Newspaper article: "Trunk call answered”. With two handwritten notes: "Also shown on S.A.B.C. Television July 1980", and, "Note some scars on bark to left of the door ...".

PhD (AGR) (Animal Science) / Department of Animal Science / Horticultural by-products such as seed and nut oil residues have the potential to replace conventional protein and energy sources in diets for ruminants. The objective of the study was to evaluate the nutritive value of Macadamia oil cake and Baobab seed cake as nutrient supplements for feedlot animals. Several experiments were carried-out to evaluate the nutritive value of Macadamia oil cake and Baobab seed cake as feed for ruminants. The nutrient composition of the cakes were determined using both proximate and modern methods of analysis of feeds and a t-test was used to compare the means of Macadamia oil cake and Baobab seed cake. The in sacco technique was used to determine the rumen degradability parameters of dry matter, crude protein and Amino acids of the cakes. This experiment was conducted using a completely randomized design. A three step-in vitro technique was used to conduct a post ruminal digestibility trial and the study was arranged in a completely randomized design. An apparent digestibility trial was conducted using metabolism cages and fecal bags to avoid the mixing of urine and faeces and the experiment was carried out as a completely randomized design arranged in a 2 x 2 factorial. A growth trial was conducted using a completely randomized block design arranged in a 2x2 factorial with two protein supplements and two inclusion levels as factors and blocked by sex of the lambs. The two cakes had similar (P>0.05) dry matter, fat, hemicellulose and gross energy contents. Baobab seed cake had significantly (P<0.05) higher ash, crude protein, acid detergent lignin and nitrogen free extract than macadamia oil cake. Macadamia oil cake had significantly (P<0.05) higher crude fiber, acid detergent fiber, neutral detergent fiber and cellulose concentrations. Baobab seed cake had significantly (P<0.05) higher calcium, magnesium, potassium, phosphorus (macroelements), zinc, and copper than macadamia oil cake. Macadamia oil cake was significantly (P<0.05) higher in manganese and iron contents than Baobab seed cake. Sodium content was not significantly (P>0.05) different between the two cakes. Baobab seed cake had more (Tryptophan, Cysteine, Arginine, Aspartic acid, Glutamic acid, Valine, Phenylalanine, Isoleucine, Leucine) Amino acids which were significantly (P<0.05) higher in quantity than macadamia oil cake with the two cakes having similar (P>0.05) remaining Amino acids contents. Generally Macadamia oil cake had more (P<0.05) saturated and mono-unsaturated fatty acids than Baobab seed cake whereas Baobab seed cake had more (P<0.05) poly-unsaturated fatty acids. v The in sacco rumen degradability characteristics of baobab seed cake and macadamia oil cake were estimated for dry matter and crude protein of the cakes. Macadamia oil cake had significantly (P<0.01) higher a value for dry matter than boabab seed cake. Baoaba seed cake had significantly (P<0.01) higher a value for crude protein than macadamia oil cake. the b, c, and a+b values for dry matter of both Baobab seed cake and Macadamia oil cake were not significantly (P>0.05) different form each other. However, the potential degradability (a+b) value for crude protein of baobab seed cake was significantly (P<0.01) higher than that of macadamia oil cake. The b and c constants of the two cakes for crude protein were not significantly (P>0.05) different from each other. The ED (Effective degradability) values calculated at three outflow rates (0.02, 0.05, 0.08) were estimated for dry matter and crude protein of Baobab seed cake and macadamia oil cake. The ED of the two cakes calculated at 0.02 outflow rate did not significantly (P>0.05) differ from each other. However, baobab seed cake had significantly (P<0.05) higher ED value at outflow rate of 0.05 whereas macadamia oil cake had significantly (P<0.05) higher ED value calculated at outflow rate of 0.08. The ED values of baobab seed cake for crude protein calculated at the three outflow rate were significantly (P<0.01) higher than those of macadamia oil cake. The two cakes did not significantly (P>0.05) differ in dry matter ruminal degradability but baobab seed cake had significantly (P<0.05) higher ruminal crude protein disappearance from 16 to 72 hours of incubation than macadamia oil cake. The in situ Amino acid degradation was determined on 0, 12, 16, 24, and 48 hour of ruminal incubation of the cakes’ samples and generally they were significant (P<0.05) differences for both cakes according to different incubation periods. The 3-step in vitro digestibility trial revealed that baobab seed cake had significantly (P<0.05) higher dry matter, crude protein and Amino acids digestibility values than macadamia oil cake. Apparent digestibility study revealed that nutrient intake, faecal and urine outputs, and digestibility of nutrients were not significantly (P>0.05) different between baobab seed cake and macadamia oil cake. However, lambs on 10% macadamia cake having retained significantly (P<0.05) more nitrogen than the lambs on 15% macadamia oil cake, 10% and 15% baobab seed cakes diets. However, the inclusion of either baobab seed cake or macadamia oil cake at 10% or 15% in the diets of lambs did not significantly (P>0.05) affect the DOMR, microbial protein yield and purine derivates output. For the growth trial the lambs were offered four diets formulated to contain 10% MOC (control), 15% MOC, 10 BSC and 15% BSC. The inclusion of 15% MOC and 10% BSC in the diets of lambs did not significantly (P>0.05) affect their final body weight, total weight gain, average daily feed intake, average daily weight gain, warm and cold carcass masses between these two vi groups. The inclusion of 10% MOC and 15% BSC in the diets of lambs did not significantly affect average daily feed intake and animal performance between these two groups. However, lambs on 10% MOC and 15% BSC had significantly (P<0.05) higher average daily feed intake and animal performance compared to lambs on 15% MOC diet. The feed conversion efficiency and of the lambs in the four diets were not significantly (P>0.05) different. The dressing percentage, carcass length, neck weight, fat thickness, body weight thickness and rib eye area of the carcasses of lambs in this trial did not differ significantly (P>0.05) except for spleen and skin with lambs on 10% BSC diets having the least skin weight and lambs on 10% MOC diet having heaver spleens. Generally BSC had higher (P<0.05) nutrient content than MOC. BSC and MOC were highly degradable in the rumen whereas BSC was higly digestible post-ruminally compared to MOC. The diets of fattening lambs formulated to include 10% or 15% of BSC or MOC as protein supplements did not affect the apparent digestibility of the diets. Macadamia oil cake can be incomporated in the diet of finishing lambs as a protein supplement at 10% inclusion level without compromising the growth and carcass characteristics of the lambs. Baobab seed cake as a protein supplement can be included in the diet of finishing lambs at up to 15% inclusion level without deleteriously compromising on the growth and carcass characteristics of the animals. ______________________________________ / NRF

The baobab tree represents a major contribution to rural communities of the south-east lowveld of Zimbabwe. The livelihood base of the study area was largely rain-fed subsistence farming whose production has declined due to frequent droughts. Harvesting of baobab tree products; leaves, fruits and bark fibre, has prospered due to poverty. These products are harvested for food, medicinal use, cash and animal harness. A mixed method approach on collection of data was employed through questionnaires, semi-structured interviews, 48-hour dietary recall and Household Food Insecurity Access Prevalence (HFIAP) template. Sixty-eight households from Wengezi and Gudyanga communities participated in this study. All the respondents from the study area indicated they were involved in using baobab products in one way or the other. According to the information collected by the HFIAP template, 76% of the households were moderate to severe food insecure. Baobab bark harvesting was common in the Gudyanga and harvesters were aware of sustainable way of harvesting it. Value-addition on baobab fruit pulp to make ice-lollies and seeds roasted to produce a coffee substitute was practised by youth projects with the help of a non-governmental organisation. Ninety-five percent of the households in the study area were in support of the idea of possible baobab tree commercial cultivation in the community. The support was in anticipation of job opportunities and reduced food insecurity. / Agriculture and  Animal Health / M. Sc. (Agriculture)

The current research was done to evaluate the nutritive values and the ruminal degradation of dry matter (DM) and crude protein (CP) from three non-conventional oil cakes, viz: amarula (Sclerocarya birrea) (AOC), macadamia (Integrifolia) (MOC) and baobab (Adansonia digitate L.) (BOC). The oil cakes were collected from biodiesel producers in Limpopo Province, transported to the ARC-Animal Production campus, where proximate and ruminal nutrient degradation analysis were conducted. Triplicates samples from each oil cake were analyzed for the nutritive values, mineral and amino acids contents. Three rumen cannulated mid-lactating (days in milk; DIM: 180±5) Holstein cows weighing 667±43 kg body weight were allocated to determine the in situ ruminal dry matter (DM) and crude protein (CP) degradation. The cows were offered a totally mixed ration (TMR) (60 concentrate: 40 forage ratio) that was compounded according to their daily nutrient requirements, and were milking was done twice per day at 12 hrs intervals. The three oil cake samples were ground using a 2-mm screen after which sub-samples (6.5 g) were put in 10 x 20 cm; 50 μm pore size polyester bags to achieve 15 mg/cm² (ratio of the sample size to surface area). The bags were then fistulated in each cow’s rumen in triplicate for a period of 2, 4, 8, 16, 24, or 48 hrs. After being incubated, the bags were removed from the rumen and washed with cold (4°C) water in 20-L buckets. Following immersing in cold water, the bags were machine washed until clean water was obtained. The bags were then dried at 60 °C in an oven for 48 hrs. The dried bags were individually weighed, and the content of each bag were removed and stored into glass vial until analysis. The remaining two duplicate sets of each sample were rinsed using cold water in order to determine solubility at 0 hrs. The AOC had higher (P<0.05) ether extract (EE) and CP content than both BOC and MOC. Macadamia oilcake (MOC) and BOC had higher (P<0.05) fractions of fibre (NDF, ADF and ADL) compared to the AOC. The AOC had greater (P<0.05) content of essential amino acids than in the BOC and MOC. Additionally, AOC had a high (P<0.05) phosphorus, but low calcium and potassium concentration. While AOC had high effective degradability of DM, it also had high water soluble as well as DM and CP rapidly degradable fractions. Effective degradation of CP was higher in AOC and BOC than in MOC. However, BOC had a high insoluble but degradable fraction of CP. Further work to determine the toxicology of these non-conventional oil cakes and animal feeding experiments is needed / Agriculture and  Animal Health / MSc. Agriculture