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  • Author: Sebastian Nowaczewski x
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Abstract

The aim of the study was to analyze eggshell temperature, embryo viability, and hatchability parameters of broiler breeders at different ages (26-30, 31-35, 36-40, 41-45, and 46-64 weeks). A total of 33,150 eggs from Ross 308 broiler breeders collected from commercial flocks were used to analyze the following: egg weight and egg weight loss during 18 days of incubation; eggshell temperature controlled on days 3, 14, and 18 of incubation; number of infertile eggs including eggs with dead embryos at early stages of development, that is, in the oviduct or after oviposition; the total percentage of embryonic mortality and the percentage of embryonic mortality at different times of incubation; unhatched, dead after hatching, and culled chicks as well as hatchability percentage from fertilized eggs. The hatchability results of Ross 308 broiler breeders were high from the beginning of reproductive season till the 40th week. However, the study failed to reveal any relationships between hatchability and the egg weight, average temperature of the shell, and egg weight loss during incubation period. The oldest hens, over 45 weeks of age, had the highest mortality of chicks and the greatest share of unhatched chicks.

Abstract

The aim of the study was to determine the usefulness of two protein concentrates composed of rapeseed meal and new cultivars of narrow-leaved and yellow lupine, peas in laying hen diets and their influence on birds’ performance and egg characteristics. The experiment was conducted with 180 layers kept in individual cages. The birds were randomly assigned to three treatments, with 60 hens in each and during the period of 17 weeks, they were fed diets: I - containing soybean meal as a protein source, II - containing protein concentrates composed of mixture of lupines, peas (19.48% of diet) and rapeseed meal, III - containing protein concentrates composed of a mixture of lupines and peas (27.68% of diet). The body weight, laying rate, egg weight, feed intake and feed conversion ratio (FCR) and egg characteristics were registered. After 9 weeks of experiment, a decrease of laying rate was recorded in treatment III. The mean value of laying rate for 17 weeks amounted to 82.7 (I), 82.5 (II) and 75.9% (III) (P<0.01). The egg weight was diversified already after 4 weeks of egg production and averaged 57.9 (I), 55.9 (II) and 54.9 g (III) (P<0.05). Feed intake amounted to 108 (I), 111 (II) and 104 g per hen/day (III), and FCR was 2.05, 3.17 and 2.23 kg/kg egg weight, respectively. As to egg characteristics, increases of white index (P<0.05), Haugh unit score and yolk colour in treatment III were observed but egg shell thickness was found significantly reduced. In conclusion, the use of about 27.68% of legume seed in laying hen diet affected negatively performance results but about 19.48% of these seeds and 8% rapeseed meal in diets could be accepted as a soybean meal substitute.

Abstract

The aim of the study was to evaluate the morphometry and shell quality of eggs laid by pheasants kept in cages, and also to analyse the dependence between egg shell colour parameters, its quality and morphometric characteristics. Four groups of 15 eggs (60 eggs), each classified according to their eggshell colours, i.e. blue, light brown, dark brown and olive, were examined. The eggs did not differ significantly between each other in their mean weight and olive-coloured eggs had a higher shape index (about 8.91 percentage points) than blue eggs. Blue and light brown coloured eggs had thinner shells than the dark brown eggs (by 33.57 and 27.97 μm, respectively). Blue eggs had the lightest shells (L* = 67.97) and the highest proportion of green colour in their shells since the a* parameter value for blue eggs was negative. A significant positive correlation was observed between the egg shape and the shell colour saturation (C*) and the proportion of yellow colour (b*) in it. In addition, a negative correlation was found between lightness in eggshell colour, its thickness and the egg shape (r = from -0.338* to -0.480**). In comparison with the data obtained from the literature concerning the quality of eggs laid by pheasants kept in aviaries and eggs laid by birds kept in cages, the eggs were described as having similar weights and morphometries along with greater shell thicknesses. Furthermore, our study confirmed that pheasant eggs with blue and light brown colour have poorer shell quality, a fact which has been shown already in earlier research. However, this fact is related to the lightness of the shell pigment rather than its colour.

Abstract

The aim of this study was to investigate the impact of slaughter weight and sex on slaughter traits and meat quality of Zlotnicka Spotted x Duroc (ZS×D) hybrid fatteners. The material comprised 56 Zlotnicka Spotted × Duroc fatteners (28 barrows and 28 gilts) which were fattened to 245th day of life. Pigs were divided into the following three groups: Group I (n=16) <110 kg; Group II (n=23) ≥110 ≤120 kg, and Group III (n=17) >120 kg. The obtained results revealed influence of the final body weight on slaughter trait values with the exception of meatiness. Fatteners from the group with the highest weight were characterised by the thickest backfat as well as by the greatest height of the loin eye. Slaughter weight exerted a significant impact on protein content, water absorbability as well as on the pH of the longissimus thoracis et lumborum (LTL) muscle. As to the influence of sex on slaughter traits, it was found that gilts were characterised by smaller backfat thickness and higher carcass meatiness than barrows. On the other hand, no effect of the slaughter weight and sex on colour parameters and sensory quality of the LTL muscle was ascertained. All the examined parameters were at high level in all slaughter weight and sex groups. The obtained results suggest that the slaughter of ZS×D crossbreds in groups I and II exerts a beneficial influence on slaughter trait levels and, at the same time, allows maintenance of high meat quality.

Abstract

In reproductive flocks of poultry it is very important to obtain a large number of eggs with normal structure, optimal morphological composition and interior quality. These elements have very significant influence on the biological value of the egg, which determines normal development of the embryo. The aim of the study was to analyse the physical characteristics, morphological composition and quality of individual components of the eggs of Cobb 500 broiler breeders during the first year of reproduction. The research material was hatching eggs (280 pcs), whose quality was assessed 7 times in the reproductive season at 5-week intervals. The eggs were examined when the hens were aged 26, 31, 36, 41, 46, 51 and 56 weeks (40 eggs for each age). The following characteristics were evaluated: egg weight (g); egg shape index (%); egg specific gravity (g/cm3); shell thickness (mm); average number of pores in the eggshell (pcs/0.25 cm2); yolk, white and shell weight (g) and their percentage in the egg mass; yolk index (%) and the number of Haugh units. The investigations proved that as the reproductive season of hens progressed, the weight of their eggs increased. Above all, this was due to the increase in the yolk weight, because its percentage in the egg weight rose with bird age, whereas the percentage of the white decreased. However, as the reproductive season progressed the quality of both the yolk and white deteriorated. No negative relationship between the age of hens and shell quality (weight, thickness) was observed. Only when the birds were aged 56 weeks, the shell thickness was found to be significantly smaller.