Nierembergia rivularis poisoning in cattle

Area of Science:

• Veterinary Medicine
• Toxicology
• Animal Science

Background:

• Enzootic calcinosis (EC) is a condition primarily associated with Nierembergia rivularis (NR) poisoning in sheep.
• The occurrence and impact of EC caused by NR in cattle have not been extensively documented.

Purpose of the Study:

• To describe and evaluate enzootic calcinosis (EC) in cattle caused by Nierembergia rivularis (NR) poisoning.
• To assess the clinical signs, pathological findings, and economic impact of NR-induced EC in cattle.

Main Methods:

• A three-year study evaluated cattle across seven paddocks with varying N. rivularis (NR) presence.
• Clinical examinations, biochemical analyses (serum calcium and phosphorus), necropsies, and carcass weight/quality assessments were performed.
• Pregnancy rates and weight gain after dietary change were also monitored.

Main Results:

• Cattle in a paddock with 7-12% NR showed increased EC morbidity (9.4% to 34.5%) over three years.
• Affected cows exhibited lower body weight, hypercalcemia/hyperphosphatemia, and characteristic soft tissue calcifications.
• Cows from the high-NR paddock had significantly lower pregnancy rates (~30%), reduced carcass weights (17.6%), and lower carcass quality.

Conclusions:

• Nierembergia rivularis (NR) is a significant cause of enzootic calcinosis (EC) in cattle, leading to substantial economic losses.
• Reduced fertility, impaired weight gain, and decreased carcass value are key economic consequences of NR poisoning in cattle.
• Controlling N. rivularis (NR) in pastures is crucial for mitigating these adverse effects in cattle farming.