The effect of protein inclusion level in diets formulated to contain an ideal amino acid composition for growing pigs

The aim of the study was to determine the optimum protein inclusion level in diets containing an ideal amino acid balance for growing pigs. The performance of commercial crossbred grower-pigs was studied in two trials in which the experimental animals were housed either in commercial-type group housing (experiment1) or in individual pens (experiment 2). Treatments consisted of diets containing 14%, 16%, 18% or 20% crude protein. Lysine, tryptophan, threonine and total sulphur-containing amino acids were included in all diets at levels equivalent to that supplied by the 18% crude protein diet. In experiment one, 144 pigs (72 boars and 72 gilts) of initial mass 30 kg were fed until slaughter at 70 kg. In experiment two, 80 pigs (40 boars and 40 gilts) of live masses ranging from 17.5 to 31.1 kg were fed until slaughter at masses between 64 and 105.5 kg. There were no differences between treatments (p > 0,05) for daily gain, feed conversion ratio, daily intake or carcass classification, but feed conversion ratio differed between sexes in experiment two (p < 0.05). It was concluded that protein inclusion levels in pig growth diets could be decreased from 18% to 14% without any detrimental effect on performance, provided that the digestible essential amino acid composition is adjusted to meet requirements. This practice is however not economically viable for South African pig producers at the prevailing price of synthetic amino acids. (South African Journal of Animal Science: 2000, 30(1): 57-61

Evaluation of in vivo techniques for the determination of apparent ileal amino acid digestibilities in feedstuffs for piglets

Three in vivo techniques were evaluated in terms of their suitability for determination of the apparent ileal amino acid digestibility (AID) of protein sources for piglets. The techniques were: ileo-rectal anastomosis (IRA), cannulation at the distal ileum and a slaughter technique. A standard diet and three diets in which 20% of the standard diet was substituted with either skim milk powder (SMP), fish meal or roasted full-fat soya beans (FFS) were used. Piglets were weaned at 21 days of age, and the respective diets were fed in 24 equal hourly portions per day from days 29-37. Ileal digesta was collected from day 33-37 in IRA and cannulated piglets. Piglets used for the slaughter technique were killed at 37 days of age and ileal digesta was collected. Chromium III oxide was used as an indigestible marker with all three techniques. Although AID means did not differ (p > 0.05) between the different techniques, the cannulation technique resulted in the lowest variation (standard error of the mean) of all treatments (8.2 vs 13.7 and 14.1 for the slaughter and IRA-techniques respectively). AID means obtained using the cannula technique were 1.8 percentage units higher for the SMP diet than values obtained using the other techniques (83.2 versus 81.4 %), and up to 9.3 percentage units higher for the FFS diet (75.4 versus 66.1 %). Growth data suggested that the cannulation technique caused less trauma for the piglets than the IRA-technique. IRA-piglets had not yet regained their initial weaning weight by 37 days of age, while the other piglets gained weight over the trial period. The cannulation technique is the most attractive method for use with piglets in terms of the lower variation in digestibility values. Practical aspects such as ease of handling and sampling, surgical trauma and piglet stress, are also important and contribute to the selection of the cannula technique as the most appropriate. (South African Journal of Animal Science, 2000, 30(1): 7-15

Die gebruik van mieliegisreste in varkgroeiniëte

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Should South Africa adopt numerical fiscal rules?

Institutional issues now loom large in the theory and practice of macroeconomic policymaking. South Africa has recently adopted two institutional innovations in monetary policy, namely inflation targeting and constitutional protection of the independence of the central bank. The South Africa fiscal authorities have implemented multi-year expenditure planning, but numerical fiscal rules do not seem to be on the agenda yet. However, the growing popularity of such rules in other countries suggests that they will eventually come under consideration in South Africa as well. The purpose of this article is to stimulate debat e on the potential of numerical fiscal rules at the national-government level in South Africa. In section 1, we introduce the rules-versus-discretion debate and summarise the practical shortcomings of discretionary regimes. Section 2 outlines options for reforms. In section 3, we draw on theory and case studies to compare the effectiveness of numerical fiscal rules and the accountability-enhancing fiscal reforms that are being implemented in South Africa. Against this background, we offer an answer to the question whether or not South Africa should adopt numerical fiscal rules in section 4. Our major conclusion is that the adoption of numerical rules is more likely to do harm than to improve fiscal policymaking in South Africa.Articl

The legacy and challenge of fiscal policy in sub-Saharan Africa

This paper traces salient aspects of the evolution of fiscal policy in sub-Saharan Africa since 1960 and highlights the need for further reforms to consolidate the gains of the recent past. The fiscal position of the sub-Saharan African region as a whole has improved markedly during the past ten years, but most countries still face formidable fiscal challenges. To consolidate the progress made during the past decade and to tackle the remaining problems, sub-Saharan African policymakers should remain firmly committed to sound fiscal policies. © 2007 The Authors; Journal compilation © Economic Society of South Africa 2007.Articl

Longer-term perspective on the 2001/02 budget

[No abstract available]Revie

Studies on the nutritive value of cowpeas (Vigna unguiculata)

Samples of I50 different cowpea cultivars, used in the breeding trials of the Summer Grain Institute at Potehefstroom, were analysed and found to have an average crude protein content of 28.4 ± 1.8% (range 24.5 to 33.9%). From these samples, five high- and five low-protein cowpea samples as well as a composite sample of the remaining 140 cowpea cultivars, were selected. Part of the composite sample was autoclaved for 15 min at 121°C. Only small differences were observed in the chemical composition of the experimental cowpea meals. No significant (P &gt; 0.05) differences were found between raw and autoclaved cowpea meal either in relative nutritional value (RNV) and true protein digestibility (PTD) determined with rats, or in amino acid availability (AAA) determined with roosters. Autoclaving resulted in significant (P &lt; 0.05) improvements in digestible energy (DE) and true metabolizable energy (TME) when determined in pigs and poultry respectively.Monsters van 150 verskillende akkerboonkultivars, afkomstig van die kultivarstudies van die Somergraan Instituut by Potchefstroom, is ontleed en het 'n gemiddelde ruproteïen-inhoud van 28.4 ± 1.8% (24.5 tot 33.9%) gehad. Vyf hoë- en vyf laeproteien-akkerboonmonsters en 'n monster, saamgestel uit die oorblywende 140 kultivarmonsters, is geselekteer. 'n Gedeelte van die saamgestelde monster is vir 15 min met stoom teen 121°C behandel. Slegs klein verskille in die chemiese samestelling van die eksperimentele akkerboonmele is gevind. Geen betekenisvolle (P &gt; 0.05) verskille is gevind tussen rou en stoombehandelde akkerbone in relatiewe voedingswaarde en ware proteïenverteerbaarheid, soos met rotte bepaal, en aminosuurbeskikbaarheid, soos met pluimvee bepaal nie. Stoombehandeling het 'n betekenisvolle (P &lt; 0.05) verbetering in verteerbare energie by varke en ware metaboliseerbare energie by pluimvee tot gevolg gehad.Keywords: Amino acid availability, cowpea meal, digestible energy, pigs, poultry, rats, relative nutritive value, true metabolizable energy, true protein digestibility

Die effek van speenouderdom op die produksievermoë van die sog

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A note on the effect of wheat versus maize on the backfat composition of baconer pigs

No Abstrac

Effect of saponified high fat sunflower oilcake and lipoic acid

Sheep fat contains relatively high levels of saturated fatty acids while poly-unsaturated fatty acids (PUFA) are toxic to cellulolytic bacteria and are also saturated in the rumen. Stabilization of residual oil in sunflower oilcake by conversion into calcium salts would be advantageous. Alpha lipoic acid acts as an anti-oxidant to ameliorate the effects of oxidative stress caused by high dietary levels of PUFA. Residual oil (14%) in mechanically extracted (expeller) sunflower oilcake (SFOC) was saponifiedin situ and compared in a complete feedlot diet (100 g crude protein and 31 g extractable fat/kg feed) with commercially extracted oilcake containing 2.4% residual oil (control diet with 29 g fat and 123 g crude protein kg feed) fed to four groups of 10 SA Mutton Merino weaner lambs (ca. 23 kg) for nine weeks. Both diets were fed either with, or without a weekly oral dosing of 500 mg &alpha;-lipoic acid. Fatty acid composition was determined on back fat samples while thiobarbituric acid-reactive substances (TBARS) were determined on samples of m. longissimus dorsi stored for zero and six months and displayed for six days. The back fat of the lambs on the saponified expeller SFOC diets contained significantly higher levels of saturated fatty acids and lower levels of mono-unsaturated fatty acids. PUFA were unaffected. High TBARS levels (>1.0) were found after six months storage. Non significant increases in TBARS were observed in the groups that received lipoic acid