Analysis of slaughter traits in geese depending on breed, sex and length of rearing period.

The aim of the study was to analyze some slaughter traits in 3 breeds of geese: the commercial hybrids of White Koluda (W-31), and birds of conservative flocks of Pomeranian (Po) and Kielecka (Ki) geese depending on sex and length of rearing period, and to determine the relationships between the analyzed traits and factors. A total of 19 traits divided into 2 groups-measured and calculated traits-were statistically analyzed. The measured traits (g) included 11 parameters: preslaughter weight, carcass weight, weights of breast muscle, thigh and drumstick, abdominal fat, skin with subcutanenous fat, neck without skin, skeleton with dorsal muscles, wings with skin, total muscles as the sum of all breast and leg muscles, and the trait broth elements as the total weight of neck, skin, skeleton and wings. The calculated traits included 8 parameters (%): dressing percentage-carcass weight to preslaughter weight, meatiness-total breast and leg muscle weight to carcass weight, abdominal fat weight to carcass weight, weight of skin with subcutaneous fat to carcass weight, weight of neck without skin to carcass weight, weight of skeleton with dorsal muscles to carcass weight, weight of wings with skin to carcass weight, as well as total weight of neck, skin, skeleton, and wings. The presented results concerning the analysis of selected slaughter traits of the Kielecka, Pomeranian and White Koluda geese indicate that these birds exhibit good slaughter value (dressing percentage from 60.80 to 66.50%). The selected values of this parameter were influenced mainly by genotype and to a lesser extent by sex. The White Koluda geese were characterized by significantly higher values of the majority of the analyzed slaughter traits, both measured and calculated ones. In turn, the lighter domestic geese of regional breeds were characterized by significantly higher carcass meat content (from 31.69 to 35.13 % vs. from 29.28 to 31.80 %) and lower carcass fatness (abdominal fat and skin with subcutaneous fat from 21.26 to 25.45 % vs. from 30.81 to 33.14 %). This points to the possibility of using these breeds of geese in breeding work aimed to produce a hybrid characterized by medium body weight (intermediate between these values for the White Koluda geese and Kielecka or Pomeranian geese), good dressing percentage as well as high carcass meat content and low carcass fatness.

Egg quality depending on the diet with different sources of protein and age of the hens.

Due to the planned limitations in the use of genetically modified soybean meal, the search for alternative sources of protein in animal nutrition is ongoing, which also supports the consumers' expectations of good quality products, such as eggs. The aim of the study was to assess and compare morphological traits of eggs, fatty acid composition in yolk lipids, and the content and activity of lysozyme in thick and thin albumen in eggs from hens fed a diet based on legume seeds as a substitute for soybean meal depending on the hens age. Analyses were carried out for 300 eggs on dates I-V (19-39 weeks age of hens), obtained from Rosa 1 hens managed in the semi-intensive system. Quality analysis was performed for 30 eggs from each group at a time. The control group of hens (A) was fed a diet based on soybean meal (SBM) and the treatment group (B) was fed a diet based on seeds from narrow-leaved lupin (Boruta), yellow lupin (Mister), and pea (Muza). Eggs were analysed for morphological traits (egg weight, the weight and density of egg components, egg shape index and egg surface area), parameters of albumen (height, Haugh units), yolk colour (La Roche, colorimetry in the CIE Lab system), lysozyme content and activity in albumen, and fatty acids composition in yolk lipids. In group B the egg shape index was higher (p = 0.002), and the eggshell colour index was lower (p = 0.007), as well as the height of thick albumen, Haugh score, and yolk colour (La Roche) were higher in group B (p < 0.05), while redness of yolk was significantly lower (p < 0.001) than in group A. Lower content of C15:0 and C18:1n9 and higher content of C18:2n6 and C18:3n3, (p < 0.05), as well as lower content of MUFA and OMEGA 9, but higher content of PUFA, OMEGA 3, OMEGA 6, PUFA/SFA, OMEGA 9/6 and OMEGA 9/3 were found in group B compared to group A (p < 0.05). There were significant differences in traits between age of hens (p < 0.05). Egg weight, yolk weight and its proportion in egg, as well as shell weight, its strength and thickness increased with the age of hens (p < 0.05). The content of lysozyme and its activity were also higher in eggs from older hens (p < 0.05). Fatty acids composition was beneficial at the beginning and end of the analysed egg production period. The proposed feed mixture based on legume seeds had no negative effect on the quality of eggs, and had a positive effect on yolk colour, the quality of albumen. There was no detrimental effect of diet and age of hens on fatty acid composition of eggs from both groups throughout the study period. To sum up, diet with legume seeds could be accepted as a substitute for soybean meal, due to the beneficial effects for some mentioned traits of eggs. Use of legumes could give a partial self-sufficient for producers from small farms, where is not possible to produce soybean meal. At the same time, the level of anti-nutrients in legumes should be considered.

Quality of Eggs, Concentration of Lysozyme in Albumen, and Fatty Acids in Yolk in Relation to Blue Lupin-Rich Diet and Production Cycle.

In recent years, the interest in lupin seeds as a source of protein in poultry nutrition has increased. The aim of this study was to assess the quality of table eggs produced by hens that were fed diets containing pea seeds and various levels of narrow-leafed lupin as a substitute for soybean meal. The share of lupin seeds in the treatment groups was 10%, 15%, 20% and 25%. Egg morphology, the fatty acid profile in egg yolk and the amount and activity of lysozyme in egg white were analysed. Results show that using 10-20% lupin seeds in feed in the diet of laying hens in intensive farming does not result in a change in weight or egg structure, their physical properties or their morphological composition. Increasing the share of lupin seeds in feed for laying hens increases the saturation of the colour of egg yolks, which is a desirable feature among consumers. The use of lupin seeds in feed for laying hens does not adversely affect the chemical properties of egg proteins, as expressed by the amount and activity of lysozyme. In feed for laying hens, replacing soybean meal with lupin seeds has a positive effect on the fatty acid profile in egg yolk (omega-3 and -6 polyunsaturated acids and hypocholesterolemic acids).

Mapping quantitative trait loci affecting some carcass and meat traits in duck (Anas platyrhynchos).

Contrary to chicken and livestock mammals, duck genome has not been explored much. Nowadays a relatively small number of reports on molecular variability and mapping of loci in Peking ducks has been published. Therefore, the objective of this study was to detect single loci affecting body weight, carcass and meat traits in Peking ducks (Anas platyrhynchos). The study was based on an F2 cross between two parental lines A-55 and GL-30. Phenotypes of 387 birds from generation F2 including carcass and meat quality traits were collected. Linkage map, of the linkage group CAU1, consisting of 29 microsatellite markers was constructed. One highly significant (p < 0.01) QTL for skin weight was identified at the beginning (0 cM) of the linkage group CAU1. Two significant QTL (p < 0.05) were found for fatness of leg muscle and leg muscle electrical conductivity - 24 hours post slaughtering (EC24h) at 178 and 100 cM, respectively. Additionally one suggestive QTL for odour of leg muscle was identified at 265 cM.