Rubber Flooring Research Articles

Effect of Rubber Flooring on Claw Health in Lactating Dairy Cows Housed in Free-Stall Barns

Multiparous dairy cows between 10 to 30 d in milk (DIM) were enrolled in a clinical trial to evaluate the effects of rubber flooring on the development of claw lesions, locomotion scores, clinical lameness, and rates of hoof growth and wear. Two groups of cows were housed in identical free-stall facilities, except that 1 pen (rubber, n = 84) had rubber alley mats covering the entire concrete floor of the pen, whereas cows in the second pen were exposed to concrete flooring (concrete, n = 82) without rubber alley mats. All cows were evaluated 3 times between 10 and 30, 74 and 94, and 110 and 130 DIM for 1) the presence of claw lesions on their rear feet, 2) the occurrence of clinical lameness based on a locomotion score, and 3) rates of claw growth and wear as observed on the dorsal wall of the right lateral claw. No differences between flooring groups at the time of enrollment were detected for lactation number, mean DIM at first examination, body condition score, and proportion of cows with claw lesions at the first examination. Odds of developing claw lesions between examinations were not different for cows exposed to the rubber surface compared with those exposed to concrete. Cows on concrete, however, had greater odds of developing or exacerbating existing heel erosion than cows on rubber flooring. Regardless of the flooring surface, the lateral claw was more likely to develop lesions than the medial claw. Odds of becoming lame by the third examination and the proportion of cows requiring therapeutic hoof trimming because of lameness were greater for concrete-exposed cows than those on rubber. Cows on rubber flooring had decreased claw growth and wear between the first and last examination compared with cows on concrete. Regardless of flooring surface, second-lactation cows had greater wear rates than those in third or greater parities. Results of our study suggest that a soft flooring surface, such as interlocking rubber, is beneficial for hoof health.

The effect of rubber versus concrete passageways in cubicle housing on claw health and reproduction of pluriparous dairy cows

The effect of covering the passageways and feed face of a cubicle house with rubber flooring was compared to concrete in terms of claw health, behaviour and reproductive performance of dairy cows from a grass-based milk production system. Sixty-two, autumn calving, pluriparous Holstein–Friesian cows were introduced to the housing treatments prior to calving. Foot lesions were scored at housing, 1, 7, 12 and 16 weeks post-partum. The behaviour (activity, posture, and location) of all cows was recorded by instantaneous scan sampling over 24 h once per week from ca. 3 weeks pre-partum to 12 weeks post-partum. Estrous activity was recorded by visual observation three times daily using tail-paint and continuously by radiotelemetry from 1 week after calving until the end of the breeding season. The rubber flooring had a negligible beneficial effect on heel erosion but no effect on haemorrhage or dermatitis scores and no effect on the proportion of cows affected by severe lesions. Furthermore, there were no benefits for estrous expression or subsequent reproductive performance. There were no differences between treatments in time spent standing by cows, but cows on concrete stood more in the cubicles, while cows on the rubber flooring stood more at the feed face. This suggests that cows prefer to stand on comfortable surfaces while not feeding and that they can use well-bedded, comfortable cubicles for standing to get relief for their feet from concrete floors. This also explains the lack of a difference between treatments in claw health.

Effects of Roughness and Compressibility of Flooring on Cow Locomotion

We examined the effects of roughness and degree of compressibility of flooring on the locomotion of dairy cows. We observed 16 cows walking down specially constructed walkways with materials that differed in surface roughness and degree of compressibility. Use of a commercially available soft rubber flooring material decreased slipping, number of strides, and time to traverse the corridor. These effects were most apparent at difficult sections of the corridor, such as at the start, at a right-angle turn, and across a gutter. Covering the walkway with a thin layer of slurry increased frequency of slipping, number of strides, and time taken to traverse the walkway. Effects of adding slurry were not overcome by increasing surface roughness or compressibility. Placing more compressible materials under a slip-resistant material reduced the time and number of steps needed to traverse the corridor but did not reduce slips, and the effects on cow locomotion varied nonlinearly with the degree of compressibility of the floor. Use of commercially available rubber floors improved cow locomotion compared with concrete floors. However, standard engineering measures of the floor properties may not predict effects of the floor on cow behavior well. Increasing compressibility of the flooring on which cows walk, independently of the roughness of the surface, can improve cow locomotion.

Impacts of a modified farrowing pen design on sow and litter performances and air quality during two seasons

The impacts of using a modified farrowing pen (MOD) on the performance of sows and their litters and on ambient air quality over a hot and a cool season were evaluated. Primiparous Yorkshire × Landrace sows farrowed either during the months of February and March (thermoneutralily, TN) or June and July (heat-stress, HS). Temperatures within each season were controlled to 21 and 29 °C, respectively, for TN and HS. Animals from each group were assigned to a standard farrowing crate (STD; TN, n = 17; HS, n = 16) or a MOD pen (TN, n = 19; HS, n = 19). The MOD pen consisted of a STD crate with a 1.5 × 1.6-m comfort zone in the back, equipped with rubber floor mats, a feeder and a nipple waterer. Litter size was standardized to 10 or 11. No creep feed was provided and piglets were weighed weekly. Sows were weighed on days 2 and 22. Feed intake of sows was monitored daily, a milk sample was obtained on day 21 for compositional analyses and jugular blood samples were collected on days 2 and 21 to measure prolactin, IGF-I and urea. Sows consumed less feed (3.4 vs. 4.7 ± 0.1 kg/day, P < 0.001) in a hot than in a cool season and, at 29 °C, sows in MOD pens consumed more feed (3.9 vs. 3.0 ± 0.2 kg/day, P < 0.01) than sows in STD pens. Sow lactation weight loss was greater (− 26.4 vs. − 19.1 ± 1.9 kg, P < 0.05) for sows in STD than MOD pens in a hot season. The reduction in prolactin concentrations from days 2 to 22 of lactation tended to be greater ( P = 0.08) in a hot season for sows in STD pens. Concentrations of urea and IGF-I increased as lactation advanced ( P < 0.01) and IGF-I was lower for HS compared to TN sows on both days ( P < 0.01), whereas urea was greater for HS sows on day 2 only ( P < 0.01). Milk DM was less in a hot than in a cool season ( P < 0.01). Average piglet weight gain was reduced in a hot compared to a cool season during the second week of lactation ( P < 0.05) and this reduction was less in MOD than STD pens during the third week of lactation ( P < 0.01). During a hot season, even though not significant, average weight gain of piglets from days 2 to 21 of lactation was reduced by 6.0% in MOD pens compared to 9.7% in STD pens.

Flooring in Front of the Feed Bunk Affects Feeding Behavior and Use of Freestalls by Dairy Cows

In 2 experiments we assessed how preferences, time budgets, and feeding behavior of dairy cows change in response to flooring surfaces in front of the feed bunk. In Experiment 1, 12 nonlactating dairy cattle were individually housed with access to 2 standing platforms filled with either concrete or sawdust. In Experiment 2, 24 nonlactating dairy cattle were given access to either concrete or Animat rubber flooring in front of the feed bunk. In Experiment 1, cows preferred the sawdust to the concrete flooring. In both experiments, cows provided with a softer floor in front of the feed bunk spent more time standing near the feed bunk without eating (Experiment 1: 67 vs. 40min/d on sawdust vs. concrete, respectively, SEM = 5.6min/d; Experiment 2: 176 vs. 115min/d on Animat vs. concrete, respectively, SEM = 20.5min/d) compared with when they were kept on concrete. The increased time spent at the feed bunk was due to a combination of more frequent eating and standing bouts, indicating that cows were more willing to move on nonconcrete flooring. Total time spent eating was significantly greater on the softer floor in Experiment 2, but not in Experiment 1 (Exp. 1: 289 vs. 275min/d on sawdust and concrete, respectively, SEM = 7.3min/d; Exp. 2: 330 vs. 289min/d on Animat and concrete, respectively, SEM = 15.4), although feed intake was increased on the sawdust treatment in Experiment 1. Cows spent significantly more time lying in the feed alley when the flooring was rubber (219 vs. 53min/d on Animat and concrete, SEM = 53.6min/d), perhaps because the lying area in Experiment 2 was inadequate. In conclusion, cows prefer to stand on softer flooring in front of the feed bunk, and are more willing to move on and spend more time standing in front of the feed bunk when provided with softer flooring. These results indicate that cows find softer flooring surfaces more comfortable to stand on than concrete, and highlight the importance of evaluating the comfort of the entire facility.

Economic decision making on prevention and control of clinical lameness in Danish dairy herds

From an economic point of view, clinical lameness is considered to be one of the major health disorders in dairy cattle. The aim of this study was to establish the costs of lameness in different herds and to improve decision-making on prevention and control of clinical lameness. Economically feasible strategies of prevention and control were defined and the potential effects were calculated by a dynamic, stochastic and mechanistic Monte Carlo model, called SimHerd. The modelled risk factors on cow level for lameness were base-risk in the herd, parity, milk yield potential, disease interrelationship, disease recurrence and season. Milk yield reduction, reduced feed intake, weight loss, reduced conception rate and mortality were modeled as effects of lameness. To study the effect of herd differences on the efficacy of the preventive methods, four different herds representing different levels of reproductive management, conception rates and milk production were designed and compared to the default situation. The loss per first case of lameness was found to be €192 in the default herd that represents the modern, average Danish dairy herd. An increase of the margin per cow-year of €22.7 was the result of halving the risk of lameness in the default herd. Implementation of footbaths and rubber flooring increased margin per cow-year by €4.2 and €17, respectively. In a sensitivity analysis, 16 model parameters were changed to their lowest and highest value found in the literature. The model seemed most sensitive to the uncertainty of the effect of lameness on milk yield.

Characteristics of Claw Horn Microstructure and the Effect of Flooring Systems on Horn Quality

Introduction: Interactions between horn quality and flooring systems significantly impact on claw health. Poor horn quality is associated with reduced milk yield, painful lesions or slaughtering. Horn quality is determined by horn cells, intercellular cement and hoof horn architecture, i.e. the structure and arrangement of the horn tubules. Soft and elastic flooring systems have been reported to have a positive influence on the microstructure of hoof horn.Aims: We wanted to correlate the microstructure of claw horn to the horn quality in a large number of samples and detect influences of the flooring system on hoof horn microstructure.Methods: Samples were obtained from two different studies: 40 cows from Hohenheim/Germany kept on slatted floor and subsequently on rubber mats for 4 months; 1000 cows from 11 farms in Luxembourg, kept on concrete floor. From all samples 7 μm‐sections were cut and stained with the PAS‐reaction. Morphometry was done with the LuciaG©‐software (Nikon GmbH, Düsseldorf, Germany) and statistical analysis was performed with SPSS® (SPSS Inc., Chicago, IL, USA). Parameters measured were area, minimal and maximal diameter of both medulla and cortex of horn tubules. Statistical analysis included: tubules per visual field, area per visual field, total medulla area, total cortex area and the limiting values of diameters.Results: Luxembourg samples showed consistency of tubule‐parameters between both dates; all farms showed an average number ranging from 13.36 to 14.79 tubules per visual field. Hohenheim horn from the hard flooring showed 19.9 and horn of the same animals kept on rubber floor showed 20.5 tubules per visual field. Maximum diameter of hard‐floor horn is 55 μm whereas 45 μm in animals kept on rubber floor.Conclusions: The results show that genetic/individual differences take smaller influence on horn quality than housing systems. These outcomes provide evidence for the economical and animal welfare benefit of soft and elastic flooring systems. Further research will focus on correlation of biodata, such as physiological state, lactation, age, and claw horn microstructure.This work was supported by Biopsytec/Rheinbach.

Health complaints and annoyances after moving into a new office building: A multidisciplinary approach including analysis of questionnaires, air and house dust samples

After moving into a new office building, employees complained about eye irritations, sore throats and unspecific symptoms. They were concerned about visible dust as a potential cause of adverse health effects. An external working group was appointed to investigate indoor air pollution and health complaints and to suggest measures to improve the situation. Air samples and floor dust samples for analysis of organic compounds were collected in three offices. Bimonthly during 8 months, measurement campaigns were conducted to assess the trend of air pollutants. A questionnaire was administered concerning environmental conditions at the work place and complaints before and after moving into the new office building. Overall the concentrations of volatile organic compounds (VOC) and formaldehyde were fairly low. However, initially high concentrations (4300–7800 mg/kg) of tris-(2-butoxyethyl)-phosphate (TBEP) and diethylhexylphthalate (DEHP: 980—3000 mg/kg) were found in dust samples. The coating of the rubber floor was identified as the source of TBEP, while no single predominant source of DEHP was found. Results of the questionnaire demonstrated an increased irritation of the mucous membranes and a reduction of well-being after the employees had moved into the new building. Perception of low relative humidity and high temperature as well as unpleasant odors were associated with respiratory complaints. After removal of the coating of the rubber floor throughout the whole building, a reduction up to 90% of TBEP in the dust samples was found. In spite of several attempts, no such marked reduction was achieved with the concentration of phthalates. Although there was no significant association between visible dust exposure and increase of complaints after moving in, room climate conditions that could increase the deposition of dust in the airways were associated with the complaints. Hence it cannot be ruled out that fine dust containing TBEP together with unfavorable indoor factors were responsible for the development of the complaints.

Effect of Rubber Flooring on the Development of Claw Lesions in Lactating Dairy Cows Housed in Free Stall Barns

With the increased numbers of confinement dairy production systems, lameness has become a major economic cost to the dairy industry. Housing factors, specifically related to concrete flooring in free stall barns, have been associated with an increased risk of claw lesions and clinical lameness. Research has suggested that alternative flooring surfaces may prevent or decrease the occurrence of lameness and claw lesions. The objective of this study was to determine the effect of rubber flooring on the occurrence of claw lesions, clinical lameness and hoof growth and wear.

Influence of floor type on the locomotion of dairy cows

Locomotion in 36 cows was tested on five different surfaces: solid and slatted concrete with and without 20 mm thick elastic (KEN ®) rubber mats and wet, compressed sand (as an example of a natural, yielding surface). The friction of the floors was measured and a trackway measurement system (measurements from footprints) was used for analysis of locomotion. The presence and severity of lameness was scored subjectively. The slatted, crude concrete floor was found to have the lowest coefficient of friction (0.31), the solid, crude concrete floor had a higher friction coefficient (0.58) and rubber mats had an intermediate friction value (0.46). In comparison with the sand surface the cows walked more slowly on the slatted, crude concrete floor, with considerably shortened strides and with the rear feet placed at greater distance behind the front ones. On the solid, crude concrete floor the cows took shorter strides and steps than on the sand surface, but the speed did not differ significantly. Elastic rubber mats on the solid as well as on the slatted concrete floor increased the length of strides and steps. In comparison with non-lame and mildly lame cows, moderately lame animals walked more slowly and had a shorter stride and step length. Analyses within each lameness degree revealed that the moderately lame cows walked with a significantly smaller step angle (which corresponds to a wider posture) on crude solid and slatted concrete in comparison with both the continuous and the slatted rubber floor. The moderately lame cows walked on the rubber mats with roughly the same step angle as on the sand surface. Comparisons of cows with different lameness scores within a floor type showed that the moderately lame cows compared with the non-lame ones had a smaller step angle on the concrete flooring while there were no significant differences between lame and non-lame animals when they walked on yielding surfaces. Step asymmetry increased progressively from the non-lame to the moderately lame cows on all floor types. Cows with moderate lameness walked most symmetrically on the sand and on the floor with continuous rubber covering. It was concluded that yielding rubber mats had a positive effect on locomotion in both lame and non-lame cows irrespective of breed and number of lactations.

Efficacy of Two Cleaning and Sanitizing Combinations on Listeria monocytogenes Biofilms Formed at Low Temperature on a Variety of Materials in the Presence of Ready-to-Eat Meat Residue

Biofilms in the food-processing industry are a serious concern due to the potential for contamination of food products, which may lead to decreased food quality and safety. The effect of two detergent and sanitizer combinations on the inactivation of Listeria monocytogenes biofilms was studied. Combination A uses a chlorinated-alkaline, low-phosphate detergent, and dual peracid sanitizer. Combination B uses a solvated-alkaline environmental sanitation product and hypochlorite sanitizer. The survival of bacterial biofilms placed at 4 and 10°C and held for up to 5 days was also addressed. To simulate conditions found in a ready-to-eat meat-processing environment, biofilms were developed in low-nutrient conditions at 10°C (with and without meat and fat residue) on a variety of materials found in a plant setting. Included were two types of stainless steel, three materials for conveyor use, two rubber products, a wall, and floor material. Biofilms developed on all surfaces tested; numbers at day 2 ranged from 3.2 log on silicone rubber to 4.47 log CFU/cm2 on Delrin, an acetal copolymer. Biofilm survival during storage was higher at 4°C (36.3 to 1,621%) than 10°C (4.5 to 83.2%). Small amounts of meat extract, frankfurters, or pork fat reduced biofilm formation initially; with time, the biofilm cell number and survival percentage increased. Cleaning efficacy was surface dependent and decreased with residue-soiled surfaces; biofilms developed on the brick and conveyor material were most resistant. Both detergents significantly (P < 0.05) removed or inactivated biofilm bacteria. The sanitizers further reduced biofilm numbers; however, the reduction was not significant in most cases for the dual peracid. Using a benchmark efficacy of >3-log reduction, combination A was only effective on 50.0% of the samples. Combination B, at 86.1%, was more effective.

Effect of rubber flooring in front of the feed bunk on the time budgets of dairy cattle.

The objective of this experiment was to study the effect of rubber flooring in front of the feed bunk on the immediate behavioral response of dairy cattle. Four groups of 12 dairy cattle were alternately housed in sections of a free-stall barn with either 1.85 m of rubber flooring or grooved concrete in the area in front of the feed bunk. Rubber flooring did not affect time spent eating. However, animals showed a slight, but detectable, increase in time standing without eating on the rubber surface (5.5%) compared with concrete (4.8%). For reasons that are unclear, this increase in time spent standing was not limited to the area in front of the feed bunk; animals spent 11.0% of the available time standing elsewhere in the pen (outside of the free stall but not in front of the feed bunk) when they had access to the rubber flooring, compared with 9.0% when housed with access to only concrete floors. In addition, animals spent slightly less time lying in the free stall when they had access to rubber in front of the feed bunk (52.5 vs. 54.3%). Time spent engaged in behaviors such as standing elsewhere in the pen and eating were variable over time. For example, time spent eating declined from 23.1 to 17.4% over the 6-wk trial. In conclusion, dairy cattle with access to rubber flooring in front of the feeder showed small differences in where and how much time they spent standing, although the biological implications of these small changes are unclear.

Health-Related Evaluation of Building Products based on Climate Chamber Tests

A procedure is developed for assessing the health effects of the emissions from building products. The procedure is based on: • emission rates measured in environment test chambers • a fixed standard room with fixed standard conditions • a maximum acceptable concentration in the indoor air of each of the chemical compounds emitted, Iv a maximum permissible contribution to Iv from building products. The procedure has two elements: evaluation of the emitted compound alone and evaluation of the compound together with other compounds and indoor air factors. The evaluation includes odour and health effects of the compounds. The procedure has been applied to the emission test results for two building products: a rubber floor covering, and a water-borne acrylic watt paint. Maximum acceptable indoor air concentrations are listed fin-selected chemical compounds emitted by these two materials.

A Study of Human Reactions to Emissions from Building Materials in Climate Chambers. Part II: VOC Measurements, Mouse Bioassay, and Decipol Evaluation in the 1-2 mg/m3 TVOC Range

Monitoring of human reactions to the emission of formaldehyde and volatile organic compounds (VOC) from four commonly used building materials was carried out. The building materials were: a painted gypsum board, a rubber floor, a nylon carpet, and a particle board with an acid-curing paint. The exposures were performed in climate chambers. The air quality was quantified on the decipol scale by a trained panel, measurements of formaldehyde and VOC being performed simultaneously. The irritating potency of the materials was measured by a mouse bioassay. The VOC measurements showed several malodorants and irritants. Some abundant VOC identified in the head-space analyses were absent in the climate chamber air. The rubber floor and the nylon carpet exhibited a marked increase in decipols compatible with a number of odorous VOC identified in the air. A high formaldehyde concentration (minimum 743μg/m3) was measured for the particle board coated with an acid-curing paint. This was not reflected by a corresponding relatively high decipol value but a long-lasting irritating potency was observed in the mouse bioassay. TVOC sampled on Tenax and expressed in mass per volume as well as in molar concentration, and decipol evaluation both have limitations and should be used with caution as indicators of (perceived) indoor air quality. Eye irritation expressed by means of the eye index reflecting the tear film quality index (comprised of break-up time, foam formation, thickness of the precorneal lipid layer of the tear film, and epithelial damage) was found to be insensitive to formaldehyde and a VOC mixture but sensitive to TVOC concentrations of 1–2 mg/m3. Lipophilic VOC may be the cause of reduced tear film quality by destabilization of the lipid multilayer of the tear film.

A Study of Human Reactions to Emissions from Building Materials in Climate Chambers. Part I: Clinical Data, Performance and Comfort

The purpose of this study was to evaluate whether asthmatic reactions and changes in tear film quality could be provoked by exposing subjects to emissions from building materials in climate chambers. Twenty asthmatics and 5 healthy controls were exposed to (1) gypsum board hung with waterborne painted wallpaper; (2) rubber floor covering; (3) nylon carpet with rubber mat; (4) particle board coated with acid-curing paint; and (5) no test materials in climate chambers for 6 h. Participants recorded symptoms by filling in questionnaires, and clinical data were evaluated by lung function measurements at intervals of 30 min to 1h, and external eye examinations before and after exposure (appearance of foam at eyelid, semi-quantitative measurements of precorneal superficial lipid layer, break-up time and epithelial damage). There was agreement between a trained panel's evaluation of perceived air quality and the participants' opinion of indoor air quality. No correlation was found between lung function measurements and exposure to the materials. However, for all materials, statistically significant changes in tear film quality were observed to varying degrees. Lipophilic Volatile Organic Compounds (VOCs) may destabilize the lipid multilayer of the tear fluid, and this mechanism is suggested to be at least partly responsible for eye irritation.

London Science Museum Opens New Chemical Industry Exhibit

The historical development of the industry is fascinating to people in the business. But how can that sense of interest and excitement be conveyed to the ordinary citizen? Or—harder yet—to blase kids? The perfect method probably hasn't been devised yet. But London's Science Museum is giving it a jolly good try, with its recently opened Chemical Industry Gallery. Steel and rubber flooring, yellow safety railing, and catwalks, to convey a chemical plant setting, unite with zippy cartoon characters to entice visitors, particularly young ones, into the gallery. Mannequins—except those showing costumes reppresenting fibers and dyes from different eras in the industry—are spray-painted a ghostly creamy white, to deflect attention. More important, in this case, is that people concentrate on the industry's workings and trappings. The new gallery—which replaces an older one dedicated to industrial chemistry—came into being as the result of a more than $600,000 donation from U.K. giant Imperia...

The Mabou Mines The Lost Ones

The Mabou Mines staged Samuel Beckett's short novel The Lost Ones at the Theatre for the New City in New York in October, 1975. The piece, lasting about 45 minutes, was part of an evening of three Beckett works, which included Play and Come and Go. Play, the first of the three works to be performed, was presented on a proscenium stage. Come and Go, the second piece, was performed in a balcony above the audience and was reflected by a mirror to appear as though it was taking place in an area beneath the stage, such as an orchestra pit. For The Lost Ones, directed by Lee Breuer, spectators were asked to remove their shoes and then were led to a small rectangular room off the main theatre area. Upon entering, they stepped on a thick, foam rubber flooring; this gave the feeling of sinking downward.

The effects of ambient temperature, nature and temperature of the floor and radiant heat on the metabolic rate of the new-born pig.

Using a closed circuit technique, the oxygen consumption of 108 piglets below one week of age have been measured while modifying the physical attributes of the thermal environment. Moving the piglets onto a wooden floor from concrete reduced the oxygen consumption rate from 37.8 ml to 34.5 ml/kg. min) at 10°C, and from 33.7 to 31.4 ml/(kg. min) on a rubber floor at the same temperature. Oxygen consumption was also significantly reduced when the piglets were placed on a straw floor, were supplied with radiant heat and when the floor temperature was raised independently of chamber temperature. It is concluded that the provision of supplementary heating either in the floor or by overhead radiation can greatly reduce the effects of a cold environment on the new-born pig and so enhance the animal's viability.

The Rayleigh step bearing applied to a gas-lubricated journal of finite length. (65-WA/ Lub-2) : F. R. Archibald and B. J. Hamrock, pp. 38–46; 12 figs., 7 refs.

Concrete is the most commonly used alley flooring in confined dairy herds because of its qualities of construction and ease of cleaning. Nevertheless, the hardness, abrasiveness, and slipperiness of concrete floors have adverse effects on animal well-being and health, and yielding rubber flooring is becoming popular as a way of improving the flooring conditions on walkways. The aim of this study was to investigate preferences of dairy cows for rubber compared with concrete flooring under the conditions of a commercial dairy farm. The study was conducted in an organic dairy herd with free-stall housing. Floor preference was tested on groups of standing cows in a 120-m2 holding pen before milking, and 1 yr later on a 12- × 3-m walkway. The holding pen and the walkway were divided lengthwise into 2 identical sections. Two types of solid rubber mats (soft and extra soft) were tested against solid concrete in the holding pen. Slatted and solid rubber mats were tested against slatted concrete in the walkway. Each floor type was tested over 4 d on the left side and 4 d on the right side of the holding pen and the walkway, respectively. Concrete flooring on both sides of the sections was tested as a control before the testing of different section materials. All observations of the distribution of cows in the sections were made from video recordings captured in association with the afternoon milking. The number of cows on each section was recorded approximately every 7 min in the holding pen, and continuously on the walkway. A significantly higher proportion of cows stood on the side with the soft and extra soft rubber mats (65.1 ± 2.7 and 69.3 ± 2.6%, respectively, mean ± SEM) compared with the control distribution when only the solid concrete was available (50.9 ± 3.9%). A significantly higher proportion of nonlame cows walked exclusively on the side with the slatted (64.5 ± 5.4%, d 4) or solid rubber mats (68.2 ± 5.1%, d 4) compared with controls (28.9 ± 4.3%). Lame cows within a group of walking cows did not show a higher preference for soft flooring as distinct as nonlame cows (52.7 ± 6.9 and 59.4 ± 6.2% for the solid and slatted rubber mats, respectively, at d 4 vs. 40.3 ± 6.2% for control), presumably because of competition with other, higher ranked cows. It was concluded that the majority of cows preferred to walk and stand on soft rubber rather than on concrete flooring.

Polybutadienes of Controlled Cis, Trans and Vinyl Structures

Abstract The physical properties of polybutadiene vulcanizates have been measured as a function of polymer microstructure. Although the over-all properties of any one polybutadiene are determined by the relative ratio of cis, trans and vinyl units in the polymer chain, marked changes in physical properties do not occur until a relatively pure configuration is approached or unless the raw polymer displays crystallinity. Thus, polybutadienes containing more than 85 per cent cis, trans or vinyl units are characteristically different from each other and the differences are accentuated as the isomeric forms approach 100 per cent of a given configuration. Polybutadiene of 95 per cent cis configuration displays very low heat generation and high resilience (equaling natural rubber in these properties) and excellent abrasion resistance. trans-Polybutadiene (90 per cent), a crystalline plastic in the raw state, becomes rubbery after vulcanization. Gum vulcanizates possess high tensile strength, and tread stocks display high modulus and tensile strength, high hardness and fair hysteresis properties. Vulcanizates of amorphous 94 per cent vinyl polybutadiene are characterized by fair tensile properties, low hysteresis, and poor low temperature properties. Crystalline syndiotactic polybutadiene, 70 per cent vinly, displays much higher gum and tread tensile strengths than its amorphous counterpart. Amorphous polybutadienes containing less than 70–80 per cent of any one configuration are generally similar in most properties, and resemble emulsion polybutadiene in many respects. The wide range of properties of the various polybutadienes makes them suitable for many applications. cis-Polybutadiene is an excellent tire rubber, which has given as much as 40 per cent greater abrasion resistance than natural rubber in passenger tire tests. Heavy duty 10:00 × 20 truck tires fabricated with a 1:1 blend of cis-polybutadiene and natural rubber in the treads have given slightly better abrasion ratings and lower running temperatures than control tires fabricated entirely from natural rubber. Amorphous 80 per cent cis-polybutadiene has been found to possess exceptionally good low temperature properties, far superior to present arctic-type unsaturated elastomers, trans-Polybutadienes by virtue of their high modulus, high tensile strength, and high hardness could be utilized in the preparation of hard rubber goods, floor tiles, and shoe soles. While none of these polybutadienes is yet available commercially, their unusual properties and potential applicability in many areas should lead to their manufacture in the future.