جستجوی مقالات مرتبط با کلیدواژه « مواد معدنی » در نشریات گروه « آبخیزداری، بیابان، محیط زیست، مرتع »

The aim of this study was to determine and compare the mineral concentration in the milk of grazing ewes in rangelands of northern and southeastern Sabalan. For this purpose, three range sites in 1800-2100, 2300-2700 and 3200-3700 meter from sea level in the rangeland of south-eastern Sabalan and 1300-1800, 1800-25800 and 2500 3200 m elevations in northern Sabalan were selected as the study site. Soil samples were collected and plant biomass in a 1 m2 were measured and grazed sheep milk grazed in these sites were collected for the measurement of mineral concentrations. The minerals concentrations of Calcium, Phosphorus, Potassium, Magnesium, Sodium, Zinc, Copper, Manganese and Iron in collected samples were measured by atomic absorption spectrophotometer and flame photometer. Data was analyzed in a completely randomized design using SAS9.1 software and the General Linear Model procedure was used for statistical analysis. The results showed that Ca (619.49 mg/kg), P (607.41 mg/kg), K (1399.29 mg/kg), Mg (165.01 mg/kg), Cu (1312.9 μg/kg), Zn (10920 μg/kg) and Mn (732.6 μg/kg) in grazing sheep milk in the site of 1300-1800 m of south-eastern Sabalan were significantly higher (P<0.05). Ca (937.57 mg/kg), P (320.55 mg/kg), Na 924.75 mg/kg), Mg (100.05 mg/kg), Fe (24041 μg/kg), Cu (2384.7 μg/kg) and Mn 1355.79 μg/kg) in grazing sheep milk at 2500-3200m elevation of northern Sabalan were significantly higher (P<0.05). According to the results, of most elements except calcium, copper and manganese in milk of grazed sheep in rangelands of south-eastern Sabalan were significantly higher (P<0.05) than the sheep grazed on northern slopes.. In general, the results showed that the ecological conditions such as altitude and aspect of rangelands has great influence on mineral concentration of sheep milk in Sabalan through their effets on the soil and plant minerals.

Determination of nutritive substances of forage and deficiencies diagnosis assist managers to improve nutrition of ruminants in rangelands.. Nutrition experts believe that deficiency of protein of grains and low energy of woody substances and imbalance of mineral elements of range forage are among the most limiting factor range animal nutrition.Magnesium, calcium, sodium, potassium and phosphorus content of dominant and halophyte shrubs of Salsola arbuscula, Salsola richteri, Halothamnus glauca, Seidlitzia rosmarinus species at three phenological stages: vegetative, full flowering and seed dissemination in desert rangeland of Sabzevar was investigated. Samples were taken to laboratory and mineral elements of them were measured.Comparison of mineral elements with the requirement of ruminant showed that the P was lower than its requirement in all three phenological stages. The highest contents of calcium, sodium, phosphorus, magnesium and ash and the least value of potassium belonged to Seidlitzia rosmarinus.