RESUMO: Buscou-se analisar a tipologia de sistemas produtivos leiteiros familiares e patronais, localizados na região leste do estado de Goiás. Foram aplicados formulários semiestruturados em 170 sistemas produtivos leiteiros nas cidades de Cristalina, Luziânia e Silvânia. Os sistemas leiteiros foram segregados em dois grupos G1: produtores familiares e G2 produtores patronais. Para as demais variáveis foi aplicada a técnica de Análise Fatorial Exploratória - AFE com método de extração de Componentes Principais - ACP. Quatro Fatores foram obtidos: F1- manejo de ordenha, F2 - escala de produção, F3 - produtividade e, F4 - social. Os grupos G1 e G2 foram comparados frente aos Fatores. Produtores de leite patronais (G2) apresentaram maiores resultados para F1 e F2 quando comparados com produtores de leite familiares (G1). Desta forma, entre os sistemas produtivos leiteiros analisados, aqueles classificados como patronais (G2) apresentaram maior escala de produção de leite, maior frequência na adoção práticas de manejo e higiene de ordenha e portanto, estão mais adequados as demandas institucionais e de mercado atuais.

ABSTRACT: This study aimed to identify a typology of corporate and family dairy farms in eastern Goiás, Brazil. A semi-structured questionnaire was administered to 170 farm operators in the municipalities of Cristalina, Luziânia, and Silvânia. Dairy farms were categorized into two groups, corporate and family farms. Data were analyzed by exploratory factor analysis using principal component analysis extraction. Four factors were identified: Milking management (F1), Production scale (F2), Productivity (F3), and Sociodemographic characteristics (F4). Corporate and family farms were then compared in terms of factor scores. Corporate farms scored higher on F1 and F2 and were characterized by larger production scale, greater adoption of milking management and hygiene practices; and consequently, greater alignment with institutional and market demands. These results indicated that corporate dairy farms in eastern Goiás have higher sustainability and are more likely to remain in business than family dairy farms.

ABSTRACT The presence of mycotoxins or related fungi in animal feed is a major problem for animal and human health. Silage and concentrated feed samples were collected from 21 dairy farms in the Western part of Paraná state in Southern Brazil. Water activity and pH of all samples were measured, and each sample was analyzed to check for the presence of aflatoxigenic Aspergillus. Water activity was observed to be lower in the concentrated feed samples. The pH was lower in the silage samples, indicating fermentation processes. Two silage samples and four concentrated feed samples were contaminated with Aspergillus spp. Seven isolates of Aspergillus spp. were obtained and their potential to produce aflatoxins was evaluated. Four of the isolates, two from the silage samples and two from the concentrated feed samples, produced the aflatoxins B1, B2, G1, and G2 in culture media. These isolates were identified as Aspergillus parasiticus and Aspergillus nomius. The presence of aflatoxigenic isolates of Aspergillus spp. in silage and concentrated feed samples is a matter of concern, because of the risk of aflatoxin production and contamination of the animal feed.

RESUMO O queijo é a forma mais antiga de se conservar os nutrientes do leite possuindo importância nutricional, económica e cultural. Objetivou-se neste estudo identificar qual a melhor época do ano para produção, e período, em meses, para maturação de queijo colonial tradicional, por meio de análise da atividade da água (AW), perda de peso e contagens de micro-organismos ácido láticos, mesófilos proteolíticos e lipolíticos. Foram mantidos os registros de temperatura e umidade relativa do ar. Foi usado delineamento experimental inteiramente casualizado em esquema fatorial duplo, considerando períodos de produção e tempos de maturação. Para todos os períodos de produção avaliados, houve uma redução significativa nos períodos para os valores de AW. As contagens de bactérias ácido-láticas oscilaram entre 104 a 109UFC/g. Houve estabilidade também no número de colónias para micro-organismos mesófilos lipolíticos, até terceiro mês de maturação. Foram constatadas baixas contagens de mesófilos proteolíticos para as amostras produzidas em maio e junho (5,70 e 5,53log), respectivamente. O período de produção referente ao mês de maio e junho correspondentes a UR de 80% e temperaturas médias de 15°C foram os mais efetivos para produção. Em função da presença de Listeria recomenda-se respeitar o tempo mínimo de 60 dias de maturação para a comercialização.

SUMMARY Cheese is the oldest form of preserving milk nutrients having nutritional, economic and cultural importance. The objective of this study was to identify the best time of the year for production, and period, in months, for maturation of traditional colonial cheese, through analysis of water activity, weight loss and counts of lactic acid, mesophilic microorganisms—proteolytic and lipolytic. Records of temperature and relative humidity (RH) were maintained. A completely randomized experimental design was used in a double factorial scheme, considering production periods and maturation times. For all production periods evaluated, there was a significant reduction in the periods for water activity values. The counts of lactic acid bacteria ranged from 104 to 109 CFU/g. There was also stability in the number of colonies for lipolytic mesophilic microorganisms, until the third month of maturation. Low counts of proteolytic mesophiles were observed for the samples produced in May and June (5.70 and 5.53 log), respectively. The production period for the months of May and June corresponding to RH of 80% and average temperatures of 15°C were the most effective for production. Due to the presence of Listeria, it is recommended to respect the minimum time of 60 days of maturation for commercialization.

Objetivou-se com este trabalho avaliar o uso oral de probióticosLactobacillus spp viáveis e inativadas ("pool" deLactobacillus spp.), sobre o desempenho, a microbiota intestinal, e parâmetros sanguíneos de leitões do nascimento aos 35 dias de idade. Foram utilizados na fase de aleitamento 108 leitões com peso médio inicial de 1,41kg e, na creche, 72 leitões com peso médio inicial de 5,47kg, distribuídos em um delineamento experimental de blocos ao acaso. Os tratamentos foram: Controle: 1 mL de caldo MRS + 1 mL de solução salina estéril; Ativo: 1 mL de probiótico ("pool" de Lactobacillus spp. e Lactobacillus plantarum) ativados no caldo MRS + 1 mL de solução salina; Inativo: 1mL de probiótico contendo células inativadas no caldo MRS + 1 mL de solução salina. Os tratamentos não influenciaram o ganho de peso total e diário dos leitões no aleitamento. Dos 21 aos 35 dias de idade, observou-se diferença entre os tratamentos para consumo de ração, consumo de ração diário, ganho de peso total e diário. As contagens de bactérias ácido-láticas e coliformes não foram influenciadas pelos tratamentos e idades. Com exceção da globulina, os demais parâmetros sanguíneos analisados não são influenciados. Na fase de creche o tratamento probiótico com células inativadas significa uma alternativa viável para uso principalmente pelo desempenho obtido para ganho de peso; no entanto os tratamentos probióticos não influenciam as contagens microbiológicas e os parâmetros sanguíneos.

The objective of the current work was to evaluate the use of oral probiotics comprised of viable and inactivated Lactobacillus spp. (referred to herein as "pool" of Lactobacillus spp.) on the performance, intestinal microbiota and blood parameters of piglets from birth to 35 days of age. Lactation piglets (n=108), with an average initial weight of 1.41kg, and nursery piglets (n=72), with an average initial weight of 5.47kg, were included in the study and distributed in a randomized complete block design. The treatments were as follows: Control: 1mL MRS broth + 1mL sterile saline; Active: 1 mL probiotics ("pool" of Lactobacillus spp. and Lactobacillus plantarum) activated in MRS broth + 1 ml saline; Inactive: 1 mL inactivated probiotics containing MRS broth + 1mL saline. Treatments were not observed to affect total and daily weight gain of piglets during lactation. Differences were observed between treatments for feed intake, daily feed intake as well as total and daily weight gain from 21 to 35 days of age. Counts of lactic acid bacteria and coliforms were not affected by treatment or age. With the exception of globulin, blood parameters are also not affected. In the nursery phase the probiotic treatment with inactivated cells means a viable alternative for use primarily by the performance obtained for weight gain; however probiotics supplementation did not influence the microbiological counts and blood parameters.

Objetivou-se estudar o armazenamento do resíduo da extração de amido da mandioca, sem a utilização de tecnologias, por meio da avaliação química, valores de pH, temperatura, desenvolvimento de microrganismos e micotoxinas. O delineamento utilizado foi em blocos casualizados com oito tratamentos (diferentes dias de estocagem: 0, 3, 6, 9, 12, 15, 18 e 21) e cinco repetições. Houve diferença significativa para o teor de MS em função dos dias de estocagem. Obteve-se efeito linear negativo para os valores de pH, os quais decresceram com os dias de armazenamento. Houve significância do período de estocagem apenas sobre a população de fungos e leveduras, que se elevou até os 17 dias de estocagem, com posterior redução, micotoxinas foram detectadas no resíduo da extração do amido da mandioca. Apesar de não apresentar alterações na composição química, a estocagem do resíduo da extração do amido da mandioca por 21 dias demonstrou ser um processo de conservação ineficiente, devido ao desenvolvimento de fungos e presença de micotoxinas

The purpose of this paper was to study the storage of the residue from the extraction of cassava starch without the use of storage technologies, through chemical evaluation, pH values, temperature, development of microorganisms and mycotoxins. A randomized block design was used with eight treatments (different storage periods: 0, 3, 6, 9, 12, 15, 18 and 21 days) and five replications. There was a significant difference for DM content, as a function of days in storage. The chemical composition of the residue from the extraction of cassava starch did not changed throughout the storage period. A negative linear effect was obtained for the pH values, which decreased with days in storage. There was significance of the storage period only for the fungus and yeast population, which increased up to 17 days of storage, with subsequent reduction. Mycotoxins were detected in the residue from the extraction of cassava starch. Despite it did not showed changes in the chemical composition the storage of residue from the extraction of cassava starch for 21 days proved to be an inefficient preservation process, due to the development of molds and mycotoxins

The objective of the present study was to characterize the food sources, as well as the composition and quality of milk obtained from household farms of western Paraná State (Brazil) with and without technical assistance during the different seasons. For such, 24 properties were selected, 12 of which only received assistance and technical support. Four milk samples were taken (summer, autumn, winter and spring) to assess the physicochemical composition, somatic cell count and total bacterial count and feed supplied to the animals to assess the chemical composition (crude protein, ash, dry matter and neutral detergent fiber). The data were analyzed in a completely randomized design with a 2 × 4 factorial arrangement; the first factor was the presence and absence of technical assistance and the second factor was the four seasons of the year. Due to the dairy tradition of properties in the region, technical assistance had no significant effects on the health and nutritional quality of food, the number of animals, the production, or total bacterial count, which suffered oscillations only depending on the seasons of the year. However, the presence of assistance contributed to reducing somatic cell counts of milk produced and marketed. The technical assistance does not affect the quality of forages and concentrates used or the milk composition; however, it improves the sanitary quality of the milk produced throughout the four seasons of the year in household farms of western Paraná.

In many industrialized countries, including Brazil, sodium intake exceeds the nutritional recommendations. Excessive consumption is associated with hypertension and premature death by cardiovascular diseases. The industry's challenge is to produce products with reduced sodium that are similar to regular products in texture and flavor and consistent with consumers' dietary habits. The present study aimed at substituting 25 and 50% NaCl for KCl in marinated beef and chicken meat with the addition of aromatic herbs and spices. The following microbiological analyses were carried out: macronutrient, chemical composition, and sensorial analysis. The meats showed a reduction in NaCl contents without any changes in their physical and chemical characteristics, and the products´ quality and microbiological safety were maintained. Beef and chicken tenderness was maintained for both treatments. Furthermore, the use of 50% KCl did not cause any changes in the products' sensory quality, and the overall acceptance of both types of meat was maintained. Results showed that a reduction by 50% in the NaCl contents of marinated meat products with a combination of herbs and spices is possible. Future applications in other meat products and sausages are highly promising.

The objective of this study was to evaluate the microbiological profile and aerobic stability of silage with Tifton 85 bermudagrass and different additives and wilting. The studied treatments were: pre-drying in the sun for two hours before ensiling; use of bacterial-enzymatic inoculant; addition of soybean peel; addition of corn grits and use of salt in the surface layer of the silo. The experimental design was completely randomized with six treatments and four replications. Plants of Tifton 85 bermudagrass with 38 days were ensiled in experimental silos with Bunsen valves, with compacting density of 236 kg silage per m³ for Tifton 85 bermudagrass, which was pre-dried in the sun; the average silage was 294 kg m-3 for the other treatments. The ratios between soybean hulls and corn grits, added to the silage, were calculated based on the initial DM content from Tifton 85 bermudagrass in order to obtain 320 g/kg DM of the material to be ensiled. There was an increase of lactic bacteria and Clostridium as well as an absence of enterobacteria after the silo opening. Fungi developed only in Tifton 85 bermudagrass and its treatments before the ensilage and yeasts developed in silages of Tifton 85 bermudagrass when they received soybean hulls or corn grits after silo opening. There was no breach regarding aerobic stability of silages during the studied period. The pH reached the highest values within 48 hours after opening the silos, but there were variations during this period.

Muitos indicadores podem ser utilizados em ensaios de digestibilidade para suínos, mas precisam ser avaliados antes de serem utilizados. O experimento foi realizado com o objetivo de determinar os coeficientes de digestibilidade ileal aparentes (CDIA) e estandardizados (CDIE) dos aminoácidos da farinha de carne e ossos, para suínos, utilizando diferentes indicadores. Oito suínos, machos castrados, foram submetidos à cirurgia para aimplantação de cânulas T simples, no íleo distal. Quatro animais receberam uma dieta isenta de proteína e outros quatro uma dieta contendo farinha de carne e ossos como única fonte protéica na dieta. Os tratamentos consistiram em avaliar o óxido crómico, cinza insolúvel em ácido naturalmente contido na dieta, celulose e lignina como indicadores para determinar os CDIA e CDIE dos aminoácidos da farinha de carne e ossos. Os dados foram submetidos a análise de variância e as médias foram comparadas pelo teste de Tukey, ao nível de 5% de significância. Os CDIA, obtidos usando o óxido crômico como indicador externo, foram menores (P<0,05) em relação aos obtidos utilizando cinza insolúvel em ácido, lignina e celulose como indicadores, observando-se diferenças para todos os aminoácidos avaliados. O CDIE de todos os aminoácidos estudados foram menores (P<0,05) quando o óxido crômico foi utilizado para a determinação do fator de indigestibilidade. Conclui-se que o óxido de cromo utilizado como indicador externo, para determinar os coeficientes de digestibilidade ileal aparente e standarizado dos aminoácidos da farinha de carne e ossos, é mais apropriado do que a lignina, celulose e a cinza insolúvel em ácido naturalmente encontrada na dieta.

Many markers can be used in digestibility assays for swine, but needs to be evaluated before its use. An assay was carried out with the objective of measuring the coefficients of ileal apparent (CIAD) and standardized digestibility (CISD) of amino acids in meat and bone meal for swine using different markers. Eight crossbred barrows were equipped with T-cannulas in the distal ileum. Four animals received a free protein diet and another four received a diet containing meat and bone meal as the only protein source in the diet. The treatments consisted in evaluating the chromic oxide, acid-insoluble ash naturally occurring in the diet, cellulose and lignin as markers to determine the apparent and standardized digestibility of the amino acids contained in the meat and bone meal. All data were submitted to analysis of variance and means were compared using the Tukey test, with a significance of 5%. The CIAD, obtained using chromic oxide as external marker, were lower (P<0.05) than those obtained when acid insoluble ash, lignin and cellulose were used as markers, observing differences for all the amino acids evaluated. Similarly, the CISD from all the studied amino acids were lower (P<0.05) when the chromic oxide was used for determining the indigestibility factor. It is concluded that chromic oxide used as a external marker, to determine the coefficients of apparent and standardized ileal digestibility of the amino acids of the meat and bone meal, is most appropriate than the acid insoluble ash naturally occurring in diets, lignin and cellulose.

O conceito de proteína ideal, para suínos, tem permitido reduzir os níveis de proteína bruta da dieta, desde que haja a inclusão de aminoácidos sintéticos, pois os aminoácidos de cadeia ramificada podem ser limitantes. Com o objetivo de determinar a exigência de isoleucina digestível para fêmeas suínas dos 15 aos 30 kg, foi realizado um ensaio de desempenho, utilizando-se 40 fêmeas suínas, mestiças de alto potencial genético, com peso vivo inicial de 15,00 ± 0,52kg, distribuídas em um delineamento experimental de blocos ao acaso, constituído de cinco tratamentos (0,45; 0,52; 0,59; 0,66; 0,73% de isoleucina digestível), quatro repetições e dois animais por unidade experimental. Foram determinadas características de desempenho e, ao final do experimento, um animal de cada unidade experimental foi abatido, para a determinação da composição de carcaça e peso de órgãos. Níveis de 0,45 a 0,73% de isoleucina digestível não influenciaram as características de carcaça e peso de órgãos dos animais. Houve efeito quadrático (P<0,05) dos níveis de isoleucina digestível sobre a eficiência de utilização de isoleucina para ganho de peso, com aumento até o nível 0,506%; cuja relação isoleucina:lisina digestível foi de 0,51.

The ideal protein concept for pigs has allowed reducing levels of crude protein in the diet, since synthetic amino acids are included because the branched chain amino acids may be limiting. In order to determine the digestible isoleucine requirement for gilts from 15 to 30 kg, a performance assay was accomplished, using 40 crossbreed gilts of high genetic potential, averaging 15.00 ± 0.52 kg of body weight, alloted in a randomized blocks design, consisting of five treatments (0.45, 0.52, 0.59, 0.66, 0.73% of digestible isoleucine), four replicates and two animals per experimental unit. Performance traits were determined and at the end of the experiment one animal per experimental unit was slaughtered to determine carcass composition and organs weight. Levels from 0.45 to 0.73% of digestible isoleucine did not affect the carcass traits and organs weight of gilts from 15 to 30 kg. A quadratic effect (P<0.05) of digestible isoleucine levels on isoleucine efficiency for weight gain was observed, that increased up to 0.506% digestible isoleucine, which ratio of digestible isoleucine: lysine was 0.51.

This research study was conducted to evaluate, by means of microbiological analyses, the preservation of wet brewery waste stored under aerobic and anaerobic conditions, regarding the development of filamentous fungi, yeasts and lactic-acid bacteria. The following treatments were used: untreated brewery waste, pre-dried brewery waste silage, brewery waste silage with effluent drainage and BW silage without effluent drainage. Silos made of PVC and equipped with Bunsen valves to allow gases to escape were used. Dry matter (DM), crude protein (CP), temperature (°C) and pH in the untreated BW, in the stored brewery waste and in the brewery waste silage upon silo opening, after 60 days of ensilage were analyzed. A completely randomized design was used. The data were subjected to analysis of variance, and the means were compared by the Tukey test at the 5% probability level. The preservation of brewery waste packaged under aerobic conditions was not appropriate due to the development of filamentous fungi and yeasts; however, storage under anaerobic conditions proved to be an effective conservation process.

O uso de probiótico na alimentação animal tem sido indicado, por reduzir a mortalidade resultante da colonização intestinal por micro-organismos patógenos, melhorar o desempenho e as características de produção sem deixar resíduos na carne. O experimento teve como objetivo isolar, a partir de amostras de fezes de suínos na fase de aleitamento, cepas de lactobacilos visando sua identificação como probióticos. Foram isoladas 92 colônias, posteriormente submetidas à prova de catalase e 60 tiveram resultados negativos. Estas colônias negativas foram submetidas à coloração de Gram foi avaliada sua morfologia. Destas, 16 apresentaram formas de bacilos. Esses isolados foram comparados pela sua habilidade de resistência em pH 3,0, crescimento na presença de sais biliares, fenol, lisozima, e sua capacidade de hidrofobicidade e antagônica. Os isolados L03, L04, L08 e L15, identificados neste trabalho apresentam melhores características para uso como probiótico, em função de demonstrar melhor comportamento sobre as condições ácidas, crescendo na presença de sais biliares e fenol, apresentando alta percentagem de hidrofobicidade quanto à presença de Escherichia coli.

The use of probiotic in animal nutrition has been identified as reducing mortality resulting from intestinal colonization by pathogenic micro-organisms, improving productive performance and characteristics, leaving no residue in meat. The experiment aimed to isolate lactobacilli from fecal samples of suckling swine, in order to be identified as probiotics. Ninety-two colonies were isolated; these pre-selected colonies were subjected to catalase analysis, for which 60 were negative. The 60 colonies were subjected to Gram-negative stain and evaluated for their morphology. Of these, 16 had forms of bacilli. These isolates were compared for their ability to resist pH 3.0, grow in the presence of bile salts, phenol, lysozyme, as well as their hydrophobicity and antagonistic abilities. Isolates L03, L04, L08 and L15 identified in this study showed better probiotic use, better performance under acidic conditions, growing in the presence of bile salts and phenol, with high percentage of hydrophobicity and in the presence of inhibiting Escherichia coli.

Neste Trabalho, objetivou-se avaliar o efeito da suplementação de dietas contendo probiótico e simbiótico sobre o desempenho de leitões dos 21 aos 49 dias, microbiota intestinal e peso dos órgãos. Foram utilizados 120 leitões mestiços desmamados aos 21 dias de idade, distribuídos em um delineamento de blocos casualizados, com três tratamentos (antibiótico, probiótico e simbiótico) e cinco repetições, sendo a unidade experimental representada pela baia, onde foram alojados oito leitões. No período de 21 a 35 dias de idade, não se observou diferença (P>0,05) no desempenho. No período de 36 até os 49 dias, pode-se observar maior ganho diário de peso (P<0,01) para o tratamento contendo antibiótico. Foi observada uma maior contagem de bactérias lácticas (P<0,05) no conteúdo do cólon, aos 35 dias de idade para o tratamento contendo probiótico. Os pesos relativos dos órgãos não foram influenciados (P>0,05) pelos tratamentos. O uso de probiótico e simbiótico nas rações foi efetivo para leitões dos 21 aos 35 dias de idade para as variáveis de desempenho e contagem de coliformes no íleo e cólon, e dos 36 aos 49 dias de idade o uso de antibiótico foi melhor em relação as variáveis de desempenho.

The objective of this study was to evaluate the effect of diets containing probiotic and simbiotic on the performance of piglets from 21 to 49 days, intestinal microorganisms and weight of organs. In this study there were used 120 crossbred piglets, weaned at 21 days of age, alloted in randomized blocks design, with three treatments (antibiotic, probiotic and simbiotic) and five replicates, being the experimental unit represented by the pen, where eight piglets were hosted. In the period from 21 to 35 days of age no difference was observed (P>0.05) for the performance results. In the period from 36 to 49 days could be observed a higher daily weight gain (P<0.01) for the antibiotic treatment. A higher count of lactic bacteria was observed (P<0.05) in the colon content, in piglets with 35 days of age, for the probiotic treatment. The relative organs weight was not influenced (P>0.05) by the treatments. The use of probiotic and simbiotic in the diets was effective for piglets from 21 to 35 days of age for performance and coliform count in the ileum and large gut, and from 36 to 49 days of age the use of antibiotic in the diet was better for the performance parameters.

Conduziu-se este trabalho, com os objetivos de avaliar a composição química e os valores energéticos de diferentes silagens de grãos úmidos de milho (SGUM) para suínos, e ajustar equações de predição para a energia digestível (ED) e metabolizável (EM) com base na composição química. Os tratamentos consistiram de oito diferentes silagens de grãos úmidos de milho, que substituíram em 30,0% a ração referência. Foram realizadas as análises de MS, PB, EE, FB, FDA, FDN, Ca e P das silagens em estudo. Na determinação dos valores energéticos, foram utilizados 36 suínos, distribuídos em delineamento experimental de blocos ao acaso com quatro repetições. Os valores de ED e EM das silagens de grão úmido de milho variaram de 3494 a 3701 kcal/kg MS e 3392 a 3613 kcal/kg MS, respectivamente. Não se obteve um bom ajustamento das equações para predizer os valores de ED e EM da SGUM, apresentando baixos coeficientes de determinação, sendo que o extrato etéreo apresentou uma correlação positiva e a fibra bruta uma correlação negativa para os valores energéticos estudados.

The objectives of this study were to evaluate the chemical composition and energetic values of diferent high moisture corn grain silages (HMCGS) for swine, and to adjust prediction equations for digestible (DE) and metabolizable (ME) energy based on the chemical composition. The treatments consisted of eight diferent high moisture corn grain silages that substitued 30.0% of the basal diet. The analysis of DM, CP, EE, ADF, NDF, Ca and P were performed for the refered silages. To determine the energetic values 36 swines were used, alloted in a randomized blocks design with four replicates. The values of DE and ME of the HMCGS varied from 3494 to 3701 kcal/kg of DM and from 3392 to 3613 kcal/kg of DM, respectively. The equations adjusted to predict the DE and ME values of the HMCGS did not show a good adjustment, showing low determination coefficients, and the fat content showed a positive relation and the CF a negative one, for the energetic values studied.

Foi realizado um trabalho com o objetivo de avaliar a granulometria do milho, a taxa de moagem, o consumo de energia elétrica de diferentes moinhos de martelos e determinar as características dos moinhos que influenciam o diâmetro geométrico médio das partículas. Para determinar os preditores da granulometria, as características dos moinhos foram consideradas as variáveis independentes utilizando o procedimento estatístico "Backward" para obtenção das equações. A equação para estimar o diâmetro geométrico médio das partículas que proporcionou um maior R² (0,85) foi a seguinte: 330,59 + 494,284TX - 11,844PM + 113,746DP - 0,186ATP. A variação da taxa de moagem e consumo de energia elétrica, de moinhos de martelos, pode ser devido às diferenças entre as características dos moinhos, do desgaste devido ao uso e da potência dos motores que equipam os moinhos. Concluiu-se que a taxa de moagem e o diâmetro dos furos das peneiras apresentaram uma correlação positiva com o diâmetro geométrico médio, e a potência do motor e a área total da peneira, uma correlação negativa.

A study was carried out to evaluate the particle size of the corn, the performance and electric power consumption of hammermills and to determine the hammermills characteristics that influence the average geometric diameter of the particles. To determine the corn particle size predictors and the hammermills characteristics, the independent parameters were considered using the "Backward" statistical process to obtain the equations. The equation to estimate the average geometric diameter that showed the higher R² (0.85) was: 330.59 + 494.284TX - 11.844PM + 113.746DP - 0.186ATP. The grinding rate variation and the electric power consumption, of the hammermills, can be due to the differences among the characteristics of the mills, the wasting due to the use and of the potency of the motors of the mills. It was ended that the grinding rate and the diameter of the hole sieves’ showed a positive relationship with the average geometric diameter, and the engine power and the total sives’ area showed a negative relationship.