• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 18
  • 8
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • Tagged with
  • 38
  • 38
  • 38
  • 11
  • 9
  • 9
  • 8
  • 8
  • 7
  • 7
  • 5
  • 5
  • 4
  • 4
  • 3
  • 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.
31

Development of a process of addition of tricalcium phosphate from burnt phosphate rock in feed for animal nutrition

Nogales Grágeda, Luis Fernando 01 January 2005 (has links) (PDF)
This study took place in Bolivia with the purpose of using thermally treated Capinota phosphate rock as a phosphorous supplement in balanced feed diets. The objective was to produce a natural phosphate substance that would be more easily accessible to the local population than commercial feed supplements. An additional objective of this study was to increase the availability of the low-fluoride phosphorous. The biological assays indicated that the diet with the added burned phosphoric rock produced similar yields to those using a commercial feed supplement (dicalcium phosphate). This indicates that the locally manufactured product, by partial acidification, can compete with similar commercial products.
32

Reassessment of bone parameters and evaluation of a bone biopsy technique for determining calcium and phosphorus status of swine from weaning to market

Combs, Nadine Rae January 1989 (has links)
Three trials, involving 300 pigs were conducted to evaluate the effect of feeding 70 to 130% of the NRC recommended Ca/P levels from weaning to market weight on the relationships between measures of Ca/P status of postweaning swine, and to derive response surfaces relating diet and time effects to observed performance and bone characteristics. Pigs were slaughtered every 4 weeks following the start of the trials to obtain third and fourth metacarpals and metatarsals. Asymptotic response surfaces, relating the effects of dietary Ca/P level and time on test to the observed performance or bone characteristics were derived. The estimated lack of fit was significant for many criteria, although the magnitude of difference in fit appeared to be very small; therefore, the asymptotic response surfaces were found to reflect well the response of performance and bone criteria to dietary Ca/P levels of 70 to 130% of NRC recommendations over the period from weaning to market. The Ca/P level associated with 95 and 98% of maximum bone length, wet weight, radius and dry fat- free ash percentage of bones appeared to be the same or lower than that required to maximize body weight, average daily gain and feed intake; the performance criteria reached near maximum for Ca/P levels approximating the NRC recommendations. Bone wall thickness, cross—sectional area, bending and shear force, bending and shear stress, extracted weight of bone, and dry fat-free ash weight appeared to require higher Ca/P levels than recommended by NRC to reach 95 or 98% of maximum. Seventy-five pigs were biopsied at 4 week intervals, and a biopsy sample was also taken from 225 pigs at slaughter, to evaluate a bone biopsy procedure for use as a live-animal sampling method in swine nutrition studies. Biopsy cores from the live and the slaughter pigs were similar, indicating that repeated sampling of the live animal did not significantly alter the composition of the biopsy core. Biopsy core measures were significantly correlated with intact third and fourth metacarpal and metatarsal bone measures. Comparisons of the least squares means and standard errors of biopsy core and bone dry fat-free ash percentage indicated that the biopsy procedure may be more useful when NRC recommended or higher Ca/P levels are fed. There was strong indications, however, that use of the biopsy procedure warrants further consideration. / Ph. D.
33

Consumer behavior towards chicken fed with genetically modified high available phosphorus (HAP) corn

Gupta, Meeta. January 2005 (has links)
Thesis (M.S.)--University of Delaware, 2005. / Principal faculty advisors: John C. Bernard and John D. Pesek, Dept. of Food and Resource Economics. Includes bibliographical references.
34

The phosphorus availability of feed phosphates in broilers

Payne, Steven George 03 1900 (has links)
Thesis (MscAgric (Animal Sciences))--University of Stellenbosch, 2005. / Broiler diets are supplemented with feed phosphates to ensure that adequate available phosphorus is provided in the diet to meet the bird’s requirements. These feed phosphates make a considerable contribution to the total available phosphorus in the diet and small differences in their availability may have significant effects on whether the bird’s requirements are met or not. The variation in availability of phosphorus between feed phosphates belonging to different classes and between feed phosphates of the same generic class is well documented.
35

Desempenho de bovinos nelore suplementados com fontes alternativas de fósforo

Lemos, Guilherme Cazerta [UNESP] 20 December 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-12-20Bitstream added on 2014-06-13T18:31:16Z : No. of bitstreams: 1 lemos_gc_me_araca.pdf: 160789 bytes, checksum: 0de461ffc42d8847ad0ddb66ab8b1f25 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Foi avaliado o desempenho produtivo e a interferência do flúor em bovinos Nelore suplementados com fontes alternativas de fósforo. As fontes de fósforo e as relações P:F foram distribuídas nos seguintes tratamentos: controle (CONTNEG), fosfato bicálcico 120:1 (FB-120), 30:1 (FB-30) e 10:1 (FB-10), monobicálcico 60:1 (MBC-60), superfosfato triplo 30:1 (SFT-30) e rocha de Cajati 10:1 (ROCHA-10). Foram utilizados 49 novilhos, desmamados, com nove meses de idade, castrados e com 230 kg de peso médio, distribuídos em sete piquetes, com água e mistura mineral completa ad libitum, exceto fósforo. A dieta padrão foi calculada para um ganho de peso aproximado de 0,500 kg/dia. Os animais do tratamento SFT-30, atingiram o peso de 520 kg, aproximadamente cinco meses antes que os do tratamento ROCHA-10, devido à solubilidade do P nas fontes. As análises de fósforo no osso mostraram diferença estatística apenas entre o tratamento CONTNEG e os tratamentos com fosfato bicálcico. As análises de flúor no osso se mostraram intimamente associados à quantidade de flúor disponível nas fontes testes. Pode-se concluir que as diferentes fontes de fósforo utilizadas interferiram nos resultados de desempenho dos animais. / The productive performance and the interference of fluorine in supplemented Nelore bovines with alternative sources of phosphorus were evaluated. The sources of phosphorus and relations P:F had been distributed in the following treatments: control (CONTNEG), dicalcium phospate 120:1 (FB-120), 30:1 (FB-30) and 10:1 (FB-10), monodicalcium 60:1 (MBC-60), triple superphosphate 30:1 (SFT-30) and Cajati Rock 10:1 (ROCHA-10). Forty nine castrated steers with nine months of age averaging 230 kg distributed in seven pens, with water available and a complete mineral mixture, except phosphorus. The ration was formulated for a weight gain of 0,500 kg/day. Animals of SFT-30 treatment had reached 520 kg approximately five months before ROCHA-10 treatment, due to the P solubility in the sources. The analyses of phosphorus in the bone had shown statistical differences only between treatment CONTNEG and the treatments with dicalcium phosphate. Bone fluorine analyses were highly associated to fluorine quantity in the phosphorous sources evaluated. It can be concluded that the different phosphorus sources used had influenced animal performance.
36

Utilization of phosphorus and other minerals from broiler litter and swine waste

Cooke, Judith A. January 1985 (has links)
Two metabolism trials were conducted with 15 wethers surgically equipped with duodenal and ileal cannulas to study the absorption of P and certain other minerals from swine waste and broiler litter. The effect of source and level of P on rumen cellulytic bacterial populations was also determined. Animals were fed a low P basal diet until serum inorganic P averaged 5.5 mg/dl, then randomly assigned to the following diets: low P basal alone, or supplemented with swine waste, broiler litter, dicalcium phosphate, or soybean meal. Trials consisted of a 7-d preliminary period, a 7-d collection of urine and feces and a 6-d sampling of duodenal and ileal digesta, and feces. Animals fed the waste diets tended to absorb more P than those fed the conventional supplements. Calculated by difference, sheep absorbed more P from swine waste and broiler litter than from dicalcium phosphate and soybean meal (P< .1). Less Ca was absorbed from the waste diets than from the conventionally supplemented diets (P< .05). Expressed as g/d, there was no difference in Mg absorption between waste and conventional diets. Sheep fed waste tended to digest more dry matter and a higher percentage of ADF in the large intestine. Lignin was primarily digested in the large intestine of all sheep. More cellulytic bacteria were isolated from the rumen of sheep fed the supplemented diets (P< .05). Both P intake and P recycling appear to be important influences on cellulytic bacteria in the rumen. Both broiler litter and swine waste appear to be good sources of P and Mg for ruminants. / Ph. D.
37

Desempenho de bovinos nelore suplementados com fontes alternativas de fósforo /

Lemos, Guilherme Cazerta. January 2006 (has links)
Orientador: Manoel Garcia Neto / Banca: Cecílio Viega Soares Filho / Banca: Júlio César Damasceno / Resumo: Foi avaliado o desempenho produtivo e a interferência do flúor em bovinos Nelore suplementados com fontes alternativas de fósforo. As fontes de fósforo e as relações P:F foram distribuídas nos seguintes tratamentos: controle (CONTNEG), fosfato bicálcico 120:1 (FB-120), 30:1 (FB-30) e 10:1 (FB-10), monobicálcico 60:1 (MBC-60), superfosfato triplo 30:1 (SFT-30) e rocha de Cajati 10:1 (ROCHA-10). Foram utilizados 49 novilhos, desmamados, com nove meses de idade, castrados e com 230 kg de peso médio, distribuídos em sete piquetes, com água e mistura mineral completa ad libitum, exceto fósforo. A dieta padrão foi calculada para um ganho de peso aproximado de 0,500 kg/dia. Os animais do tratamento SFT-30, atingiram o peso de 520 kg, aproximadamente cinco meses antes que os do tratamento ROCHA-10, devido à solubilidade do P nas fontes. As análises de fósforo no osso mostraram diferença estatística apenas entre o tratamento CONTNEG e os tratamentos com fosfato bicálcico. As análises de flúor no osso se mostraram intimamente associados à quantidade de flúor disponível nas fontes testes. Pode-se concluir que as diferentes fontes de fósforo utilizadas interferiram nos resultados de desempenho dos animais. / Abstract: The productive performance and the interference of fluorine in supplemented Nelore bovines with alternative sources of phosphorus were evaluated. The sources of phosphorus and relations P:F had been distributed in the following treatments: control (CONTNEG), dicalcium phospate 120:1 (FB-120), 30:1 (FB-30) and 10:1 (FB-10), monodicalcium 60:1 (MBC-60), triple superphosphate 30:1 (SFT-30) and Cajati Rock 10:1 (ROCHA-10). Forty nine castrated steers with nine months of age averaging 230 kg distributed in seven pens, with water available and a complete mineral mixture, except phosphorus. The ration was formulated for a weight gain of 0,500 kg/day. Animals of SFT-30 treatment had reached 520 kg approximately five months before ROCHA-10 treatment, due to the P solubility in the sources. The analyses of phosphorus in the bone had shown statistical differences only between treatment CONTNEG and the treatments with dicalcium phosphate. Bone fluorine analyses were highly associated to fluorine quantity in the phosphorous sources evaluated. It can be concluded that the different phosphorus sources used had influenced animal performance. / Mestre
38

Planos nutricionais com redução dos níveis de fósforo disponível e cálcio em rações contendo fitase para leitões desmamados / Feeding programs with reduced levels of available phosphorus and calcium on rations containing phytase for weanling piglets

Sélos, Aline Nantes 21 August 2014 (has links)
Made available in DSpace on 2015-03-26T13:55:26Z (GMT). No. of bitstreams: 1 texto completo.pdf: 312365 bytes, checksum: e0f44062b37f48c3517825cbdd3705f4 (MD5) Previous issue date: 2014-08-21 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Aiming to evaluate feeding programs (FP) with different levels of calcium (Ca) and available phosphorus (aP) on rations containing phytase for piglets, one hundred sixty- eight barrows and females weighing 8.11 ± 0.61 kg were weaned at 28 days and blocked according to initial body weight. Inside each block, piglets were randomly distributed to one of seven feeding programs with eight replicates and three piglets per experimental unit.The treatments consisted of control FPwithout phytase and six with decreasing levels(%) of aP and calcium (Ca) with the addition ofphytase(2,000 FTU/kg), as follows: FP1: (aP: 0.435-0.385-0.315; Ca: 0.850-0.825-0.768); FP2: (aP: 0.370-0.320-0.250; Ca:0.850-0.825-0.768); FP3: (aP: 0.305-0.255-0.185; Ca: 0.850- 0.825-0.768); FP4: (aP: 0.435-0.385-0.315; Ca:0.690-0.665-0.608); FP5: (aP: 0.370- 0.320-0.250; Ca: 0.690-0.665-0.608); FP6: (aP: 0.305-0.255-0.185; Ca: 0.690-0.665- 0.608). The FP3, FP5 and FP6 resulted in higher average daily gain and feed intake in comparison to control,from 28 to 35 days. Only FP6 resulted in higher average daily gain in comparison to control, from 28 to 49 days. The FP6 resulted in lower verage daily gain when compared to FP1, from 28 to 63 days.The FP1, FP2, FP4 and FP5provided greater bone mineralization when compared to control. The FP1resulted in greater bone mineralization than FP3, FP5 and FP6. The FP3 resulted in less bone mineralization than FP1, FP2 and FP4. Bone Ca was lower on FP5 when compared to FP1. With the exception of the FP3, phosphorus (P) of the bone was higher on all treatments when compared to control, however, the FP3 treatment resulted in less bone P than FP1. The FP4, FP5 and FP6 resulted in lower bone Ca:P ratio when compared to control. The serum Pconcentrations were lower in FP3 and FP6 in comparison to control. Considering only treatments containing exogenousphytase, the FP3 resulted in lower serum P than FP1, FP4, FP5; and FP6 resulted in lower serum P in comparison to FP5 as well. In conclusion, the FP6 results in satisfactory performance of pigs from 28 to 63 days of agealthough providing lower growth rate when compared to FP5. / Objetivando-se avaliar planos nutricionais comdiferntesníveis de cálcio (Ca) e fósforo disponível (Pd) em rações contendo fitase, 168 leitões, machos castrados e fêmeas, com peso corporal inicial de 8,11±0,61kg foramdesmamados aos 28 dias de idade e distribuídos em delineamento em blocos ao acaso, conforme o peso corporal, em sete tratamentos, com oito repetições e três animais por unidade experimental. Os tratamentos foram planos nutricionais (PN), sendo um controle sem fitase e os demais com níveis (%) decrescentes de Pd e Ca com 2.000 FTU de fitase, conforme segue: PN1: (Pd:0,435-0,385-0,315; Ca: 0,850-0,825-0,768); PN2: (Pd:0,370-0,320-0,250; Ca:0,850-0,825-0,768); PN3: (Pd: 0,305-0,255-0,185; Ca: 0,850-0,825-0,768); PN4: (Pd: 0,435-0,385-0,315; Ca:0,690-0,665-0,608); PN5: (Pd: 0,370-0,320-0,250; Ca:0,690-0,665-0,608); PN6: (Pd: 0,305-0,255-0,185; Ca: 0,690-0,665-0,608). O ganho de peso e o consumo de ração diários dos 28 aos 35 dias foram maiores para o PN3, PN5 e PN6 em comparação ao plano controle. Dos 28 aos 49 dias, o ganho de peso diário proporcionado pelo PN6 foi maior em comparação ao controle. O ganho de peso diário foi menor no PN6 em comparação ao PN1, dos 28 aos 63 dias. Os tratamentos PN1, PN2, PN4, PN5 proporcionaram maior mineralização óssea comparados ao controle. O PN1 resultou em maior mineralização óssea que o PN3, PN5 e PN6. OPN3 proporcionou menor mineralização óssea que os PN1, PN2 e PN4. O PN5 resultou em menor Ca ósseo comparado ao PN1. Com exceção do PN3, todos os tratamentos resultaram em P ósseo maior em relação ao controle, mas o PN3 resultou em P ósseo menor que o PN1. O PN4, PN5 e PN6 resultaram em menor relação cálcio:fósforo ósseo em relação ao controle. O P sérico foi menor no PN3 e PN6 em relação ao tratamento controle. Dentre os tratamentos contendo fitase, o PN3 resultou em menor P sérico que o PN1, PN4, e PN5; e o PN6 em menor P sérico que o PN5. Conclui-se que oPN6, correspondente a 0,305-0,255-0,185 de Pd, 0,690-0,665-0,608 de Cae2000 FTU/kgde fitase, apesar de proporcionar menor taxa de crescimento em relação ao PN5, resulta em desempenho satisfatório de leitões dos 28 aos 63 dias de idade.

Page generated in 0.24 seconds