Seasonal variations of some serum electrolyte concentrations in sheep and goats

The aim of this study was to evaluate the serum concentration of calcium, chloride, phosphorus, magnesium, sodium, and potassium, in sheep and goats, during 12 months. The experimental subjects were six female sheep (Valle del Belice breed; aged 4±1 years; mean weight, 68 ±6 kg) and six female goats (Maltese breed; aged 3±1 years; mean weight, 45±3 kg). All subjects were clinically healthy and not pregnant nor lactating before and during the study. Blood samples were collected every 30 days at the same time (09:00) for 1 year (12 months). On the obtained sera, calcium, chloride, phosphorus, and magnesium were assessed by means of UV spectrophotometry; sodium and potassium were assessed by means of semiautomatic flame photometry. The application of the periodic model and statistical analysis of the cosinor procedure demonstrated seasonal rhythms of calcium, chloride, and sodium only in goats. Calcium showed the acrophase during the spring season, whereas the sodium and chloride serum values showed a seasonal rhythm with the acrophase in early summer. Our study sheds light on the seasonal difference existing between sheep and goats and provides useful information in livestock productions.