Determination of some serum macroelement minerals levels at different lactation stages of dairy cows and their correlations

Abstract

Minerals levels in blood affects animal performance, such as reproduction, immunity, and lameness. Minerals blood levels are recorded for all world tropics to be affected by lactation yield. This study aims to determinate the effects of different lactation stages of dairy cows on the serum Ca, P, Mg, Na and K minerals levels.The study involved 37 dairy cows, of parity order ranging between 2 to 6, at different stages of lactation. The animals were divided into four groups based on their stage of lactation, including postpartum, early, mid, and late stage cows. At the different lactation stages, serum profiles of Ca, P, Na, K and Mg as well as average daily milk yield were estimated. The data of serum profile was analyzed for the significance of stage of lactation by analysis of covariance, taking parity order as a covariate.The descriptive statistics of the studied traits showed that calcium serum level showed the most discrepancies among observations (coefficient of variation of 73.39%), whereas sodium serum level had the lowest level of discrepancies (coefficient of variation of 2.41%). The average daily milk yield was significantly higher at mid stage of lactation than those at the other stages of lactation. Serum level of all of the studied macro minerals were not statistically variable among stages of lactation, however, calcium showed statistically insignificant high levels during the early and mid of lactation, whereas, showed the lowest level at prepartum and postpartum stages. Calcium positively correlated with daily milk yield and negatively with potassium serum level.Results offer a base-line data concerning minerals levels during different lactation stages specially during prepartum and postpartum for normal healthy cows. Different lactation stages may affect and determinate macro-elements minerals levels. prepartum and postpartum periods are the most important stages that affects minerals levels. Some minerals showed tendency to correlate positively or negatively with other.