Assessment of lameness prevalence and associated individual and herd risk factors in small-scale Algerian dairy farms.

A cross-sectional study was conducted from October 2021 to May 2022 on 19 small-scale dairy farms across two agro-ecological zones in northeastern Algeria to estimate the prevalence of lameness in dairy cows and identify associated risk factors. A total of 556 lactating cows were visually examined using a four-point gait scoring system (0–3), with scores ≥ 2 classified as clinically lame. Farm management practices, cow characteristics, and environmental conditions were recorded through interviews and direct observation. Associations between each potential risk factor and lameness were evaluated using univariable generalized linear mixed models (GLMM), incorporating farm as a random effect to account for clustering. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Lameness prevalence was 11% at the cow level, and 57.8% of farms had at least one lame animal. Significant factors associated with lameness included parity (p = 0.048), breed (p = 0.001), flooring system (p = 0.013), grazing practice (p = 0.001), and hoof trimming frequency (p = 0.013). First-parity cows had lower odds of lameness than cows in later parities (OR = 0.28; 95% CI: 0.10–0.78). Holstein cows were at substantially higher risk compared with the Brown Atlas (OR = 9.08; 95% CI: 2.73–30.24). Earth flooring appeared protective (OR = 0.14; 95% CI: 0.02–0.99), whereas spring-restricted grazing (OR = 4.04) and zero-grazing systems (OR = 12.80) increased lameness likelihood. Infrequent hoof trimming, either once annually or irregular, was associated with markedly higher odds of lameness. No significant associations were observed for age, region, herd size, housing type, or footbath use (p > 0.05). Multiple Correspondence Analysis (MCA) followed by Hierarchical Ascending Clustering (HAC) identified three distinct herd typologies (all p < 0.001). Cluster 1 (traditional systems) grouped farms with earth flooring, year-round grazing, local breeds, and absence of trimming; this cluster showed the lowest proportion of lame cows, consistent with its protective characteristics. Cluster 2 (transitional systems) combined concrete flooring, tie-stalls, mixed breeds, and occasional trimming and showed an intermediate lameness frequency. Cluster 3 (modernized systems), characterized by Prim’Holstein predominance, sand flooring, restricted spring grazing, and systematic footbath use, showed the highest lameness occurrence, aligning with the high-risk factors identified in the GLMM. These findings highlight how structural and management practices co-occur within production systems and shape the distribution of lameness across dairy farms.