effect of environmental factors on air quality. Five farms of each type (free housing and tie housing) using straw bedding material and equipped with mechanical ventilation were visited. Sampling visits were conducted in winter with no activity (e.g., bedding spreading) in buildings. Dust was evaluated using the DustTrakTM DRX Aerosol Monitor, and bioaerosols were sampled in triplicates for 10 minutes using the SASS®3100 Dry Air Sampler. Finally, soiled bedding was collected throughout the barn. No type of housing seems to be linked with poorer air quality, but some air quality indicators stood out in some outliers. The most recently designed free-housing buildings and the greater air volume may have played a role in the absence of detected differences. Escherichia coli, Enterococcus spp., Clostridium perfringens, Aspergillus fumigatus, Staphylococcus aureus, Saccharopolyspora rectivirgula, Coxiella burnetii, and Klebsiella pneumoniae were detected in high concentrations in both types of buildings. Soiled bedding concentrations, ventilation rates, and animal density seemed to have a significance on air quality in dairy barns. Keywords: Air Quality, Bioaerosols, Housing, Occupational exposure.

Milking system and premilking routines have a strong effect on the microbial community in bulk tank milk

In this study, we investigated the variation in the microbial community present in bulk tank milk samples and the potential effect of different farm management factors. Bulk tank milk samples were collected repeatedly over one year from 42 farms located in northern Sweden. Total and thermoresistant bacteria counts and 16S rRNA gene-based amplicon sequencing were used to characterize microbial community composition. The microbial community was in general heterogeneous both within and between different farms and the community composition in the bulk tank milk was commonly dominated by Pseudomonas, Acinetobacter, Streptococcus, unclassified Peptostreptococcaceae, and Staphylococcus. Principal component analysis including farm factor variables and microbial taxa data revealed that the microbial community in milk was affected by type of milking system. Milk from farms using an automatic (robot) milking system (AMS) and loose housing showed different microbial community composition compared with milk from tiestall farms. A discriminant analysis model revealed that this difference was dependent on several microbial taxa. Among farms using an automatic milking system, there were further differences in the microbial community composition depending on the brand of the milking robot used. On tiestall farms, routines for teat preparation and cleaning of the milking equipment affected the microbial community composition in milk. Total bacteria count (TBC) in milk differed between the farm types, and TBC were higher on AMS than tiestall farms (log 4.05 vs. log 3.79 TBC/mL for AMS and tiestalls, respectively). Among tiestall farms, milk from farms using a chemical agent in connection to teat preparation and a more frequent use of acid to clean the milking equipment had lower TBC in milk, than milk from farms using water for teat preparation and a less frequent use of acid to clean the milking equipment (log 3.68 vs. 4.02 TBC/mL). There were no significant differences in the number of thermoresistant bacteria between farm types. The evaluated factors explained only a small proportion of total variation in the microbiota data, however, despite this, the study highlights the effect of routines associated with teat preparation and cleaning of the milking equipment on raw milk microbiota, irrespective of type of milking system used.

Influence of the Housing System and the Season on Some Parameters Indicative of the Welfare of Dairy Cows in Eastern Algeria

The purpose of this study is to evaluate the effect of housing systems (free vs. tie-stall) and season (winter vs. spring) on the welfare of dairy cows through indices of cleanliness, leg health (straightness, hocks and knees), lameness score, body condition and milk production. This is to test the hypothesis that dairy cows in spring and free-stalls have a better quality of well-being than those kept in tie stalls in winter. For that, 299 dairy cows of the Holstein and Montbeliard breeds were selected from dairy farms in 6 communes of the Constantine governorate in eastern Algeria. The results showed that tie-stalled farms in winter were characterized by a lack of hygiene (P <0.001), with a stall cleanliness score of 7.62 and a frequency of 32.60% of dirty to very dirty cows. In the spring, the incidence of severe lameness does not exceed 9% in farms with tie stalls and more than 41% in mild lameness in housing with free stalls (P <0.001). Cows in tie stalls show a deviation of legs of 17° to 24° (57.97%). On the other hand, more than half of cows in free stalls show integumentary lesions (alopecia and swelling) of the carpal (60.25%) and tarsal joints (54.22%) (P <0.001). The percentage of fairly lean cows (score 2-2.5), housed in tie stalls, was significantly higher (18 to 44%) with a significantly low milk production (P <0.001). These results reflect a lack of comfort in tie-stall farms during winter which has an impact on dairy performance.

Survey of feeding practices on dairy farms in Ontario and western Canada

To establish a baseline understanding of feeding practices on Canadian dairies, a survey was distributed online to dairy producers. Responses were split into three categories as follows: western provinces (WP; Alberta, British Columbia, Manitoba, and Saskatchewan; n = 84), Ontario freestall farms (n = 75), and Ontario tiestall (OT) farms (n = 71). Regional differences were observed for many feed ingredients; for example, corn and soybean meal were more commonly used in Ontario, whereas barley, wheat products, and grass hays were more commonly used in the WP (P ≤ 0.01), consistent with local production of those crops. Producers ranked the most important factors in balancing rations in the following order: production (lactating cattle or heifers) or health (dry cows), cost, simplicity, and nutrient management; however, nutrient management was more important in the west for all types of diets (P < 0.01). Most farms frequently tested for ration dry matter and nutrient composition, although OT farms tested less often than other groups (P = 0.09). Overall, feeds aligned with common crops grown within region. Canadian farmers have a stated interest for improving production and health and place less emphasis on other factors such as cost, simplicity, and nutrient management.

Making tiestalls more comfortable: IV. Increasing stall bed length and decreasing manger wall height to heal injuries and increase lying time in dairy cows housed in deep-bedded tiestalls

Poor stall configuration can negatively affect cow welfare by impairing lying behavior and leading to injuries in dairy cows. The comfort of the stall bed in tiestalls is affected by the material components of the stall bed (stall base and bedding), but also by the amount of space provided. The amount of space cows are able to access lengthwise in a tiestall is determined by the stall bed length and the height of the manger wall (the front limit of the stall bed), which can limit access into the space available at the front of the stall. This project aimed to maximize cow comfort in deep-bedded tiestalls by investigating the combined effect of increased bed length and decreased manger wall height in a crossover experiment (2 periods with 1 wk habituation + 6 wk data collection). Two rows of 12 tiestalls were modified (n = 24 cows). Each row was a different length, short (178 cm; length commonly found in Quebec) or long (188 cm), and cows remained on the same row (same stall bed length) for the entire experiment. In each row, there were 6 stalls of each manger wall height treatment: high (20 cm, upper limit recommended) or low (5 cm). During period 2, cows switched manger wall height treatments. A 7.6-cm-deep straw bedding layer was added to all stalls by adding a bedding keeper to the ends of stalls. All initially injured locations healed over the 14-wk study, and 2 patterns of healing emerged. Improvement in hock injury (lateral tarsal and calcanei) was observed from wk 1 to 6 for all treatments. A plateau in injury severity score reduction was observed in period 2 for the hock (lateral, dorsal, and medial calcanei), anatomical knee, carpal joints (front knees), and proximal and medial neck, which was likely the result of the insensitivity of the injury scoring scheme rather than healing not occurring. Cows in long stalls were found to spend more time lying (14.1 vs. 13.3 h/d) and had longer lying bouts than cows in short stalls (74.1 vs. 52.9 min/bout). Manger wall height did not affect injury or lying time, but may affect how cows position themselves while lying. Higher lying times in our study were comparable to those reported in deep-bedded loose pens, indicating that cows with more bedding, especially those in long stalls, were more comfortable. Our results suggest that deep-bedded straw stalls with bedding keepers have the potential to be beneficial to cow comfort on tiestall farms.

Short communication: Use of the Clegg hammer measure as an indicator of stall-surface compressibility in tie-stall housing and its relationship with stall comfort

Stall base and stall surface (i.e., with or without bedding) are key risk factors in cow comfort in dairy herds. In Canada, rubber mats, concrete floors, and mattresses are the most common stall bases used in tie-stall systems. Straw, wood shavings, and sand, at variable depths, are the most commonly used type of bedding. The Clegg hammer (Clegg Impact Soil Tester Hammer; Lafayette Instrument Company, Lafayette, IN) is a tool used by engineers to test the compressibility of pavement or golf course surfaces. Recently, this tool has also been used to measure the compressibility of the stall surface on freestall dairy farms. A total of 32 tie-stall dairy herds were selected in Québec to test the usefulness of the Clegg hammer as a tool to assess stall surface compressibility in tie-stall housing. This study had 2 main objectives: (1) identify the location and the number of measurements needed to obtain a stable indicator of compressibility, and (2) identify differences in the compressibility of the stall surface depending on the stall base and bedding depth. On each farm, we tested the compressibility of 10 stalls. No significant differences were found between the front and the back of the stall for the location of the Clegg hammer measures. The differences in readings of the Clegg hammer were nonsignificant after the third measure taken at the same location, meaning that 3 measures are sufficient at one location to obtain a compressibility measure. Significant differences were found among the different stall base and surface combinations tested. Rubber mats were less compressible than mattresses. When a large quantity of bedding (>7.5 cm) was added on top of rubber mats, the compressibility results were equal to those of mattresses ≥10 yr old without bedding. To appropriately test the compressibility of stall surface in tie-stall farms, we recommend measuring the compressibility of the stall base on its own and with the usual amount of bedding used on the farm. Our study establishes that both stall base and surface affect compressibility, and that a large quantity of bedding helps increase the compressibility of the bed, especially on a harder stall base.

Short communication: Summer on-farm environmental condition assessments in Québec tiestall farms and adaptation of temperature-humidity index calculated with local meteorological data

Temperature-humidity index (THI) calculation following the equation developed by the National Research Council (A Guide to Environmental Research on Animals, 1971) requires ambient temperature (AT) and relative humidity (RH). Those data are widely and readily available at local meteorological stations. However, studies showed that using average AT and RH retrieved from the closest stations is not appropriate for estimating on-farm conditions. The present objectives were (1) to study summer on-farm environmental conditions, (2) to explore the relationship between summer THI calculated with on-farm data and summer THI calculated with local weather station data, and (3) to verify whether THI calculated with summer meteorological station data could be adapted to better represent summer on-farm conditions. Six tiestall dairy farms located in 2 regions of the province of Québec [Eastern Québec (EQ) and Southwestern Québec (SWQ)] were enrolled in this study. Within-barn conditions were monitored using 3 remote data loggers from August 2016 through August 2017. Two loggers were installed inside at varying distances relative to the ventilation inlet (L1: closest to inlet; L2: farthest from inlet) and a third was installed just outside of the barn (L3). Values retrieved from each logger and the closest local meteorological station were used to calculate daily THI according to the National Research Council formula and were ultimately compared. Our results showed that THI varied within the barn depending on the proximity relative to the inlet because THI measured by L1 was lower than THI measured by L2 in both regions. Moreover, our results showed that in both regions AT measured on-farm was consistently higher than AT measured at the weather station. The opposite was observed with RH, as it was significantly lower on-farm in EQ and numerically lower in SWQ compared with RH extracted from weather stations. Overall, this led to THI being lower by 4.6 and 3.7 units at the weather stations compared with within-barn conditions for EQ and SWQ farms, respectively. Hence, using local meteorological station data to estimate on-farm conditions would lead to an underestimation of heat stress level in dairy cows. Adapting THI calculations by including daily maximum AT and minimum RH retrieved from the local weather station instead of their average counterparts led to a better estimation of within-barn conditions. However, the difference between THI measured on-farm and the adapted THI calculated with weather station data remained significant. Although the adaption made to THI allowed for a closer relation to on-farm conditions, THI calculated with weather station data should only be used to assess heat stress level in dairy cows when heat stress thresholds are adapted for such data.

Associations between on-farm cow welfare indicators and productivity and profitability on Canadian dairies: II. On tiestall farms

The use of tiestall housing for dairy cows is often criticized due to the reduced freedom of movement it offers for the animals. Maximizing comfort is especially important in tiestall farms to ensure an acceptable level of cow welfare. Motivating dairy producers to make financial investments directly aimed toward the improvement of their animals' welfare can be challenging, especially when financial returns are uncertain. The aim of this study was to evaluate the existence of associations between on-farm animal welfare and indicators of farm productivity and profitability in tiestall farms. The prevalence of animal-, resource-, and management-based welfare indicators was collected on 100 Canadian tiestall farms during a cow comfort study. Records from the dairy herd improvement agency were retrieved and used to calculate the farms' productivity and profitability measures. Univariable and multivariable linear regressions were used to assess the associations between welfare indicators and milk production, milk quality, cow longevity, and economic margins calculated over replacement costs. Increased yearly average corrected milk production was associated with longer average lying time [β = 272; 95% confidence interval (CI): 94, 450] and a higher proportion of cows fitting the tie-rail height (β = 6; 95% CI: 1, 11). Lower yearly average somatic cell count was associated with lower percentages of stalls mostly soiled with manure (β = -3.7; 95% CI: -1.9, -5.4) and a lower proportion of cows with body condition score ≤2 (β = -5.1; 95% CI: -2.3, -8.3). The average margin per cow over replacement costs was positively associated with average lying time (β = 147; 95% CI: 27, 267), percent of stall not soiled with manure (β = 7.2; 95% CI: 3.0, 11.3), and the frequency of scheduled hoof trimming per year. Some of the relationships found included interactions between animal- and management-based welfare measures. For example, the relationship between lameness prevalence and average milk production was modified through the milk production genetic index. Overall, the results show that improved cow comfort and welfare on tiestall farms is associated with increased productivity, cow longevity, and profitability when estimated through margins calculated over the replacement costs. Producers should aim to optimize all aspects of stall comfort to enhance their cows' productivity.

Is the profitability of Canadian tiestall farms associated with their performance on an animal welfare assessment?

In order for dairy producers to comply with animal welfare recommendations, financial investments may be required. In Canada, a new dairy animal care assessment program is currently being implemented under the proAction Initiative to determine the extent to which certain aspects of the Code of Practice are being followed and to assess the care and well-being of dairy cattle on farm. The aim of the current study was to evaluate the association between meeting the proAction animal-based and the electric trainer placement criteria and certain aspects of productivity and profitability on tiestall dairy farms. The results of a previous on-farm cow comfort assessment conducted on 100 Canadian tiestall farms were used to simulate the results of a part of the proAction Animal Care assessment on these farms. Each farm's productivity and profitability data were retrieved from the regional dairy herd improvement associations. Univariable and multivariable linear regressions were used to evaluate the associations between meeting these proAction criteria and the farms' average yearly: corrected milk production, somatic cell count (SCC), calving interval, number of breedings/cow, culling rate, prevalence of cows in third or higher lactation, and margins per cow and per kilogram of quota calculated over replacement costs. The association between milk production and the proAction lameness criterion was moderated through an interaction with the milk production genetic index which resulted in an increase in milk production per year with increasing genetic index that was steeper in farms that met the proAction lameness criterion compared with farms that did not. Meeting the proAction body condition score criterion was associated with reduced SCC and meeting the proAction electric trainer placement criterion was associated with SCC through an interaction with the farms' average SCC genetic index. The increase in SCC with increasing SCC genetic index was milder in farms that met this criterion compared with farms that did not. Farms that met the proAction electric trainer placement criterion had 4.6% more cows in their third or greater lactation. These results suggest that some associations exist between the productivity of Canadian tiestall farms and meeting several parameters of the proAction Animal Care assessment. Meeting these criteria is unlikely to impose any economic burden to the dairy industry as a whole.

Producer estimates of prevalence and perceived importance of lameness in dairy herds with tiestalls, freestalls, and automated milking systems

Lameness is one of the most important welfare and productivity concerns in the dairy industry. Our objectives were to obtain producers' estimates of its prevalence and their perceptions of lameness, and to investigate how producers monitor lameness in tiestall (TS), freestall with milking parlor (FS), and automated milking system (AMS) herds. Forty focal cows per farm in 237 Canadian dairy herds were scored for lameness by trained researchers. On the same day, the producers completed a questionnaire. Mean herd-level prevalence of lameness estimated by producers was 9.0% (±0.9%; ±SE), whereas the researchers observed a mean prevalence of 22.2% (±0.9%). Correlation between producer- and researcher-estimated lameness prevalence was low (r = 0.19) and mean researcher prevalence was 1.6, 1.8, and 4.1 times higher in AMS, FS, and TS farms, respectively. A total of 48% of producers thought lameness was a moderate or major problem in their herds (TS = 34%; AMS =53%; FS = 59%). One third of producers considered lameness the highest ranked health problem they were trying to control, whereas two-thirds of producers (TS = 43%; AMS = 63%; FS = 71%) stated that they had made management changes to deal with lameness in the past 2 yr. Almost all producers (98%) stated they routinely check cows to identify new cases of lameness; however, 40% of producers did not keep records of lameness (AMS = 24%; FS = 23%; TS = 60%). A majority (69%) of producers treated lame cows themselves immediately after detection, whereas 13% relied on hoof-trimmer or veterinarians to plan treatment. Producers are aware of lameness as an issue in dairy herds and almost all monitor lameness as part of their daily routine. However, producers underestimate lameness prevalence, which highlights that lameness detection continues to be difficult in in all housing systems, especially in TS herds. Training to improve detection, record keeping, identification of farm-specific risk factors, and treatment planning for lame cows is likely to help decrease lameness prevalence.

Validation of the Ability of a 3D Pedometer to Accurately Determine the Number of Steps Taken by Dairy Cows When Housed in Tie-Stalls

The automation of farm tasks in dairy production has been on the rise, with an increasing focus on technologies that measure aspects of animal welfare; however, such technologies are not often validated for use in tie-stall farms. The objectives of the current study were to (1) determine the ability of the IceTag 3D pedometer to accurately measure step data for cows in tie-stalls, and (2) determine whether the leg on which the pedometer is mounted impacts step data. Twenty randomly selected Holstein dairy cows were equipped with pedometers on each rear leg and recorded for 6 h over three 2-h periods. Two observers were trained to measure step activity and the total number of steps per minute were measured. Hourly averages for right and left leg data were analyzed separately using a multivariate mixed model to determine the correlation between pedometer and video step data as well as the correlation between left and right leg step data. The analysis of the video versus pedometer data yielded a high overall correlation for both the left (r = 0.93) and right (r = 0.95) legs. Additionally, there was good correlation between the left and right leg step data (r = 0.80). These results indicate that the IceTag 3D pedometers were accurate for calculating step activity in tie-stall housed dairy cows and can be mounted on either leg of a cow. This study confirms that these pedometers could be a useful automated tool in both a research and commercial setting to better address welfare issues in dairy cows housed in tie-stalls.

A survey of dairy calf management practices among farms using manual and automated milk feeding systems in Canada.

Dairy calves in North America traditionally are housed individually and fed by manual milk feeding (MMF) systems with buckets or bottles. Automated milk feeders (AMF) allow for more natural milk feeding frequencies and volumes, and calves are usually housed in groups. The objectives of this study were to (1) determine the prevalence of various milk-fed calf management and feeding practices and (2) compare these practices between dairy farms using MMF and AMF systems. A national online survey was performed from January to May 2015 to quantify management practices for the care of milk-fed dairy calves in Canada. A total of 670 responses were received (6% of all dairy farms in Canada). Among respondents, 16% used AMF and 84% used MMF. Seventy percent of the farms using AMF had freestall barns compared with only 48% of those using MMF. A greater proportion of AMF farms (30%) also had automatic milking systems (AMS) compared with MMF farms (8%). Among tiestall farms, a herd size of >80 milking cows was associated with having an AMF [odds ratio (OR) = 3.8; 95% confidence interval (CI): 1.6-11.4]. For freestall or bedded-pack farms, a herd size of >80 milking cows (OR = 3.5; CI: 1.8-6.6), having an AMS (OR = 3.1; CI: 1.6-5.7), and use of cow brushes (OR = 3.1; CI: 1.3-6.9) were associated with having an AMF. Calves fed with AMS typically were housed in groups of 10 to 15, whereas almost 76% of the farms with MMF housed calves individually. Although both AMF and MMF farms fed similar amounts of milk in the first week of life (median = 6 L/d), the cumulative volume fed in the first 4 wk differed significantly, with a median of 231 versus 182 L for AMF and MMF, respectively. Median peak milk allowance was higher for AMF than for MMF (10 vs. 8 L/d, respectively). In summary, farms using AMF were larger, provided more milk to calves, and used more automation in general (i.e., in other areas of their operation). These data provide insights into calf-rearing practices across Canada and into how the use of AMF is affecting calf feeding and management on dairy farms.

Description of measurable parameters related to animal welfare in freestall and tiestall farms in Northwestern Spain

The aim of this characterization study was to describe several welfare indicators on the farm and find possible difference between the prevalence of hock injuries, body condition (BCS), and hygiene score across 15 free stalls with cubicles (F) and 15 tie stalls (T) dairy cattle farms in northwestern Spain (Galicia). Data were collected once and it included direct measures of the welfare based on the animal (BCS, hock injuries, locomotion score, hygiene score) and, indirect measures based on facilities (stall design, surfaces, feed bunk, ventilation and milking) and management practices (cleanliness, preventive treatment programs, outdoor access). In the following results, higher values are indicative of a poorer status. Herd-level prevalence of overweight cows to the stage of lactation was greater (p<0.05) in F than T (28.9 vs 10.5%) and underweight cows were lower (p<0.05) in F than T (21.8 vs 41.1%). Hock injuries were common in both housing systems, averaging 41.7% in F and 38.5% in T. Prevalence of lameness (score 3, 4, 5) averaged 10.6% in F (not scored in T). Udder hygiene score averaged 2.1 in F and 2.2 in T, upper leg/flank was 2.3 in F and 2.4 in T and lower leg score was higher (p<0.01) in F than T (3.0 vs 2.4 points on average). Low prevalence of these indicators in some farms should be taken into reference by the other farms to achieve better results. Moreover, considerable variation in facilities management and measurements was described in both housing systems, highlighting the small areas of T, too narrow alleys in F and, inadequate barn design for natural ventilation in both systems and at holding area in F farms.

Body traits, carcass characteristics and price of cull cows as affected by farm type, breed, age and calving to culling interval

Beef production from cull cows is an additional source of income for dairy farms and greatly contributes to red meat production, but the sources of variation of live animal characteristics and the carcass traits of cull cows have rarely been examined. This study investigated the effects of the farm type, breed, age at slaughter (AGE) and calving to culling interval (Calv_Cull) on the body traits and carcass characteristics of dairy and dual-purpose cull cows. Data from 555 cull cows from 182 herds belonging to five farm types, characterised by a combination of housing and feeding systems, were recorded and analysed. Dairy breeds, such as Holstein Friesian and Brown Swiss, and dual-purpose breeds (Simmental, Rendena) were included in the trait assessments. The day before slaughter, the cows were weighed and scored for body condition (BCS) and fleshiness, and then, their heart girth and wither height were measured. At the slaughterhouse, the carcass weight (CW), dressing percentage (DP), carcass conformation and fatness scores, carcass price per kg and carcass total value were obtained. On average, the cows were slaughtered at nearly 71±27 months of age, 285±187 days after the last calving; 615±95 kg BW; and provided a 257±51 kg CW. Nearly 50% of the cows fell within the BCS range of 2.75 to 3.50, and the carcasses were mostly graded in the lowest class of conformation and fatness scores. Cull cows from free-stall farms had a higher DP, carcass conformation score and price than those from traditional tie-stall farms. The breed influenced the AGE, live animal characteristics and carcass traits. Cows from dairy breeds were younger at slaughter, had a lower BCS and fleshiness, and greater body measurements, but a lower DP and carcass price than those from dual-purpose breeds, although differences between the breeds were found within both groups. The age of the cows at slaughter influenced the Calv_Cull and increased the BW, body measurements and CW, but not the fleshiness and fatness appreciation (both in vivo and postmortem) or carcass price. The increasing Calv_Cull improved the BW, BCS, fleshiness, CW and carcass conformation and fatness. In conclusion, the decision to cull dairy cows should also take into account the factors that affect their carcass value in regards to improving the carcass price of cows.

Prevalence of and risk factors for hock and knee injuries on dairy cows in tiestall housing in Canada

Leg injuries on dairy cows are a common and highly visible welfare concern on commercial dairy farms. With greater attention being placed on food animal welfare and limited research being conducted on tiestall farms, this study aimed to identify prevalence and risk factors for hock and knee injuries on dairy cows housed in tiestall barns in Ontario (n=40) and Quebec (n=60). A sample of 40 cows was purposively selected per farm and several animal- and farm-based measures were taken. Both hocks and both knees on each cow were scored as injured (presence of lesions or swelling) or not injured (no alterations or hair loss), and the highest score of each of the 2 knees and the 2 hocks was considered the cow’s hock or knee score. Possible animal- and farm-based risk factors were incorporated into 2 separate multivariable logistic models for hock injuries and knee injuries respectively at the cow level. Mean (±SD) percentage of cow with hock injuries per farm was found to be 56±18% and mean percentage of knee injuries per farm was found to be 43±23%. Animal-based factors found to be associated with a greater odds of hock injuries at the cow level were increased days in milk (DIM), lower body condition score (BCS), lameness, higher parity, higher cow width, median lying bout duration, and median number of lying bouts. Environmental factors found to be associated with hock injuries at the cow level were province, stall width, tie rail position, stall base, chain length, and age of stall base. Animal-based factors found to be associated with knee injuries at the cow level were DIM, BCS, and median lying time. Environmental factors found to be associated with knee injuries at the cow level were stall width, chain length, province, stall base, and bed length. Quadratic and interaction terms were also identified between these variables in both the hock and knee models. This study demonstrates that hock and knee injuries are still a common problem on tiestall dairy farms in Canada. Several animal- and housing-based factors contribute to their presence. Further research to confirm causal relationships between these factors would help identify the cause of knee and hock injuries and determine how to best reduce the incidence of injuries in cows on commercial tiestall dairy farms in Canada.

Can automated measures of lying time help assess lameness and leg lesions on tie-stall dairy farms?

The time that dairy cows spend lying down is an important measure of their comfort and lameness and injuries to hocks and knees are associated with alterations in lying time. We examined whether automated measures of lying time could identify cows and farms with problems of lameness or leg lesions. Data were collected from 40 lactating Holstein dairy cows from each of 100 tie-stall farms. The occurrence of lameness, hock and knee injuries was recorded and lying times were recorded automatically using accelerometers. There was large variation between individual cows, and between farms in all measures of lying time. At the cow level, there was no relationship (P>0.10) between being lame and daily duration of lying time. A lower daily duration of lying time was found among cows with hock injuries (mean±SE: non-injured=12.79±0.06h, injured=12.21±0.06h; P<0.001) and cows with knee injuries (mean±SE: non-injured=12.54±0.05h, injured=12.25±0.06h; P=0.04) than those without lesions. The median daily duration of lying time on a farm was negatively correlated with the prevalence of lameness (rp=−0.27, P=0.006), of hock injuries (rp=−0.35, P=0.003) and of knee injuries (rp=−0.28, P=0.004). A canonical discriminant function with canonical coefficients of 0.63 for mean daily duration of lying down, and of 0.54 for mean bout frequency could correctly identify 72% of the farms that were above the median for percent of cows with hock or knee injuries or being lame (linear discriminant function: constant=−95.10, daily duration=11.39, bout frequency=4.83) and 68% of the farms below the median (linear discriminant function: constant=−106.95, daily duration=11.92, bout frequency=5.30) (Wilks Lambda test P=0.002). A criterion of a median lying time between 12h and 13h alone could identify over 60% of farms above or below the median for lameness, hock and knee lesion prevalence. Automated measures of lying time may be a useful animal-based measure to indicate farms with a high percentage of lame cows or cows with leg lesions.

An assessment tool to help producers improve cow comfort on their farms

Effective management and an appropriate environment are essential for dairy cattle health and welfare. Codes of practice provide dairy producers with best practice guidance for the care and handling of their cattle. New Canadian recommendations have been established for the dairy industry. The objectives of this study were to develop an on-farm assessment tool that helps producers assess how well they are meeting their code of practice and that identifies management and environment modifications that could improve dairy cow comfort on their farms. The assessment tool addressed critical areas of dairy cow comfort, including accommodation and housing (stall design, space allowance, stall management, pen management, milking parlor, and transfer alleys), feed and water (body condition scoring, nutrition), and health and welfare (lameness, claw health, and hoof-trimming). Targets of good practices were identified from the requirements and recommendations of the code of practice. Each farm received a score for each target, ranging from 0 (target not reached) to 100 (target reached). One hundred tiestall and 110 freestall farms were surveyed in 3 provinces of Canada (Quebec, Ontario, and Alberta). The duration of the assessment, in 2 visits lasting, on average, 8 and 9h (range between freestall and tiestall farms) and 4 and 4.1h, was beyond the targeted 3 to 4h due mainly to the animal-based measures; strategies to reduce the duration of the assessment were discussed. Standard operating procedures were developed to ensure consistency in measuring and recording data. Periodical checks were conducted by trainers to ensure all 15 assessors remained above target agreement of weighted kappa ≥0.6. Average scores for all critical areas ranged from 25 to 89% for freestall farms and from 48 to 95% for tiestall farms. These scores need to be considered with caution when comparing farms because scores could not always be calculated the same way between housing systems. An evaluation report was provided and discussed with each producer, identifying strengths and areas for improvement that could benefit dairy cow comfort on their farms. The producers were convinced of the effectiveness of our tool for assessing cow comfort (freestall: 86%; tiestall: 95%) and in assisting them to make decisions for improvements (freestall: 83%; tiestall: 93%). Our cow comfort assessment tool served as background material for the Dairy Farmers of Canada animal care assessment program.

Potential use of milk urea nitrogen to abate atmospheric nitrogen emissions from wisconsin dairy farms.

Urinary urea N (UUN) is the principal nitrogen (N) source controlling emissions of ammonia (NH) and nitrous oxide (NO) from dairy manure. The objectives of this study were (i) to study the integrative nature of dietary crude protein (CP) management, secretion of milk urea N (MUN), excretion of UUN, and N emissions from dairy production systems; (ii) to evaluate how associative changes in dietary CP, MUN, and UUN affect atmospheric N emissions from dairy farms; and (iii) to discuss some of the challenges and opportunities to an expanded use of MUN to enhance dietary CP use and decrease UUN excretion and N emissions from dairy farms. Milk urea N records of 37,889 cows in 197 herds in Wisconsin revealed that approximately one half of tested cows were likely consuming dietary CP in excess of requirement. Farm simulations were used to quantify the effect of dietary CP on whole-farm N emissions. At a statewide average MUN of 12.5 mg dL, 48 to 87% of UUN was emitted as NH, with the lowest loss from pasture-based farms and the greatest loss from tie-stall farms. Each 1 mg dL decrease of MUN (range, 16-10 mg dL) provided an associated daily decrease in UUN of 16.6 g per cow, which decreased NH and NO emissions from manure by 7 to 12%. Although more site-specific information is required on herd MUN-UUN relationships and more a reliable interpretation of MUN assay results is needed, monitoring of MUN may be used to enhance dietary CP use and to reduce UUN excretion and N emissions from Wisconsin dairy farms.

The Effect of the Housing System on the Welfare Quality of Dairy Cows

The aim of this study was to assess the effect of the housing systems (loose vs tie-stall) on the welfare of dairy cows and to test the hypothesis that dairy cows in loose housing systems have a better welfare quality than those kept in tie-stalls. Sixty commercial dairy farms (30 with loose and 30 with tie-stall housing system) were selected for evaluation, using mainly animal-based measures, as the applied Welfare Quality® protocol allows it. A total number of 2624 milking cows were assessed in the winter period. There were significant differences between the two housing systems for the majority of the parameters within the four welfare principles. Significant differences were also found in terms of the mean scores of the welfare criteria and principles, with the majority pointing out the loose system as better. Based on the scores of the four principles, most of the farms with loose housing were classified as enhanced, while the majority of the tie-stall farms were acceptable. The results show that the welfare quality of dairy cows is greatly influenced by the housing system, and that the loose system is more advantageous when it comes to the feeding, housing and behaviour of the dairy cow.