Secondary sexual traits and semen characteristic of chicken germline chimeras.

Birds obtained by embryo engineering are used to study embryo development and to produce transgenic birds. As this method of producing birds still generate strong emotions of the public opinion head ornaments, testes and semen characteristics of sex chimera roosters were examined to check whether they differ from chickens obtained by non-manipulated methods. Measurements of head ornaments, testes and semen were correlated with each other. Semen quality factor (SQF) was calculated, as well as the level of fluctuating asymmetry (FA) of bilateral traits (wattles and testes). Positive correlation was found for comb width and wattle length and comb thickness and sperm concentration. Semen characteristics and FA did not exceed the level encounter in other chicken lines. Results obtained indicate that germline chimeras are similar in appearance of secondary sexual traits, and semen and testes characteristics to chickens produced in non-manipulated way.

Stage of goose embryo development at oviposition depending on genotype, flock age, and period of laying.

Embryo development and chick quality are influenced by parental genotype, age, nutrition, environment, and flock management. The aim of study was to determine if genotype, age of goose or eggs laid near the onset of egg production vs. eggs laid near the end of reproduction influence the stage of embryo at oviposition. Three experiments were undertaken. To compare genotypes (Experiment 1) 150 eggs were collected from 3-year-old commercial line White Koluda (WK) geese and from two breeds involved in a genetic resources conservation program, Zatorska (Za) and Bilgoraj (Bi). Age comparison (Experiment 2) was conducted with 200 eggs collected from 1-, 2-, 3-, and 4-year-old WK geese. To compare laying periods (Experiment 3), 150 WK eggs were collected at the first week of March and 100 at the second half of June. Eggs were stored for 72 h at 16°C, staged using Eyal-Giladi and Kochav (EGK, Roman numerals) and Hamburger and Hamilton (HH, Arabic numerals) procedures. Experiment 1: Individual breed differences were evident with Stage X EGK embryos comprising 42.4, 33.3, and 38.7% in the eggs examined from the WK, Bi, and Za, respectively. For all breeds combined, 38.8% of the embryos were in Stage X, but in the next order in WK there was stage XI (18.2%), while in geese from the genetic reserve it was stage XIII (Bi - 33.3; Za - 29.0%). Experiment 2: In eggs of 1-, 2-, and 3-year-old WK geese, the majority of embryos (38.7, 32.4 and 42.2%, respectively) were in Stage X. In contrast, in 4-year-old geese the embryos were in Stage XI (36.1%). Experiment 3: In eggs collected in March and in June most of embryos were in Stage X (33.7% and 43.6%, respectively). In addition, more developmentally advanced stages (XI-XIII) were similar in both periods. However, embryos in Stage 2 HH were only observed in eggs collected at the end of laying season. Interestingly, earlier stages (VI-IX) were observed exclusively in the eggs collected in March.

Goose embryonic development from oviposition through 16 hours of incubation.

Normal tables provide an objective step-wise description of the morphological development of an embryo. Such tables have been described for the chicken, turkey, quail, and duck embryos, but there is no such staging table for goose embryos. As the goose has one of the longest incubation periods of all the poultry species and embryo mortality during incubation is relatively high, a normal table of goose embryo development would be useful in assessing the morpho-genetic status of the goose embryo before and during incubation. In this study, embryos were isolated from commercial White Koluda goose eggs stored no longer than four days in a cool room (18°C) prior to incubation and after 4, 8, 12, and 16 h of incubation. Embryo staging was based on the normal tables described for the chicken by Eyal-Giladi and Kochav (EGK) and Hamburger and Hamilton (HH). Goose embryos from unincubated eggs were at Stage X and XI EGK and after 16 h of incubation the majority of embryos were between Stages 2 and 4 HH. Our results suggest that while the stage of development of the embryo in the unincubated goose egg is similar to that reported for the chicken, although the diameter of goose embryo is slighter larger. Following incubation, a goose embryo advances more slowly than a chicken embryo up to 16 h of incubation.