Manganese, Zinc and Chloride Content of Milk of West African Dwarf Goats as Influenced by Stage of Lactation
O. A. Ogunwole *
Department of Animal Science, Agricultural Biochemistry and Nutrition Unit, University of Ibadan, Ibadan, Nigeria
*Author to whom correspondence should be addressed.
Abstract
The manganese, Zinc and chloride content in milk of West African dwarf (WAD) goats as influenced by stage of lactation was assessed using three WAD does aged 18 months of age, weighing from 19 to 20 Kg. They were kept for lactation studies lasting for two 10-weeks periods. Individual milk samples were taken from each animal daily for the first seven days (colostrums), from day one after parturition and once per week for 10 weeks. The samples collected were thereafter assayed chemically for Mn, Zn and Cl. Colostrum was much higher in its content of Mn (0.24±0.02 mg/L), Zn (14.40±0.19 mg/L) and Cl (237.14±14.0 mg / 100 mL) compared with the mature milk which contained Mn (0.12±0.01 mg/L), Zn (4.40±0.15 mg/L) and Cl (192.70±2.2 mg/100 mL). The three elements decreased highly significantly (P<0.01) with stage of lactation. The decreasing trends were neither linear nor quadratic (P>0.05). In conclusion, the content of these minerals in milk of goat was highly dependent on the stage of lactation.
Keywords: Milching does, colostrums' content, mature milk, milk micro minerals, milk trace elements