An Investigation Into The Use Of Dicalcium Phosphate And Complex AD3E On Mineral Status And Homeostasis Of Free Ranging Beef Cattle During Dry Season

Abstract

In South African commonage beef production, revenue is adversely affected by low mineral concentration in pastures especially during the winter season. Therefore, this study was undertaken to accurately determine the mineral status of grasses, blood and the blood metabolite important for effective livestock production. Body weights, body condition score, hair coat condition, and blood mineral status and blood metabolites were physiological parameters used as indicators for growth and health. A total of thirty Bonsmara calves were blocked according to age and randomly assigned to 3 groups. In the three groups D1 was allowed maintenance ration only, D2 was given dicalcium phosphate lick adlib and D3 was fed dicalcium phosphate lick adlib and were also inoculated with a shot of vitamin AD3E plus minerals on top of the maintenance ration on monthly intervals after sample collections. Grass P concentrations ranged between 1.12 mg g -1 and 1.52mg g-1, Ca from 6.18 mg g-1 to 13.03 mg g-1 and Mg from 1.50 mg g-1 to 2.48 mg g-1 and were lower than those recommended to meet animal mineral requirements. Highest mean (P <0.05) values (245.13kg and 239.00kg) for BW were recorded in April and May, respectively, while the lowest mean value (204.20kg) was recorded in July. Body scoring condition (BCS) recorded highest (P <0.05) mean value (5.87) in April with comparable mean values (5.70 and 5.67) in May and June, respectively, while the lowest mean value (5.50) was observed in July. Hair coat condition (HCC) was highest (P <0.05) in animals offered D3 with comparable mean value (3.2) in animals treated with D2, while the lowest value (3.08) was recorded in animals receiving the D1 diet. Blood P and Mg were higher (1.74 mmol/L, 0.60 mmol/L and 1.85 mmol/L, 0.75 mmol/L) in animals receiving D2 and D3, respectively, than those on D1 diet (0.78 mmol/L and 0.44 mmol/L). Blood Ca increased across the treatments with highest value (3.70 mmol/L) in animals receiving D3, while the lowest value (1.57 mmol/L) was observed in animals fed with D1. Albumin, blood urea nitrogen, creatinine and total protein with highest (P <0.05) mean values (45.33 G/L, 5.56 uMOL/L. 147.68 FLMOL/L and 73.83 g/l) were recorded in animals receiving D1, while lowest values were observed in animals receiving diets D2 and D3, respectively. Higher glucose mean values (3.25 and 3.36 mmol/L) were recorded in D2 and D3, respectively, compared to D1 (1.99 mmol/L). Faecal P (2.40 mg g-1, 2.27 mg g-1 and 2.24 mg g-1) and Ca (12.63 mg g-1, 13.21 mg g-1 and 12.70 mg g-1) were highest in May, June and July, respectively, while the lowest Faecal P value (1.06 mg g- 1) and Faecal Ca (10.13 mg g-1) were recorded at the beginning of the experiment. Higher (5.10mg g-1) Faecal Mg was documented in June with comparable mean values (1.91mg g- 1 , 1.95 mg g-1 and 2.73 mg g-1 ) recorded for April, May and July, respectively. The study indicates that minerals can be successfully utilized in the wintering of replacement calves on communal grazing systems.