Thesis (M.S.P.H.)--University of Michigan, 1940.

Thesis (M.S.P.H.)--University of Michigan, 1940.

Doctor of Philosophy / Department of Agronomy / Doohong Min / Alfalfa is an important forage legume grown in the central Great Plains. However, producers still lack information about the productivity of alfalfa grown with cool-season grasses and the proper time of the last cut of alfalfa in the fall. Two studies are presented in this dissertation. The first study was to determine during a three-year period (2015-2017) the dry matter yield (DMY) and forage nutritive value of alfalfa-grass mixtures compared to alfalfa and grasses grown in monoculture and to assess the effect of nitrogen fertilizer on the dry matter yield and nutritive value of alfalfa-grass mixtures. During the three-years, the DMY was significantly higher in monoculture alfalfa and alfalfa-grass mixtures than in grass monocultures. No significant differences in DMY between alfalfa monoculture and alfalfa-grass mixtures were found. For all treatments, nitrogen application significantly increased DMY compared to the control. In 2016 and 2017, acid detergent fiber (ADF) and neutral detergent fiber (NDF) in smooth bromegrass and tall fescue were higher than in other treatments. Nitrogen fertilizer application did not affect nutritive values such as crude protein (CP), ADF, NDF, and relative feed value (RFV) in different treatments of the forage species. The second study determined the effect of timing of a fall cut on dry matter yield, nutritive value, and stand persistence of alfalfa in Northeastern Kansas in the United States. The DMY of first cut in 2016 was significantly higher in the Roundup Ready variety of alfalfa than in the low-lignin variety of alfalfa. There were no significant differences in DMY between alfalfa varieties in the remaining seasonal cuttings in 2016 and 2017 and in the annual total yield in both years. The DMY of the last cut in the fall was the highest in 2015, 2016 and 2017 in plots that were harvested on September 30. In 2017 the highest DMY in first cut was found in plots that were cut on October 15 in the previous year. The last harvests of the 2016 season, which were on October 15 and October 30, had the highest nutritive value. Opposite results on October 15 and October 30 were observed in 2017. Alfalfa cut on September 15 and September 30 had a higher stand persistence compared to alfalfa cut on October 15 and October 30. In conclusion, last fall cutting of alfalfa, which could be up to October 15, appeared to be acceptable because it did not affect forage dry matter yield.

Please read the abstract in the section, 00front of this document / Dissertation (MSc)--University of Pretoria, 2008. / Animal and Wildlife Sciences / MSc / Unrestricted

Apesar da evolução tecnológica, estudos sobre a estabilidade de nutrientes em alimentos preparados em Serviços de Alimentação têm recebido pouca atenção. No entanto, é cada vez maior o número de pessoas que fazem suas refeições nestes estabelecimentos. Uma vez que o conteúdo em vitaminas é um dos fatores mais importantes na determinação da qualidade dos alimentos processados, o objetivo deste estudo foi definir métodos de análise quantitativa para tiamina, riboflavina e ácido nicotínico por CLAE em carnes, para, então, avaliar a influência da preparação em Serviço de Alimentação sobre o conteúdo destas vitaminas em diferentes cortes de carnes bovina, suína e de frango. Objetivou-se também avaliar a estabilidade das vitaminas citadas após métodos de preparação tradicionais comparados com métodos de preparação em forno combinado (um dos equipamentos de cocção mais modernos utilizados em Serviço de Alimentação). As amostras de carnes foram grelhadas, fritas, assadas e refogadas ou cozidas sem imersão em água utilizando-se o forno combinado e também equipamentos industriais de modelo convencional. Os resultados obtidos mostraram que a tiamina foi a vitamina mais afetada pelos métodos de preparo em Serviço de Alimentação (47,2 a 84,7% de retenção em carne bovina; 49,6 a 79,8% de retenção em carne suína e 53,7 a 81,1% de retenção em carne de frango). Para riboflavina as porcentagens de retenção foram de 69,3% a 91,4% em carne bovina; 71,8% a 92,7% em carne suína e 60,1 a 92,3% em carne de frango. A estabilidade do ácido nicotínico foi, de um modo geral, maior em carne bovina (60,7 a 91,5% de retenção), intermediária em carne de frango (65,1 a 84,4% de retenção) e menor em carne suína (62, 8 a 77,0% de retenção). Para a grande maioria das preparações, o uso do forno combinado (em comparação com os equipamentos convencionais) preservou mais as três vitaminas, sugerindo que este equipamento é a melhor opção para preparação de carnes bovina, suína e de frango quando se deseja uma maior estabilidade destas vitaminas. Nos três tipos de carnes preparadas de formas semelhantes as perdas das vitaminas foram associadas às perdas de umidade e às condições de preparo das carnes / Despite the progress achieved, studies on nutrient retention in food service preparation have not received much attention. However, more and more people eat at these places. Since vitamin content is one of the most important factors in determining processed food quality, the objetive of this study was to define quantitative analysis methods for thiamin, riboflavin and nicotinic acid by high-performance liquid chromatography (HPLC) in meat in order to evaluate the influence of food service preparation on the content of these vitamins on different beef, pork and chicken cuts. Another objeticve was to evaluate these vitamins\' retention under conventional preparation methods, compared to combined oven, one of the most modern cooking methods used in food service. Samples of meat were charbroiled, fried, roasted and cooked without water in a combined oven and in conventional equipments. The results showed that thiamin was the vitamin most affected by the food service preparation methods (47.2 to 84,7% of retention in beef; 49.6 to 79.8% of retention in pork and 53.7 to 81.1% of retention in chicken). Riboflavin content retention was from 69.3 to 91.4% in beef; 71.8 to 92.7% in pork and 60.1 to 92.3% in chicken. Nicotinic acid retention was, in general, higher in beef (60.7 to 91.5%), medium in chicken (65.1 to 84.4%) and lower in pork (62.8 to 77.0%). For most preparations, the use of combined oven preserved the three vitamins better than the other conventional equipments. The results obtained indicate that, as far as food service is concerned, the combined oven is the best option for beef, pork and chicken preparation when a greater thiamin, riboflavin and nicotinic acid stability is desired. In the three types of meat prepared in a similar manner, vitamins losses were associated to moisture loss and to the conditions of meat preparation

Apesar da evolução tecnológica, estudos sobre a estabilidade de nutrientes em alimentos preparados em Serviços de Alimentação têm recebido pouca atenção. No entanto, é cada vez maior o número de pessoas que fazem suas refeições nestes estabelecimentos. Uma vez que o conteúdo em vitaminas é um dos fatores mais importantes na determinação da qualidade dos alimentos processados, o objetivo deste estudo foi definir métodos de análise quantitativa para tiamina, riboflavina e ácido nicotínico por CLAE em carnes, para, então, avaliar a influência da preparação em Serviço de Alimentação sobre o conteúdo destas vitaminas em diferentes cortes de carnes bovina, suína e de frango. Objetivou-se também avaliar a estabilidade das vitaminas citadas após métodos de preparação tradicionais comparados com métodos de preparação em forno combinado (um dos equipamentos de cocção mais modernos utilizados em Serviço de Alimentação). As amostras de carnes foram grelhadas, fritas, assadas e refogadas ou cozidas sem imersão em água utilizando-se o forno combinado e também equipamentos industriais de modelo convencional. Os resultados obtidos mostraram que a tiamina foi a vitamina mais afetada pelos métodos de preparo em Serviço de Alimentação (47,2 a 84,7% de retenção em carne bovina; 49,6 a 79,8% de retenção em carne suína e 53,7 a 81,1% de retenção em carne de frango). Para riboflavina as porcentagens de retenção foram de 69,3% a 91,4% em carne bovina; 71,8% a 92,7% em carne suína e 60,1 a 92,3% em carne de frango. A estabilidade do ácido nicotínico foi, de um modo geral, maior em carne bovina (60,7 a 91,5% de retenção), intermediária em carne de frango (65,1 a 84,4% de retenção) e menor em carne suína (62, 8 a 77,0% de retenção). Para a grande maioria das preparações, o uso do forno combinado (em comparação com os equipamentos convencionais) preservou mais as três vitaminas, sugerindo que este equipamento é a melhor opção para preparação de carnes bovina, suína e de frango quando se deseja uma maior estabilidade destas vitaminas. Nos três tipos de carnes preparadas de formas semelhantes as perdas das vitaminas foram associadas às perdas de umidade e às condições de preparo das carnes / Despite the progress achieved, studies on nutrient retention in food service preparation have not received much attention. However, more and more people eat at these places. Since vitamin content is one of the most important factors in determining processed food quality, the objetive of this study was to define quantitative analysis methods for thiamin, riboflavin and nicotinic acid by high-performance liquid chromatography (HPLC) in meat in order to evaluate the influence of food service preparation on the content of these vitamins on different beef, pork and chicken cuts. Another objeticve was to evaluate these vitamins\' retention under conventional preparation methods, compared to combined oven, one of the most modern cooking methods used in food service. Samples of meat were charbroiled, fried, roasted and cooked without water in a combined oven and in conventional equipments. The results showed that thiamin was the vitamin most affected by the food service preparation methods (47.2 to 84,7% of retention in beef; 49.6 to 79.8% of retention in pork and 53.7 to 81.1% of retention in chicken). Riboflavin content retention was from 69.3 to 91.4% in beef; 71.8 to 92.7% in pork and 60.1 to 92.3% in chicken. Nicotinic acid retention was, in general, higher in beef (60.7 to 91.5%), medium in chicken (65.1 to 84.4%) and lower in pork (62.8 to 77.0%). For most preparations, the use of combined oven preserved the three vitamins better than the other conventional equipments. The results obtained indicate that, as far as food service is concerned, the combined oven is the best option for beef, pork and chicken preparation when a greater thiamin, riboflavin and nicotinic acid stability is desired. In the three types of meat prepared in a similar manner, vitamins losses were associated to moisture loss and to the conditions of meat preparation

Diss. (sammanfattning). Uppsala : Sveriges lantbruksuniv. / Härtill 4 uppsatser.

The aim of the diploma paper was to consider a nutritive value of the maintenance granular feed mixtures for adult dogs. The nutritive value was determined in the five complete maintenance dog foods. The dog foods were chosen from different classes of quality. The consideration was made especially on the basis of following indicators: moisture content, determination of nitrogen substances, fat, sugars, fibre, ash, calcium, phosphorus and protein digestibility. There was also determined digestibility and palatability in one of these dog foods. This diploma paper was solved in conjunction with the company Dibaq a.s.

Master of Science / Department of Agronomy / Robert M. Aiken / Doohong Min / Finding a high-value forage crop with limited water requirements to produce livestock feed is becoming increasingly important as producers adapt to restricted water supply conditions. Our objectives were to determine the forage yield, nutritive values, and crop water productivity (CWP) of teff grass (Eragrostis tef [Zucc.] Trotter) under field conditions when compared to sorghum sudangrass (SS, S. x drummondii[(Nees ex. Steud.) Millsp. & Chase]) and pearl millet (PM, P. glaucum [L.]R.Br.). Crop water productivity was determined by dividing above-ground biomass by crop water use. Crop water use was determined by the summation of soil water depletion, precipitation, and irrigation. Yield was determined by quadrat area clippings of above-ground biomass. Nutritive value was determined using wet chemical analysis. Cultivars showed significant differences in biomass production and CWP in both years. Excalibur teff grass variety had the greatest CWP (418 kg ha-1 cm-1) 40 days after planting (DAP) in 2016, and was similar to SS and PM for the rest of the season until 58 DAP. Pearl millet had the greatest overall CWP (443 kg ha-1 cm-1) at 44 DAP. In 2017, sorghum sudangrass had significantly greater CWP than teff grass and pearl millet throughout most of the season. Among the teff varieties, Haymore had the greatest CWP (239 kg ha-1 cm-1) when harvested 10 days after boot stage (DAB). Crude protein values of teff grass varieties ranged from 9.3% to 21.3%, depending on the harvest date and year. Teff grass showed equivalent or greater nitrogen use efficiency (27.8 – 88.8 kg biomass kg-1 N applied) in our study than previously reported. Teff grass demonstrated potential to provide producers with a fast-growing and competitive forage crop with less overall water use due to a shortened growing season.

The scarcity of feed resources often imposes a major challenge to the development of animal production in the tropics and subtropics. However, by-products have long been recognised in providing cheaper alternative feed ingredients relative to conventional feed ingredients, thus alleviating the challenge. The aim of the present study was to investigate the potential of three waste products from the subtropical fruit processing industry in animal feeding. The products include avocado meal (AM), macadamia oil cake (MOC) and macadamia chips (MCH). The samples were obtained from the processing plants in Nelspruit of Mpumalanga Province, Makhado (Louis Trichardt) and Tzaneen of Limpompo Province. Eight samples of each waste product were collected, prepared and their chemical composition, in vitro dry matter digestibility and, in situ ruminal dry matter and crude protein (CP) degradability were determined. A broiler growth trial was conducted as well to determine the effect of replacing maize with AM on performance of broilers under commercial production thus establishing the replacement value of avocado meal in broiler feeds. As the products under study were from the oil extraction process of the two fruits, there were high remnants of oil in all three waste products. As a result the ether extract (EE) content of the three waste products was higher compared to any of the commonly used oilseed meals. The MCH had the highest EE concentration, followed by the MOC and the AM had the lowest. However, after defatting the AM had the highest (P<0.05) EE concentration compared to either the MOC or MCH. The CP concentration of the MOC was significantly higher than that of the AM and MCH. There was no significant difference observed between the AM and MCH in CP concentration. A better amino acid profile was observed with the MOC compared to the AM and MCH. None of the products can be regarded as a protein source. The fibre fractions of the MCH were significantly higher than that of AM and MOC, with the exception of the acid detergent lignin (ADL) concentration. The ADL concentration of the AM and MCH did not differ significantly although the MCH concentration was higher. The MOC had the lowest (P<0.05) ADL concentration compared among these waste products. Generally, the fibre concentration in the MOC was lower compared to other waste products but higher compared to the SBM and POCM. The acid detergent insoluble nitrogen (ADIN) concentration of the AM was significantly higher than that of MOC and MCH. There was no significant difference observed between MOC and MCH. The condensed tannin (CT) concentration of the waste products differed significantly with the AM being the highest and the MOC the lowest. The ADIN concentration of the MOC could be compared to that of the SBM and lower than that of the POCM. There were some significant differences observed in the mineral composition between the waste products under study. The mineral concentrations were below the maximum tolerable levels of animals except for iron (Fe) in AM which can be toxic to sheep as it was above the maximum tolerable level of 500mg/kg. The in vitro dry matter digestibility of the three waste products differed significantly, with the MOC being the highest and the MCH the lowest. Huge variation within waste products was observed and it could be due to the contamination levels of the products with the indigestible portions of the parent fruits. The in situ degradability of dry matter and CP of the AM and MOC differed significantly, with the MOC surpassing the AM in most of the degradability characteristics. The potential degradable fraction (“b”) and the degradation rate of the b fraction (“c”) fractions of the AM and MOC did not differ significantly. The MCH had more indigestible particles of the kernel and as a result it could not be analysed statistically and was therefore omitted. The effect of replacing maize with AM at different inclusion rates led to decreased feed intake and the final mass of the broilers during the trial period. The feed intake of the broilers on commercial diet was significantly higher than that of the broilers on commercial diets with avocado meal, except for the inclusion rate of 10% AM. The final mass, the ADG and the FCE of the broilers on commercial diet were significantly higher compared to the broilers on diet with AM irrespective of the inclusion rate. No mortalities observed during the experimental period. Copyright / Dissertation (MSc(Agric))--University of Pretoria, 2012. / Animal and Wildlife Sciences / unrestricted