Species' life history traits, including maturation age, number of reproductive bouts, offspring size and number, reflect adaptations to diverse biotic and abiotic selection pressures. A striking example of divergent life histories is the evolution of either iteroparity (breeding multiple times) or semelparity (breed once and die). We analysed published data on salmonid fishes and found that sem...

the purpose of the present study was to evaluate the impact of vitamin e and selenium (se) supplementation on the performance, egg quality and hatchability of eggs from japanese breeding quails. the experiment was conducted over a 60 day period using 135 quails in a completely randomized design (crd) with two levels of vitamin e and two levels of selenium (80 mg/kg of vitamin e+0.2 mg/kg organi...

AIM The present study was conducted to evaluate the performance of gray, brown, and white varieties of Japanese quail (Coturnix coturnix japonica) with respect to body weight, egg production, and egg quality traits in the coastal climatic condition of Odisha. MATERIALS AND METHODS A total of 500-day-old straight run Japanese quail chicks of three varieties, viz., gray, brown, and white were r...

The evolution of elaborate forms of parental care is an important topic in behavioral ecology, yet the factors shaping the evolution of complex suites of parental and offspring traits are poorly understood. Here, we use a multivariate quantitative genetic approach to study phenotypic and genetic correlations between parental and offspring traits in the burying beetle Nicrophorus vespilloides. T...

Understanding the genetic basis of phenotypic variation is essential for predicting the direction and rate of phenotypic evolution. We estimated heritabilities and genetic correlations of morphological (fork length, pectoral and pelvic fin ray counts, and gill arch raker counts) and life-history (egg number and individual egg weight) traits of pink salmon (Oncorhynchus gorbuscha) from Likes Cre...

Little is known about how inbreeding alters selection on ecologically relevant traits. Inbreeding could affect selection by changing the distribution of traits and/or fitness, or by changing the causal effect of traits on fitness. Here, I test whether selection on egg size varies with the degree of inbreeding in the seed-feeding beetle, Stator limbatus. There was strong directional selection fa...

this experiment was conducted to evaluate the effects of different levels of costmary(tanacetum balsamita)medicinal plant on performance, egg traits, and blood biochemical parameters of laying hens. hundred-eighty of hi-line laying hens (w 36) from 46 until 58 weeks of age were used in a completely randomized design in five treatments and three replicates (12 birds per replicate). the treatment...