Introgressive crossbreeding between Red-Stirling and Chitralada tilapia was carried out to assess the association of STR loci polymorphisms located in the growth hormone (GH1) promoter and intron-I with growth performance. The growth of seven genetic groups was assessed using a mixed linear model. We considered sex, age, and initial weight class of each animal as fixed effects, while genetic group, STR-promoter, and STR-intron were considered as random effects. We found six alleles in the STR-promoter, which were arranged in 18 of the 21 genotypic possible combinations. Alleles 191 and 196 of the STR-promoter correspond to 80% of the assessed individuals’ total alleles, and genotypes 196/196, 191/196, and 196/201 were the most frequent. We found only three alleles in the STR-intron. The loci STR-promoter showed a significant association with the animals’ weight. Genotypes 181/181, 181/191, and 196/206 showed better average performance, and genotypes 196/201, 201/201, and 191/196 showed the worst performance. The polymorphism in the STR-intron was not associated with fish weight. The proposed approach is unprecedented for STR found in the GH1 gene. The observed association indicates that GH1 gene polymorphism could be used as a tool in tilapia breeding programs.
Objetivou-se avaliar a influência dos diferentes intervalos de coleta total de excretas sobre a digestibilidade e o valor energético de rações para frangos de corte. O ensaio metabólico foi conduzido no Setor de Avicultura do Departamento de Zootecnia da Universidade Federal de Lavras, em Lavras, MG, utilizando 72 pintos dos 30 aos 37 dias de idade, machos, da linhagem Cobb-500, distribuídos aleatoriamente em gaiolas metabólicas em delineamento inteiramente casualizado em esquema fatorial 2x2 (dois alimentos – farelo de soja e farinha de carne e ossos – e duas metodologias de coleta – uma ou duas diárias) totalizando quatro tratamentos com quatro repetições de três aves cada. Os coeficientes de metabolizabilidade da matéria seca (CMMS), da proteína (CMPB) e da energia (CME) e os valores de energia metabolizável aparente (EMA) e aparente corrigida (EMAn) de cada alimento foram determinados utilizando a metodologia de substituição. As formas de coleta influenciaram o CMMS e os valores de EMA e EMAn apenas da farinha de carne e ossos. Conclui-se que a metodologia de coleta total de excretas em frangos de corte deve ser realizada em duas coletas diárias com a farinha de carne e ossos e, para o farelo de soja, apenas uma coleta diária é suficiente.
Article history Fish diseases represent a significant limiting factor in aquaculture systems. Among the many pathogens, bacteria are probably the most significant group of etiological agents. Thus, the objective of this work was to isolate and to report the incidence of streptococcosis and other possible pathogens in fish polyculture systems in the region of Lavras, state of Minas Gerais, Brazil. Fish samples were randomly collected from seven fish polyculture systems in the region, including the following municipalities:
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.