The low productivity and unpredictable nature of resources in tropical waters would appear to make resource partitioning among predators difficult. Yet, stable isotope data from the present study suggest that substantial resource partitioning occurs among tropical seabird communities, both between and within species. In the present study, we compared δ13C and δ15N levels among 8 sympatric tropi...

The objectives of this study were 1) to investigate the effect of changes in carcass market prices due to bovine spongiform encephalopathy (BSE) occurrences on estimates of genetic parameters and economic weights for carcass traits; and 2) to compare direct and indirect approaches for prediction of genetic merit of Japanese Black cattle for profitability of their progeny. The direct approach ut...

this study was carried out by using two hundred ewes (2-4 years old) as  pure breeding (zel × zel) and crossbreeding (chal × zel). in each treatment, 30 male and 30 female lambs were fattened in a feedlot experiment for three periods; 75, 100 and 125 days. at the end of each period, 10 lambs of each treatment were slaughter and carcasses analysis was down. the lean meat percentage and bone perc...

We conducted a study of the breeding biology of the Thorn-tailed Rayadito (Aphrastura spinicauda) in secondary forests on the continental island of Chiloé (428 S), southern Chile. Rayaditos are small insectivorous furnariids inhabiting the south-temperate forests of Chile and Argentina. We followed the reproduction of rayadito pairs breeding in nest-boxes. Rayaditos build their nests mainly of ...

The wild ground squirrel is a typical seasonal breeder. In this study, using RT-PCR, western blot and immunohistochemistry, we investigated the mRNA and protein expressions of androgen receptor (AR), estrogen receptors α and β (ERα and ERβ) and aromatase cytochrome P450 (P450arom) in the medial preoptic area (MPOA) of hypothalamus of the wild male ground squirrel during the breeding season (Apr...

For many crops, the benefits of traditional breeding practices are difficult to achieve because the crops have long juvenile periods that necessitate long breeding cycles, desired genotypes for a cross do not have synchronized flowering because of photoperiod or vernalization requirements, or preferred lines are propagated asexually and have limited flowering potential. In light of these limita...

For many crops, the benefits of traditional breeding practices are difficult to achieve because the crops have long juvenile periods that necessitate long breeding cycles, desired genotypes for a cross do not have synchronized flowering because of photoperiod or vernalization requirements, or preferred lines are propagated asexually and have limited flowering potential. In light of these limita...

This experiment was conducted to evaluate the effects of different levels of nettle (Urtica dioica) a medicinal plant in starter and grower feeds on performance, carcass traits, blood biochemical and immunity parameters of broilers. A completely randomized design was used with 324 broilers (Ross-308) divided in nine treatments and three replicates (with 12 birds in each replicate) 1 to 42 days....