Iranian chicken genetic resources are characterized by a long history and a vast diversity. This study represents the first results from the selection and evaluation of five polymorphic microsatellite markers for the genetic assessment of five native chicken populations located in the northwestern (West Azerbaijan), northern (Mazandaran), central (Isfahan, Yazd), and southern (Fars) provinces of Iran. The number of alleles ranged from three to six per microsatellite locus. All populations were characterized by a high degree of genetic diversity, with the lowest heterozygosity found in the Isfahan population (62%) and the greatest in the populations from West Azerbaijan and Mazandaran (79%). The largest Nei's unbiased genetic distance was found between the Isfahan and Fars populations (0.696) and the smallest between the Mazandaran and Yazd populations (0.097). The Isfahan population was found to be the most genetically distant among all populations studied. These results serve as an initial step in the plan for genetic characterization and conservation of Iranian native chickens.

Using a deterministic model of profit equation compatible to cocoon production system in Iran, equations for estimating economic values of cocoon weight, shell weight, shell percentage, fecundity, fertility, and hatchability of three commercial varieties of silkworm Bombyx mori (L.) were derived. Economic values of these traits as well as their relative economic importance (REI) compared with cocoon weight were estimated. Estimates of economic value of a given trait differed among the varieties. Cocoon weight, shell weight, and shell percentage had the highest economic value in variety 107. The highest economic value for fecundity, fertility, and hatchability was estimated in variety 110. Shell weight and shell percentage were the most important production traits, and fecundity was the most important reproduction trait. The REI values of shell weight and shell percentage were higher than that of cocoon weight. The sensitivity of estimated economic values to principal factors of production system was studied by altering cocoon weight, shell percentage, fecundity, variable costs, and cocoon price by +/- 10%. The traits varied in the rate of sensitivity of their economic values to changes in production factors. Economic values of cocoon weight, fecundity, fertility, and hatchability had the most sensitivity to the changes in shell percentage. The most important factor affecting economic values of shell weight and shell percentage was the grade 1 cocoon price. Economic value equations provided in this study can help silkworm breeders to concentrate on the most important factors in predicting the future. Furthermore, when these factors change, silkworm breeders will be able to determine to what extent breeding goals have to change.

No abstract

No abstract

The effect of Lactofeed probiotic and different sources of fat on performance, carcass characteristics, intestinal morphology and ghrelin gene expression of broiler chickens was studied in an experiment using a total of 240 one-day-old male chickens from commercial strain (Ross 308) in a completely randomized design via 6 treatments with 4 replicates (10 birds per replicate). The experimental diets included: (1) basal diet (control); (2) diet containing 3% animal fat from tallow (fat); (3) diet containing 3% plant oil from soybean (oil); (4) control + probiotic; (5) probiotic + (fat) and (6) probiotic + (oil). The results showed some improvement in performance in the third group (P<0.05). A significant difference in the length, width and depth of crypt was observed between the treatments 3 and 4, and the control group (P<0.05). There was a significant difference in ghrelin gene expression of the treatments 2 and 4 in comparison with the control group (P<0.05). The results generally showed that there were benefits from the separate use of probiotic and soybean oil in the diet of broiler chicken.