Effect of season and age on blood minerals, liver enzyme levels, and faecal egg counts in Nguni goats of South Africa

The objective of the study was to determine the relationships between age of the goat and faecal egg counts, liver enzymes, and minerals in the wet and dry seasons in male and female Nguni goats of South Africa. Fifty-six female and forty male Nguni goats were used for the study. Faecal and blood samples were collected once in the dry (August) and wet (January) season. Faecal egg counts (FEC) were determined by the modified McMaster technique while trematodes were determined by the sedimentation method. Blood was analyzed for phosphorus, calcium, magnesium, alkaline phosphatase (ALP), alanine transaminase (ALT), creatine kinase (CK), aspartate aminotransferase (AST), and gamma-glutamyltransferase (GGT) levels. Faecal egg counts were significantly higher in the wet compared with the dry season. Most (P < 0.05) of the goats were within the reference values for calcium, phosphorus, and magnesium in both seasons. Phosphorus concentrations were significantly affected by age with higher levels in the young (2.1 ± 0.06) compared to the adult (2.0 ± 0.03) goats. Alkaline phosphate was significantly affected by age with higher levels in young than in mature goats. Higher AST, CK, and GGT concentrations were recorded in the wet compared to the dry season (P < 0.05). Higher CK and AST were recorded in male than in female goats while for ALP, the values were higher in female than in male goats. Linear negative relationships (P < 0.05) existed between age and ALP, phosphorus, and FEC, while quadratic relationships existed between age and strongyles and Strongyloides egg counts. Calcium was linearly related (P < 0.05) to FEC, while CK was related to FEC in a quadratic fashion. Age of the Nguni goats can be used to predict faecal egg counts, phosphorus, and ALP levels.