Department of Animal Environment and Health, SLU, Skara Sophie Atkinson August 2005

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1 Department of Animal Environment and Health, SLU, Skara Sophie Atkinson August 2005 A comparison of 2 different floor types (cement slats with straw bedding and rubber slats with no straw bedding) in single animal overnight holding pens with regard to effluent drainage and provision of an acceptable laying surface for cattle. Introduction The purpose of slatted floors in holding pens for cattle is to provide a floor surface that allows animals to comfortably stand and lay down on, while having the ability to drain urine and faeces. A high percentage of slot area allows good run off of urine and faecal matter, allowing for a dryer lying area and a non-slippery surface. To have a high proportion of slot area, there must either be very many or very wide slots. However insufficient slat to slot dimensions such as having too large slot widths, can cause pain and injury to cattle s hooves (Kirchner, 1989). Lying is an important behaviour for cattle occupying approximately 50-60% of their daily time budget (Herlin, 1997). Minimum average lying times for cattle on straw were 600 minutes and 576 minutes for concrete in a day (Singh et al 1993). Cattle that are not able to rest and lay down have been shown to have high activity of stress hormones (Krohn and Munksgaard, 1993), and it reduces their welfare (Haley et al. 1999). The total time spent lying per day and synchrony of lying are important indicators of cow comfort (Krohn et al., 1992). Haley et al. (1999) concluded that lack of comfort in cattle is indicated by reduced time spent lying, reduced frequency of lying and standing, and an increase in time cows spend standing idle. Concrete slatted floors have a tendency of becoming damp and slippery. Putting straw on the floor in order to increase comfort can create problems with drainage, which leads to dirty animals and an unacceptable ambient environment for the livestock (Nilsson and Svenerstedt, 2000). Studies have shown that cows did not slip when lying down and getting up on rubber slatted floors, and they were much cleaner than cows kept on cement-slatted floors (Lundberg, 1999). Hultgren and Bergsten (2001) found that compared to solid floors, cows were less contaminated with manure when kept on rubber slatted floors with dimensions of 53mm wide slats and 29mm 1

2 gaps in between (slots). Stefanowska et al. (2002) found that calves spent significantly more time lying on wooden floors compared to synthetic floors. By increasing the softness of flooring (rubber compared to concrete), cow laying times were increased concluding that their comfort levels were higher (Haley, et al. 2000). Background Conventional floor systems in abattoir single animal lairage pens consist of concrete slats. If cattle are to be kept over night on these pens, abattoirs must legally provide straw (for reasons of animal welfare to make the surface more comfortable for the animal). This procedure has been questioned as it reduces effluent drainage. Rubber slatted floor surfaces have recently been developed for use in lairage pens, with the aim of providing an adequate bedding surface while allowing good drainage. However, before this floor can be acceptable as an alternative to straw covered cement slats, it must be investigated for effectiveness both in terms of cow comfort and animal hygiene. Project objectives This project aimed to investigate the ability of 2 different floor types; cement slats with straw bedding and rubber slats with no straw bedding, to assess the floors ability to 1) drain effluent 2) provide an acceptable laying surface for cattle. Material and method One abattoir has installed a rubber slatted floor system (ACONSOFT, produced by company Abetong) in one aisle parallel to the conventional cement slatted floor system (both aisles consisting of 9 pens). This provided a suitable setting for comparative trials to be made. A pilot trial was conducted before the experiment to investigate what amount of straw would be suitable to use on the cement slat floor system. Saw dust was also tested. In the straw trail, 2 cattle per test were bedded on 3 kg, 6 kg and 12 kg of straw over night. In the saw dust trial, 2 cattle per test were bedded on 12 kg, 18kg, 24 kg and 40 kg of saw dust. The following morning, an assessment was made for amount of bedding left on each pen floor by a representative from the local animal welfare authority, animal welfare agency, department of animal environment and heath, Swedish Meats and the abattoir owner. A consensus was made that sawdust bedding provided insufficient bedding material while 6 kg straw was the minimum amount of straw that 2

3 could be used. Any less than this tended to be insufficient as straw was either scraped from underneath the animal s feet, or had been pushed through the slats and out of the pen. Assessments in the abattoir In the cement pens, 6 kg straw was placed in each pen before each trial. All animals in the trial received one feed during the lairage period of approximately 2-3 kg hay. After over night holding, assessments on the floor and animals were made on animals in both straw bedded cement pens and rubber pens. After each experiment, pens were cleaned out, and prepared for the next trial. The following information was recorded for each animal in the trial: pen number and type general condition of the animal (body condition, wounds, scars, etc) transport time from farm to slaughter breed, age and sex lactation status time held in lairage During the filming sessions, animals were filmed in parallel pens i.e. one animal on straw, and one animal on rubber, and filmed at the same time. Both rubber and cement pens had the approximate box dimensions of 160cm high, 262cm long and 85cm wide. Each pen had a total of 16 drainage slats per pen, with the slat area 13cm wide, and the drainage gap 3 cm wide. The rubber pens had a different design than the cement pens, with each slat row being divided in 2 with drainage holes alternating from l26cm long to 122 cm long, with a 6cm gap in between (figure 1). It took approximately 60 minutes each experiment to clean and bed each pen with 6kg straw for each of the 9 pens. Placing the straw in all of the 9 pens took at least 30 minutes. 3

4 Cement pen Rubber pen Figure 1: Floor designs of cement and rubber pens with white areas showing the drainage holes and grey areas showing solid floor area (slats) Animals Animals used in this study were randomly placed in pens during routine arrival times at the abattoir. Table 1 shows the number of each animal class in rubber and straw pens in the trial during the hygiene assessments. Table 2 shows the number of each animal class filmed for the behavioural assessments. Table 1: Number of each animal class in straw and rubber pens during the hygiene assessment trials Bulls Steers Dry cows & heifers Lactating cows Straw Rubber n=90 4

5 Table 2: Number of each animal class in straw and rubber pens that were filmed for behaviour assessments Bulls Steers Dry cows & heifers Lactating cows Straw Rubber n=14 The animals used in the film sessions were transported from 1 to 6 hours. Table 3 shows the varied transport times for these animals. Table 3: Transport times and number of animals used in the film sessions 1 3 hrs 4 6 hrs Straw 10 4 Rubber 11 3 n=14 Hygiene assessments animals All animals used in the experiment were examined before and after overnight lairage on one side. This was because it was not possible to see the other side due to animals in the parallel aisle blocking the view. The entire floor surface of the pens were inspected the next morning and assessed for effluent contamination. A score from 1-3 was used to indicate level of soiling on the animal before lairage (table 4). The number of new areas on the body with contamination after lairage was recorded by counting the areas of new contamination. Table 4. Definition of soiling score system for hygiene assessment on animal before lairage Soiling Definition Score 0 None or almost no contamination with manure/dirt 1 One large area or several small areas of manure/dirt covering less than one eighth of the animal (light soiling) 2 One large area or several small areas of dirt/manure, together covering more than one eighth of the animal (medium soiling) 3 More than one eighth of the body area covered with heavy manure or mud (Heavy soiling) 5

6 Hygiene assessment on floor Each pen was examined and the numbers of slats covered in manure were recorded as well as the location of the contamination. In the straw pens the amount and location of straw left in the pen was also recorded. All information was recorded on a set form (appendix 1, page 20). Assessment for animal comfort A total of 14 animals (7 animals in each treatment) were filmed during overnight lairage. A total of 120 hours of film footage was recorded (60 hours of animals on cement pens with 6kg straw bedding, and 60 hours of animals on rubber floored pens). Small surveillance video cameras were set up to film the overnight behaviour of the cattle on each floor type (rubber pens with no straw bedding versus cement pens with 6kg straw bedding). The cameras were either set to film from below or above in order to provide different angles for assessing the animal s behaviour at laying times. Filming from below allowed for a clearer view of the head and front legs of the animal, which provided information on how the animal lay down, and if it had difficulties or not. Filming from above meant that 2 animals could be filmed at once in parallel aisles, i.e. one animal on the straw and one animal on the rubber. However this footage showed only if and when the animal lay down, not specifically how. Twelve cattle were filmed from an angle below (6 on straw and 6 on rubber), and 16 animals (8 on rubber and 8 on straw) were filmed from an angle above. All cameras were attached to VHS video recorders so the footage could be recorded for the period of one VHS video tape. The recording period was generally for 246 minutes per animal, except on one occasion, when 2 cattle (one on rubber, one on straw), were filmed from above over 8 consecutive hours, when the video was set to long play. The filming started after animals were sorted into prepared pens in the evening (between 6 and 7 pm). Occasionally new animals arrived to the abattoir during the filming sessions, but these animals were placed in pens several aisles away from the filmed animals. The video footage was later examined, recording the number of times an animal lay down and for the length of time during the 4 hour film period. Any observations of unusual behaviour such as extended time taken to lie down were also recorded. 6

7 Results Floor and animal Hygiene A total of 180 randomly selected animals were investigated, 90 animals examined on rubber pens, and 90 animals on straw covered cement pens. All results were transcribed into an excel file. Table 5 summarises the results of the hygiene scores on both the animals and pens. After overnight lairage cattle on straw covered cement slats became more contaminated with manure than those on rubber. A total of 63 animals or 70% of the total were contaminated on straw compared to 11 (12%) on rubber, however most of this contamination occurred due to straw and manure getting stuck between the claws of the back hooves (47 animals or 52% of total). Manure contamination on the body only (and not on the hooves) occurred on 16 (18%) animals on straw pens and 9 (10%) animals on rubber pens. The actual number of spots on the animal with more contamination after lairage was higher on straw than rubber. Table 5: Contamination levels after over night lairage of cattle and pen surfaces for straw and rubber No. Animals with added contamination after overnight lairage Straw 63 (*47) (70% of total no. animals) Rubber 11 (*2) (12% of total no. animals) Total score for contamination areas on animals body after overnight lairage Total number of slats covered in effluent after overnight lairage * No of animals with contamination between back hoof claws only The number of slats covered in manure was recorded for each pen type. Straw pens were covered in manure and effluent over a larger area than rubber pens. On average for straw covered pens, 4 slats per pen were contaminated after lairage, and on rubber pens 1 slat was covered. In total, the score for manure contamination over the pen surface and on the animal was larger in straw pens than in rubber pens (Figure 2, 3). 7

8 Total score for floor contamination after overnight lairage No. of slats contaminated Rubber Straw Figure 2. Floor contamination scores Total score for contamination on animal after overnight lairage 90 No. of contaminated areas on animal Rubber Straw Figure 3. Animal contamination scores 8

9 Table 6 summarises the areas of the cement slatted floors that were covered in straw after overnight lairage. In most pens there was an adequate amount of straw left. In many cases there were bare patches left however, and this occurred either due to the animal eating the straw, or due to the straw being scraped from under the hooves if the animal moved a lot in the pen. Table 6: Characteristics of remaining straw left in pens after over night lairage Details of straw Number of pens Not much straw remaining 13 (14%) Adequate amount of straw remaining 77 (86%) Bare patches remaining 43 (48%) Wet contaminated areas in centre of pen 19 (21%) Figures 4 to 6 show typical patterns of soiling after over night lairage in rubber pens, cement pens with no straw bedding, and cement pens with 6 kg straw bedding. In the straw pens, the contamination tended to be spread over a larger pen area compared to rubber pens where the manure remained mostly in the back part of the pen. Straw pens tended to become wet in the central part of the pen, possibly reducing comfort to the animals, and reducing laying behaviours, where as the rubber pens were drier. 9

10 Figure 4. Typical soiling in rubber pens Figure 5. Typical soiling in cement pens with no straw Figure 6. Typical soiling in cement pens with 6kg straw 10

11 Time spent laying and standing Appendix 2 (page 21) shows all results in the trial, with appendix 3 (page 22) showing a graph of lay and stand times specifically for each parallel animal in rubber pens and straw pens per film session. Figure 7 shows the times each animal lay in parallel per film session on straw and rubber. % lay time per animal per film session % time laying per film session straw rubber Film session Figure 7: Percent of time each animal lay per film session for cattle on both straw and rubber pens respectively 11

12 The average percent of time each animal lay over a recording session in rubber pens was 66% and for straw 67%. Of cattle that lay during a 4 hour film period on rubber, the total lay time ranged from 17 minutes (7% of a recording session) to 243 minutes (99% of the recording session). Of cattle that lay on straw pens, the total lay time ranged from 39 minutes (16% of time) to 244 minutes (99% of time). One animal on rubber stood during the whole filming period (a lactating cow), while 3 animals on straw (1 lactating cow, 1 heifer and 1 bull with an infected preputial area) stood during each filming period. Animals on both pens types lay for up to 5 sessions or bouts, with the range being from 0 to 5, and the average being 2.8 for straw, and 2.7 for rubber pen types (figure 8). 6 Number of laying bouts each film session for cattle on straw and rubber pens 5 Straw pens Rubber pens 4 No of bouts Film session and sample number Figure 8 : Number of laying bouts or sessions for each animal on rubber and straw pens per film session Table 7 shows the total number of lay sessions, the average time each animal lay per session and the % of total time that animals lay in the entire study for animals on rubber and straw pens 12

13 respectively. During the 13 sessions of 4 hours (245 minutes) film per session, animals lay for an average time of 58 minutes on rubber, and 61 minutes on straw. The longest lay sessions were for 2 heifers on straw, both lying for 135 minutes of the 245 minutes. The longest lay session on rubber was a heifer lying for 133 minutes of 245 minutes. Table 7: % of total time spent laying, number of lay bouts and average time per lay bout of cattle in rubber and straw pens % of total film time animals spent laying Total no. of laying sessions during total film time Straw 62% 31 61mins Rubber 52% 35 58mins Average time spent laying per film session per animal Most cattle lay for over 80% of the film sessions in both straw and rubber pens (figure 9). In total respectively, 7 cattle lay more than 50% of the time per film session on straw pens, and 10 cattle on rubber pens. 6 5 Straw Rubber No. of animals % of time spent laying Figure 9: Number of cattle lying in time ranges of 20% increments Behaviour shown during laying or standing The time it took for each animal to lay was recorded. Most animals took approximately 6 seconds to lie and 6 seconds to stand in both rubber and straw pens, with the range being 5 to 11 seconds. There were no large differences in time to lay or stand in rubber or straw pens, with 13

14 the average times being 6.0 seconds for rubber (range 3-10 seconds) and 5.9 seconds for straw (range 5-11 seconds). Abnormal behaviour during laying or standing were observed in only one animal in the trial, and that was a bull penned on rubber, which sat like a dog on its way from lay to stand position for 5 minutes. Three animals on straw and 3 on rubber pens (table 8), showed failed attempts to lie down by going down on one or two knees, and then raising up again. Table 8: Number animal showing failed attempts to lay down during a film session No. animals showing failed lay attempts No. of failed lay attempts in total Straw pens 3 5 Rubber pens 3 7 Discussion Floor/Animal hygiene In every pen, the contaminations always lay in the back part of the pen, as animals had no capacity to turn around, and were restricted in forward and backward movements (especially larger cattle). There did not appear to be any correlation between contamination during lairage on the animal and hours spent in lairage. Some animals that spent larger amounts of time in lairage had lower body contamination than animals that spent less time in lairage and vies versa. Contamination in straw pens occurred due the straw clogging between the slats and reducing the effectiveness of the slats, and there were often bare patches occurring under where the feet were (figure10). Manure contamination in rubber pens was pushed through the slats when the animal stepped on the contaminated areas, effectively reducing contamination compared to straw pens (figure 11). In additions, this was observed to be the same effect in cement pens with no straw. 14

15 Figure 10: Straw clogging the cement slats at the back of the pen, with bare patches left under where the animals back feet were. Figure 11: Typical pattern of soiling in rubber pens after overnight lairage 15

16 Animals penned on straw bedded cement were generally more soiled after over night lairage than animals penned on rubber. Most of the soiling occurred on the back legs, with manure and straw being trapped between the claws of the hoof, and this was the cause for contamination on 75% of the animals that had added dirt scores after over night lairage. Some animals also had soiled areas on the stomach area due to lying on manure soaked straw. Animals on rubber were cleaner on the body area, as there was less spreading of manure from the back area of the pen to the front, or under the animal s body. The manure generally clumped in the back of the pen, and was mostly pushed through the slats. Video Results on laying and standing behaviour In general the laying times and the behaviour of cattle on both floor types fitted well with what has previously been discussed in relevant literature (figure 7). Animals that lay on both floor types showed that they could lie in the one position for prolonged periods without showing discomfort behaviour. Many animals however did show restless behaviour while standing on both straw and rubber pens. Some animals tried to turn around, while others moved forwards and backwards, or stood from one front foot to another. This behaviour could be related to restricted box size, boredom, hunger, or discomfort due to the unfamiliar environment. Six of 14 animals (43%) in the trial, showed failed lay attempts; 3 on the straw pens, and 3 on the rubber pens. This is likely to be related to the box size. Some animals were observed hitting the front of the pen with their head as they threw their weight forward when laying or rising. This was observed mostly on the larger framed cattle. The most abnormal behaviour during laying or standing was observed in only one animal in the trial, and that was a bull penned on rubber, which sat like a dog on its way from lay to stand position for 5 minutes. This animal was filmed when the session of filming lasted 8 hours, and it was a large dairy bull which lay for 89% of the film time, with 2 lay sessions over the 8 hour period. This bull may have had some injury or muscle soreness in the back which contributed to this behaviour. One other abnormal behaviour to note was during the same film session but the animal on straw (also a bull) which lay down 3 times getting up immediately after laying. Many of the straw pens became wet which could be why the bull did not lay. However the bull did eventually lay for a session of 127 minutes, lying for 32% of the total film session. One animal penned on straw did slip as it was getting up. This is most likely due to the wet straw bedding under its feet. No animals on rubber pens were seen to slip when laying or rising. 16

17 No animals in the trial lay in synchronised bouts. All animals lay in sessions independent of the animal next to them. On one occasion only, did parallel animals stand at the same time, and this was at the end of the film session, perhaps from a disturbance such as new animals arriving at the abattoir. Three of the 4 animals in the trial that stood during the whole film session had possible explanations for this behaviour. Two of the animals, 1 on straw, and 1 on rubber, were lactating cows with swollen udders leaking milk, and this could have made it too uncomfortable for them to lie. The third animal, a bull on straw, had an infected preputial area, which could have made laying painful. It was not possible to explain why the fourth animal (a non lactating heifer on straw) did not lay down. She was however, standing parallel with the lactating cow on rubber that did not lay down. Perhaps there was some influence from that, although animals in the trial generally did not show any synchronised behaviour patterns. There was a tendency for animals that were transported longer to lay for longer times. Seven of 14 animals were transported over 3 hours, and 6 of these lay for over 80% of the film session, while 1 did not lie but it was the bull with an infected sheath area. The 2 animals that were transported the longest (6 hours) lay for over 90% of the film session (both on straw pens). During the study it was observed that animals which were not part of the study, but were penned in the other aisles consisting of cement slats and no straw bedding, lay in regular and random bouts. It is difficult to know what motivates an animal to lay or stand during a set period. Many factors such as the animals need for rest, the body weight, the health status, the feet conditions, injuries to the body, and its previous experiences can influence this behaviour. Animals were in lairage from a minimum time of 12 hours to a maximum time of 18 hours. 120 animals or 83% were lairaged between 14 and 18 hours. 17

18 Conclusions Straw pens were covered in manure and effluent over a larger area than rubber pens. The number of animals in the trial with added contamination after lairage was higher on straw than on rubber. The rubber pens provided better hygiene conditions for animals than the straw bedded cement pens. There appears to be minimal differences between animals on rubber pens compared to straw pens with regard to laying and standing behaviour. On both pen types, animals demonstrated that they could lie for long periods of time, with the time of the laying session on average and the number of lying bouts per film session being almost the same for both straw and rubber respectively. From these results it cannot be determined which floor type is more comfortable for animals. Both floor types seem to provide adequate comfort for cattle to lie down on during lairage. References Haley, D.B., de Passillé, A. M., Rushen, J Assessing cow comfort: effects of two floor types and two tie stall designs on the behaviour of lactating dairy cows. Applied Animal Behaviour Science 71: Haley. D.B., Rushen. J., de Passillé. A.M Behavioural indicators of cow comfort: activity and resting behaviour if dairy cows in two types of housing. Canadian Journal of Animal Science 80: Herlin, A Comparison of Lying Area Surfaces for Dairy Cows by Preference, Hygiene and Lying down Behaviour Swedish Journal of Research 27: Kirchner, M Pens with slatted floors for fattening bulls. 11 th International Agricultural Engineering Congress, Vol 1-4, pp Krohn C.C. and Munksgaard, L Behaviour of dairy cows kept in extensive (loose housing/pasture) or intensive (tie-stall) environments. II. Lying and lying-down behaviour. Applied Animal Behaviour Science. 37,

19 Krohn C.C. and Munksgaard, L. and Jonasen, B Behaviour of dairy cows kept in intensive (loose housing pasture) or intensive (tie-stall) environments. 1. Experimental procedure, facilities, time budgets diurnal and seasonal conditions. Applied Animal Behaviour Science 34: Lundberg, F Manure draining rubber slatted floors as part of the stall floor for tied up dairy cows. Exam work, Institute for agriculture engineering, Swedish Agriculture University, Uppsala. Nilsson, C. and Svenerstedt, B Draining rubber floors for cattle design, animal behaviour and draining capacity. Special Report 234. Swedish University of Agricultural Sciences, Alnarp, Sweden. Hultgren, J. and Bergsten, C Effects of a rubber-slatted flooring system on cleanliness and foot health in tied dairy cows. Preventative Veterinary Medicine, 52: Singh, S.S., Ward, W.R., Lautenbach, K., Murray, R.D Behaviour of lame and normal dairy cows in cubicles and in a straw yard. Veterinary Record. 133: Stefanowska, J., Swierstra, D., Smits, A.C., van den Berg, J., Mertz, J.H.M Reaction of calves to two flooring materials offered simultaneously in one pen. Acta Scandinavica, vol 52: 2:

20 Appendix 1. Date: Arrival Time: Duration of lairage: Transport time: Pen type: Rubber Pen No: Straw Soiling Code: 1: Light 2. Medium 3. Heavy Cow details (breed, sex, condition -thin, fat, injuries, lactation status, temperament). Describe and mark on animal diagram dirt before overnight holding: Describe and mark on animal diagram dirt on animal after overnight holding: Describe and mark areas on floor diagram where dirt and manure is after overnight holding. 20

21 Appendix 2. Recording session 1 2 Animal straw Hrfd cow horns dry SRB cow lactating Animal rubber Transport time (hrs)straw Transport time(hrs) rubber Total time standing straw (mins) Total time Standing rubber (mins) Total time laying straw mins,(% of film session) Total time laying rubber (mins) No of laying sessions straw No of laying sessions rubber Ave laying time per session straw (mins) Ave laying time per session rubber (mins) Ave standing time per session straw (mins) SLB cow dry (16%) 230(93%) SLB bull small (33%) 168(69%) SLB heifer dry SRB heifer dry (93%) 170(69%) SRB Bull SLB bull (37%) 76(31%) SLB Bull SLB bull (54%) 17(7%) SLB Cow lactating SLB heifer dry SRB Bull horns (46%) SLB Cow lact horns SRB heifer dry SLB Bull (99%) 126(51%) SRB heifer dry horns SLB Bull (93%) 125(51%) SRB Bull SRB Bull (98%) 204(83%) SRB Bull SRB Bull (91%) 243(99%) SRB heifer 12 dry SRB Bull (93%) 213(89%) SRB Bull SRB Bull (32%) 389(83%) SLB bull horns SLB bull horn (83%) Total Average (67%) 175 (66%) Ave standing time per session rubber (mins) 21

22 Appendix Time each cow stood and lay in parallel pens on rubber and straw pens Time spent standing on straw Time spent laying on straw Time spent standing on rubber Time spent laying on rubber Time (minutes) Film session and sample number 22