Open Access Agricultural Journals published by Institute of Agricultural Economics and Information

The aim of this study was to compare carcass traits, meat quality and sensory attributes in two different genotypes of geese according to age and sex. The experiment was carried out on 160 birds of two genotypes of geese: the Czech Goose (CG) breed and a Eskildsen Schwer (ES) hybrid. One-d-old goslings were divided into four groups according to genotype and sex. Two dates for slaughtering (at 8 and 16 wk of age of goslings) were undertaken. The slaughter weight, cold carcass weight and dressing percentage were affected by all the studied factors, and significant interactions between age, genotype and sex were detected in the slaughter weight (p<0.001) and cold carcass weight (p = 0.004). The pH was not affected by any of studied factors, whereas in terms of meat colour parameters there were observed significant effects of age on L* and b* value and a significant effect of sex on a* value. The meat fat content was higher (p = 0.002) in ES. Higher score for overall acceptance of goose meat was recorded for ES at both ages compared to CG. ES had higher dressing percentage and better sensory attributes, whereas CG exceled in the favourable nutritional value of the meat.

The objective of the present study was to determine the relationship between eggshell thickness and other eggshell characteristics in eggs produced in litter housing system and enriched cages. Eggs were collected from 200 birds of ISA Brown genotype at 40–42 weeks of age. Half of the birds were housed in enriched cages (750 cm²/hen, 10 hens/cage) and the other half were housed in littered pens (9 hens/m², 10 hens/pen). Eggs in each housing system were split into three categories varying in shell thickness: the first category (thin shells 0.28–0.30 mm), the second category (medium shells 0.33–0.36 mm) and the third category (thick shells 0.39–0.41 mm). Results indicated that eggshell parameters differ significantly according to eggshell thickness. Significant interaction of shell category and housing system were observed in eggshell strength. As expected, the eggshell strength was increased with eggshells becoming thicker. Moreover, eggs with the thickest shells from enriched cages had significantly stronger shells than those from litter system. Eggshell weight was significantly increased in the thick eggshell category being higher in enriched cages (7.23 g) than in litter system (5.14 g). The Pearson’s correlation coefficients showed a positive correlation between eggshell parameters and eggshell thickness in both housing systems. Moreover, the correlation between eggshell thickness and eggshell strength was higher on litter (0.64, p < 0.001) in comparison with enriched cages (0.48, p < 0.001). Results of the present study indicated that in thin shells, housing system plays an important role in determining the eggshell strength.

The aim of the present study was to evaluate the effects of quantitative feed restriction (FR) in fast-, medium-, and slow-growing meat-type male and female chickens on their growth, feed consumption, economic efficiency, carcass composition, and gastrointestinal microbiota. In the experiment, fast-growing Ross 308, medium-growing Hubbard JA 757 and slow-growing ISA Dual chickens of both sexes were exposed to quantitative FR between 14 and 21 d of age. During the FR, restricted chickens received 70% of the amount of feed consumed by the ad libitum (AL) group. Live weight at the end of the experiment was affected by genotype (P < 0.001), sex (P < 0.001), feeding regime (P < 0.001), and their interaction (P < 0.001). The highest final weight was in AL and FR ISA Dual males and the lowest was in AL and FR females of the same genotype. A similar tendency was observed in daily weight gain and feed intake. Carcass traits were predominantly affected by genotype. However, interactions of genotype, sex, and feeding regime were observed in thigh (P < 0.001) and abdominal fat (P < 0.001) proportions. Concerning gastrointestinal microbiota, only Escherichia coli was affected by genotype. Feed restriction in slow-growing dual-purpose chickens might improve economic potential; however, further research is needed to reveal the involvement of variable processes, which are unclear and affect production.

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1. The potential growth of modern turkey genotypes was measured using male and female BUT 6 (BUT) and Hybrid Converter (HYB) strains. At one-day-old, 720 male and 960 female poults were randomly allocated to 48 littered pens in two houses with 30 males or 40 females of each strain per pen. Five feeds of decreasing protein content were fed to both sexes during the growing period. 2. Birds were weighed at 1, 7, 14, 21, 35, 56, 77, 119 d (males only), 126 d (females only) and 140 d (males only) and, on each occasion, six birds were selected and removed for carcass analysis. 3. Growth was similar in both strains, but the growth rate of females appeared to decline relative to the earlier trajectory after 70 d, and this tendency being greater in HYB females. 4. HYB birds of both sexes had more feathers than BUT to 77 d, but thereafter these differences were non-significant. A single allometry between feather and body protein weight was observed over all genotypes with no differences apparent between sexes within strains. The Gompertz curve adequately described the growth of body protein, water and ash. 5. Body lipid (g/100g bodyweight) declined in the early stages of growth. This might reflect an energy deficiency in the diet or might indicate that the present description of lipid growth does not apply in turkeys as it does in other species. 6. Whereas the description of body growth, feather growth and the chemical components of growth given in this paper may not fully reflect the true potential of the genotypes used, nevertheless they provide useful information regarding the latest genotypes available in the turkey industry. Some of the observations suggested that current performance might be improved if further research is conducted regarding dietary energy transactions