• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 28
  • 28
  • 5
  • 3
  • 2
  • 1
  • 1
  • Tagged with
  • 88
  • 88
  • 27
  • 20
  • 19
  • 15
  • 11
  • 11
  • 11
  • 9
  • 9
  • 8
  • 8
  • 8
  • 8
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

The effect of zilpaterol hydrochloride on feedlot performance and carcass characteristics in weaner steers

Mantiziba, Chipo Winnie 12 January 2015 (has links)
An experiment was conducted using forty-one Bonsmara steers (age ± 7 months) to determine the effect of zilpaterol hydrochloride (ZH) on the growth performance and carcass characteristics. The trial was structured using a completely randomized design with two treatments, control and ZH group. The steers were fed ZH for 28 consecutive days at the end of the finishing period and ZH was withdrawn from the diet 2 days prior to slaughter of the animals. The steers were placed in individual pens and weighed fortnightly throughout the 4 months trial. Zilpaterol hydrochloride (ZH) was included in the diet at a rate of 8.3 mg/kg of DM. Feeding of ZH increased (P< 0.05) body weight (BW) gain and ADG (1.102 vs. 1.444) and tended to increase (P = 0.067) feed efficiency (F:G) during the last month of the finishing period. There were no significant differences (P> 0.05) in daily dry matter intakes (DMI). For the control group, high treatment weight gains were significantly associated with high initial weight (r = 0.424, P = 0.049) and also high pre-treatment body weight (r = 0.678, P= 0.001). Treatment weight gain increased as the initial and pre-treatment weight gain increased in the control group. For the steers that were fed ZH, there was no significant correlation between the treatment body weight gain with initial weight (r = 0.097, P = 0.694) and also pre- treatment live weight (r = 0.393, P = 0.096). Supplementation of ZH significantly increased (P < 0.0001) the dressing percentage (56.4% vs. 58.4%) and had no significant (P>0.05) effect on the carcass weight. The outcome of the study suggest that supplementation of ZH in the diet during the last month of the finishing period enhances growth performance and shows the repartitioning capacity of the feed additive as a beta- agonist. / Agriculture and  Animal Health / M. Sc. (Agriculture (Animal Science)
82

SUBPRODUTOS DA UVA PARA UTILIZAÇÃO EM DIETAS DE FRANGO DE CORTE

Rotava, Rui 19 December 2007 (has links)
The aim of this experiment was to determine in vitro the composition, the antibacterial, antioxidant and tanning activity of grape by-products (Vitis vinifera) for its exploitation in the poultry industry. The crude fiber content of the pomace of 31, 6% and for lignin of the seeds it was 61,2%. The pressed seeds contained 13,4% of crude oil, whose composition of fat acid has 67,73% of linoleic acid. To be studied as growth promoter of birds, polar compound had been extracted from the defatted grape seed in a solution with acetone: water: acid ascetic, resulting in 10,3% of extract from the defatted grape seed extract (ESUD) that, when analyzed, evidenced the presence of anthocyanic pigments and condensed tannins. The ESUD presented high antibacterial activity against strains of S. aureus and E. coli, but not against Salmonella sp. The antioxidant activity of the ESUD presented a percentage of inhibition of 1,1-difenil-2-picrilhidrazila comparable to the ascorbic acid, whose effect reached its maximum at 200 μg/ml. The capacity of tannins to bind protein was considered low for the seed and SUD and high for the ESUD. Later on, the inclusion effect of the grape seed and by-product as additives in the diets of poultry upon growth performance had been evaluated for apparent digestibilidade of the dry matter (CDMS), organic matter (CDMO) and crude protein (CDPB), blood levels of cholesterol, triglycerides, total proteins and glucose, beyond cecal pH. Six hundred day old Ross chicks were distributed in completely randomized design, from 1 to 21 days of age, with six treatments, five repetitions of 10 birds, inoculated or not with strains of E. coli, constituting a 6x2 factorial. Initial feed was used constituting the following treatments: T1-negative control; T2-positive control-0.05% of flavomycin and colistin sulphate; T3-0,04% extract of ESUD; T4-0,1% of grape seed (SUI); T5-0,47% of SUI and T6-2,35% of SUI. The inclusion of grape by-products did not influence the rates growth parameters, apparent digestibilidade or cholesterol levels but decrease levels of blood triglycerides. The inoculation decreased body weight, the weight gain, decreased the levels of blood total protein, and increased triglycerides and glucose and when associated with the ESUD, improved the CDMO. The contradictory results indicate the need for further experiments. / O objetivo deste trabalho foi determinar in vitro a composição centesimal, a atividade antibacteriana, antioxidante e tanante de subprodutos da uva (Vitis vinifera) para seu aproveitamento na indústria avícola. O conteúdo de fibra bruta do bagaço foi de 31,6% e de lignina das sementes foi de 61,2%. As sementes prensadas renderam 13,4% de óleo bruto, cuja composição de ácidos graxos tem 67,73% de ácido linoléico. Para serem estudados como aditivos em dietas para aves compostos polares foram extraídos da semente de uva desengordurada numa solução com acetona: água: ácido acético, resultando em 10,3% de rendimento de extrato de semente de uva desengordurada (ESUD) que, quando analisado, evidenciou a presença de taninos condensados e pigmentos antociânicos. O ESUD apresentou atividade antibacteriana alta contra cepas de S. aureus e E. coli mas não contra Salmonella sp. A atividade antioxidante do ESUD apresentou um percentual de inibição do 1,1-difenil-2- picrilhidrazila comparável ao ácido ascórbico, cujo efeito atingiu seu máximo em concentrações de 200μg/ml. A capacidade de complexar proteínas dos taninos foi considerada baixa para a semente e a SUD e alta para a ESUD. Posteriormente foram avaliados os efeitos da inclusão de subprodutos da uva como aditivos nas dietas de frango de corte sobre variáveis de desempenho zootécnico e digestibilidade aparente da matéria seca (CDMS), matéria orgânica (CDMO) e proteína bruta (CDPB), níveis plasmáticos de colesterol, triglicerídeos, proteínas totais e glicose, além de pH cecal. Foram utilizados 600 pintos de corte machos Ross, de 1 a 21 dias de idade, distribuídos em delineamento inteiramente casualizado, com seis tratamentos, cinco repetições de 10 aves, inoculados ou não com cepas de Escherichia coli, constituindo um fatorial 6x2. Utilizou-se ração inicial para a criação constituindo os seguintes tratamentos: T1-controle negativo; T2-0,05% de flavomicina e sulfato de colistina-controle positivo; T3-0,04% ESUD; T4-0,1% de semente de uva integral (SUI); T5-0,47% de SUI e T6-2,35% de SUI. A inclusão de subprodutos da uva não influenciou as variáveis zootécnicas, coeficientes de digestibilidade, nem as taxas de colesterol, mas diminuiu os níveis de triglicerídeos plasmáticos. A inoculação piorou o peso final, o ganho de peso, diminuiu os níveis plasmáticos de proteínas totais, aumentou triglicerídeos e glicose e quando associada com o ESUD melhorou o CDMO. Os resultados contraditórios indicam a necessidade de novos experimentos.
83

Desempenho,composição e utilização de nutrientes no híbrido (cachara x jandiá) alimentados com variações de carboidratos e lipídio na dieta / Performance, carcass composition, and use of nutrients of the hybrid of carnivorous Pseudoplastitoma reticulatum X omnivorous Leiarius marmoratus fed a varied carbohydrate and lipid diet

Bernardes, Célio Luiz 05 March 2012 (has links)
Made available in DSpace on 2016-05-02T13:55:33Z (GMT). No. of bitstreams: 1 CelioLuizBernardes-Dissertacao.pdf: 591497 bytes, checksum: 3c6604ea02d2ceebbbe446b5f072e787 (MD5) Previous issue date: 2012-03-05 / This study evaluated the influence of different carbohydrate/lipid ratios (CHO:L) in the diet of hybrid catfishes, carnivorous Pseudoplastitoma reticulatum x omnivorous Leiarius marmoratus, on the performance, body composition and nutrient utilization. Four isoproteic diets were formulated containing 43% crude protein, with increasing levels of lipids with CHO: diet I, 1.3; diet II, 1.1; diet III, 0.9; diet IV, 0.8. The fishes were fed at 5% of the living body weight (LBW) for the triplicate groups of 6 fishes (18 ± 1.5 g) during 8 weeks. Although the final weight and the absolute weight gain decreased with the increase of lipids in the diet, no significant difference was found in the ration daily consumption (DC) between the treatments. In addition, the viscerosomatic index (VSI) and the hepatosomatic index (HIS) showed no statistic difference between the dietary treatments. Protein efficiency retention (PER), lipid efficiency retention (LER) and protein gain (PG) were higher in the 1.3 CHO:L group, but no significant difference was found between the 0.9 and 0.8 CHO:L groups. In conclusion, high CHO:L ratios around 1.3 produced great benefit due to the best growth performance in the studied hybrid model. / Avaliou-se a influência de diferentes níveis de carboidratos / lipídios na dieta de peixes (CHO/ L) sobre o desempenho , composição corporal e utilização de nutrientes de híbrido, carnívoros (Pseudoplastistoma reticulatum ) x onívoros (Leiarius marmoratus) . Quatro dietas isoproteicas foram formuladas contendo proteína bruta a 43%, com aumento dos níveis de lipídios na dieta, usando-se o CHO com os seguintes índices: L: dieta 1, 1,3; dieta 2, 1,1; dieta 3, 0,9. e dieta 4, 0,8. Os peixes foram alimentados a 5% do peso vivo (PV) para os grupos triplicados, de 6 peixes (18 ± 1,5 g) durante 8 semanas. Apesar do peso final e do ganho em peso absoluto ter diminuído com o aumento de lipídios na dieta, não houve diferença significativa no consumo diário de ração (CD) entre os tratamentos. Além disso, o índice viscerossomático (IVS) e índice hepatossomático (IHS) não apresentaram nenhuma diferença estatística entre os tratamentos dietéticos. O teor de proteína muscular foi alto e significativo para os peixes alimentados com a dieta 1. Contudo, houve a diminuição de umidade e lipídios nos peixes alimentados com a dieta 4. A retenção de eficiência protéica (ERP), a retenção de eficiência lipídica (ERL) e o ganho de proteína (GP) foram superiores no grupo 1,3 CHO/L, mas nenhuma diferença significante foi encontrada entre os grupos 0.9 e 0.8 CHO:L. Em conclusão, CHO alta: cerca de 1,3 L relações apresentaram grande benefício, pelo melhor crescimento no modelo estudado no híbrido.
84

Effects of 4x4 full diallel crossbreeding of chickens on growth production performance, genetics and phenotypic characteristics

Mogoje, Barileng Leonard 12 1900 (has links)
Poultry provide affordable animal protein products compared to other animal products in agricultural industry. The demand of organic food by world health organisation and call for discard of conventional laying cage production method led to this research study. The aim of the study was to determine how (4 x 4) full diallel crossbreeding of the Potchefstroom Koekoek (PK), Naked neck (NN), Lohmann Brown (LB) and White Leghorn (WL) had an effect on production performance, egg parameters, genetic and phenotypic characteristics of F1 crossbreed offspring. The study was conducted at the Agricultural Research Council (ARC), Livestock Production Improvement at the Irene Campus, which is situated about 25 km south of Pretoria. The (4 x 4) full diallel crossbreeding design used on four chicken breeds to produce four pure breeds, six crossbreeds and six reciprocal crosses. The total number of 352 chickens with16 treatments (2 cocks and 20 hens) used in phase 1 and 384 chickens 16 F1-treatments (3 cocks + 21 hens) used in phase 2. Data was analysed by full factorial analysis of variance (ANOVA), General Linear Model procedures and Scheffe post-hoc for multiple comparison of the means of different variable data. The outcome had shown that crossbreeding had an effect on the production performance, genetic and phenotypic characteristics. The performed F1 crossbreeds emerge from crossbreeding between the local dual-purpose PK and commercial LB chicken breeds. PKLB dominated on growth and production performance traits compared to other crossbreeds. All set null hypothesis differ significantly at (p < 0.05), the outcome of all five hypothesis of this study were rejected. In conclusion PKLB was the best performing F1 crossbreed, based on its best performance on growth, FCR, cost of rearing, productive, high quality safe eggshell, economic efficiency and consumer preference (brown eggshell and yolk colour). / Dikgogo di neelana ka dikumo tsa poroteine ya diphologolo go tshwantshanngwa le dikumo tsa diphologolo tse dingwe mo intasetering ya temo. Tlhokego ya dijo tse di bolang mo mekgatlhong ya boitekanelo ya lefatshe le pitso ya go latlha mekgwa ya kumo ya dikgetshe tsa go beela tsa tlwaelo di ne tsa isa kwa thutong ya patlisiso eno. Maikaelelo a thuto eno ke go tlhomamisa gore tsadiso ya kgabaganyo ya dilo tse pedi kgotsa go feta go tshwantshanya kgolagano ya mofuta wa dijene le tikologo tse di tletseng tsa (4 x 4) tsa Potchefstroom Koekoek (PK), Naked Neck (NN), Lohmann Brown (LB) le White Leghorn (WL) di na le ponalo mo tiragatsong ya kumo, diparametera tsa mae, le dijene le diponagalo tsa kgolagano ya mofuta wa dijene le tikologo tsa ditsadiso tsa kgabaganyo tsa ngwana wa F1. Thuto e ne ya diragadiwa kwa Agricultural Research Council (ARC) le Tokafatso ya Kumo ya Diruiwa kwa khempaseng ya Irene, e e agilweng bokana ka 25 km jwa borwa jwa Pretoria. Ditsadiso tsa kgabaganyo tsa dilo tse pedi kgotsa go feta go tshwantshanya kgolagano ya mofuta wa dijene le tikologo tse di tletseng tsa (4 x 4) di ne tsa dirisiwa mo mefuteng ya ditsadiso tsa dikgogo go ntsha mefuta ya ditsadiso e e tletseng e mene, ditsadiso tsa kgabaganyo tse thataro le dikgabaganyo tse di tshwanang tse thataro. Palo e e tletseng ya dikgogo tse di 352 ka ditiragatso di le 16 (mekoko e le 2 le dithole di le 20) di ne tsa dirisiwa mo letlhakoreng la 1 le dikgogo di le 384 ka ditiragatso tsa F1 di le 16 (mekoko e le 3 + dithole di le 21) di ne tsa dirisiwa mo letlhakoreng la 2. Data e ne ya tshetshereganngwa ka tshetshereganyo ya dintlha tse di tletseng tsa pharologantsho (ANOVA), dikgato tsa General Linear Model le tshwantshanyo ya bontsintsi ya morago (ANOVA), dikgato tsa General Linear Model le tshwantshanyo ya bontsintsi ya morago ga tiragalo ya Scheffe ka mekgwa ya data ya pharologantsho e e farologaneng. Ditlamorago di ne tsa bontsha gore ditsadiso tsa kgabaganyo di na le ponalo mo tiragatsong ya kumo, ga mmogo le diponagalo tsa dijene le setlhopha sa kgolagano ya mofuta wa dijene le tikologo. Go ne ga diriswa mefuta ya ditsadiso tsa kgabaganyo ya F1 tse di tlhagelelang go tswa mo ditsadisong tsa kgabaganyo magareng ga mefuta ya ditsadiso tsa dikgogo tsa PK tsa lebaka la gabedi la selegae le LB ya kgwebo. PKLB e ne ya fekeetsa metlhala ya tiragatso ya kgolo le kumo go tshwantshanngwa le mefuta ya ditsadiso tsa kgabaganyo tse dingwe. Setlhopha sotlhe sa dikakanyo tsa lefela se x farologana mo go bonagalang ka (p < 0.05) le ditlamorago tsa dikakanyo tse tlhano tse tsotlhe tsa thuto eno di ne tsa kganediwa. Kwa bokhutlong, PKLB e ne ya nna mofuta wa ditsadiso tsa F1 o o diragatsang go gaisa, go ikaegilwe ka tiragatso mabapi le kgolo, FCR, tshenyegelo ya go tsadisa, kumo, boleng jo bo kwa godimo jwa dikgapetla tsa mae tse di babalesegileng, bokgoni jwa ikonomi le boikgethelo jwa modirisi (dikgapetla tsa mae tse di tshetlha le mmala wa tlhae). / Agriculture and  Animal Health / Ph. D. (Agriculture)
85

Study on the locally available aquatic macrophytes as fish feed for rural aquaculture purposes in South America

Velásquez, Yorcelis Carmelina Cruz 19 May 2016 (has links)
Zur Sicherung der Fischbestände muss die Aquakultur ihren Beitrag zur Weltfischversorgung weiter steigern. Solange jedoch die Fischfutter Produktion stark von der Gewinnung von Fischmehl abhängig ist, bestehen für die Aquakultur natürliche Begrenzungen und die Gefahr der Überfischung der Fischbestände bleibt erhalten. Wenn das Wachstumspotenzial der Aquakultur ausgeschöpft werden soll, müssen beträchtliche Mengen von Nährstoffeinträgen in Form von vollständigen Aquakultur-Mischfuttermitteln auf einer nachhaltigen Basis verfügbar sein. Aufgrund des gestiegenen Preises von kommerziellem Fischfutter sind Kleinproduzenten nicht in der Lage dieses zu erwerben. Daher ist es notwendig, ihnen alternatives Fischfutter zur Verfügung zu stellen. Wasserpflanzen können eine bedeutende Nahrungsquelle für herbivore- und omnivore Fische sein. Dennoch ist die Nutzung dieser Pflanzen als Zusatz für Fischfutter durch eine Reihe antinutritiver Substanzen, welche das normale Fischwachstum negativ beeinträchtigen, begrenzt. Unterschiedliche Behandlungen der Pflanzen können den Anteil an antinutritiven Substanzen reduzieren. Das Ziel dieser Dissertation war es, das nutritive Potential von Wasserpflanzen zu bestimmen. Die Wirkung der Behandlungen wie Sonnentrocknung oder Fermentierung zu bewerten und den Effekt ihrer Nutzung als Fischfutter auf das Wachstum von kultivierten Fischen zu erfassen. Dazu wurden Rationen mit einem geringen Gehalt an Fischmehl (3%) und bis zu 25% der Wasserpflanzen an die Fischspezies P. brachypomus und O. niloticus verfüttert. Die Ergebnisse der Untersuchung zeigen dass, eine ausschließlich auf aquatischen Makrophyten basierende Fütterung nicht empfehlenswert ist. Indem sie jedoch mit anderen lokal verfügbaren Agrar-Nebenerzeugnissen oder sogar mit kommerziellen Futtermitteln kombiniert werden, könnten die Futterkosten erheblich reduziert werden und bäuerlichen Kleinbetrieben eine Möglichkeit zum Wettbewerb auf den lokalen Märkten eröffnen. / It is commonly known that aquaculture needs to increase further its net contribution to the total world fish supplies. However, at present almost all farming operations, based on the use of fish feed, are highly dependent on available fishery resources for the production of fish meal, becoming a reducing activity rather than an activity suppling fishery resources. If the aquaculture growth potential is to be maintained, then considerable quantities of nutrient inputs in the form of aquafeeds will have to be available on a sustainable basis. On a long-term the small producers will be unable to depend on commercial aquafeeds based traditionally on fish meal, due to its increased price. Small-scale farmers need an alternative fish feed wherever possible based on the use of non-food grade locally feed resources, which is available in rural areas, is low-cost and is suitable for the proper growth and maintenance of native fish. Aquatic plants are considered important nutritional sources for herbivorous-omnivorous fish. However, the use of plant-derived materials as fish feed ingredient is limited by the presence of wide variety of antinutrients that affect the normal fish growth negatively; so that plants should be processed to reduce the effects of these compounds. Considering these aspects, this study assessed the nutritional potential of aquatic plants available in rural Colombia treated by sun drying and by fermentation and the effect of their use as fish feed on the growth performance of common cultured tropical fish (Piaractus brachypomus and Oreochromis niloticus) fed low fishmeal diets (3%) and until 25% of aquatic plants. The results of this study showed that a feeding exclusively based on aquatic plants is not recommendable; but to combine them with other locally available by-products of agriculture or even with commercial diets might considerably reduce feeding cost and provide to the small-scale farmers the opportunity to compete in local markets.
86

Ernährungsphysiologische Bewertung von Spirulina platensis für den Einsatz in nachhaltig ressourcenschonenden Ernährungskonzepten der Schweine- und Hähnchenmast / The nutritional-physiological evaluation of Spirulina platensis in sustainable resource-saving nutritonal concepts for fattening pigs and cickens

Neumann, Carmen 05 November 2018 (has links)
No description available.
87

Interaktionen zwischen Boden und Bestockung auf Kippenstandorten des Niederlausitzer Braunkohlenrevieres am Beispiel der Rekultivierungsbaumarten Gemeine Kiefer, Gemeine Birke und Traubeneiche : Wachstums-, ernährungs- und bodenkundliche Untersuchungen

Stähr, Falk 12 August 2003 (has links) (PDF)
Auf repräsentativen Kippenstandorten des Niederlausitzer Braunkohlenrevieres wurden typische Forstökosysteme der ersten Generation analysiert. Gegenstand der Untersuchung waren mittelalte Bestände (46- bis 70 Jahre) der Rekultivierungsbaumarten Kiefer (n = 22) und Birke (n = 12) sowie 24- bis 45jährige Jungbestände der Baumarten Trauben- (n = 7) und Roteiche (n = 2). Die Roteichenbestände dienten primär vergleichenden Untersuchungen. Für altersspezifische und standortsvergleichende Betrachtungen wurden Ergänzungsbestände auf Kippenstandorten und Vergleichsbestände auf unverritzten Waldstandorten zusätzlich einbezogen. Die untersuchten Erstaufforstungen stocken auf Kippenkomplexen, die klimatisch, hydrologisch und geomorphologisch vergleichbar sind und baumartenweise weitestgehend identischen bodenmeliorativen Maßnahmen sowie waldbaulichen Behandlungsverfahren unterzogen wurden. Ziel der Untersuchung war die Qualifizierung der Wechselwirkungen zwischen Kippenstandort und aufstockendem Bestand. Als Leitgrößen für die Wirkung standörtlicher Merkmale auf die Baumarten dienten wachstums- (Leistungsparameter) und ernährungskundliche Kenndaten (Vitalitätsweiser). Quantität und Qualität der Humusauflage sowie die bodengenetische Entwicklung wurden als Indikatoren für die Rückwirkungen der bestandesbildenden Rekultivierungsbaumarten auf den Standort verwendet. Besondere Berücksichtigung fand das lokale Depositionsgeschehen.
88

Interaktionen zwischen Boden und Bestockung auf Kippenstandorten des Niederlausitzer Braunkohlenrevieres am Beispiel der Rekultivierungsbaumarten Gemeine Kiefer, Gemeine Birke und Traubeneiche : Wachstums-, ernährungs- und bodenkundliche Untersuchungen

Stähr, Falk 28 May 2003 (has links)
Auf repräsentativen Kippenstandorten des Niederlausitzer Braunkohlenrevieres wurden typische Forstökosysteme der ersten Generation analysiert. Gegenstand der Untersuchung waren mittelalte Bestände (46- bis 70 Jahre) der Rekultivierungsbaumarten Kiefer (n = 22) und Birke (n = 12) sowie 24- bis 45jährige Jungbestände der Baumarten Trauben- (n = 7) und Roteiche (n = 2). Die Roteichenbestände dienten primär vergleichenden Untersuchungen. Für altersspezifische und standortsvergleichende Betrachtungen wurden Ergänzungsbestände auf Kippenstandorten und Vergleichsbestände auf unverritzten Waldstandorten zusätzlich einbezogen. Die untersuchten Erstaufforstungen stocken auf Kippenkomplexen, die klimatisch, hydrologisch und geomorphologisch vergleichbar sind und baumartenweise weitestgehend identischen bodenmeliorativen Maßnahmen sowie waldbaulichen Behandlungsverfahren unterzogen wurden. Ziel der Untersuchung war die Qualifizierung der Wechselwirkungen zwischen Kippenstandort und aufstockendem Bestand. Als Leitgrößen für die Wirkung standörtlicher Merkmale auf die Baumarten dienten wachstums- (Leistungsparameter) und ernährungskundliche Kenndaten (Vitalitätsweiser). Quantität und Qualität der Humusauflage sowie die bodengenetische Entwicklung wurden als Indikatoren für die Rückwirkungen der bestandesbildenden Rekultivierungsbaumarten auf den Standort verwendet. Besondere Berücksichtigung fand das lokale Depositionsgeschehen.

Page generated in 0.0889 seconds