Magnesium requirement of young West African dwarf goats for maintenance

Résumé

Eighteen growing West African dwarf WAD goats of equal number of sexes, aged 6-7 months with average weight of 6.23 +0.50kg were used in a 9-wk feeding trial to study the influence of dietary supplementation of magnesium sulphate (MgSO, 7H,0) at 0, 1 and 2% in isonitrogenous (11.50%CP) and isocaloric (2.83 ME Mcal/kg) diets with a view to estimating Mg requirement for maintenance. The three levels of supplementation were used to obtain three diets 1, 2 and 3 containing 0.02, 0.13 and 0.22% Mg respectively. The goats were divided into three groups of six animals, and each group was randomly allotted to one of the three diets. Results showed that Mg supplementation had significant (P<0.05) effects on Mg intake, absorption, balance, serum Mg, red blood cell (RBC) and white blood cell (WBC) counts: and highly significant (P<0.01) effects on dry matter intake (DMI), growth rate, serum glucose (GLU), total protein (TP) and haemoglobin (Hb) concentration. Treatment effect on packed cell volume (PCV) was not significant (P >0.05). The general trend depicted an increasing dietary Mg supplementation with decreased DMI, body weight change, serunt GLC, TP, PCV, Hb concentration, RBC and WBC counts at 2% Mg level of supplementation. Dietary supplementation of Mg at 1% (D2) however supported best animal performance as evidenced by the outstanding responses of the goats in terms of DMI (0.446 g/day/kgLW), body weight change (30.01g/day), feed conversion 

114.48), Mg digestibility (80.51%), Mg balance (0.091 g/day/kgLW), PCV (36%) and TP (70.70g/1). 72 x model relating Yg intake to balance gave Mg minimum requirement of young WAD goats for 

: - kgLIT with significant (P < 0.05) correlation coefficient (r = 0.98). Dietary O V ER H. however must not exceed 1% of the total diet to avert a decline in animal