Welwitschia International Journal of Agricultural Sciences

The effect of arboricide application on soil chemical properties at Neudamm farm, Namibia

Absalom Kahumba — 2022-09-09

Abstract

This study assessed the effects of chemical treatments on soil chemical properties at Neudamm farm. A total of 6 composite soil samples were randomly collected from all three 250 m² belt transects in each of the three chemically treated and control sites at a depth of 15 cm using a soil auger. The soil was analysed for pH, organic matter, organic carbon and soil minerals. A GLM procedure of SAS was used for analyses. The soil pH was significantly (P < 0.05) higher in the chemically treated site of 2015 (6.06), followed by the control (5.61) and the chemically treated site of 2017 (5.5). The OC and OM percentages were greater (P < 0.05) in the chemically treated site of 2015 than in all three sites. The chemically treated site of 2016 had the highest soil Ca (551 ppm), K (197.3 ppm), Mg (76 ppm), P (23.3) contents, followed by the site of 2015, than the control site. The study concluded that chemically treated sites had improved soil fertility through controlled bush density. The study recommends that arboricides should be applied as aftercare and for long term monitoring be carried out routinely to acquire systematic trends of the soil chemical properties.

Modelling supply response and volatility of Swakara pelts in Namibia

Leigh-Ann T Nehoya — 2022-10-03

The karakul industry has been experiencing a continuous decline in the number of pelts supplied since the late 1970s. This decline is speculated to be a result of the anti-fur movement. Coincidently, throughout the years, the price of Karakul pelts is seen to increase. This abnormal mismatch in supply and demand has challenged economic theory which explains that price increases should increase supply. This paper uses time-series data from 1960 to 2019 to model supply response and volatility in the karakul industry. The dataset was tested for unit root and an autoregressive distributed lag model was run to examine the extent to which the local production of Swakara pelts responds to the supply determinants. Pelt supply lagged one year, cost of production, average pelt producer price, average mutton producer price yield, and the exchange rate has significant implications on the current pelt supply. The influence of the anti-fur movement, however, equally has a significant relationship. The results indicated high volatility between all variables with social awareness being the outlier. The global anti-fur movement has played a large role, that Namibian farmers reduced their Karakul stock. Since 2012, nationally but also globally, prices of all pelt and fur are on a continuous decline which points to a “dying” industry. The survival of the Namibian pelt industry requires further research on the global demand, adjustments of some legislation, and supported production incentives for farmer welfare.

Effect of legume hay supplementation on feed intake, growth, digestibility and volatile fatty acid production of Xhosa goats

John Mupangwa — 2022-09-13

Abstract

The objective of this study was to evaluate the effects of sex and supplementing Chloris gayana hay with either Lablab purpureus or Vigna unguiculata on growth, volatile fatty acid (VFA) production and apparent nutrient digestibility. Eighteen goats, one-year-old, of average live weight 14.13 ±0.24kg was apportioned in a completely randomized design to three diets which were iso-nitrogenous and iso-energetic. Animals were housed individually with 6 animals per treatment composed of three males and three females. Total DM intake was higher (P < 0.05) in T₂ (694.8 g/head/day) and T₃ (688.1 g/head/day) compared to T₁ (607.8 g/head day). The goats gained at a rate of 35.0g/d; 45.0g/d and 38.3g/d for T₁, T₂, and T_3,respectively. Goats on T₂ showed a non-significantly higher (P > 0.05) growth rate exhibiting total gain of 2.68kg compared to 2.08kg and 2.33kg for T₁and T_3,respectively_.Animals on T₁ (19.16) exhibited a significantly lower FCR (P < 0.05) than T₂ (15.44) and T₃ (18.11). Apparent DM digestibility were significantly different (P < 0.05) among treatment diets. Sex significantly influenced DM, ADF and NDF digestibilities (P < 0.05). There were no significant (P > 0.05) differences in individual VFA molar concentrations among treatment diets and due to sex for acetate, propionate, valerate, iso-butyrate and iso-valerate. However, diets significantly influenced butyrate concentration (P < 0.05) with 0.25, 0.95 and 0.25mM for T₁, T₂ and T_3, respectively. The percentage molar concentration for acetate was 75%, 73%, and 77% while the propionate concentration was 12%, 8% and 10.7 % for T₁, T₂, and T_3, respectively. The acetate to propionate ratio was 6.2, 9.12 and 7.15 for T₁, T₂, and T_3, respectively. In conclusion, the study demonstrated that Cowpea and Lablab forages can support growth in goats at the same level of CP as in commercial pellets.

Public Spending as a Predictor of Livestock Total Factor Productivity in Namibia

Helmke Jens Sartorius von Bach — 2022-09-11

This paper investigates public spending and its catalytic role towards a productive agricultural sector. This was done empirically by testing how agricultural total factor productivity could be increased. Data used is for the period 1991 to 2021. A Tornqvist-Theil Index was developed. A simultaneous equation became the chosen and implementable analytical tool for this study. While an agricultural total factor productivity index for Namibia did not exist before, the livestock component was generated for the first time in this study to fill this gap. Stunning is the fact that the Malabo declaration in terms of its convergence target of 10% is not yet met. The results show that by increasing productive labour to the livestock subsector by 10%, real gross domestic product will increase by 12%. Likewise, should capital formation and spending towards agriculture be increased to 10%, the growth of the agricultural sector will increase by 8.5%. This would require input-base needs to be expanded for output to increase. The work done by the Namibian Government so far yearn for further efforts to create more jobs, increase food production, and foreign income earning, remains to be addressed. To achieve all these, compliance with the Malabo declaration would be necessary.

Characterization of the nutritional values of agro-industrial by-products in Namibia as potential supplements of the bush-based feeds

Magdalena Kamati — 2022-09-11

The objective of this study was to characterize the nutritional values of Namibian agro-industrial by-products (AIBPs) as potential supplements for bush-based feeds. Fourteen AIBPs’ samples were collected from Namibian local cereals and oilseed processing companies. Cereal by-products were malt dust fine (MDF), pearl millet bran (PMB), malt dust coarse(MDC), white maize chop (WMC), wheat bran(WB), brewer’s spent grains(BSG), sorghum brew residue (SBR) and sorghum spent grains (SSG), while oilseed byproducts were olive oil cake(OIC), marula oil press (MOP), jojoba oil cake (JOC), !nara oil cake(NAC), manketti oil cake (KOC) and marula oil cake (MOC). Chemical compositions, in vitro gas production, in vitro organic matter digestibility, and metabolizable energy of the AIBPs were determined in a randomized complete block design and the data were statistically analyzed using a Statistical Package for Social Science. Crude protein, ether extract, neutral detergent fiber, and acid detergent fiber ranged from 7.90 (SSG)-21.95 %( BSG), 1.37(MDF)-9.29%(PMB), 22.23(WMC)-73.06%(BSG), 7.22 (PMB) -30.46% (BSG) respectively for cereal by-products and 7.55(OIC)-37.3% (MOP), 8.11(KOC)-53.55%(MOC), 11.40 (MOC)-58.26%(KOC) and 8.21(MOP)-52.26%(MOP) in oil seeds by-products respectively. The in vitro gas production, in vitro organic matter digestibility, and metabolizable energy ranges for cereal and oilseed by-products were 31.50 (BSG)-70.20ml/200mgDM(WMC), 55.55 (BSG)-83.50%DM(WMC), 9.30(BSG)-14.00MJ/Kg(white maize chop), and 3.80 (MOP)-35.30ml/200mgDM(jojoba oil cake), 38.95(MOP)-59.35%(JOC), and 7.45(MOC)-15.95MJ/Kg(MOP), respectively. The AIBPs investigated in this study comprised of minimal fiber contents, adequate crude protein, and metabolizable energy contents above minimum requirements for ruminant animals. However, promotion to maximally utilize these AIBPs in animal diets requires further evaluation.