Associations of herd-level housing, management, and lameness prevalence with productivity and cow behavior in herds with automated milking systems

摘要

Lameness is problematic for herds with automated milking systems (AMS) due to negative effects on milking frequency and productivity. The objective of this study was to evaluate how management, barn design, and the prevalence of lameness relate to productivity and behavior at the herd level in AMS. Details about barn design, stocking density, and management were collected from 41 AMS farms in Canada (Ontario: n = 26; Alberta: n = 15). We collected milking data for all cows on each farm, plus lying behavior data for 30 cows/farm during a 6-d period. Farms averaged 105 ± 56 lactating cows and 2.2 ± 1.3 AMS units. Forty cows/ farm were gait scored (or 30% of cows for herds with >130 cows) using a numerical rating system (NRS; 1 = sound to 5 = extremely lame). Cows were defined as clinically lame with NRS ≥3 (mean = 26.2 ± 13.0%/ herd) and severely lame with NRS≥4 (mean = 2.2 ± 3.1%/herd). The prevalence of both clinical and severe lameness were negatively associated with environmental temperature. Clinical lameness tended to be less prevalent with more frequent scraping of manure alleys. The prevalence of severe lameness was positively associated with stocking density and curb height of the lying stalls. Milking frequency/cow per day was negatively related to the ratio of cows to AMS units. Doubling the prevalence of severe lameness (i.e., from 2.5 to 5%) was associated with reductions in milk production of 0.7 kg/ cow per day and 39 kg/AMS per day. Milk/AMS was positively associated with more cows/AMS (+32 kg/ cow). Fewer cows were fetched to the AMS with more frequent alley scraping. Lying behavior was associated with the frequency of feed push-ups, stall base, and environmental temperature. These results highlight the need for AMS producers to identify and reduce clinical lameness because 26% of cows/herd were clinically lame. Further, the results indicate that more frequently scraped alleys and optimal stocking densities are associated with improved cow mobility, productivity, and voluntary milking behavior.