Blood Mineral Concentrations Research Articles

Effects of Dietary Energy and Phosphorus Content on Blood Chemistry and Development of Growing Horses

Growth and clinical biochemistry were examined over 30 wk in 42 light horse weanlings fed high-forage diets (73 to 77% alfalfa) or high-concentrate diets (63 to 65% grain and grain by-products) that were either low (.24 to .35%), normal (.68%) or high (.95 to 1.06%) in P. Body weights and blood samples were taken every 2 wk. Forage and concentrate diets contained 2.65 and 3.09 Mcal digestible energy/kg DM, respectively. Calcium and P digestibilities were highest (P less than .01) in those horses fed the low P diets, but only horses fed forage-low P diets may have absorbed insufficient P. Serum alkaline phosphatase activity, serum Ca, serum Mg and plasma Cu concentrations were unaffected by diet but varied (P less than .01) among sampling periods. The concentrations of serum Ca and P of all groups fluctuated to wk 10 before being stabilized at means of 2.77 and 2.03 mmol/liter, respectively. Plasma Zn concentrations increased quadratically with age and were 3.8% greater (P less than .05) for concentrate-fed horses than for forage-fed horses. Mild to moderate physitis and flexure limb deformities occurred in 88% of the weanlings principally between wk 6 and 8 of the study. Limb deformities had largely resolved by wk 12. Marginally deficient P intakes did not alter productivity, feed intake, blood mineral concentration in the final 20 wk or the occurrence of musculoskeletal abnormalities in weanling horses.

Effects of Long-Term Consumption of Sewage Solids on Blood, Milk and Tissue Elemental Composition of Breeding Ewes

Fine-wool ewes received for 2 yr a complete pelleted basal diet (11% protein) or the basal diet fortified with 3.5% cottonseed meal (CSM; 12% protein) or gamma-irradiated (1 megarad) dried solids (SS; 12% protein) from primary (undigested) sewage (Las Cruces, New Mexico, municipal sewage). Five ewes fed each diet were sampled to determine Ag, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb and Zn in blood, milk and tissues. Tissues and blood were sampled at slaughter 40 d after weaning of lambs. Mean whole blood mineral concentrations were similar (P less than .05) among treatments 3 d postpartum; however, at 42 d after lambing (mean +/- SE) both basal- (54 +/- 2 micrograms/ml) and sewage-fed (54 +/- 2 micrograms/ml) ewes had elevated (P less than .05) blood Ca compared with ewes fed CSM (46 +/- 2 micrograms/ml). No biologically important differences were detected in the concentrations of elements in milk. Ewes fed SS had lower (P less than .05) blood Fe than animals in the other groups. Sewage-fed ewes also had higher (P less than .05) liver Fe (1,092 +/- 100 micrograms/g) than basal-fed ewes (626 +/- 100 micrograms/g); whereas Fe in CSM-fed ewes (873 +/- 100 micrograms/g) was similar to both. Basal-fed animals had 1.1- to 1.3 times more (P less than .05) liver Mg and two- to threefold higher liver Na than CSM or SS. Livers from SS-fed ewes had higher concentrations (P less than .05) of Cd (1.5- to 1.6-times) and Pb (1.4- to 1.9-times) than livers from CSM- or basal-fed ewes.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of Varying Amounts of Calcium and Phosphorus in Rations for Dairy Cows

Different dietary percentages and ratios of calcium and phosphorus were studied with 48 dairy cows in a randomized block design. The respective members of each block were assigned to one of three ration treatments: a) Ca: P ratio approximately 3:1, 0.4% phosphorus; b) Ca:P 3:1, 0.6% phosphorus; and c) Ca:P 1.5:1, 0.6% phosphorus. Response criteria were blood mineral concentrations, milk yield and composition, parturient paresis, and reproductive performance. Average blood serum inorganic phosphorus was lower (P<.05) in the cows fed the 0.4% phosphorus ration than in the other treatment groups at all times, except on the day of calving. Blood serum calcium was highest in the group fed the 0.4% phosphorus ration. No differences in blood serum magnesium, potassium, copper and zinc, or in milk production and composition were attributed to the ration treatments. In the lowest phosphorus group (.4% P), incidence of ovarian dysfunctions was higher, and in addition, a larger number of services per conception were required in the second breeding season.

The concentration of minerals in the blood of genetically diverse groups of sheep. III. Correlations among calcium, phosphorus, magnesium, potassium, sodium, chlorine, and copper concentration

SUMMARYTwo sets of correlations among blood mineral concentrations were calculated (1) those attributable to the effects of various factors (breed, age, lambing performance, etc.) and (2) those remaining (residual) when the effects of such factors had been removed as sources of variation in mineral concentration (the equivalent of correlations within subclasses).Correlations arising from breed differences in mineral concentrations were highest for Ca.P (– 0·81), Ca.Cu (0·83) and P.Cu (–0·95). Correlations consequent on changes with the age of the sheep were most marked for Ca.Mg (0·97, P &lt; 0·01) and Cu.K (–0·92, P &lt; 0·05) and approximately 0·8 (P &lt; 0·1) for Ca.K, P.Mg, P.K and K.C1.Residual correlations were all below 0–2 (although seven of the twenty-one were statistically significant, P &lt; 0·05) suggesting that within subclasses most of the variation in the concentration of anyjone mineral was independent of that in the other minerals. Simple and partial correlations were very similar in magnitude suggesting that the associations found between pairs of minerals were not attributable to joint co-variance with any of the other five minerals.As the sheep grew older, changes in the concentrations of Ca, P and Mg were significantly correlated with the increases in live weight. Within subclasses, differences among the sheep in live weight were significantly (P &lt; 0·05) and positively correlated with differences in the concentrations of Ca (r, 0·11), Mg (0·13) and Cu (0·11).