Nutritional Evaluation of Marula (Sclerocarya birrea) Seed Cake as a Protein Supplement in Dairy Meal

摘要

Aims: To investigate the nutritional properties of Marula ( Sclerocarya birrea ) Seed Cake as a protein supplement in dairy cattle ration. Study Design: Experimental design used was a completely randomized design (CRD). Place and Duration of Study: Department of Animal Science, University of Swaziland, between September 2014 and December 2014. Methodology: Three dairy cattle rations were formulated using Marula seed cake (MSC) as follows: Marula Seed Meal (MSM) = a formulated diet containing Marula seed cake as a protein supplement; soya bean meal + Marula seed cake (SBM+MSC) = a formulated diet containing 50% Marula seed cake and 50% soya bean meal (SBM) as a protein supplement; and control diet (CD) = a formulated diet containing soya bean meal as a protein supplement. Marula seed cake which is the protein supplement and the formulated diets were then analysed for dry matter (DM), crude protein (CP), ash, ether extract (EE) and crude fibre (CF). Non-fibre carbohydrates (NFC), nitrogen-free extracts (NFE) and metabolisable energy (ME) were calculated. In vitro digestibility of the feed was analysed while the apparent dry matter digestibility (ADMD) was calculated. Results: The CP, CF, EE and ash content of MSC were 47.21, 4.79, 28.96 and 6.61% (w/w) respectively, and had ME value of 1544.64 MJ/kg DM. The MSC has an in vitro dry matter digestibility (IDMD) and nitrogen digestibility (ND) of 83.33 and 81.46% (w/w) respectively. The CP content, EE and ME value of the formulated diets ranged from 22.22% in MSM to 24.23% CD, 4.39% in CD to 7.32% MSM (w/w) and 1073.84 MJ/kg in CD to 1163.98 MJ/kg in MSM respectively. The IDMD and ND ranged from 79.09% in CD to 81.52% in MSM and from 77.33% (w/w) in CD to 79.45% (w/w) in SBM+MSC respectively. Conclusion: Marula seed cake is rich in CP and is digestible and thus can be used as a protein supplement in dairy cattle rations.