Making tiestalls more comfortable: II. Increasing chain length to improve the ease of movement of dairy cows

Welfare of dairy cows

This Scientific Opinion addresses a European Commission's mandate on the welfare of dairy cows as part of the Farm to Fork strategy. It includes three assessments carried out based on literature reviews and complemented by expert opinion. Assessment 1 describes the most prevalent housing systems for dairy cows in Europe: tie-stalls, cubicle housing, open-bedded systems and systems with access to an outdoor area. Per each system, the scientific opinion describes the distribution in the EU and assesses the main strengths, weaknesses and hazards potentially reducing the welfare of dairy cows. Assessment 2 addresses five welfare consequences as requested in the mandate: locomotory disorders (including lameness), mastitis, restriction of movement and resting problems, inability to perform comfort behaviour and metabolic disorders. Per each welfare consequence, a set of animal-based measures is suggested, a detailed analysis of the prevalence in different housing systems is provided, and subsequently, a comparison of the housing systems is given. Common and specific system-related hazards as well as management-related hazards and respective preventive measures are investigated. Assessment 3 includes an analysis of farm characteristics (e.g. milk yield, herd size) that could be used to classify the level of on-farm welfare. From the available scientific literature, it was not possible to derive relevant associations between available farm data and cow welfare. Therefore, an approach based on expert knowledge elicitation (EKE) was developed. The EKE resulted in the identification of five farm characteristics (more than one cow per cubicle at maximum stocking density, limited space for cows, inappropriate cubicle size, high on-farm mortality and farms with less than 2 months access to pasture). If one or more of these farm characteristics are present, it is recommended to conduct an assessment of cow welfare on the farm in question using animal-based measures for specified welfare consequences.

Testing the ability of contact mats to identify problematic stall configurations

Comparing the frequency of cow contact with stall rails across multiple stall designs may help to determine which stall configurations best promote cow ease of movement and reduce injury risk. The objective of this study was to compare the frequency of cow contact with the dividers across different stall treatments using the contact mat (CM) system to identify problematic stall designs. A total of 6 stall treatments were each tested against for 6 consecutive weeks against control (CON) stall condition: 3 treatments that modified the placement of the tie-rail (TRFARM, TRNEW1, TRNEW2), and 3 separate treatments that increased chain length (LCL), doubled stall width (DSW), and shortened manger wall height (SMW). CM were affixed to the stall dividers to record the frequency of cow contact per second. Cows were ranked in descending order from highest frequency of divider contact to lowest frequency of divider contact for each week. TRNEW1 and TRNEW2 were the only stall treatments with a consistently lower frequency of divider contact than CON, while DSW was consistently higher than CON. The results suggest that the CM system can be used to identify problematic stall configurations to independently substantiate findings related to cow comfort.

Making tiestalls more comfortable: III. Providing additional lateral space to improve the resting capacity and comfort of dairy cows

Dairy cows housed in tiestalls are restricted to one space; therefore, this space should be designed to accommodate all the activities cows need to perform. Lying is a very important behavior for dairy cows as well as a critical measure in the assessment of stall designs, to ensure that the cows' needs for resting space are met. The objective of this study was to determine if increasing tiestall width alters the lying behavior of lactating dairy cows. Two treatments were compared: the current recommendation (139 cm) and a double stall (284 cm). Sixteen cows were blocked by parity and lactation stage, then randomly allocated to a treatment and a stall within 1 of 2 rows in the research barn, for 6 wk. The average stall length was 188 cm. Leg-mounted accelerometers were used to record lying behaviors. Cows were video-recorded 24 h/wk using surveillance cameras positioned above the stalls. Video data from wk 1, 3, and 6 were extracted at a rate of 1 image/min and analyzed by a trained observer to assess the position and the location of the cow's body, head, and limbs during the lying hours. Lying behaviors and frequency of each position and location were analyzed in SAS (SAS Institute Inc., Cary, NC) using a mixed model in which treatment, block, and week were included as fixed factors, and cow and row as random factors. Multiple comparisons were adjusted using the Scheffé method. Results indicate that cows in double stalls fully extended their hindlimbs more often than single stall cows (21.7 vs. 7.6% of lying time). Cows in double stalls also intruded in the neighboring stalls with their hindlimbs less often (1.3 vs. 14.7% of lying time), instead positioning them inside their own stall more often (92.7 vs. 84.6% of lying time). Use of the second stall in the double stall group totaled 11.6, 5.1, 33.8, and 18.0% of lying time, respectively, for the head, front legs, hind legs, and body. Total lying time was not statistically different between double (716 min/d) and single stall (671 min/d) groups. Contacts with stall hardware during lying-down movements were also less frequent in double stalls (43.1 vs. 77.1% of lying events) compared with single stalls. These results suggest that dairy cows housed in double stalls modified their resting habits and used the extra space made available to them. Increasing stall width beyond the current recommendation is likely to benefit the cows by improving their ability to rest.