Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of the present study was to evaluate the effect of the use of different fat sources on feedlot steers finishing diets, on their performance, economic evaluation, carcass and meat characteristics. Twenty steers, with average initial age and weight of 20 months and 260 kg, were used. The offered roughage was corn silage and the tested concentrates were: TCB basic concentrate; TFAI basic concentrate + integral rice bran + rice oil; TM3 - basic concentrate + 3% of fatty acids calcium salts and TM6 basic concentrate + 6% of fatty acids calcium salts. The roughage:concentrate used relation was of 66:34. The dry matter, crude protein, digestible energy, neutral and acid detergent fibers intakes were similar between treatments, as well as average weight gain and final weight (P>.05). However, difference was observed for ether extract daily intake, being the higher value for the animals that consumed 6% of fatty acid calcium salts (.77 kg), intermediary value for the ones that consumed 3% of fatty acid calcium salts and the ones that consumed integral rice bran plus rice oil (.51 kg) and lower value for the ones that consumed basic concentrate (.25 kg). Concentrate and total diet costs, as well as the weight gain necessary to cover feed costs was higher for animals that consumed 6% of fatty acid calcium salts, however gross and net incomes were similar. The animals that consumed 6% of fatty acid calcium salts presented higher subcutaneous fat thickness (5.21 mm) and carcass total fat content (27.9%). Meat characteristics from steers that consumed integral rice bran and oil or fatty acid calcium salts were similar from the ones that didn t consume fat. / O objetivo do presente estudo foi avaliar o efeito do uso de diferentes fontes de gordura na dieta de novilhos confinados em terminação sobre o desempenho, apreciação econômica, características de carcaça e carne. Foram utilizados 20 novilhos, com idade e peso vivo médios iniciais de 20 meses e 260 kg. O volumoso oferecido foi a silagem de milho e os concentrados testadas foram: TCB concentrado base; TFAI concentrado base + farelo de arroz integral e óleo de arroz; TM3 concentrado base + 3% de sais de cálcio de ácidos graxos e TM6 concentrado base + 6% de sais de cálcio de ácidos graxos. A relação volumoso:concentrado utilizada foi de 66:34. Os consumos de matéria seca, proteína bruta, energia digestível, fibras em detergente neutro e ácido foram similares entre os tratamentos, bem como o ganho de peso médio diário e peso final (P>0,05). Entretanto, houve diferença no consumo de extrato etéreo diário, sendo maior para os animais que consumiram 6% de sais de ácidos graxos (0,77 kg), intermediário para aqueles que consumiram 3% de sais de ácidos graxos e para aqueles que consumiram farelo de arroz integral e óleo (0,51 kg) e inferior para os que consumiram concentrado base (0,25 kg). Os custos com concentrado e da dieta total, bem como o ganho de peso necessário para compensar os custos com a alimentação foram maiores para os animais que consumiram 6% de sais de cálcio de ácidos graxos, entretanto as receitas brutas e líquidas foram semelhantes. Os animais que consumiram 6% de sais de cálcio de ácidos graxos apresentaram maiores espessura de gordura subcutânea (5,21mm) e conteúdo total de gordura na carcaça (27,9%). As características das carnes dos novilhos que consumiram farelo de arroz integral e óleo de arroz ou sais de ácidos graxos foram semelhantes aos que não ingeriram gordura.

Objetivo: Este estudio tuvo como finalidad determinar la cantidad de arsénico total (Ast) presente en el arroz integral comercializado en los supermercados y mercados de Lima Metropolitana, enero-febrero, 2020. Metodología: Se recolectaron nueve muestras de granos de arroz integral que representaron a la totalidad de las marcas expendidas al momento de realizar el muestreo, 8 de ellas se encontraron embolsadas y 1 a granel. Se empleó la técnica de espectrometría de masas con plasma inductivamente acoplado (ICP-MS) para la determinación de metales pesados en alimentos. Resultados: Ninguna de las muestras analizadas sobrepasó el contenido de Ast pues presentaron un promedio de 0,147 mg/kg con una desviación estándar de 0,021. Discusión: Los resultados del estudio indican que en general, el valor de Ast en el arroz integral que se comercializa en Lima Metropolitana se encuentra por debajo de los niveles máximos establecidos por diferentes entidades nacionales e internacionales que vigilan la inocuidad de los alimentos. Sin embargo, debido al alto impacto que este contaminante puede tener en la salud de las personas, los profesionales de la nutrición deberían estar expectantes a que las autoridades competentes realicen un adecuado control y monitoreo de este cereal, y de esta manera tener mayor seguridad en la recomendación de su consumo, ya que este se ha incrementado en los últimos años por sus diversos beneficios en la salud. Conclusión: En las muestras de arroz integral la cantidad de Ast no superó los límites máximos recomendados para As en el arroz según el Codex Alimentarius, MERCOSUR/GMC Resolución Nº 12/11 y la NTP 205.011:2014. / Objective: This study aimed to determine the amount of total arsenic (Ast) in brown rice sold in the supermarkets and markets of Metropolitan Lima, January-February, 2020. Methodology: Nine samples of brown rice grains were collected, representing all the brands found at the time of sampling, 8 of them were packed and 1 in bulk. The inductively coupled plasma mass spectrometry (ICP-MS) technique was used for the determination of heavy metals in food. Results: None of the samples analyzed exceeded the Ast content as they presented an average of 0,15 mg/kg with a standard deviation of 0,021. Discussion: The results of the study indicate that, in general, the value of Ast in brown rice that is sold in Metropolitan Lima is below the maximum levels established by different national and international entities that monitor food safety. However, due to the high impact that this pollutant can have on people's health, nutrition professionals should expect for the competent authorities to carry out an adequate control and surveillance of this cereal, and thus have greater reassurance in the recommendation of its consumption, since it has increased in the past years for its various health benefits. Conclusion: In the brown rice samples the amount of Ast did not exceed the maximum recommended limits for As in rice according to the Codex Alimentarius, MERCOSUR/GMC Resolution Nº 12/11 and NTP 205.011: 2014. / Tesis