Conteúdo químico e energético do milho antes e após pré-limpeza

The poultry industry normally has little control over the raw material that arrives at the processing plant. This experiment aimed to evaluate chemical and energetic quality of corn obtained in a feed mill before and after pre-cleaning. Twenty samples of 30 kg of corn each were taken from trucks delivering corn to the mill. The trucks were then unloaded and the material passed through a pre-cleaning process when another sample was taken. Samples were graded and physical properties evaluated: density (g/L), grain percentages of foreign material, impurities, fragments, broken, soft, insect damaged, fire-burnt, fermented, damaged, cracked and fine particles, as well as chemical composition analysis: Apparent metabolizable energy for poultry (AME), ether extract (EE), crude fiber (CF), starch (STA), water activity (WA), crude protein (CP), digestible and total lysine, methionine, cystine, threonine, tryptophan, valine, isoleucine, leucine, phenylalanine, histidine and arginine. The experiment was a randomized design with two treatments (before and after pre-cleaning) and twenty replications. Data was analyzed using SAS ® and treatment differences obtained using F test. Correlations and principal components were calculated. There was a decrease in density after the pre-cleaning process, which was probably due to the removal of earth and stones rather than grain and its fractions. Significant increases were found for insect damage, fermented and damaged grain while fire-burn was significantly reduced after the pre-cleaning process Starch increased after pre-cleaning which is a result of contaminants that normally are poor in this carbohydrate, but fiber levels increased too. Apparent metabolizable energy, aminoacids, digestible (P<0.05) and total (P<0.05) histidine, total lysine and methionine (P<0.1) levels were reduced after pre-cleaning. Density was higher when there were fewer impurities such as straw, husk or small grains. Broken corn was positively correlated (P<0.05) with foreign material (0.63) and fragments (0.76), while proportion of damaged corn was positively correlated with foreign material (0.68), fragments (0.58) and broken corn (0.83). In this study, even in samples classified as excellent quality before pre-cleaning, the pre-cleaning process was effective in reducing humidity and water activity which helps control the growth of fungi or other microorganisms. Starch and fiber levels increased after pre-cleaning while apparent metabolizable energy levels was not improved by pre-cleaning.A indústria avícola normalmente tem pouco controle sobre a matéria-prima que chega à unidade de transformação. Este experimento teve como objetivo avaliar a qualidade química e energética do milho obtida em uma fábrica de rações, antes e após a pré-limpeza. Vinte amostras de 30 kg de milho, foram retiradas de caminhões que entregavam milho para o moinho. Após os caminhões serem descarregados e o material passar por processo de pré-limpeza, outra amostra foi retirada. As amostras foram classificadas e as propriedades físicas foram avaliadas: densidade (g/L), percentagens de grãos de material estranho, impurezas, fragmentados, quebrados, chocho, danificados por insetos, queimados, fermentados, danificados,avariados e quirera, bem como análises de composição bromatológica: energia metabolizável aparente para aves (EMA), extrato etéreo (EE), fibra bruta (FB), amido (A), atividade de água (AA), proteína bruta (PB), lisina digestível e total, metionina, cistina, treonina, triptofano, valina, isoleucina, leucina, fenilalanina, histidina e arginina. O delineamento experimental foi o inteiramente casualizado com dois tratamentos (antes e após a pré-limpeza) e vinte repetições cada. Os dados foram analisados usando o programa SAS ® e as diferenças entre os tratamentos obtidos pelo teste F. Correlações e componentes principais foram calculados. Houve diminuição na densidade após o processo de pré-limpeza que foi provavelmente devido à remoção de terra e pedras em vez de grão e as suas fracções Aumentos significativos foram encontrados para danos causados por insetos, grãos fermentados e danificados, enquanto o nível de queimados foi significativamente reduzido após o processo de pré-limpeza. O amido aumentou após a pré-limpeza já que contaminantes normalmente são pobres neste componente, porém os níveis de fibra também aumentaram. Os níveis de energia metabolizável aparente, aminoácidos, digestibilidade aparente (P <0,05) e total (P <0,05) da histidina, de lisina total e metionina (P <0,05) foram reduzidos após a pré-limpeza. A densidade foi maior quando havia menos impurezas, como a casca de palha ou grãos pequenos. A presença de milho quebrado foi positivamente correlacionada (P <0,05) com material estranho (0,63) e fragmentos (0,76), enquanto que a proporção do milho danificado foi positivamente correlacionado com material estranho (0,68), os fragmentos (0,58) e milho quebrado (0,83). Neste estudo, mesmo as amostras sendo classificadas como de excelente qualidade antes da pré-limpeza, o processo de pré-limpeza foi eficaz em reduzir a umidade e atividade da água, que ajuda a controlar o crescimento de fungos ou outros microorganismos nas rações. Os níveis de amido e fibra aumentaram após a pré-limpeza, enquanto que os níveis de energia metabolizável aparente não foram melhorados pela pré-limpeza

Quality assessment of corn batches received at a feed mill in the Brazilian cerrado

This study aimed at investigating factors that contribute to changes in the quality of corn used in compound poultry feeds. Samples were collected from 6488 bulk cargos received at a feed mill located close to Brasília, Brazil. The parameters studied were divided into two groups: those related to corn chemical composition, including crude protein (% CP), ether extract (% EE), crude fiber (% CF), nitrogen-free extract (% NFE), and estimated metabolizable energy (ME), and corn physical characteristics, including density, moisture, and grain physical damage. High coefficients of determination (R²) and low coefficients of variation (CV) were determined for the chemical and physical parameters. The analysis of variance showed low to medium R². Month, year, supplier, and their interactions influenced (p <0.05) all chemical properties, as well as density, moisture, and ME. Physical characteristics were less affected by those factors, except for quantity of damaged grains. The principal component analysis separated the physical and chemical factors. The coefficients of the first component explained 54% of the total variation between variables. The first principal component showed that NFE and ME increased as humidity decreased. The second component also showed a decrease of physical problems due to reduction in humidity. Results indicate that the feed mills should take preventive measures when selecting suppliers, and diets should be formulated according to the differences in chemical and physical composition of corn supplied in different months and years

CHEMICAL AND ENERGETIC CONTENT OF CORN BEFORE AND AFTER PRE-CLEANING

The poultry industry normally has little control over the raw material that arrives at the processing plant. This experiment aimed to evaluate chemical and energetic quality of corn obtained in a feed mill before and after pre-cleaning. Twenty samples of 30 kg of corn each were taken from trucks delivering corn to the mill. The trucks were then unloaded and the material passed through a pre-cleaning process when another sample was taken. Samples were graded and physical properties evaluated: density (g/L), grain percentages of foreign material, impurities, fragments, broken,  soft, insect damaged, fire-burnt, fermented, damaged, cracked and fine particles, as well as chemical composition analysis: Apparent metabolizable energy for poultry (AME), ether extract (EE), crude fiber (CF), starch (STA), water activity (WA), crude protein (CP), digestible and total lysine, methionine, cystine, threonine, tryptophan, valine, isoleucine,  leucine, phenylalanine, histidine and arginine. The experiment was a randomized design with two treatments (before and after pre-cleaning) and twenty replications. Data was analyzed using SAS ® and treatment differences obtained using F test. Correlations and principal components were calculated. There was a decrease in density after the pre-cleaning process, which was probably due to the removal of earth and stones rather than grain and its fractions. Significant increases were found for insect damage, fermented and damaged grain while fire-burn was significantly reduced after the pre-cleaning process. Starch increased after pre-cleaning which is a result of contaminants that normally are poor in this carbohydrate, but fiber levels increased too. Apparent metabolizable energy, aminoacids, digestible (P<0.05) and total (P<0.05) histidine, total lysine and methionine (P<0.1) levels were reduced after pre-cleaning.  Density was higher when there were fewer impurities such as straw, husk or small grains.  Broken corn was positively correlated (P<0.05) with foreign material (0.63) and fragments (0.76), while proportion of damaged corn was positively correlated with foreign material (0.68), fragments (0.58) and broken corn (0.83).  In this study, even in samples classified as excellent quality before pre-cleaning, the pre-cleaning process was effective in reducing humidity and water activity which helps control the growth of fungi or other microorganisms. Starch and fiber levels increased after pre-cleaning while apparent metabolizable energy levels was not improved by pre-cleaning. Keywords: density; energy; humidity; protein; starch

Conteúdo químico e energético do milho antes e após pré-limpeza

A indústria avícola normalmente tem pouco controle sobre a matéria-prima que chega à unidade de transformação. Este experimento teve como objetivo avaliar a qualidade química e energética do milho obtida em uma fábrica de rações, antes e após a pré-limpeza. Vinte amostras de 30 kg de milho, foram retiradas de caminhões que entregavam milho para o moinho. Após os caminhões serem descarregados e o material passar por processo de pré-limpeza, outra amostra foi retirada. As amostras foram classificadas e as propriedades físicas foram avaliadas: densidade (g/L), percentagens de grãos de material estranho, impurezas, fragmentados, quebrados, chocho, danificados por insetos, queimados, fermentados, danificados,avariados e quirera, bem como análises de composição bromatológica: energia metabolizável aparente para aves (EMA), extrato etéreo (EE), fibra bruta (FB), amido (A), atividade de água (AA), proteína bruta (PB), lisina digestível e total, metionina, cistina, treonina, triptofano, valina, isoleucina, leucina, fenilalanina, histidina e arginina. O delineamento experimental foi o inteiramente casualizado com dois tratamentos (antes e após a pré-limpeza) e vinte repetições cada. Os dados foram analisados usando o programa SAS ® e as diferenças entre os tratamentos obtidos pelo teste F. Correlações e componentes principais foram calculados. Houve diminuição na densidade após o processo de pré-limpeza que foi provavelmente devido à remoção de terra e pedras em vez de grão e as suas fracções. Aumentos significativos foram encontrados para danos causados por insetos, grãos fermentados e danificados, enquanto o nível de queimados foi significativamente reduzido após o processo de pré-limpeza. O amido aumentou após a pré-limpeza já que contaminantes normalmente são pobres neste componente, porém os níveis de fibra também aumentaram. Os níveis de energia metabolizável aparente, aminoácidos, digestibilidade aparente (P <0,05) e total (P <0,05) da histidina, de lisina total e metionina (P <0,05) foram reduzidos após a pré-limpeza. A densidade foi maior quando havia menos impurezas, como a casca de palha ou grãos pequenos. A presença de milho quebrado foi positivamente correlacionada (P <0,05) com material estranho (0,63) e fragmentos (0,76), enquanto que a proporção do milho danificado foi positivamente correlacionado com material estranho (0,68), os fragmentos (0,58) e milho quebrado (0,83). Neste estudo, mesmo as amostras sendo classificadas como de excelente qualidade antes da pré-limpeza, o processo de pré-limpeza foi eficaz em reduzir a umidade e atividade da água, que ajuda a controlar o crescimento de fungos ou outros microorganismos nas rações. Os níveis de amido e fibra aumentaram após a pré-limpeza, enquanto que os níveis de energia metabolizável aparente não foram melhorados pela pré-limpeza.The poultry industry normally has little control over the raw material that arrives at the processing plant. This experiment aimed to evaluate chemical and energetic quality of corn obtained in a feed mill before and after pre-cleaning. Twenty samples of 30 kg of corn each were taken from trucks delivering corn to the mill. The trucks were then unloaded and the material passed through a pre-cleaning process when another sample was taken. Samples were graded and physical properties evaluated: density (g/L), grain percentages of foreign material, impurities, fragments, broken, soft, insect damaged, fire-burnt, fermented, damaged, cracked and fine particles, as well as chemical composition analysis: Apparent metabolizable energy for poultry (AME), ether extract (EE), crude fiber (CF), starch (STA), water activity (WA), crude protein (CP), digestible and total lysine, methionine, cystine, threonine, tryptophan, valine, isoleucine, leucine, phenylalanine, histidine and arginine. The experiment was a randomized design with two treatments (before and after pre-cleaning) and twenty replications. Data was analyzed using SAS ® and treatment differences obtained using F test. Correlations and principal components were calculated. There was a decrease in density after the pre-cleaning process, which was probably due to the removal of earth and stones rather than grain and its fractions. Significant increases were found for insect damage, fermented and damaged grain while fire-burn was significantly reduced after the pre-cleaning process. Starch increased after pre-cleaning which is a result of contaminants that normally are poor in this carbohydrate, but fiber levels increased too. Apparent metabolizable energy, aminoacids, digestible (P<0.05) and total (P<0.05) histidine, total lysine and methionine (P<0.1) levels were reduced after pre-cleaning. Density was higher when there were fewer impurities such as straw, husk or small grains. Broken corn was positively correlated (P<0.05) with foreign material (0.63) and fragments (0.76), while proportion of damaged corn was positively correlated with foreign material (0.68), fragments (0.58) and broken corn (0.83). In this study, even in samples classified as excellent quality before pre-cleaning, the pre-cleaning process was effective in reducing humidity and water activity which helps control the growth of fungi or other microorganisms. Starch and fiber levels increased after pre-cleaning while apparent metabolizable energy levels was not improved by pre-cleaning

Quality assessment of maize and prediction of metabolizable energy for use in poultry

Tese (doutorado)—Universidade de Brasília, Faculdade de Agronomia e Medicina Veterinária, 2009.Objetivou-se com este trabalho discutir os principais pontos que contribuem para as perdas de qualidade do milho utilizado para o balanceamento de rações para aves. Foram retiradas 6488 amostras de cargas a granel. Para as propriedades físicas mês, ano, fornecedor, bem como as suas interações, afetaram (P<0,05) todas as propriedades químicas (Proteína Bruta, Fibra Bruta, Extrato Etéreo (EE) e Extrato Não Nitrogenado), bem como densidade, umidade e a Energia Metabolizável (EM) estimada, enquanto que as características físicas foram menos afetadas por estes fatores, com exceção dos avariados. A maior ocorrência de grãos ardidos e carunchados resultou em redução do EE e EM. Um ensaio metabólico foi realizado para avaliar as frações avariadas do milho determinando seu conteúdo energético e digestibilidade de nutrientes. Foram utilizados 170 frangos de corte machos, com 22 dias de idade. Os tratamentos consistiram de cinco milhos classificados como: bom, fermentados, carunchado, ardido e o milho controle. As substituições foram feitas com base na matéria natural, sendo 60% da dieta referência + 40% de cada fração do milho avaliada. Foi utilizado o método tradicional de coleta total de excretas e foram determinados, por meio de cálculos, os valores de energia metabolizável aparente (EMA) e corrigida para balanço de nitrogênio (EMAn) e os coeficientes de digestibilidade da matéria seca (CDMS), proteína bruta (CDPB), extrato etéreo (CDEE) e da energia bruta (EB) do milho e suas frações. As diferentes frações dos milhos testados apresentaram diferentes valores em suas composições químicas quando comparados ao milho bom e às Tabelas Brasileiras. Houve a influência linear da densidade sobre a EMA e EMAn e os coeficientes de digestibilidade dos nutrientes. Em geral, os milhos de menores valores de densidade apresentaram os menores coeficientes de digestibilidade em relação aos demais avaliados. Baseando-se nas análises físicas de outras 5094 amostras independentes e utilizando os dados acima encontrados de energia metabolizável para diferentes frações de milhos, e também umidade e densidade, foram desenvolvidas equações de predição para estimativa da EMA e a EMAn para milhos com diferentes composições físicas por meio de regressões múltiplas. Para o desenvolvimento das equações adotou-se agrupamento das frações de grãos (em percentual): atacados por fungos (Fun), fragmentados (Frim), atacados por insetos (Ins), grãos quebrados (Quebr) e, a fração de grãos avariados por diversas causas (ADC). As equações apresentaram coeficientes de determinação (R2) elevados, sendo 0,994 para EMA, e 0,987 para EMAn, indicando excelente ajuste das equações aos dados e foram: EMA = 3310.06- 0.00013085Dens -0.19867Quebr -0.20547Frim -0.60084Fun -1.88072 Ins -0.2281ADC e EMAn = 3381.18-0.00027Dens -0.27963Quebr - 0.28623Frim -0.7911Fun -2.06007Ins -0.29799ADC-0.232Umidade. Análises discriminantes foram feitas para separar os milhos em dois grupos, consideradas de alta qualidade (grupo 1) e o de baixa qualidade (grupo 2), considerando para tal, valores acima e inferiores a média da EMA obtida pelas equações, sendo 3375 kcal/kg, respectivamente. As variáveis mais importantes para separação entre grupos foram às frações de grãos danificados, impurezas, quirera e chochos. Estimou perdas semelhantes nos valores de EM entre os milhos de diferentes qualidades. Torna-se importante conhecer, além do valor energético, a composição física das diferentes frações de milhos, o que é determinante do seu valor nutricional, para que se atenda adequadamente às necessidades nutricionais das aves. _________________________________________________________________________________ ABSTRACTThe aim of this study is to discuss the main points that contribute to the loss of quality of corn used for the balance of feed for poultry, and based on it, make some proposals to improve the quality in use in the formulation of diets with use of prediction equations for metabolizable energy. Initially 6488 samples were taken from trucks. The parameters studied included those related to the chemical composition of corn: crude protein (CP), ether extract (EE), crude fiber (CF), not extract Nitrogen (NFE) and estimated metabolizable energy (MEest), and physical traits: density, moisture and physical damage of the grains. Month, year, supplier, and their interactions, affected (P <0,05) all chemical properties (CP, CF, EE, NFE) and density, moisture and MEest, while the physical characteristics were less affected by these factors, except for damaged grains. The higher occurrence of grain rot and insect damage resulted in reduction of EE and ME of grain. An experiment was conducted to evaluate the fractions of corn damaged by determining their energy content and digestibility of nutrients using170 male broilers with 22 days of age. Treatments consisted of five corns classified as good, fermented, insect damaged, burnt and a control. Substitutions were made on the basis of fresh matter, 60% of reference diet + 40% of each fraction of the maize evaluated. The traditional method of total excreta collection were used and were determined by means of calculations, the values of apparent metabolizable energy (AME) and corrected for the nitrogen balance (AMEn) and digestibility coefficients of dry matter (DMCD), Gross protein (CPCD), ether extract (CDEE) and gross energy (GECD) in maize and its fractions. The various fractions of corn tested showed different values in their chemical compositions when compared to control maize and Brazilian tables. Lower-density grains showed lowest digestibility coefficients. Based on the physical analysis of 5094 independent samples, metabolizable energy was estimated for different fractions of corn with different moistures (Umi) and densities (dens). Prediction equations were developed to estimate AME and AMEn for corn with different physical compositions through multiple regressions. For the development of the equations is adopted group of fractions of grains (in percentage): attacked by fungi (Fun), fragmented (Frim), insect damaged (Ins); broken grains (Quebr), and the fraction of grains damaged by various causes (ADC). The equations had high coefficients of determination (R2), 0.994 for AME and 0.987 for AMEn. The equations were: EMA = 3310.06- 0.00013085Dens -0.19867Quebr -0.20547Frim -0.60084Fun -1.88072 Ins - 0.2281ADC e EMAn = 3381.18-0.00027Dens -0.27963Quebr -0.28623Frim -0.7911Fun - 2.06007Ins -0.29799ADC-0.232Umi. Discriminant analysis were used to separate the corn into two groups, high quality and low quality, using results above and below the average (3375 kcal/kg) AME obtained by equations. The most important variables for separation between groups were the fractions of damaged grains, impurities and chochos. Similar losses were estimated in the values of ME among samples of different qualities. It is important to know, besides the energy, the physical composition of different fractions of corn, which is critical in determining its nutritional value, to adequately meet the nutritional needs of birds

Prediction of apparent metabolizable energy and metabolizable energy corrected for nitrogen of corn according to physical classification of the grain

ABSTRACT The objective of this study was to develop an equation to determine the apparent metabolizable energy (AME) and metabolizable energy corrected for nitrogen balance (AMEn) using a physical-based classification of corn. A total of 5,055 samples were taken from bulk cargo trucks, over a five-year period. The parameters studied were the variables related to the physical characteristics of grains. The density of maize was evaluated, and AME and AMEn were calculated. The average value for AME was 3,375 kcal/kg, and two groups were formed of high quality and low quality for all samples. Stepwise regression analysis was then carried out using grain quality to estimate AME and AMEn, and the validation of the equations was carried out with 6,490 independent samples. The average value for density was 767.7 kg/m3. The multiple regressions used to estimate AME and AMEn as a function of humidity, density, and physical composition of corn kernels showed that moisture was included for AME, but not for AMEn. The equations presented high coefficients of determination (R2) for AME (0.994) and AMEn (0.987). The discriminant analyses correctly classified 98% of the high-quality samples and 96.69% of low-quality samples, so the error was smaller than the expected. The calculated equations were shown to be good at discriminating between samples of high and low quality of corn according to its physical composition, and the most important variables for separation between groups were damaged grain fraction, impurities, burnt, and soft. The correlation between calculated (independent samples) and estimated metabolizable energy and AMEn were, respectively, 0.9942 and 0.9859. The corn energy values can be estimated based on physical evaluation of the grain

Conteúdo químico e energético do milho antes e após pré-limpeza

v. 16, n. 2, p. 158-168, abr./jun. 2015.Submitted by Marlene Santos ([email protected]) on 2015-05-06T21:04:06Z No. of bitstreams: 1 CHEMICAL AND ENERGETIC CONTENT OF CORN BEFORE AND AFTER PRE-CLEANING.pdf: 488049 bytes, checksum: 1bc5fa29ede9a07a0fdbfd1bd984429a (MD5)Approved for entry into archive by Luanna Matias ([email protected]) on 2015-07-14T13:55:52Z (GMT) No. of bitstreams: 1 CHEMICAL AND ENERGETIC CONTENT OF CORN BEFORE AND AFTER PRE-CLEANING.pdf: 488049 bytes, checksum: 1bc5fa29ede9a07a0fdbfd1bd984429a (MD5)Approved for entry into archive by Claudia Moura ([email protected]) on 2015-10-05T14:59:28Z (GMT) No. of bitstreams: 1 CHEMICAL AND ENERGETIC CONTENT OF CORN BEFORE AND AFTER PRE-CLEANING.pdf: 488049 bytes, checksum: 1bc5fa29ede9a07a0fdbfd1bd984429a (MD5)Made available in DSpace on 2015-10-05T14:59:59Z (GMT). No. of bitstreams: 1 CHEMICAL AND ENERGETIC CONTENT OF CORN BEFORE AND AFTER PRE-CLEANING.pdf: 488049 bytes, checksum: 1bc5fa29ede9a07a0fdbfd1bd984429a (MD5) Previous issue date: 2014-10-10Programa de Apoio à Publicações Periódicas Científicas (PROAPUPEC) da UFG;CNPq; CAPESThe poultry industry normally has little control over the raw material that arrives at the processing plant. This experiment aimed to evaluate chemical and energetic quality of corn obtained in a feed mill before and after pre-cleaning. Twenty samples of 30 kg of corn each were taken from trucks delivering corn to the mill. The trucks were then unloaded and the material passed through a pre-cleaning process when another sample was taken. Samples were graded and physical properties evaluated: density (g/L), grain percentages of foreign material, impurities, fragments, broken, soft, insect damaged, fire-burnt, fermented, damaged, cracked and fine particles, as well as chemical composition analysis: Apparent metabolizable energy for poultry (AME), ether extract (EE), crude fiber (CF), starch (STA), water activity (WA), crude protein (CP), digestible and total lysine, methionine, cystine, threonine, tryptophan, valine, isoleucine, leucine, phenylalanine, histidine and arginine. The experiment was a randomized design with two treatments (before and after pre-cleaning) and twenty replications. Data was analyzed using SAS ® and treatment differences obtained using F test. Correlations and principal components were calculated. There was a decrease in density after the pre-cleaning process, which was probably due to the removal of earth and stones rather than grain and its fractions. Significant increases were found for insect damage, fermented and damaged grain while fire-burn was significantly reduced after the pre-cleaning process. Starch increased after pre-cleaning which is a result of contaminants that normally are poor in this carbohydrate, but fiber levels increased too. Apparent metabolizable energy, aminoacids, digestible (P<0.05) and total (P<0.05) histidine, total lysine and methionine (P<0.1) levels were reduced after pre-cleaning. Density was higher when there were fewer impurities such as straw, husk or small grains. Broken corn was positively correlated (P<0.05) with foreign material (0.63) and fragments (0.76), while proportion of damaged corn was positively correlated with foreign material (0.68), fragments (0.58) and broken corn (0.83). In this study, even in samples classified as excellent quality before pre-cleaning, the pre-cleaning process was effective in reducing humidity and water activity which helps control the growth of fungi or other microorganisms. Starch and fiber levels increased after pre-cleaning while apparent metabolizable energy levels was not improved by pre-cleaning.A indústria avícola normalmente tem pouco controle sobre a matéria-prima que chega à unidade de transformação. Este experimento teve como objetivo avaliar a qualidade química e energética do milho obtida em uma fábrica de rações, antes e após a pré-limpeza. Vinte amostras de 30 kg de milho, foram retiradas de caminhões que entregavam milho para o moinho. Após os caminhões serem descarregados e o material passar por processo de pré-limpeza, outra amostra foi retirada. As amostras foram classificadas e as propriedades físicas foram avaliadas: densidade (g/L), percentagens de grãos de material estranho, impurezas, fragmentados, quebrados, chocho, danificados por insetos, queimados, fermentados, danificados,avariados e quirera, bem como análises de composição bromatológica: energia metabolizável aparente para aves (EMA), extrato etéreo (EE), fibra bruta (FB), amido (A), atividade de água (AA), proteína bruta (PB), lisina digestível e total, metionina, cistina, treonina, triptofano, valina, isoleucina, leucina, fenilalanina, histidina e arginina. O delineamento experimental foi o inteiramente casualizado com dois tratamentos (antes e após a pré-limpeza) e vinte repetições cada. Os dados foram analisados usando o programa SAS ® e as diferenças entre os tratamentos obtidos pelo teste F. Correlações e componentes principais foram calculados. Houve diminuição na densidade após o processo de pré-limpeza que foi provavelmente devido à remoção de terra e pedras em vez de grão e as suas fracções. Aumentos significativos foram encontrados para danos causados por insetos, grãos fermentados e danificados, enquanto o nível de queimados foi significativamente reduzido após o processo de pré-limpeza. O amido aumentou após a pré-limpeza já que contaminantes normalmente são pobres neste componente, porém os níveis de fibra também aumentaram. Os níveis de energia metabolizável aparente, aminoácidos, digestibilidade aparente (P <0,05) e total (P <0,05) da histidina, de lisina total e metionina (P <0,05) foram reduzidos após a pré-limpeza. A densidade foi maior quando havia menos impurezas, como a casca de palha ou grãos pequenos. A presença de milho quebrado foi positivamente correlacionada (P <0,05) com material estranho (0,63) e fragmentos (0,76), enquanto que a proporção do milho danificado foi positivamente correlacionado com material estranho (0,68), os fragmentos (0,58) e milho quebrado (0,83). Neste estudo, mesmo as amostras sendo classificadas como de excelente qualidade antes da pré-limpeza, o processo de pré-limpeza foi eficaz em reduzir a umidade e atividade da água, que ajuda a controlar o crescimento de fungos ou outros microorganismos nas rações. Os níveis de amido e fibra aumentaram após a pré-limpeza, enquanto que os níveis de energia metabolizável aparente não foram melhorados pela pré-limpeza

Prediction of apparent metabolizable energy and metabolizable energy corrected for nitrogen of corn according to physical classification of the grain

<div><p>ABSTRACT The objective of this study was to develop an equation to determine the apparent metabolizable energy (AME) and metabolizable energy corrected for nitrogen balance (AMEn) using a physical-based classification of corn. A total of 5,055 samples were taken from bulk cargo trucks, over a five-year period. The parameters studied were the variables related to the physical characteristics of grains. The density of maize was evaluated, and AME and AMEn were calculated. The average value for AME was 3,375 kcal/kg, and two groups were formed of high quality and low quality for all samples. Stepwise regression analysis was then carried out using grain quality to estimate AME and AMEn, and the validation of the equations was carried out with 6,490 independent samples. The average value for density was 767.7 kg/m3. The multiple regressions used to estimate AME and AMEn as a function of humidity, density, and physical composition of corn kernels showed that moisture was included for AME, but not for AMEn. The equations presented high coefficients of determination (R2) for AME (0.994) and AMEn (0.987). The discriminant analyses correctly classified 98% of the high-quality samples and 96.69% of low-quality samples, so the error was smaller than the expected. The calculated equations were shown to be good at discriminating between samples of high and low quality of corn according to its physical composition, and the most important variables for separation between groups were damaged grain fraction, impurities, burnt, and soft. The correlation between calculated (independent samples) and estimated metabolizable energy and AMEn were, respectively, 0.9942 and 0.9859. The corn energy values can be estimated based on physical evaluation of the grain.</p></div

Conteúdo químico e energético do milho antes e após pré-limpeza

The poultry industry normally has little control over the raw material that arrives at the processing plant. This experiment aimed to evaluate chemical and energetic quality of corn obtained in a feed mill before and after pre-cleaning. Twenty samples of 30 kg of corn each were taken from trucks delivering corn to the mill. The trucks were then unloaded and the material passed through a pre-cleaning process when another sample was taken. Samples were graded and physical properties evaluated: density (g/L), grain percentages of foreign material, impurities, fragments, broken, soft, insect damaged, fire-burnt, fermented, damaged, cracked and fine particles, as well as chemical composition analysis: Apparent metabolizable energy for poultry (AME), ether extract (EE), crude fiber (CF), starch (STA), water activity (WA), crude protein (CP), digestible and total lysine, methionine, cystine, threonine, tryptophan, valine, isoleucine, leucine, phenylalanine, histidine and arginine. The experiment was a randomized design with two treatments (before and after pre-cleaning) and twenty replications. Data was analyzed using SAS ® and treatment differences obtained using F test. Correlations and principal components were calculated. There was a decrease in density after the pre-cleaning process, which was probably due to the removal of earth and stones rather than grain and its fractions. Significant increases were found for insect damage, fermented and damaged grain while fire-burn was significantly reduced after the pre-cleaning process Starch increased after pre-cleaning which is a result of contaminants that normally are poor in this carbohydrate, but fiber levels increased too. Apparent metabolizable energy, aminoacids, digestible (P<0.05) and total (P<0.05) histidine, total lysine and methionine (P<0.1) levels were reduced after pre-cleaning. Density was higher when there were fewer impurities such as straw, husk or small grains. Broken corn was positively correlated (P<0.05) with foreign material (0.63) and fragments (0.76), while proportion of damaged corn was positively correlated with foreign material (0.68), fragments (0.58) and broken corn (0.83). In this study, even in samples classified as excellent quality before pre-cleaning, the pre-cleaning process was effective in reducing humidity and water activity which helps control the growth of fungi or other microorganisms. Starch and fiber levels increased after pre-cleaning while apparent metabolizable energy levels was not improved by pre-cleaning.A indústria avícola normalmente tem pouco controle sobre a matéria-prima que chega à unidade de transformação. Este experimento teve como objetivo avaliar a qualidade química e energética do milho obtida em uma fábrica de rações, antes e após a pré-limpeza. Vinte amostras de 30 kg de milho, foram retiradas de caminhões que entregavam milho para o moinho. Após os caminhões serem descarregados e o material passar por processo de pré-limpeza, outra amostra foi retirada. As amostras foram classificadas e as propriedades físicas foram avaliadas: densidade (g/L), percentagens de grãos de material estranho, impurezas, fragmentados, quebrados, chocho, danificados por insetos, queimados, fermentados, danificados,avariados e quirera, bem como análises de composição bromatológica: energia metabolizável aparente para aves (EMA), extrato etéreo (EE), fibra bruta (FB), amido (A), atividade de água (AA), proteína bruta (PB), lisina digestível e total, metionina, cistina, treonina, triptofano, valina, isoleucina, leucina, fenilalanina, histidina e arginina. O delineamento experimental foi o inteiramente casualizado com dois tratamentos (antes e após a pré-limpeza) e vinte repetições cada. Os dados foram analisados usando o programa SAS ® e as diferenças entre os tratamentos obtidos pelo teste F. Correlações e componentes principais foram calculados. Houve diminuição na densidade após o processo de pré-limpeza que foi provavelmente devido à remoção de terra e pedras em vez de grão e as suas fracções Aumentos significativos foram encontrados para danos causados por insetos, grãos fermentados e danificados, enquanto o nível de queimados foi significativamente reduzido após o processo de pré-limpeza. O amido aumentou após a pré-limpeza já que contaminantes normalmente são pobres neste componente, porém os níveis de fibra também aumentaram. Os níveis de energia metabolizável aparente, aminoácidos, digestibilidade aparente (P <0,05) e total (P <0,05) da histidina, de lisina total e metionina (P <0,05) foram reduzidos após a pré-limpeza. A densidade foi maior quando havia menos impurezas, como a casca de palha ou grãos pequenos. A presença de milho quebrado foi positivamente correlacionada (P <0,05) com material estranho (0,63) e fragmentos (0,76), enquanto que a proporção do milho danificado foi positivamente correlacionado com material estranho (0,68), os fragmentos (0,58) e milho quebrado (0,83). Neste estudo, mesmo as amostras sendo classificadas como de excelente qualidade antes da pré-limpeza, o processo de pré-limpeza foi eficaz em reduzir a umidade e atividade da água, que ajuda a controlar o crescimento de fungos ou outros microorganismos nas rações. Os níveis de amido e fibra aumentaram após a pré-limpeza, enquanto que os níveis de energia metabolizável aparente não foram melhorados pela pré-limpeza