WS Survey of serum trace mineral concentrations in weaned Montana ram lambs

Abstract Text:  Clinical and subclinical trace mineral deficiencies can limit productivity in western sheep production systems. The objective of the study was to quantify trace mineral status among Montana ram lambs post weaning. Based on prior research investigating forage trace mineral concentrations and trace mineral status in cattle, we hypothesized that clinical and subclinical deficiencies would be most prominent with Zn and Se. To test this hypothesis, serum samples (n = 201) were collected from ram lambs 8 to 10 mo of age (BW 52.8 ± 16 kg) at 21 locations throughout Montana and analyzed for Co, Cu, Fe, Mn, Mo, Se, and Zn. The average concentration and range for each trace mineral analyzed in the serum samples were: Co (1.00 ± 0.079 ng/mL; 0.09-6.22 ng/mL), Cu (0.84 ± 0.016 µg/mL; 0.3-1.61 µg/mL), Fe (154.85 ± 3.682 µg/dL; 26-350 µg/dL), Mn (2.56 ± 0.225 ng/mL; 0.7-31.3 ng/mL), Mo (40.14 ± 5.001 ng/mL; 2.8-456.5 ng/mL), Se (111.42 ± 3.31 ng/mL; 16-197 ng/mL), and Zn (0.73 ± 0.015 µg/mL, 0.3-1.74 µg/mL). The two most deficient and marginally deficient minerals across Montana were Se (19% of ranches deficient; 24% of ranches marginally deficient) and Zn (14% of ranches deficient; 52% of ranches marginally deficient). All Se deficient samples were obtained from western Montana. There was considerable variation in serum trace mineral concentrations within individual flocks. Descriptive statistics were analyzed using SAS. Given that Se and Zn play major roles in growth, fertility, and immunity, results suggest opportunities for more effective supplementation strategies. Producers and nutritionists alike can use these results to identify mineral deficient areas and develop cost effective mineral supplementation management practices. 

Keywords:

trace minerals, zinc, selenium, Montana, sheep, ram lambs