Álvaro García
Lameness is a significant global issue affecting dairy cow well-being, leading to notable economic losses and behavioral changes. Over 90% of lameness cases are due to hoof lesions, which can be either noninfectious (e.g., sole hemorrhage, sole ulcer, white line disease) or infectious (e.g., digital dermatitis, foot rot). According to an overview of the prevalence and factors associated with lameness in dairy herds, hoof lesion prevalence varies between 20% and 37%, depending on housing systems and farms. Research on the relationship between lameness and reproductive performance, however, yields conflicting results, often focusing on locomotion scoring rather than specific hoof lesions (HL). Locomotion scoring when performed by observers is subjective and may not align with HL. With the advent of automated 3D imaging technology however, this source of inconsistency has changed dramatically. Studies have examined various reproductive metrics in lame cows, such as ovarian activity resumption, calving-to-first-service interval, and conception to first service. Disparities in findings may be due to differences in HL types and timing relative to reproductive events.
Hoof Lesions and the Pituitary-Ovarian Axis
Hoof horn lesions in dairy cows, such as sole ulcers or white line disease, profoundly impact reproductive performance through complex inflammatory and stress responses. These lesions initiate local tissue damage, triggering an inflammatory reaction that releases cytokines and acute-phase proteins like haptoglobin. Cytokines, as signaling proteins, contribute to tissue repair and systemic inflammatory effects in dairy cows. Acute-phase proteins, such as haptoglobin, are elevated during inflammatory conditions in cows, serving as markers of systemic inflammation and stress. Additionally, pain and stress from HL increase cortisol production, which helps reduce inflammation but can impair reproductive hormone balance crucial for fertility.
Disruption of the Hypothalamus-Pituitary-Ovarian Axis is critical for regulating reproductive hormones. Inflammation and elevated cortisol interfere with this axis. Cortisol suppresses the release of gonadotropin-releasing hormone (GnRH) from the hypothalamus, reducing secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the pituitary gland. These hormones are vital for developing and maturing ovarian follicles, ovulation, and maintaining the corpus luteum. Disruption of this hormonal cascade can lead to poor ovarian function, delayed ovulation, and reduced fertility.
Hoof horn lesions often lead to poorer reproductive performance in dairy cows, impacting metrics such as delayed resumption of ovarian cyclicity postpartum, longer intervals from calving to first service, reduced pregnancy per artificial insemination rates, and increased pregnancy loss. The combined effects of inflammation, stress, and hormonal imbalance create a challenging environment for maintaining optimal reproductive health in affected cows.
In summary, hoof horn lesions initiate a cascade of inflammatory and stress responses that significantly impair reproductive performance in dairy cows. The interaction between localized inflammation, systemic stress markers like haptoglobin and cortisol, and the disruption of the Hypothalamus-Pituitary-Ovarian axis underscores the importance of effective hoof health management to support reproductive success in dairy herds. Effective management strategies targeting early detection and treatment of hoof lesions are essential to improve reproductive outcomes and overall herd productivity.
Actual farm example:
Cow number 1125, a multiparous dairy cow currently at 380 days in milk, has encountered challenges in becoming pregnant, largely attributed to her persistent lameness. Despite maintaining a BCS of 3.5 up to 150 days in milk and improving it to 3.8 by her sixth insemination at 300 days in milk, her reproductive performance has been impacted by recurrent lameness as measured by 3D imaging technology.
These episodes, notably observed at days 240, 271, 295, 339, and 368, coincided with drops in milk production of 16, 30, 16, and 10 pounds (red arrows in the graph) during the first three and the fifth episodes, respectively.
Analyzing her reproductive performance reveals significant insights into the challenges faced by this cow. From calving to conception, she experienced a prolonged period of 338 days open. Her first insemination took place at 130 days in milk, therefore the interval from her first service at 130 days in milk to conception at 300 days in milk was 170 days.
These observations underscore the impact of lameness on dairy cow fertility, showcasing the difficulty in achieving timely conception despite multiple insemination attempts. Effective management of lameness is crucial not only for improving reproductive performance but also to enhance overall herd health and productivity in dairy farming practices.
© 2025 Dellait Knowledge Center. All Rights Reserved.
