The aim of this study was to evaluate the physiological, zootechnical, and environmental benefits of the use of growth-promoting virginiamycin in the pirarucu diet. The research was conducted at the Carlos Eduardo Matiazze Fish Center, Federal University of Rondônia. In this study, 96 pirarucu fish were distributed in excavated nursery, divided into two treatment groups, control (0.0 mg kg−1) and treatment (75.0 mg kg−1) of feed with virginiamycin, with 8 replications in a completely randomized design. With virginiamycin being incorporated into commercial feed, for 107 days of cultivation, the fish were slaughtered with an average weight of 9.18 kg. Carcass weight, flesh, residues, and internal organs/guts were evaluated to calculate slaughter yields, Spearman’s correlation, and subsequently regression. For the quantification of micronuclei, a count of 1,000 cells per blade was determined. The means of the results obtained were contrasted by the Student’s t-test (α = 0.05). Virginiamycin did not cause oscillations in the limnological variables of the nursery but could reduce micronucleated erythrocytes. The average yields in carcass, flesh, and waste were 67.43, 53.4, and 43.14%, respectively. Virginiamycin provided strong correlations (ρ2) for better productive yields and lower slaughter residue. The hepatosomatic index indicated a strong relationship between liver weight and fat. Virginiamycin may be recommended for fish farming in pirarucu fattening because it contributes to the productive efficiency and sustainability of the fish farm system.

The aimed of the study was to evaluate the caloric value as a function of the proximal composition and correlate the selling price with the nutritional values ​​of commercial cuts of tambaqui (Colossoma macropomum) and pirarucu (Arapaima gigas) in different weight classes. The sample collections were performed in two processing units located in the state of Rondônia, Brazil. Were 200 tambaquis in five weight classes were studied. And, were 77 pirarucus were studied in seven weight classes. The design was completely randomized, with processing carried out in triplicate. The Kruskal-Wallis test (α=0.05) was used to compare the averages and the Spearman correlation (ρ) between price and nutrients. The commercial cuts with the highest caloric value were the tambaqui filet (145.70 kcal/100g) and the pirarucu filet mignon (119.11 kcal/100g) (p<0.05). And the less caloric commercial cuts were steak of tambaqui (100.47 kcal/100g) and pirarucu loin 102.01 kcal/100g) (p<0.05). It was also observed that the variables caloric value and protein content did not correlate with the price of the kilo of fish for the different commercial cuts, which leads to infer that, possibly, the sensorial, market and cultural factors were responsible for the price variations. Regarding the caloric value according to the composition of the tambaqui, the Class 4 was the most efficient category for production and commercialization. And in the composition of the pirarucu, the Class 4 presented satisfactory values of proteins and lipids and a good percentage of mineral matter.

The aimed of this study was to evaluate the mineral composition in commercial cuts of tambaqui (Colossoma macropomum) and pirarucu (Arapaima gigas). Were compared to the minimum values of daily consumption of minerals recommended by the World Health Organization (WHO). The experimental design was completely randomized, with processing performed in triplicate. Data were submitted to ANOVA. If ANOVA appeared statistically significant (α=0.05), the means were compared by Tukey’s Test. There was a difference (p<0.05) between commercial cuts of the tambaqui for different minerals. Tambaqui ribs and band presented the highest values of total iron 1.08 ± 0.12 mg/100g compared to other commercial cuts. The mineral elements Na+, K+, Ca2+ and Mg2+ expressed the highest values for the tambaqui steak, 301.00 ± 80.58, 457.00 ± 129.33, 36.00 ± 4.36 and 46.90 ± 4.68 mg/100g, respectively. There was a difference (p<0.05) between commercial cuts of the pirarucu for different minerals. The mineral elements Total Iron, Na+, K+ and Ca2+ expressed the highest values for pirarucu loin, 0.80 ± 0.07, 406.00 ± 117.50, 529.30 ± 130.58 and 32.00 ± 5.12 mg/100g, respectively. However, Mg2+ expressed a higher value for pirarucu tail fillet 37.10 ± 4.99 mg/100g. The tambaqui steak and pirarucu loin were the cuts that best met the minimum needs for mineral supply.

O estudo avaliou os custos e benefícios do programa de inseminação artificial (IA) na Região Central de Rondônia e sua evolução no período de 2011 até 2016.  Dados foram fornecidos pela Entidade Autárquica de Assistência Técnica e Extensão rural do Estado de Rondônia (EMATER-RO) - Regional de Ji-Paraná-RO. Os dados foram registrados durante o Programa de Melhoramento Genético em Bovinos de Leite, por meio do Projeto Inseminar em 13 municípios, nos quais foram incluídas, 278 propriedades rurais de produção de leite. As variáveis utilizadas para mensuração da eficiência do programa foram: quantidade média de nitrogênio (N) líquido consumido, número de associações beneficiadas e número de produtores por município; número médio de vacas inseminadas e porcentagem de bezerros nascidos; porcentagem de bezerros machos e fêmeas; despesas e rentabilidade.  O programa de IA durante o período de 2011 a 2016 apresentou lucratividade de R$ 195.639,17; chegando a valor médio de R$ 1.774.500,00; alcançados nas vendas de bezerros, com índice de 11 % em despesas e uma rentabilidade média de 89 %. Os valores obtidos nas vendas de bezerras reduziram no decorrer do período analisado, enquanto os custos se mantiveram estáveis. Estratégias para o manejo reprodutivo eficiente e conscientização das associações e produtores são necessárias na região para obtenção de melhores resultados.

O objetivo do trabalho foi avaliar a melhor frequência alimentar sobre a conversão alimentar aparente e o desempenho zootécnico de juvenis de tambaqui de cultivo. O estudo foi desenvolvido no Centro de Pesquisa em Piscicultura Carlos Eduardo Matiazze, Universidade Federal de Rondônia, Presidente Médici, Rondônia. Foram utilizados 225 juvenis de tambaqui, com peso inicial 595,46±19,71 g, distribuídos em 15 hapas em delineamento inteiramente casualizado. O estudo foi desenvolvido em cinco tratamentos de diferentes frequências de alimentação: fornecimento de ração uma vez ao dia (1XD), composto por três horários distintos, para comparar os três diferentes horários; fornecimento de ração duas vezes (2XD) e três vezes (3XD) ao dia. Foi fornecido ração extrusada contendo 28 % de proteína bruta a taxa alimentar de 1,8 e 1,4 %. As variáveis limnológicas mantiveram-se estáveis e dentro das médias recomendadas ao cultivo de tambaqui. Os valores de peso final e ganho de peso médio corporal, apresentaram médias de 1.043,08 e 450,59 g, respectivamente. Os tambaquis que receberam ração duas vezes ao dia, apresentam melhores resultados de conversão alimentar e de desempenho produtivo. Portanto, alimentar juvenis de tambaqui duas vezes ao dia, apesar de demandar menor mão de obra é o suficiente para manter a conversão alimentar aparente e o desempenho zootécnico adequados.