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  • 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.
91

Zeolite in pig diet : effect on growth performance and air quality

Choinière, Denis. January 1999 (has links)
Zeolite (77% clinoptilolite) was supplemented in grower hog rations at a rate of 2 or 5%. The growth performance (weight gain, daily consumption and feed conversion) and air quality were compared against a control group's where zeolite was replaced by fine sand. A significant reduction in the feed/gain ratio and daily consumption was observed when 2% zeolite was fed to pigs weighing less than 40 kg. The same results were obtained when 5% zeolite was fed to pigs weighing more thoun 50 kg. No significant difference in air quality (CO 2, NH3, H2S and temperature) was noticed between the control and the zeolite room even if the NH3, level fell from 12.5 to 8.7 ppm when the zeolite level was increased from 2 to 5%. A slight reduction of odor intensity was observed in the zeolite room. In parallel with this research, a dynamic automated olfactometer for six lists was conceived and built according to American and European guidelines. This instrument measures agricultural odors with precision and speed.
92

Ação de beta-glucanos em leitões recém-desmamados alimentados com dietas com diferentes densidades nutricionais

Saleh, Mayra Anton Dib [UNESP] 14 January 2014 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-01-14Bitstream added on 2014-06-13T18:07:19Z : No. of bitstreams: 1 saleh_mad_dr_botfmvz.pdf: 400935 bytes, checksum: 36306a3bc495dbf821b670944563a52d (MD5) / A nutrição exerce influência na modulação do sistema imune e na melhoria da resistência dos animais à infecção, visto que os nutrientes são necessários para a multiplicação celular durante a resposta imune e síntese de moléculas relacionadas à comunicação celular. Dois experimentos foram conduzidos com leitões desmamados aos 21 dias de idade e submetidos ao desafio com 150 μg kg-1 PV de lipopolissacarídeo (LPS) de Escherichia coli sorotipo 055:B5. Objetivou-se avaliar efeitos da adição de beta-glucanos originários da levedura Saccharomyces cerevisiae (0 e 300 ppm) em dietas com densidade nutricional baixa e elevada (3300 e 3450 kcal de EM kg-1) sobre o desempenho (Experimento I) e morfometria intestinal (altura de vilosidades: AV, profundidade de criptas: PC, relação AV:PC e área das placas de Peyer: PP) e peso de órgãos (fígado, timo e baço) dos leitões (Experimento II). No experimento I foram utilizados 96 leitões em delineamento de blocos ao acaso (oito repetições), em esquema fatorial 2 x 2 (2 níveis de beta-glucanos x 2 densidades nutricionais), enquanto no segundo experimento, 40 leitões foram distribuídos em delineamento de blocos ao acaso (cinco repetições) com arranjo fatorial dos tratamentos 2 x 2 x 2 (2 níveis de beta-glucanos x 2 densidades nutricionais x 2 épocas de abate: uma semana antes da primeira inoculação com LPS e uma semana após a segunda inoculação com LPS). Nos experimentos foram realizadas análises estatísticas dos dados utilizando o procedimento GLM (Experimento I) e análise multivariada (Experimento II) do SAS, sendo as médias comparadas pelo teste de Bonferroni P(<0,05). A dieta de baixa densidade nutricional sem beta-glucanos proporcionou maior (P<0,05) AV e AV:PC do duodeno e jejuno. Não foram observados efeitos (P>0,05) dos beta-glucanos e da densidade nutricional da dieta no desempenho, PC do jejuno e na área... / Nutrition influences the modulation of the immune system and improves the resistance to infection, because the nutrients are required for cell proliferation during the immune response. Two experiments were conducted with piglets weaned at 21 days old and immunologically challenged with 150 μg kg-1 BW lipopolysaccharide of Escherichia coli serotype 055:B5 to evaluate the effects of two levels of beta-glucans (0 and 300 ppm) of yeast Saccharomyces cerevisiae and two levels of nutrient density (3300 and 3450 kcal ME kg-1) on growth performance (Experiment I) and intestinal morphometry (villus height: VH, cript depth: CD, VH:CD, Peyer’s patches area: PP) and organs weight (liver, spleen and thymus) of weanling pigs (Experiment II). In Experiment I, 96 weanling pigs were randomly assigned in a complete block design in a 2 x 2 factorial arrangement (2 levels of beta-glucans: 0 and 300 ppm, and 2 levels of nutrient density: 3300 and 3450 kcal ME kg-1) with 8 replications per treatment and 3 pigs per pen. In Experiment II, 40 weanling pigs were randomly assigned in a complete block design in a 2 x 2 x 2 factorial arrangement with the same levels of beta-glucans and nutrient density of experiment I at two slaughter moments with 5 replications per treatment and one pig per pen. Data were analyzed in accordance with GLM procedure (Experiment I) and multivariate procedure (Experiment II) by SAS, and the treatment means were compared by Bonferroni test (P<0.05) in both experiments. The low nutrient density diet without beta-glucans had higher (P<0.05) VH and VH:CD in duodenum and jejunum. No differences concerning levels of beta-glucans and nutrient density were observed (P>0.05) on growth performance, and CD in jejunum neither in PP ileal area. The addition of beta-glucans and high nutrient density diets are not viable for pigs from 21 to 59 days of age, once no effects were observed on growth... (Complete abstract click electronic access below)
93

Efeitos do incremento da fibra em detergente neutro, sobre parâmetros de desempenho, de digestibilidade dos componentes dietéticos e da morfologia intestinal de marrãs

Gomes, Jacinta Diva Ferrugem [UNESP] 08 February 1996 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:59Z (GMT). No. of bitstreams: 0 Previous issue date: 1996-02-08Bitstream added on 2014-06-13T19:26:25Z : No. of bitstreams: 1 gomes_jdf_dr_botfmvz.pdf: 534381 bytes, checksum: ae99b49a5e8b0ffe9bc4f1a31533cea1 (MD5) / Embora os suínos apresentem limitada capacidade em degradar material fibroso, é possível utilizar fontes fibrosas na ração de determinadas categorias animais, como por exemplo suínas em fases pré-púbere e púbere, devido à necessidade de moderado ganho de peso neste período. Por ocasião do primeiro cio útil (terceiro cio fisiológico), as fêmeas devem apresentar valores mínimos de 110 kg de peso corporal e 1,8-2,0 cm de espessura de toucinho. O objetivo desta pesquisa foi o de determinar os efeitos causados pelo emprego de 0; 6,6; 13,2 e 19,8% de fibra em detergente neutro (FDN), na ração basal de fêmeas suínas em fase pré-púbere e púbere (marrãs). As concentrações de FDN na ração, foram obtidas através da inclusão de 0, 10, 20 e 30 % de feno de coast cross (Cynodon dactylon), respectivamente. Foram utilizadas 20 marrãs puras e mestiças, das raças Landrace e Large White, com peso e idade médias iniciais de 52,85 kg e 110 dias, em um experimento em blocos casualizados, com cinco repetições/tratamento. Em relação às características de desempenho animal, o incremento de FDN na ração de marrãs, promoveu respostas lineares (P<0,01) no ganho diário de peso (0,675; 0,607; 0,525; 0,483 g/d); no peso corporal por ocasião do primeiro cio útil (118,0; 114,0; 102,2; 98,2 kg); na conversão alimentar (3,6; 4,0; 4,7; 5,3); e resposta quadrática (P<0,05) na espessura de toucinho (3,28; 3,34; 2,82; 1,74 cm). No referente à idade de ocorrência do primeiro cio útil, não houve registro de efeito significativo (P>0,10) sobre esta característica, a qual apresentou valor médio de 203 dias. A digestibilidade dos componentes dietéticos foi influenciada pela presença de fibra dietética na ração das marrãs. A adição de FDN promoveu resposta linear (P<0,01) na digestibilidade da matéria seca... / Although swines show limited capability in degrading fiber, it is possible utilization of feeds in the diet of some animal categories such as gilts. These animals need to gain moderate weight during this period that precede breeding and by the time females exhibit their third physiological heat, they have to weight a minimum of 110 kg and have at least 1.8-2.0 cm of subcutaneous fat. The objective of this research was to assess the effects caused by utilization of 0; 6.6; 13.2 and 19.8 % of neutral detergent fiber (NDF) in the basal diet of gilts. These concentrations of NDF were obtained through inclusion of 0; 10; 20 and 30 % of coast-cross hay (Cynodon dactylon), respectively. This trial was conducted with 20 pure and crossbred Landraceand Large White females with average weight of 52.8 kg and 110 days old. The experimental design employed was a completely randomized block design with five repetitions per treatment. Increasing concentration of NDF in the diet of gilts led to linear response (P<0.01) on the daily weight gain (0.675; 0.607; 0.525; 0.483 g/d); on the body weight by the onset of the third physiological heat (118.0; 114.0; 102.2; 98.2 kg); on the feed efficiency (3.6; 4.0; 4.7; 5.3); and quadratic response (P<0.05) on the subcutaneous fat thickness (3.28; 3.34; 2.82; 1.74 cm). However, no significance was found (P>0.10) on the third physiological heat onset age which average 203 days. Nutrient digestibility was also affected by addition of hay to the basal diet. Dry matter digestibility had linear response... (Complete abstract click electronic access below)
94

Farelo de abacaxi como fonte de fibra na alimentação de leitões desmamados

Ramos, Géssica Ferreira [UNESP] 04 March 2015 (has links) (PDF)
Made available in DSpace on 2015-08-20T17:10:00Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-03-04. Added 1 bitstream(s) on 2015-08-20T17:26:02Z : No. of bitstreams: 1 000844537.pdf: 614846 bytes, checksum: 60b12d9da9cbe8ff05921e601e1bcd08 (MD5) / Objetivou-se avaliar dietas com teores crescentes (0%, 3,4%, 6,8% e 10,2%) de farelo de abacaxi na alimentação de leitões desmamados. Foram utilizados 56 leitões, dos 21 aos 63 dias de idade, avaliados quanto aos seguintes parâmetros: desempenho zootécnico; incidência de diarreia; digestibilidades das dietas; excreções nas fezes, totais e por unidade de peso vivo ganho, de matérias seca (MS), mineral (MM) e orgânica (MO), nitrogênio (N) e fósforo (P); morfologia da mucosa intestinal; pesos dos órgãos do trato digestório; tempo de trânsito da digesta; e índices de custos das dietas. As avaliações foram efetuadas em três períodos: I - dos 21 aos 35 dias; II - dos 21 aos 49 dias; III dos 21 aos 63 dias de idade dos leitões. Os animais foram distribuídos em blocos casualizados, de acordo com seus pesos ao início do experimento, com quatro tratamentos e sete repetições. No período II os animais submetidos as dietas com 3,4 e 6,8% de farelo de abacaxi consumiram mais ração (P<0.05), e no período III verificou-se maior ganho de peso (P<0.05) somente dos animais que receberam a dieta com 3,4% de farelo de abacaxi, ambos em relação aos leitões controle. No período III todos os animais que receberam as dietas com adição de farelo de abacaxi apresentaram excreções de MS, MM, MO e N superiores (P<0.05) as dos animais controle. Contudo, as excreções destes componentes nas fezes por unidade de peso vivo ganho no período III, não diferiram (P>0.05) entre os leitões que receberam as dietas sem farelo de abacaxi e os que consumiram a dieta com 3,4% do produto. A adição de farelo de abacaxi as dietas dos leitões diminuiu (P<0.05) as digestibilidades dos nutrientes em todos os períodos e o tempo de trânsito gastrintestinal no período 1. Contudo, não se observou aumentos significativos nos pesos dos órgãos gastrintestinais e danos a estrutura da mucosa intestinal dos animais. A inclusão do farelo de abacaxi em... / The aim of this research was to evaluate diets with growing levels of pineapple meal, as a fiber source, in weaned piglets feeding. Fifty six piglets, from 21 to 63 days old, were fed diets composed mainly by corn, soybean meal and dairy products, with the addition of pineapple byproduct in 0%, 3,4%, 6,8% and 10,2%. The parameters evaluated were: growth performance; diarrhea incidence; diets digestibility; excretion in feces, total and per unit of weight gain, of dry (DM), mineral (MM) and organic (OM) matters, nitrogen (N) and phosphorous (P); intestinal mucosa morphology; digestive organs weight; digesta transit time; indices of costs. The trial was divided in three periods: I - from 21 to 35 days; II - from 21 to 49 days; and III - from 21 to 63 days of age. The animals were allotted into a complete randomized design, according with their weight in the beginning of the trial, with four treatments and seven repetitions. In period II the animals fed diets with 3.4 and 6.8% of pineapple meal consumed more feed (P <0.05) than those fed the control diet, and in period III only the animals that received the diet with 3.4% of pineapple presented a higher weight gain (P <0.05) than control piglets. In period III all animals fed diets with added pineapple meal presented higher (P <0.05) excretions of DM, MM, OM and N than the control animals. However, checking the excretions of these components in the feces per unit of live weight gain in period III, it was found that there was no difference (P> 0.05) among the piglets fed diets without pineapple meal and those who consumed the diet with 3.4% of the product. The use of diets with increasing levels of pineapple meal for weanling piglets worsened nutrients digestibility of diets, but no negative effect on the weights of digestive tract organs and intestinal mucosal structure were observed. There were no differences (P> 0.05) in the indices of costs evaluated. Thus, the inclusion of 3.4% of ...
95

Bem-estar e qualidade da carne de suínos alimentados com dietas contendo milho geneticamente modificado

Girão, Lúcio Vilela Carneiro [UNESP] 10 October 2013 (has links) (PDF)
Made available in DSpace on 2014-11-10T11:10:01Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-10-10Bitstream added on 2014-11-10T11:57:22Z : No. of bitstreams: 1 000725878_20141210.pdf: 299659 bytes, checksum: 40654f951ed8434b8d6c427148be67bf (MD5) Bitstreams deleted on 2014-12-12T11:34:17Z: 000725878_20141210.pdf,Bitstream added on 2014-12-12T11:34:48Z : No. of bitstreams: 1 000725878.pdf: 943992 bytes, checksum: 83a93624969ce8062de8996659f195fe (MD5) / Esta pesquisa teve como objetivo avaliar a digestibilidade dos nutrientes, balanço de nitrogênio e desempenho de suínos nas fases de crescimento e terminação alimentados com dietas contendo milho híbrido comum e geneticamente modificado. Foram realizados dois experimentos: digestibilidade aparente das rações contendo híbridos de milho comum e transgênicos, e desempenho de suínos nas fases de crescimento e terminação alimentados com transgênicos. O delineamento do experimento da digestibilidade aparente foi em blocos (DBC) com quatro tratamentos, sete repetições, totalizando 28 animais mestiços (LD x LW) com peso médio inicial de 50 ±1,1 kg, sendo a unidade experimental o animal; e o desempenho teve delineamento em blocos casualizados (DBC) com três tratamentos e dez repetições totalizando 60 animais mestiços, machos castrados e fêmeas (LD x LW) com peso médio inicial de 30 ±2,2 kg, sendo a unidade experimental a baia contendo dois animais. Os tratamentos do experimento digestibilidade foram: R1- ração basal (referência) contendo milho híbrido variedade 2B587®; R2- 60% da R1 e 40% do milho híbrido comum variedade 2B587®; R3- 60% da R1 e 40% do milho híbrido transgênico 2B587Hx® e R4- 60% da R1 e 40% do milho híbrido transgênico 2B707Hx®. Os tratamentos do experimento de desempenho foram: D1- ração contendo milho híbrido comum variedade 2B587®; D2- ração contendo milho híbrido transgênico variedade 2B587Hx® e D3- ração contendo milho híbrido transgênico variedade 2B707Hx®. Os dados obtidos foram analisados utilizando-se o software estatístico SAS. Não foram observadas diferenças entre os milhos híbridos comuns em relação aos transgênicos para os parâmetros de digestibilidade dos milhos e variáveis de desempenho (P > 0,05). Foram encontrados efeitos sobre o balanço de nitrogênio e digestibilidade das rações (P < 0,05), ... / This research aimed to evaluate nutrient digestibility, nitrogen balance and performance of pigs in the growing and finishing phases. They were fed with diets containing hybrid common corn and genetically modified corn. Two experiments were conducted: apparent digestibility of diets containing hybrid common corn and transgenic corn, and performance evaluation of pigs fed with diets containing hybrid common corn and transgenic corn, in the growing and finishing phases. The design of the apparent digestibility experiment was in blocks using four treatments and seven replications totaling 28 crossbred (LW x LD) animals with an initial BW of 50 ± 1.1 kg. The animal was considered the experimental unit. The performance experiment addoted was randomized block design using with three treatments and ten replications. There were 60 crossbred barrows and gilts (LW x LD) animals with an average initial weight of 30 ± 2.2 kg. The experimental unit was the pen containing two animals. The digestibility experiment treatments were: reference diet-R1 containing hybrid corn (2B587®); R2- 60% of R1 and 40% of common hybrid corn (2B587®), R3- 60% of R1 and 40% of transgenic hybrid corn (2B587Hx®), and R4- 60% of R1 and 40% of transgenic hybrid corn (2B707Hx®). Performance experiment treatments were: D1-ration containing common hybrid corn (2B587®); D2-ration containing transgenic hybrid corn (2B587Hx®) and D3-ration containing transgenic hybrid corn (2B707Hx®). The data were analyzed using the SAS statistical software. No differences were observed between common hybrid corn and transgenic hybrid corn for corn digestibility parameters and performance variables (P > 0.05). Effects were found in nitrogen balance and digestibility (P < 0.05), probably these results are not directly linked to the presence of the Cry transgenic gene. It was concluded that there was no difference in nutrient digestibility, ...
96

Zeolite in pig diet : effect on growth performance and air quality

Choinière, Denis. January 1999 (has links)
No description available.
97

Methodology to evaluate the nutritive value of feedstuffs for poultry and swine

Ravindran, Velmurugu January 1982 (has links)
Six tropical feedstuffs were analyzed for proximate composition, Van Soest components, mineral contents and amino acid composition. The crude protein contents (dry basis) of cassava tuber meal, sesame oil meal, coconut oil meal, rubber seed meal, cassava leaf meal and sweet potato leaf meal were 2.9, 35.2, 21.8, 12.0, 20.2 and 10.4%, respectively. The corresponding values for acid detergent fiber were 5.0, 23.5, 29.4, 39.1, 35.0 and 46.4%, respectively. Cassava tuber meal contained 88.4% nitrogen-free extract, but was poor in minerals and amino acids. Sesame oil meal had a silica content of 12.2% possibly indicating adulteration with sand; it was rich in all the minerals, especially Ca (2.32%), Mg (.56%), P (1.04%) and Fe (.32%). Coconut oil meal contained high amounts of Na (852 ppm) and K (1.83%), whereas the Zn (249 ppm) and Mn (252 ppm) were higher in cassava leaf meal. With the possible exception of sesame oil meal, the sulphur amino acids are likely to be the most limiting when these feedstuffs are fed to livestock. True metabolizable energy (TME) values of cassava tuber meal, cassava leaf meal and sesame oil meal were determined using 24 adult Single Comb White Leghorn roosters. After 24 hours of fasting, six roosters were force-fed 25 g of each of these feedstuffs. Six roosters were fasted for another 48-hour period and served as negative controls. Excreta were collected for two consecutive 24-hour periods. Length of collection period had no effect on the TME of cassava tuber meal and sesame oil meal, indicating that a 24-hour collection period was adequate for these feedstuffs. A collection period of 48 hours or longer was, however, required for roosters force-fed cassava leaf meal. The mean TME values (dry basis) of cassava tuber meal, cassava leaf meal and sesame oil meal were determined to be 3.76 ± .06, 1.99 ± .28 and 2.42 ± .09 kcal/g, respectively. Three digestion trials, each involving 12 crossbred gilts averaging 35.2 kg body weight, were conducted to determine the effects of crude fiber and Virginiamycin on digesta rate of passate (RP) and nutritional parameters. Two levels (3.2 and 7.3%) of crude fiber and two levels (0 and 11 ppm) of Virginiamycin were used in a 2 x 2 factorial arrangement of treatments. All diets were isonitrogenous and isocaloric. RP was determined by noting the time required for a change in feces color following the addition of 0.5% chromic oxide to the diet. The high fiber diet had a faster (P<.001) RP and this was associated with depressions (P<.001) in the digestibility of dry matter (DM), energy (E), cell content, cell wall (CW), acid detergent fiber (ADF), hemicellulose, cellulose, lignin and ash. Virginiamycin supplementation slowed (P<.01) the RP of both low and high fiber diets, but improved (P<.10) the DM, E and CW digestibility of the high fiber diet only. Non-significant improvements (P<.15) in the digestibility of ADF and cellulose were also observed when Virginiamycin was supplemented to the high fiber diet. Fiber increased (P<.05) fecal nitrogen, whereas Virginiamycin supplementation decreased (P<.05) fecal nitrogen. Results suggest that Virginiamycin supplementation improved the energy utilization in a high fiber diet, but had little effect on a low fiber diet. A study was conducted, concurrent to the first total collection digestion trial, to evaluate the applicability of chromic oxide indicator method to estimate the digestibility of nutrients. Digestion coefficients derived from the indicator method were in close agreement with those determined by the conventional total collection method for the low fiber diet, but underestimate the values for the high fiber diet. / Master of Science
98

Corn responses to high levels of copper application as copper rich pig manure

Bajracharya, Keshari January 1987 (has links)
The use of copper (Cu) in pig production to stimulate growth and improve feed efficiency is presently being questioned due to the potential environmental hazards associated with the repeated disposal of the resulting Cu rich manure in agricultural land. Results of field experiments conducted on three diverse Virginia soils indicated that the long-term application of Cu as either copper sulfate or Cu rich pig manure, even at high application rates (average application rate for 9 years was 108 metric tons of manure ha⁻¹ year⁻¹ or 32 kg Cu ha⁻¹ year⁻¹), had no adverse effects on corn yields. Copper levels in corn grain and leaf tissue were not increased by the nine annual applications of Cu rich manure or CuSO₄ , except for a slight increase in Cu concentration in corn grain from CuSO₄ application on only one soil. Copper concentrations in all plant tissues were well within normal ranges for all treatments at all sites. Corn grain yields were not decreased by Cu application on any of the three soils. / M.S.
99

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.
100

The effect of high-fiber diets on nutrient utilization and intestinal morphology of growing pigs

Moore, Robert J. January 1986 (has links)
Three balance experiments were conducted to determine the effects of dietary fiber on mineral balance and intestinal.morphology of growing pigs. Fiber sources were added to corn-soybean meal diets at levels which increased neutral-detergent fiber levels by 6 to 8%. In experiment 1, 10% oat hulls (OH) decreased Ca (P<.06) and Zn (P<.01) balances of pigs after a 7 d feeding period. Wheat bran (20%) increased Mg intake and balance (P<.02), but did not affect Ca and Zn balances. In experiment 2, pigs were fed diets (with or without supplements of Zn, Fe and Mg) containing 15% OH or soybean hulls (SH) for 5 d or 26 d. SH increased Fe intake and balance (P<.01) and ( Mg absorption (P<.01). Compared with balances at 5 d, Zn balance was similar, while Fe and Mg balances were higher at 26 d for pigs fed the basal (P<.05) or SH (P<.01) diets. However, Zn balance was lower (P<.05) at 26 d 1 but Fe balance did not change over time for pigs fed the OH diets. At each time period, Zn balance was not different between pigs fed the basal or high-fiber diets. In experiment 3, Ca, Zn and Mg absorption were not affected by 15% OH or SH or 20% alfalfa meal (AM) after 67 d or 39 d, although SH and AM increased Fe balance (P<.01). Intestinal surface morphology of 12 pigs fed in experiment 3 was examined by scanning electron microscopy. Villus morphology was variable in jejunum, ileum and colon, although evidence of villus blunting and folding accompanied by erosion of microvilli and loss of epithelial cells was observed in small intestine of some pigs fed the SH and AM diets. Damage was not consistent in all sites examined in individual pigs, and did not occur in all pigs fed any specific diets. Although Ca and Zn balances were decreased by OH in two of the balance trials, the inability of OH to consistently decrease mineral balance suggests that the ability of the pig to adapt to different diets may be sufficient to overcome the mild inhibitory effect on mineral absorption of some fiber sources. When viewed together, the results of the balance trials indicate that moderate amounts of dietary fiber have a minimal negative impact on mineral balance of pigs fed practical corn-soybean meal diets. However, the results also indicate that fiber sources such as SH and AM, are rich sources of some minerals for the pig, particularly Fe. Evidence of intestinal damage was evident in pigs fed the high-fiber diets. However, not all animals fed a particular diet were affected, which suggests that some pigs within a given population may be susceptible to detrimental effects of dietary fiber on intestinal structure or function. / Ph. D.

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