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Forage may undergo extensive proteolysis during fermentation. The objectives of this study were to determine if treatment of forage with heat can reduce proteolysis during subsequent fermentation. In Experiment 1, direct-cut barley and alfalfa were either microwaved or steamed then ensiled in laboratory silos as were untreated and wilted forage. Silages of microwaved or steamed forage showed marked increase in NDIN and recovery of hot water insoluble N; however, alfalfa silages also had high pH and butyric acid. In Experiment 2, steaming was compared to formic acid and anhydrous ammonia treatments for their ability to prevent proteolysis in alfalfa silages. Steamed and ensiled alfalfa also was evaluated with addition of microbial inoculant or formic acid. Silage of steamed alfalfa had greater NDIN and recovery of precipitable N than controls, formic acid, or ammonia treated silage. There was no difference in precipitable N between formic acid and ammonia treatments. Silage of steam treatment had lower pH than wilted or direct-cut controls, and additives to steamed forage favored a more homolactic fermentation. Additives to steamed forage also increased aerobic stability of the silage. Steamed silage had less aerobic stability than direct-cut silage. Rumen degradability of silage CP and OM from both experiments were evaluated. In Experiment 1, CP degradability of microwaved or steamed silages was 8 to 26% less than unheated silages, but all had similar undegraded CP after incubation for 72 h. In Experiment 2, wilting, steam, formic acid and ammonia treatments had similar, but decreased CP degradability when compared to direct-cut silage. Longer duration heat in Experiment 1 resulted in greater silage protein preservation, and greater decrease in rumen degradability of CP than Experiment 2. / Master of Science

Orientadores: Marlene Rita de Queiroz, Silvia Azucena Nebra / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-06T18:33:55Z (GMT). No. of bitstreams: 1 MaccariJunior_Agenor_D.pdf: 3445454 bytes, checksum: 37eec05e26454a38f5395bd5eb688edc (MD5) Previous issue date: 2005 / Resumo: o cultivo e o processamento da erva-mate (1. paraguariensis) têm importante papel na economia dos Estados do Sul do Brasil, uma vez que tais atividades estão presentes em pequenas propriedades e indústrias, gerando milhares de empregos. Entretanto, o setor enfrenta dificuldades, sendo que as indústrias devem reduzir custos e gastos com energia, mantendo qualidade na produção. Uma alternativa é a adequação da tecnologia utilizada no processamento da erva-mate. Para tanto, este trabalho foi realizado em três etapas. (1 ) Levantamento de dados sobre as ervateiras em funcionamento. Os dados foram compilados e usados na elaboração de um diagnóstico do setor, o qual mostra uma redução no número de unidades ervateiras, em particular no número de pequenas indústrias. (2) Coleta de dados e amostras de erva-mate em unidades ervateiras, com avaliação de desempenho de equipamentos (sapecadores e secadores) e das unidades. Os resultados mostraram que boa parte da umidade presente na erva-mate (mais de 50%) é evaporada durante o sapeco, embora a energia consumi da seja superior à de processos de secagem convencionais. A secagem da erva-mate é realizada nos sistemas de secagem lenta e de secagem rápida, com diferentes tipos de secadores. Isto afeta o desempenho energético, o uso da mão-de-obra e a qualidade do produto. (3) Análise da qualidade da erva-mate obtida em diferentes sistemas de secagem, cujos resultados revelaram que o tempo de secagem afeta a cor, o sabor e o aroma do produto / Abstract: he cultivation and the processing of the mate (1. paraguariensis) have an important role ir the economy of Southem states in Brazil, because such activities are present in smali properties and industries, creating thousands of jobs. However, the sector faces difficuities. and the industries must reduce costs and expenses with energy, keeping quality in production. These goals can be achieved by the optimization of the technology of mate processing that Ü in use. To do so, this work was divided in three stages: (1) Data acquisition, which suppliee information about operating units, which showed a reduction in the number of these units, especially smallest ones. (2) Measurements to evaluate equipments performance (sapecadOi and dryers). The results showed that water content (more then 50%) is evaporated during th( mate "sapeco process" (an enzyme inactivation process). The mate drying process is carriec out by slow and fast drying systems, in different types of driers, which were differentiated ir energetic performance, costs and quality ofproduct. (3) Chemical and sensorial analysis ofth( mate obtained in the different conditions showed that sensorial properties (color, taste ane flavor) of the product were affected by the drying systems and characteristics of mate tree / Doutorado / Tecnologia Pós-Colheita / Mestre em Engenharia Agrícola

Thesis (MSc. (Agriculture Pasture Science)) -- University of Limpopo, 2018 / This study was conducted at the University of Limpopo’s Experimental Farm (Syferkuil), in the Limpopo Province, South Africa. The objective was to determine the effect of foliar fertilizers on the dry matter production over a period of two growing seasons. The experiment was laid out in a 3 x 3 factorial arrangement, fitted in a randomized complete block design (RCBD), with 4 replications. The experiment was planted on 28th March 2014 for season 1 (2014) and 31st March 2015 for season 2 (2015). Three sources of fertilizer (Nitrospray Plus, Potaspray and a combination of the two) were applied to stooling rye at three different fertilizer application rates (0 kg or ℓ/ha, 2.5 kg or ℓ/ha and 5.0 kg or ℓ/ha). The Nitrospray Plus and Potaspray fertilizers were applied on the 09th May, 02nd July, 27th August and 30th October 2014 for Season 1 (2014). During the Season 2 (2015), they were applied on 11th May, 04th July, 29th August and 02nd November 2015. The application was done using a knapsack sprayer. Above-ground biomass was harvested four times during each season when the plants reached a height of 25–30 cm. During 2014, harvesting was done on the 27th May, 24th July, 12th September and the 17th November 2014. During 2015, harvesting was done on the 29th May, 26th July, 14th September and the 19th November 2015. The dry matter production was determined by harvesting 1 m2 quadrates at 3 cm height. After weighing fresh material, it was oven–dried at 55oC until a constant mass was reached. Samples were then weighed again and the DM production (kg/ha) was calculated. Results were compared, using analysis of variance and the Fisher’s LSD test at P≤ 0.05 within each season. Based on the Least Significance Difference test, treatments were grouped in different production classes. During both seasons, fertilizer application rates had a significant (P≤0.001) influence on dry matter production. In 2014, the highest total dry matter production obtained was 5323 kg/ha in the high potassium fertilizer treatment and the lowest total dry matter was 4049 kg/ha in the control or zero application treatment. xiii In 2015, the highest total dry matter production obtained was 5595 kg/ha in the high potassium fertilizer treatment and the lowest 3678 kg/ha in the control treatment. Potassium fertilizers produced significantly (P≤0.001) higher than nitrogen fertilizers in both seasons. The main conclusions from this study were that high foliar fertilizer application rates (5.0 kg/ha) led to high, low foliar application rates (2.5 kg/ha) to lower and no fertilizer to low dry matter production. High levels of potassium produced the best, followed by combinations of intermediate potassium and nitrogen, and high nitrogen application rates. Yields of above 5000 kg/ha were obtained under high potassium rates. Lower rates led to total productions of more than 4000 kg/ha, while no foliar application produced between 3700 and 4000 kg/ha. It was also concluded that stooling rye is a suitable winter fodder crop for the Pietersburg Plateau Bushveld, but that the application of fertilizers is necessary for increased dry matter production. Both and Nitrospray and Potaspray Plus, as individual foliar fertilizers or in combination, can be applied to increase the dry matter production of stooling rye. However, it is essential to investigate the adaptability of stooling rye in other areas of the Limpopo bushveld, to determine its suitability as a fodder crop in other areas in the province. Keywords: Dry matter production, cutting dates, foliar fertilizers, Nitrospray Plus, Potaspray.

Thesis (MSc Food Sc )--Stellenbosch University, 2003. / ENGLISH ABSTRACT: The effect of drying conditions on the retention of harpagoside, a glucoside iridoid found in the indigenous Southern African plant Harpagophytum procumbens (Devil's Claw), was investigated. Additionally, the feasibility of using near infrared spectroscopy (NIRS) as a rapid and nondestructive analytical tool for the prediction of the iridoids harpagoside (HS), 8-p-coumaroyl harpagide (8pCHG) and moisture contents, as well as the HS:8pCHG ratio in Devil's Claw was also studied. Due to the purported medicinal activity ofthe tuberous secondary roots, Devil's Claw is of commercial interest with a well established export market in Germany. The stability of HS during processing has, however, never been investigated and the current study evaluated the effect of three drying methods (sun, tunnel and freeze-drying), as well as three tunnel-drying temperatures (40°C, 50°C and 60°C, dry bulb temperature) on HS content. Methanolic extracts (70% methanol-water) were analysed by high-performance liquid chromatography (HPLC) and a multiple extraction test (n = 12) indicated a 91.70% recovery for HS. The comparative drying results showed significant (P < 0.05) differences between tunnel and freeze drying on the one hand and sun-drying on the other, with the latter being the most detrimental technique. In comparing tunnel-drying temperatures, at a constant relative humidity (RH) of30%, drying at 40°C showed the lowest retention ofHS, differing significantly (P < 0.05) from that at 50°C. Drying at 60°C did not differ significantly (P > 0.05) from either of the other two conditions, but also resulted in lower retentions ofHS content than drying at 50°C. Overall, freeze-drying showed excellent results for HS retention (1.565% ± 0.394%; mean ± standard deviation), but economic constraints limit the commercial application of this drying method. Although further study is required to optimise tunnel-drying conditions, this method indicated acceptable and practical results (1.526% ± 0.396%), especially with conditions set to 50°C and 30% RH (1.750% ± 0.438%). Future research should concentrate on elucidating the degradation mechanisms of HS during processing, transport and storage of dried Devil's Claw root. The analysis of dried, ground Devil's Claw root by NIRS was referenced to HPLC analyses of the same methanolic extracts used in the drying studies. The spectra were generated on two different NIRS instruments by measuring diffuse reflectance of the powder whilst calibrations were performed by partial least squares regression. Both independent data set validation and full cross-validation were used to evaluate the performance and predictive abilities of the various models. Excellent moisture content (MC) calibrations were developed with a standard error of prediction (SEP) ofO.24% (range: 2.44% to 10.43%) and correlation coefficient (r) of 0.99. For the given MC range, the model performed very well against the standard error of laboratory (SEL) ofO.14%. Considering the sensitivity of the HPLC reference method (SEL = 0.035%), the HS content calibration (range: 0.693% to 2.244%) performed admirably with an SEP ofO.134%. The available range was, however, relatively small and future NIRS studies should incorporate a larger range if possible. The 8pCHG model (range: 0.069% to 0.290%) performed similarly, with a standard error of cross-validation of 0.028% and SEL of 0.007%. By inclusion of a second species, H. zeyheri, both the 8pCHG content and especially HS:8pCHG ratio (range: 1.84 to 34.48) calibrations were evaluated as possible methods of distinguishing between species. With 8pCHG values of ca. 0.9%, good separation was achieved for the first model but, contrary to previous studies, the ratio was found to be less successful. Principle component analysis of the spectra, however, showed great potential as a qualitative tool for this purpose. It is believed that NIRS can become an invaluable tool for the division of Devil's Claw into export classes, depending on HS content. This content is, however, dependant on the drying conditions used and drying parameters should be optimised to ensure the best possible quality and retention ofHS. / AFRIKAANSE OPSOMMING: Die invloed van drogingskondisies op die behoud van harpagosied, 'n iridoïed glikosied wat in die inheemse Suider-Afrikaanse plant, Harpagophytum procumbens (Duiwelsklou) voorkom, is ondersoek. Die uitvoerbaarheid van naby infra-rooi spektroskopie (NIRS) as 'n vinnige en niedestruktiewe analitiese metode vir die voorspelling van die inhoud van iridoïede, harpagosied (HS), 8-p-kumaroïel-harpagied (8pCHG) en vog, sowel as die HS:8pCHG verhouding in Duiwelsklou is ook ondersoek. Die beweerde medisinale aktiwiteit van die knolagtige sekondêre wortels van Duiwelsklou het gelei tot 'n gevestigde uitvoermark in Duitsland, en is dus van kommersiële belang. Die stabiliteit van HS gedurende prosessering is nog nooit ondersoek nie. Die huidige studie het die invloed van drie drogingsmetodes (son-, tonnel- en vriesdroging) en drie tonneldrogingstemperature (40°C, 50°C en 60°C, droëbol temperatuur) op die HS inhoud evalueer. Metanolies ekstrakte (70% metanol-water) is met hoë-druk vloeistof chromatografie ("HPLC") geanaliseer en 'n veelvoudige ekstraksie toets (n =12) het 'n 91.70% herwinning van HS getoon. Betekenisvolle (P < 0.05) verskille is gevind tussen tonnel- en vriesdroging enersyds en sondroging andersyds, met laasgenoemde die nadeligste metode. Die vergelyking van tonneldrogingstemperature, by 'n konstante relatiewe humiditeit (RH) van 30%, het getoon dat droging by 40°C die minste HS behou het en betekenisvol (P < 0.05) verskil het van droging by 50°C. Alhoewel die droging by 60°C nie betekenisvol verskil het van die ander twee kondisies nie, het dit laer HS waardes as droging by 50°C getoon. Vriesdroging het uitstekende resultate ten opsigte van die behoud van HS gelewer (1.565% ± 0.394%; gemiddelde ± standaard afwyking), maar ekonomiese beperkings plaas noodgedwonge limiete op die toepaslikheid van hierdie drogingsmetode. Verdere studie om tonneldrogingskondisies te optimiseer word is nodig (1.526% ± 0.396%), maar veral droging by 50°C en 30% RH (1.750% ± 0.438%) het prakties aanvaarbare resultate gelewer. Toekomstige navorsing moet daarop gemik word om die spesifieke degradasie meganismes van HS gedurende die droging, vervoer en opberging van Duiwelsklouwortel te verklaar. Die NIRS ontleding van gedroogde, gemaalde Duiwelsklou wortel is vergelyk met HPLC analises van dieselfde metanolise ekstrakte wat tydens die drogingstudies gebruik is. Twee verskillende NIRS instrumente is gebruik om spektra deur diffuse weerkaatsing in die poeier te meet en kalibrasies is daaropvolgend met gedeeltelike minste vierkante ("PLS") regressie gedoen. Beide onafhanklike data stel validasie en volle kruisvalidasie is gebruik om die prestasie en voorspellingsvermoë van die onderskeie modelle te evalueer. Uitstekende voginhoud (VI) kalibrasies met 'n standaard voorspellings fout (SVF) van 0.24% (klasinterval: 2.44% tot 10.43%) en 'n korrelasie van 0.99 is gevind. Die model het goed vergelyk met die standaard laboratorium fout (SLF) van 0.14%, oor die gegewe klasinterval. Met inagneming van die sensitiwiteit van HDVC as verwysingsmetode (SLF = 0.035%), het die HS inhoud kalibrasie (klasinterval: 0.693% tot 2.244%) aanvaarbaar gepresteer met 'n SVF van 0.134%. Die beskikbare klasinterval was egter relatief klein en toekomstige NIRS studies moet gebruik maak van 'n wyer klasinterval indien moontlik. Die 8pCHG model (klasinterval: 0.069% tot 0.290%) het soortgelyk gepresteer, met 'n standaard kruisvalidasie fout van 0.028% en SLF van 0.007%. Met die insluiting van monsters van 'n tweede spesie, H. zeyheri, is beide die 8pCHG inhoud en HS:8pCHG verhouding (klasinterval: 1.84 tot 34.48) kalibrasies as moontlike metodes vir onderskeiding tussen die spesies geëvalueer. Met'n 8pCHG inhoud van ca. 0.9% het die eerste model 'n goeie skeidingsvermoë getoon. In teenstelling met vorige studies egter, het die verhoudingsmodel minder sukses getoon. Hoofkomponent analise ("PCA") van die spektra was egter baie belowend as 'n kwalitatiewe onderskeidingsmetode. Volgens hierdie studie kan NIRS 'n waardevolle tegniek wees vir die verdeling van Duiwelsklou in uitvoer klasse op grond van HS inhoud. Hierdie inhoud is egter grotendeels afhanklik van die drogingskondisies en drogingsparameters wat verder verfyn behoort te word om 'n produk van die hoogste kwaliteit met behoud van HS te verseker.

MSCAGR (Animal Science) / Department of Animal Science / Forage and browse legumes play an important role in sustaining livestock in small holder farming systems in the tropics, mainly as a result of their contribution to economic and environmental sustainability of livestock production. The study was conducted to determine the chemical composition, ruminal degradability and in vitro digestibility of dry matter (DM) and crude protein (CP) of Dichrostachys cinerea and Bauhinia thonningii leaves. The browse tree leaves were harvested in the wild in Shayandima, Limpopo province. The leaves were collected, oven-dried, milled to pass through a 1.0 mm sieve and analysed for chemical composition in the Animal Science Nutrition Laboratory, at the University of Venda. The browse tree leaves were analysed for DM nitrogen, neutral detergent fibre (NDF) and acid detergent fibre (ADF). Approximately 5 g of leaf sample milled to pass through through a 1 mm sieve were placed in nylon bags (external dimension: 6 × 12 cm, pore size of 41 μm) and incubated in duplicates for 0, 4, 8, 16, 24, 48, 72, 96 and 120 hours periods in the rumen of three cannulated Bonsmara steers. The residues were then analysed for DM and nitrogen. Parameters to describe the dynamics of ruminal degradability of DM and CP were obtained by fitting the data on the exponential equation P = a + b (1 - e-ct) using NEWAY computer program, where “a” is the rapid degradable fraction, “b” is the slow degradable fraction and “c” is the outflow rate. The in vitro DM and CP degradability of rumen undegradable residue collected after 24 and 48 hour incubation was determined by sequential in vitro digestion in pepsin (abomasal) and pancreatin (small intestine) solutions. DM and CP content differed significantly (P ˂ 0.05). D. cinerea leaves had higher levels of DM and CP content than B. thonningii leaves. DM and CP disappearance increased (P < 0.01) as the incubation period increased. There was no difference (P > 0.05) in soluble fraction ‘a’ and ‘b’ of DM of the two species. The CP components for both fraction ‘a’ and ‘b’ differed significantly (P < 0.01) for CP among the two species. There was significant difference (P < 0.01) in post-ruminal digestibility among the two species. CP digestibility of B. thonningii and D. cinerea leaves was reduced (P < 0.01). In conclusion, B. thonningii and D. cinerea leaves showed significant difference based on their fermentation kinetics and in vitro digestibility, suggesting a good nutritional quality which can be used as protein source for ruminants in dry season and supplement to low-quality diets. / NRF