Concrete slats versus rubber-covered slats

Researchers in Teagasc Grange have assessed the effect of concrete slats versus rubber-covered slats on the performance and welfare of finishing and weanling cattle.

Results of these studies were presented in a paper published by Bernadette Earley, Mark McGee, Edward O’Riordan, Alan Kelly and Cathy McGettigan as part of the BEEF2024 Open Day. The full paper is available to read below.

Summary

• Compared to concrete slats (CS), animal growth and feed efficiency was significantly improved in finishing steers accommodated on slats overlaid with rubber mats (RM).
• Finishing steers on RM lay down for longer and had more frequent getting up and lying down movements.
• No hoof lesions were found on either floor type.
• Steers accommodated on RM were dirtier than those on CS by the end of the finishing period.
• Intake, growth performance, hoof health and cleanliness of weanling cattle accommodated on CS and RM was similar.

Introduction

Measuring the responses of animals to different floor types, in terms of intake, growth performance, hoof score, dirt scores, behaviour, and physiological variables provides an insight into their welfare during indoor housing.

Two of the most important metrics in the evaluation of animal ‘comfort’ in relation to floor type ‘environment’ are duration of standing and lying behaviour, and the number of getting-up and lying-down movements.

Two experiments were conducted at Teagasc, Grange to investigate the effect of concrete slats (CS) and concrete slats overlaid with rubber mats (RM) on; i) growth performance, behaviour, hoof wear, dirt scores, physiological response and carcass traits of ‘finishing’ beef steers, and ii) growth performance, hoof health and dirt scores of spring-born, suckler-bred weanling cattle undergoing a ‘backgrounding/store’ period (i.e. first winter indoor feeding period).

Experiment 1 - 'Finishing' cattle

One hundred and forty Charolais and Limousin crossbred steers, with a mean initial live weight of 597kg were allocated to one of two treatments for 120 days; (i) CS (17 pens of four animals) or (ii) RM (18 pens of four animals) at a space allowance of 2.89m² per animal. Durapak mats (Durapak Agri Ltd. Ballincollig, Co. Cork, Ireland), 22mm thick (compressibility of 0.839 mm, mean wet friction of 0.59 µ, mean dry friction of 0.71 µ) were fitted to the respective pens including the concrete apron at the feed face by a commercial technician. Mats were slotted and overlaid on the concrete slats to allow drainage through the void spaces (Figure 1). The drainage area/void space of CS and RM pens was 12.1% and 5.2%, respectively. Adjacent pens were separated by a metal ‘gate-like’ structure that allowed visual and limited physical contact between animals.

Figure 1: Photograph showing (A) concrete slatted floor pen (CS), and (B) the concrete slats overlaid with rubber mats (RM)

Steers were offered a total mixed ration (TMR) based on high dry matter digestibility (DMD ~74%) grass silage and a rolled barley-based concentrate (60:40 DM basis), ad libitum. Animal daily feed dry matter intake (pen basis), live weight (14-day intervals), feed conversion ratio, carcass weight and hide weight was determined. 

Animal behaviour was recorded continuously in each pen for 24 hour throughout the study using high definition infra-red cameras connected to a network video recorder. Additionally, hoof health (presence of hoof lesions, and toe angle and length) was measured at the start and end of the experiment, animal cleanliness (16-body dirt scoring system) was determined every 28 days, and animals were blood sampled to measure blood metabolic and haematological variables.

Total dry matter intake did not differ between the two floor types at any stage (Table 2). However, finishing steers accommodated on RM had a 0.17kg greater average daily live weight gain, resulting in a 17% superior feed conversion ratio compared to those on CS. Carcass weight was 11kg heavier for steers accommodated on RM compared to CS. There was no difference in kill-out proportion, carcass conformation score or carcass fat score between the floor types.

Steers on RM lay down for longer, had more frequent getting up and lying down movements and lying and standing bouts. There was no effect of floor type on eating behaviour or drinking behaviour. In terms of dirt scores, there was no difference between treatments from day 0 to day 56 but from day 56 until ‘finished’ steers housed on RM were dirtier than those on CS. Overall, there was no difference in toe length or toe net growth between treatments; however, the steers housed on RM had an increase in sharpness in the toe angle of the right front medial claw and left hind lateral claw. No hoof lesions were reported on either floor type. There was no effect of floor type on blood metabolic or haematological variables.

Table 1. Total dry matter intake, live weight gain, food conversion ratio (kg dry matter intake/ kg live weight gain) and carcass traits of finishing steers housed on concrete slats (CS) or concrete slats overlaid with rubber mats (RM) (Experiment 1)

¹NS = not statistically significant; * P <0.05; *** P <0.001

Experiment 2 – ‘Weanling’ cattle

A total of 200 weanling heifers and steers with a mean initial live-weight of 315kg and age of 262 days were allocated to one of two treatments for 84 days; (i) CS (20 pens with 5 animals/pen) or (ii) RM (20 pens with 5 animals/pen) at a space allowance of 2.5m² per animal. The animal accommodation, dimensions of the experimental pen and rubber mats used in this experiment were the same as described above for Experiment 1.

The weanlings were offered a diet consisting of high dry matter digestibility (DMD ~75%) grass silage only ad libitum supplemented with a general-purpose mineral-vitamin supplement daily, or the same grass silage ad libitum supplemented with 2.0 kg/head daily of a rolled barley-based concentrate. Animal daily feed intake (pen basis), live weight (weekly), hoof health (lesions) and animal cleanliness (16-body dirt scoring system) were determined as described in Experiment 1. Overall, housing weanling cattle on CS or RM had no effect on dry matter intake, daily live weight gain or final live-weight (Table 2). Furthermore, there was no effect of floor type on dirt scores or on hoof health).

Table 2. Total dry matter intake, live weight and live weight gain of suckler-bred weanlings housed on concrete slats (CS) or concrete slats overlaid with rubber mats (RM) (Experiment 2)

¹NS = not statistically significant

Conclusions

Compared to CS, growth performance and feed efficiency of finishing steers was significantly improved as a result of housing on RM. The production benefits were complemented by enhanced animal behaviour traits indicative of greater resting and underfoot comfort of steers accommodated on the RM floor type and the absence of any negative impacts on hoof wear, haematological and metabolic variables. The growth performance benefit associated with the RM floor type found with finishing steers was not evident in the lighter weanling animal undergoing a ‘store’ period. Floor type had no effect on hoof health or cleanliness of weanlings.

This paper was published as part of the BEEF2024 Open Day in Teagasc Grange. Find out more about the research presented at the event here.