versión On-line ISSN 0121-3709
CEDENO-QUEVEDO, Darío A.; CEBALLOS-MARQUEZ, Alejandro; GARZON, Catalina y DAZA-BOLANOS, Carmen A.. A comparative study of metabolic mineral profiles on dairy farms from two regions in Nariño department. Orinoquia [online]. 2011, vol.15, n.2, pp. 160-168. ISSN 0121-3709.
The present study was aimed at assessing the calcium (Ca), phosphorus (P) and magnesium (Mg) concentration in the blood of dairy cows from two areas of the Nariño department, Colombia, during dry, postpartum and peak production periods; 351 Holstein cows were evaluated from herds grazing at 2,600 to 3,200 metres above sea level in Pasto and Tuquerres Guachucal. The types of pasture found on the farms were kikuyu (Pennisetum clandestinum), orchardgrass (Dactylis glomerata), rye grass (Lolium sp), Yorkshire fog (Holcus lanatus), red clover (Trifolium pratense) and white clover (Trifolium repens). The cows were divided into three groups according to their production state (dry period, beginning and peak lactation). Colorimetry was used for determining Ca, P and Mg concentration in blood and descriptive statistics were used for presenting the results. Average Ca levels (1.94 mmol/L) in cows from Pasto regarding the three production states were considered to be below the average reference value; average Ca concentration (2.3 mmol/L) was higher in Guachucal-Tuquerres. Unlike the results observed for Ca, no differences were found for P (1.81 mmol/L) or Mg concentration (1.03 mmol/L) by region, production status or number of calvings (p>0.05). This study's results thus led to concluding that phosphorus and magnesium concentrations came within the reference range, indicating that clinically-healthy cows' transition period (regarding both input and the homeostatic mechanism regulating their blood levels) were suitable and ensured serum concentrations compatible with optimal nutritional metabolic profiles and mineral balance in the cows in question. However, there were differences in calcium values regarding the Pasto and Guachucal-Tuquerres areas, reflecting changes in these cows' nutritional management.
Palabras llave : Calcium; phosphorus; magnesium; Holstein.