Factors associated with cattle cleanliness on Norwegian dairy farms

Ammonia and methane emissions from small herd cattle buildings in a cold climate

Ammonia (NH3) and methane (CH4) emission measurements that reflect local production conditions are required to track progress in national emission policies and verify emission factors. The findings can also be used to better understand key factors influencing emissions. This is especially important in Norway, which has long cold winters, and small cattle herds in mechanically ventilated buildings. However, until now, NH3 and CH4 emissions from Norwegian cattle buildings have not been reported in literature. Moreover, in other cold climates, NH3 and CH4 emissions are often taken from large dairy herds in naturally ventilated buildings, with less focus on suckler cows. The objectives were to assess indoor climate, report NH3 and CH4 emissions and examine the impact of climatic factors on NH3 and CH4 emissions in three small herd dairy and suckler cow buildings over three seasons. Three of the buildings had mechanical ventilation, while one was naturally ventilated. The suckler building had higher relative humidity (RH > 90 %) and NH3 concentrations (> 25 ppm) due to lower minimum air change rate (ACH = 1.2 h-1). The suckler building also had the highest NH3 emissions (2.04 g Livestock Unit (LU)-1 h-1) followed by the mechanically ventilated dairy building (1.92 g LU-1 h-1) with the highest ACH. These two buildings had the lowest stocking densities and floor areas. In contrast, the suckler building had the lowest CH4 emissions (6.8-10.7 g LU-1 h-1). Methane emissions from the dairy building with the supply-exhaust air mixing system (16.4-19.3 g LU-1 h-1) was higher than the other dairy buildings (11.7-13.8 g LU-1 h-1). Temperature influenced NH3 emissions however, the direction of association between temperature and NH3 emissions differed among buildings. Relationship between RH and NH3 emissions was positive, but the correlation coefficient (R2 = 0.67) was strongest in the building with the highest RH.

Identification of Contamination Sources and Assessment of Risk Factors Associated with the Occurrence of Escherichia coli O157:H7 on Small-scale Cow-calf Operations in Oklahoma and Louisiana

Escherichia coli O157:H7 is a human pathogen that exists as part of the commensal microflora of cattle and is shed in animal feces. Little is known about the effect of management practices on its occurrence and transmission on small-scale cow-calf operations. Identification of risk factors associated with farm practices could help implement effective measures to control E. coli O157:H7. This study quantified the risk of E. coli O157:H7 occurrence associated with cow-calf farm practices using risk modeling. Management practices of small-scale cow-calf operations in OK and LA were assessed through survey-based research. Fecal, water, sediments and water-trough-swab samples were collected to determine the incidence of E. coli O157:H7, and potential on-farm contamination sources and risk factors identified. Association between the occurrence of pathogen and farm practices was determined using two risk assessment models (I and II). Model I determined the association of E. coli O157:H7 occurrence with water source, water container, feed, cattle breed, and herd density, while Model II determined its association with farm cleanliness. For both models, logistic regression was followed using a two-step approach, univariable and multivariable analysis. In OK and LA, E. coli O157:H7 was present in 5.8% and 8.8% fecal, 4.4% and 9.4% water, 10.3% and 9.6% sediments, and 1.5% and 10.6% water-trough-swab samples, respectively. In Model I, univariable analysis identified water container and feed, whereas multivariable analysis identified feed as a significant risk factor. In Model II, the univariable analysis found cleanliness of cattle-contact areas, such as, alleyways, water-trough, chute and equipment, to be a significant risk factor. In multivariable analysis, only the cleanliness of water-trough was identified to be a significant risk factor. Results from the study could aid in the development of on-farm best management practices for the reduction of E. coli O157:H7.

Development of a benchmarking tool to assess the welfare of dairy cattle on small-scale farms

Public concern about the welfare of farm animals and the livestock industry's awareness of the need to improve animal welfare have led to the implementation of new tools designed to meet this objective. Especially in the case of small-scale farms in marginalized areas, the lack of available data specifically for assessing welfare led to the present study. Its aim was to use animal- and resource-based indicators that are representative of small-scale farms, to establish an index and develop a benchmarking tool that can be used to dynamically evaluate the welfare of cattle on farms with different husbandry systems and provide farmers, veterinarians, extension officers, and stakeholders with reliable information that can be used as a decision support tool. For this reason, 1,891 cows from 204 herds housed in freestall (n = 111) and tiestall (n = 93) husbandry systems in South Tyrol (Northern Italy) were evaluated. The results showed that 17.6% of herds (36 farms) had an average score below 60 (out of 100), which means that immediate intervention should be adopted to improve welfare. South Tyrolean dairy farms performed well in terms of lameness, skin alterations, avoidance behavior, number and space of lying areas, and dystocia occurrence scores, whereas water supply, cow cleanliness status, claw conformation, and getting-up behavior offered significant potential for improvement. Significant differences were observed between housing systems scoring less than 60 out of 100 points in 9.9% (n = 11) and 26.9%, (n = 25), of the herds kept in freestalls and tiestalls, respectively. A slight difference was found when comparing the percentage of herds with high scores, which corresponded to 30.6% (n = 34) of herds housed in freestalls and 22.6% (n = 21) of herds housed in tiestall housing systems. In addition, it was shown that animals reared on farms with tiestalls more often had problems with body condition, cleanliness, and skin alterations. All individual welfare indicators in the top 25% of herds had scores above 80, indicating that this may be an attainable target for freestall and tiestall herds, respectively, to promote good dairy cow welfare. The overall aim must be to adopt measures to increase the scores on all farms closer to this level.

Beef Cattle Preference and Usage of Environmental Enrichments Provided Simultaneously in a Pasture-Based Environment

Environmental enrichment can improve livestock welfare through increasing environmental complexity to promote a greater range of natural behaviours. However, there is limited understanding of the need for and impacts of enrichments for extensively managed beef cattle that can sometimes be kept in grassed paddocks devoid of additional natural and artificial features, i.e., ‘barren pastures’. This trial assessed which enrichments beef cattle preferred and utilised in a barren paddock environment. Eight groups of seven Angus steers housed on pastured paddocks devoid of natural or artificial features were observed during daylight hours for two days a week over a period of three weeks, after being presented with four enrichments simultaneously: a cattle brush, a piece of hanging rope, a tree stump, and a woodchip pile. Although enrichment use generally decreased over time, the brush, stump, and woodchip maintained a higher level of use than the rope, based on the frequency of interactions and number of displacements around the enrichments (both p < 0.001). This suggests that the brush, stump, and woodchip pile were more valuable resources to the cattle, allowing for grooming and lying behaviours, although oral manipulations also occurred on the stump, woodchip, and rope. The inclusion of these enrichments can increase the complexity of barren pasture environments and allow for the increased expression of natural behaviours, potentially contributing to improved welfare.

Effect of low and high concentrate supplementation on health and welfare indicators in different breeds in small-scale mountain dairy farms

We investigated and compared the effects of low and high concentrate supplementation in terms of animal welfare, health and reproductive performance in two different dairy cow breeds on small-scale mountain farms. 64 South Tyrolean dairy farms were evaluated using an on-farm assessment for animal-based and resource-based welfare indicators, data from test day records, and a questionnaire for the farmer. Farms were divided into four groups: low input Tyrolean Grey (L-TG), low input Brown Swiss (L-BS), high input Tyrolean Grey (H-TG) and high input Brown Swiss (H-BS). Effects of intensity level, breed and their interaction were calculated and analyzed statistically. The predominant husbandry system across all groups was tie-stall. The average energy-corrected milk yield increased with increasing concentrate level, with L-TG showing the lowest and H-BS showing the highest milk yield. Age at first calving was lowest in H-BS when compared to all other systems, while numbers of lactations were higher in L-TG compared to H-BS. Feed efficiency (percentage of milk out of roughage) was significantly higher in L-TG and L-BS when compared to H-TG and H-BS. L-BS showed the poorest results for most of the welfare indicators such as lean cows, lesions and percentage of dirty animals. In conclusion, a higher concentrate level in diets does not lead automatically to lower animal welfare for dairy cows in alpine regions. Indeed, keeping high yielding breeds in extensive systems seems to be challenging. The dual-purpose breed TG showed some clear advantages in that calving interval was lower and the number of lactations greater.

Effects of surface materials of self-draining beds on cattle behavior in a temperate climate

Objective

The objective of the present experiment was to construct self-draining beds to keep surface bedding materials clean and dry for beef cattle comfort in a temperate climate.

Methods

In Experiment 1, a self-draining bed was covered with sand at depths of 10 cm (S-10a), 15 cm (S-15), and 20 cm (S-20) respectively. In Experiment 2, self-draining beds of different sizes were covered with 10 cm of sand (S-10b) and wood shavings (WS) at depths of 15 cm and 20 cm (WS-15 and WS-20). Fifteen cattle were engaged to evaluate the comfort of self-draining beds covered with different bedding materials.

Results

No cattle lay in the feed alley and cattle spent more time lying on S-10a than S-15 or S-20 in Experiment 1 (p<0.01). No difference in lying time was detected between S-15 and S-20 (p>0.05). In Experiment 2, no cattle selected the feed alley as the lying area. Cattle preferred WS-15 as the lying area and time spent lying on WS-20 was slightly higher than on S-10b (p<0.05). Feces weight was higher in the feed alley than in the different bedding areas in both Experiments 1 and 2 (p<0.01).

Conclusion

Sand-bedding depth at 10 cm and WSs at 15 cm above the self-draining bed can provide for the lying comfort of beef cattle. Design of a special feed alley to hold most of the feces to keep bedding materials clean and dry is desirable for organic beef cattle in a loose barn.

Assessment of on-farm welfare for dairy cattle in southern Spain and its effects on reproductive parameters

In this Research Communication we analyse the animal welfare status of dairy farms located in southern Spain and test the hypothesis that monitoring of wellbeing could increase the profitability of dairy herds by improving indices of reproduction. Twenty dairy farms were visited and a total of 1650 cows were assessed using the Welfare Quality® (WQ) protocol to determine their welfare status. These farms were selected as representatives of the main types of dairy farms found in the south of Spain. No farms attained a welfare status of 'excellent', but all obtained an adequate score for most parameters. Feeding assessment showed relatively low variability among farms, whereas housing and health assessments exhibited high variability. Significant correlations were found between a number of welfare parameter pairings: between percentage of collisions and time needed to lie down; between cleanliness of water points and cleanliness of various animal parts; between farms with access to an outdoor loafing area and an inadequate body condition score and with animal cleanliness; between the frequency of animals lying partly or completely outside of the lying area and the percentage of integument alterations and finally between the presence of respiratory problems and farm hygiene parameters. Furthermore, significant correlations between welfare parameters, reproductive indices and milk production were found. The percentage of cows exhibiting an inadequate body condition score and farms where cows took longer to lie down were correlated with the calving-first insemination interval. Animals showing a higher incidence of coughing and hampered respiration presented lower heat detection rates and milk production and finally farms with dirtier animals had lower milk production. This study is the first step towards including welfare in the recording of routine data in dairy cattle farms in southern Spain.

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.

Production of recycled manure solids for bedding in Canadian dairy farms: I. Solid-liquid separation

Canadian dairy producers have an increasing interest in recycled manure solids (RMS) as bedding material because of reduced availability of traditional bedding resources. Information regarding methods to obtain RMS and composition of RMS is very limited. Hence, a 2-part investigation was developed to compare the performances of 3 mechanical solid-liquid manure separators (part I) and 4 composting methods (part II; companion paper in this issue) for the production of high quality RMS. In this first study, a roller press, a screw press, and a decanter centrifuge were tested for the separation of slurry manure from a commercial dairy farm. During the experiment, the quantity of slurry manure processed and the volume and mass of the liquid and solid fractions were measured. The energy consumption of each separator was recorded, and samples of the slurry, liquid, and solid effluents were collected for analysis. The type of separator did not significantly influence the chemical and bacteriological composition of RMS produced. The choice of a separator for Canadian dairy producers should thus be based on the equipment cost and its capacity, targeted solids dry matter (DM) content and structure, and fertilizing quality of the separated liquid. The decanter centrifuge produced the solid phase with the highest DM and best separation efficiencies for DM, N, and P. However, its low production capacity (1.5 m³/h vs. 9.1-20.3 m³/h) combined with its high acquisition cost (Can$145,000 vs. Can$75,000) and energy consumption (4.99 kWh/m³ vs. 0.10-0.35 kWh/m³) reduce its technical and profitability values. Besides, the centrifuge produced fine structured RMS and a low-quality liquid fraction, not suitable as dairy cow bedding and fertilizer, respectively. Both presses reached acceptable production capacity at a minimal operation cost. However, the poor performance in terms of DM (25%) of the model of screw press used in this study produced RMS unsuitable for immediate use without further processing. The model of roller press used in this study had the advantages of almost reaching the recommended DM content in RMS (>34%), being flexible in terms of inputs, and producing fluffy RMS. Nevertheless, its compression process seemed to allow greater passage of solids into the liquid fraction compared with the screw press. Part II of this work explores different composting methods to reduce the health risks associated with screw-pressed RMS before their use as bedding.

Survey of interdigital phlegmon outbreaks and their risk factors in free stall dairy herds in Finland

Background

Severe outbreaks of interdigital phlegmon (IP) associated with a high morbidity and major economic losses have occurred in Finland in the past decade. A survey was performed to indicate the current occurrence of infectious hoof diseases and to identify herd level risk factors predisposing to an outbreak of IP.

Results

Responses to a questionnaire revealed that an outbreak of IP defined as morbidity ≥5% within the 1st month of the outbreak, had occurred in 18.0% of the respondent study farms. Risk factors for an outbreak included animal transport between herds, i.e. either animal purchase or contract heifer rearing, enlargement or renovation of the barn, and if the fields of the farm had been organically cultivated. Having any kind of mechanical ventilation in comparison to natural ventilation seemed to lower the risk of IP. Additionally, the farms that had experienced an outbreak of IP often had other infectious hoof diseases. However, it was unclear which disease appeared first.

Conclusions

More attention is needed before and during enlargement or renovation of the barn and substantial planning is crucial for every part of the enlargement process in dairy farms.

Effect of cow cleanliness in different housing systems on somatic cell count in milk

The aim of the study was to analyse the effect of the housing system (tie-stall vs free-stall) on cow cleanliness, and the effect of the degree of cow dirtiness on the milk somatic cell count. Over 33% of the cows were found to be clean, with more of them in the free-stall barn. Analysis of the cleanliness of body parts showed that the highest hygiene level was characteristic of the udders and underbelly (scores of 1 for 47% and 56% of the cows, respectively). In the free-stall barn, there were over twice as many cows with clean udders (58%) and almost twice as few cows with very dirty udders. Regardless of the housing system, the degree of udder dirtiness created differences (P ≤ 0.01) in the natural log somatic cell count. The natural log somatic cell count increased from 11.54 to 12.37 on average with increased dirtiness of the udder. Greater differences in the cytological quality of milk were found in cows housed in the free-stall system. When analysing the effect of overall dirtiness of the cows and the body parts on the percentage of SCC classes, it was found that highest quality milk (< 200 000 somatic cells/ml) was produced by clean cows (71.52%). The proportion of cows with subclinical and clinical mastitis was found to increase with decreasing cleanliness of the udder, especially in the free-stall system. Overall, the proportion of cows with clinical mastitis increased from 2.51% (clean cows) to 14.29% (dirty cows).

The significance of clean and dirty animals for bacterial dynamics along the beef chain

This study investigated the bacterial dynamics along the beef chain for clean and dirty cattle in the slaughter and processing lines, using classic quantitative methods and molecular analyses. In addition, the Norwegian national guidelines for Good Hygiene Practices in Norway were evaluated. In these guidelines, cattle presented for slaughter are categorised according to hide cleanliness, resulting in separate processing lines for meat from very dirty animals and reduced prices to farmers. The study was conducted in two commercial abattoirs in Norway. Two groups were compared; 40 visually clean cattle and 40 visually dirty cattle presented for slaughter, with 20 from each group at each abattoir. The same animals were sampled at five sampling sites: hides, carcass surfaces after dehiding, just before chilling, after chilling, and meat trimmings. Meat trimmings were sampled in only one abattoir. Three hundred and sixty samples were collected by swabbing 100 cm(2) of the brisket area at the first four sampling sites, and sampling 200 g of meat trimmings at the fifth site. The results showed that the hides of dirty cattle had more Enterobacteriaceae and higher Aerobic Plate Counts (APC) than visually clean cattle (P<0.05), however there was no significant difference for Escherichia coli. For the other sampling sites, there were no differences between the dirty and the clean group. An effect of chilling/drying of the carcass surfaces was demonstrated by the significant reduction in the number of carcasses on which E. coli and Enterobacteriaceae were detected; from 11% and 39% before chilling to 1% and 16% after chilling, respectively. Enterobacteriaceae and E. coli were detected in only three and one of the meat trimming samples, respectively. Amplification and sequencing of the 16S rRNA gene from 643 Enterobacteriaceae colonies derived from 107 samples demonstrated that Escherichia/Shigella were dominant within this family on the hides. However, after dehiding, after grading, and after chilling, the genera Citrobacter and Enterobacter dominated. The meat trimmings were dominated by the genera Kluyvera, Hafnia, and unclassified Enterobacteriaceae. The relative proportions of Escherichia/Shigella were higher for dirty animals than for clean animals, and were higher on hides than from sampling sites further down the chain (P<0.05). The minor differences in contamination on carcass surfaces and meat trimmings between clean and dirty cattle indicate that separate processing lines in Norwegian abattoirs seem to be unnecessary.