ABSTRACT This study aimed at assessing the effect of pelleted and expanded maize-based feeds prepared with different moisture levels (ML, 0.8 and 1.6%) particle size (PS, 650 and 850µ) of ingredients on metabolizable energy, ileal digestibility of amino acids and broiler performance. A total of 720 one-day-old male broiler chicks of the Cobb strain were used. The experiment was performed over a period of 40d (days) and birds received water and feed ad libitum. From 10 to 13d higher AMEn values were obtained for birds fed expanded feeds with 1.6% ML and 850µ PS. Higher values AMEn were encountered when adding 0.8% ML in pellet feeds with 850µ or 1.6%ML/650µ PS. Expanded and pelleted diets with 1.6% ML (independent of PS, 650 or 850µ) presented higher amino acid digestibility. For diets with 0.8% of ML, better result for the digestibility of amino acids were obtained with PS 650µ for expanded and 850µ for pelleted diets. Higher weight gain was observed in broilers fed diets with 1.6% moisture at 21 and 40d. Feed conversion was improved by adding 1.6% ML only at 21d. Regarding carcass characteristics, expanded diets combined with PS of 650µ led to a higher accumulation of abdominal fat. The birds fed expanded diets at 1.6% moisture had higher breast yields. We concluded that to increase the use of nutrients, EMAn and broiler performance, it is recommended that pelleted diets be prepared with the addition of 1.6% water to the mixer and a particle size of 850µ.

ABSTRACT Two trials were performed to determine apparent metabolizable energy (AME) and AME corrected for zero nitrogen balance (AMEn) values and coefficients of apparent metabolizability of nitrogen (CAMN) and of ether extract (CAMEE) of slow- and fast-growing broilers (Isa label and Cobb, respectively) fed four different diets between 10 to 17 days or 28 to 35 days of age. The method of total excreta collection was applied. The tested feedstuffs were corn, whole corn germ (WCG), sorghum, and soybean meal (SBM). A randomized block experimental design was applied, with two treatments (breeds) and four replicates of ten animals each in the first trial, and four replicates of six animals each in the second trial. No differences in CAMN values were observed between the breeds; however, Isa Label birds presented higher CAMEE for all tested feedstuffs. The AME and AMEn values obtained in Isa Label chickens fed the corn diet were 5.75 and 3.44% higher relative tothe Cobb birds, respectively. Breed did not influence AME and AMEn values of the other tested feedstuffs. Independently of breed, age influenced the AME and AMEn values of WCG, sorghum and SBM, suggesting that birds become utilize feed more efficiently as they age.

The present study was carried out to evaluate the effects of alternative feedstuffs as partial substitutes of corn and soybean in free-range broiler diets on performance, carcass yield and technical-economic viability. A total of 400 Pescoço Pelado broilers were distributed in a completely randomized experimental design (CRD), with four treatments (treatment 1:Control; treatment 2: 10% rice bran inclusion; treatment 3: 10% ground cassava leaves; and treatment 4: 10% ground lead tree hay) with four replicates per treatment. Each replicate consisted of a group of 25 birds per paddock, separated per sex. Initial weight (IW), final weight (FW), body weight (BW), daily weight gain (DWG), feed intake (FI) and feed conversion ratio (FCR) were evaluated. Carcass, cuts (breast, thigh, drumstick, back, neck, leg and wings), abdominal fat and giblets (gizzard, heart and liver) yields were determined. The technical-economic viability of each treatment was assessed by determining the cost of feed per kg body weight, economic efficiency index and cost. The highest final weights were obtained with the use of rice bran. Rice bran and cassava leaves promoted higher carcass yield, as well as lower back and abdominal fat yields. The use of cassava leaves showed better economic efficiency among the treatments with alternative feedstuffs. The use of alternative feedstuffs at 10% inclusion in substitution of corn and soybean meal did not not result in major changes in performance and carcass parameters, and economic efficiency, and therefore, their use is recommended when the availability or the price of key ingredients, such as soybean meal and corn, increase.

O complexo Thamnophilus punctatus foi recentemente revisado, com base em caracteres morfológicos e vocais, sendo dividido em seis diferentes espécies. Duas dessas novas espécies, embora bem definidas com base em distinções morfológicas, não puderam ser definitivamente diferenciadas por seus cantos. Thamnophilus pelzelni (choca-do-planalto) e T. ambiguus (choca-de-sooretama) são mais facilmente diferenciadas por sutis e localizadas mudanças de coloração da plumagem de machos e fêmeas. Neste estudo, foram utilizadas seqüências de DNA mitocondrial (região controle, Citocromo b e ND2) a fim de avaliar os níveis de diferenciação molecular entre estas duas espécies. A divergência genética média entre as duas espécies foi de 3,8%, enquanto para cada região mitocondrial esta variou entre 2,7% e 4,9%. Embora tenha sido observada grande variabilidade entre haplótipos dentro das espécies, especialmente para T. ambiguus, os resultados sugerem que a divergência genética observada entre T. ambiguus e T. pelzelni é suficientemente elevada para corroborar o status de espécies separadas destes dois Thamnophilidae.

The Thamnophilus punctatus complex has been recently reviewed on the basis of morphological and vocal characters, and is divided in six different species. Two of the new species, although well defined on the basis of morphological differences, could not be unambiguously distinguished through their loudsongs. The Planalto Slaty-antshrike (Thamnophilus pelzelni) and the Sooretama Slaty-antshrike (T. ambiguus) are most easily distinguished by subtle and localized changes in plumage colors of males and females. In the present study we used sequences of the control region, Cytochrome b, and ND2 genes, of the mitochondrial DNA (mtDNA) to evaluate the levels of molecular differentiation between these two species. The mean pairwise distance between the two species was 3.8%, while it varied from 2.7% to 4.9% for each mtDNA region. Although extensive variation was also detected among haplotypes within species, especially for T. ambiguus, we suggest that the genetic divergence found between T. ambiguus and T. pelzelni is high enough to corroborate the separate species status of these two antbird taxa.

A fragmentação florestal afeta populações de aves de muitas maneiras, modificando a composição das comunidades e favorecendo espécies de áreas abertas. A Mata Atlântica é considerada um dos biomas mais importantes do mundo, devido à sua grande biodiversidade, aos altos níveis endemismo e de desmatamento. Apesar destas características, poucos estudos avaliaram os efeitos da fragmentação florestal na estrutura genética de populações de aves desse ecossistema. Dessa forma, este estudo visa verificar os efeitos da fragmentação florestal na variabilidade genética de Conopophaga lineata, através de marcadores RAPD. Assim, foram capturados 89 indivíduos de C. lineata em nove fragmentos florestais da Mata Atlântica do Estado de Minas Gerais. Os dados de RAPD indicam que a fragmentação florestal não afetou a variabilidade genética de Conopophaga lineata (Mann-Whitney U = 3,50; p = 0,11). Grande parte da variabilidade dessa espécie se encontra dentro das populações e não foi observada correlação entre a distância geográfica e a distância genética (Teste de Mantel t = 0,6250; p = 0.73). A análise UPGMA não mostrou clados definidos e todos os ramos apresentaram baixo suporte estatístico. A reduzida diferenciação populacional observada nessa espécie pode ser devida a intenso fluxo gênico entre as populações ou à recente fragmentação na região. Assim, a situação atual das populações de C. lineata indica que essa espécie não é significativamente afetada pela fragmentação. Entretanto, futuros estudos genéticos são essenciais para melhorar as estratégias de conservação da avifauna da Mata Atlântica do Brasil.

Forest fragmentation affects bird populations in many ways, modifying the composition of communities and favouring open country species. The Atlantic Forest is considered one of the most important biomes in the world, due to its great biodiversity, accelerated rates of deforestation, and high endemism. Despite these characteristics, few studies have evaluated the effects of forest fragmentation in the genetic structure of Atlantic forest bird populations. So, this study aims to verify the effects of forest fragmentation in the genetic population structure of Conopophaga lineata, through RAPD markers. To achieve this goal, 89 C. lineata individuals were captured in nine Atlantic Forest fragments in Minas Gerais State. The RAPD data indicate that forest fragmentation has not affected the genetic variation of C. lineata populations (Mann-Whitney U = 3.50; p = 0.11). Great part of the genetic variability of this species is found within populations and it was not observed a correlation between genetic and geographic distance (Mantel test t = 0.6250; p = 073). UPGMA analyses did not show defined clades and all branches showed low statistical support. The low population differentiation observed in this species can be due to a high gene flow among populations or a recent fragmentation. Thus, the current diversity status of C. lineata populations indicates that this species is not significantly affected by fragmentation. However, more genetic studies are essential to improve conservation strategies of Brazilian Atlantic Forest birds.

A ariranha (Pteronura brasiliensis) é um mamífero aquático da família Mustelidae, endêmico da América do Sul. Sua distribuição original se estendia desde as Guianas até o centro-norte da Argentina, mas está extinta ou à beira da extinção na maior parte de sua distribuição histórica. Atualmente a espécie é considerada como ameaçada de extinção pela World Conservation Union (IUCN). Em função de sua distribuição no continente sul-americano e de algumas características morfológicas, duas subespécies foram sugeridas: P. brasiliensis brasiliensis, com ocorrência nas bacias do Amazonas e Orinoco, e P. brasiliensis paranensis, ocorrendo nas bacias dos Rios Paraná e Paraguai. Inexiste, contudo, um consenso sobre a validade da divisão em subespécies e nenhum estudo detalhado foi realizado para elucidar esta questão. Este trabalho tem o objetivo de avaliar a diversidade genética e a estrutura populacional de P. brasiliensis ao longo de sua distribuição no Brasil para verificar a existência de duas subespécies baseando-se também em um critério de monofilia recíproca. A região controle e os genes do Citocromo b e da Subunidade I da Citocromo c Oxidase do DNA mitocondrial foram analisados em diversas populações de ariranha que ocorrem nas bacias dos rios Amazonas e Paraguai. As análises indicaram um grau moderado de correlação geográfica e um alto nível de divergência inter-populacional, embora a divisão em subespécies não seja bem sustentada. Como uma forte estruturação populacional foi observada, não é possível descartar a existência de outras subdivisões nesta espécie. Os resultados indicam a presença de uma estrutura populacional mais complexa em P. brasiliensis, o que implica que medidas de conservação deveriam concentrar seus esforços preservando todas as populações locais remanescentes.

The giant otter (Pteronura brasiliensis) is an aquatic mammal of the Mustelidae family, endemic to South America. Its original distribution corresponds to the region from the Guyanas to Central-North Argentina, but it is extinct or on the verge of extinction in most of its historical range. Currently, the species is considered endangered by the World Conservation Union (IUCN). Based on its geographic distribution in the South American continent and on some morphological characters, two subspecies were suggested: P. brasiliensis brasiliensis, occurring in the Amazon and Orinoco River Basins, and P. brasiliensis paranensis, in the Paraná and Paraguai River Basins. However, there is no consensus on assuming this subspecies division and no detailed studies have been carried out to elucidate this question. This study aims to evaluate the genetic diversity and population structure of Pteronura brasiliensis along its range in Brazil to check the possibility of the existence of two distinct subspecies using also a reciprocal monophyly criterion. We analyzed the control region, and the Cytochrome b and Cytochrome c Oxidase subunit I genes of the mitochondrial DNA in several giant otter populations from the Amazon and Paraguai River Basins. Analyses have indicated some degree of geographic correlation and a high level of inter-population divergence, although the subspecies division is not highly supported. As we observed strong population structure, we cannot rule out the existence of further divisions shaping the species distribution. The results suggest that a more complex population structure occurs in P. brasiliensis, and the conservation practice should concentrate on preserving all remaining local populations.