The study was conducted on 90 Isa Brown hens aged 28 weeks, randomly allocated to 6 groups of 15 birds each and maintained in individual laying cages throughout 12 weeks of the experiment. Hens of control group were fed a standard diet containing 19 g crude fat per kg, diets for the experimental groups contained 38 g crude fat per kg due to enrichment of the formula with 50 g of regular linseed cv. Opal or Omega (HA), low α-linolenic linseed cv. Linola (LA), 20 g of LA linseed oil, or 20 g of soyabean oil. The increase in the dietary fat content in experimental groups decreased feed intake by 5% (P<0.05), increased egg production by 4% (P<0.05) except in the group with LA oil, and decreased egg weight by 2% on average (P<0.05), in comparison with the control group. The total cholesterol content averaged 284 mg per egg in groups fed LA linseed or soyabean oil and in the control group, while in the groups fed LA linseed and LA oil, it averaged 291 mg per egg (P<0.05). In conclusion, linseed cultivars with a high content of linoleic acid cannot be considered useful in production of functional eggs.

The study aimed to determine the effect of nutrients of wheat (nine cultivars) and maize (nine cultivars) grain on nitrogen balance and apparent metabolizable energy (AMEN) content for broiler chickens. In vivo digestibility and balance trials were carried out with 90 Ross 308 chickens (2 × 9 groups with 5 birds per group) aged from 42 to 49 days, separately for each cultivar. Considerable variation within each cereal species in fiber and non-fiber carbohydrate fractions and nutrient digestibility of grain were demonstrated. Additionally, regression equations were proposed which allow the estimation of AMEN content of wheat and maize grain varieties based on simple analytical procedures, including cell wall components, starch, and sugars. For practical purposes, these equations seem to be the best solution while reducing time, labor, and cost of analytical procedures.

The experiment was carried out on 90 Ross 308 broiler chickens (9 groups of 10 birds each) kept in individual cages. Nine diets based on Polish wheat (Triticum aestivum) cultivars: Zebra, Bryza, Vinjett, Torka, Rysa, Mikula, Turnia, Satyna and Bombona were prepared. The diets contained 732.6 g/kg wheat grain, soyabean meal, fi sh meal, lysine, methionine, vitamins and minerals. Broilers were provided experimental diets ad libitum from 14 to 42 days of age. Performance was measured, and on the last week of the experiment a marker was added to the diets, excreta were collected, analysed, and nutrient digestibility and metabolizable energy value were calculated. After completion of the experiment, jejunal digesta pH and viscosity were measured. Jejunal digesta viscosity was higher in birds fed diets with Bryza and Satyna cvs. than with the remaining cultivars, while apparent protein digestibility was 67.9% in birds fed diets with Rysa and Bombona cvs., and 84.6 on average, in birds fed diets with Zebra, Torka, Mikula, Turnia and Satyna cvs. Wheat cultivar neither infl uenced the AME N value of diets, which averaged 12.5 MJ/ kg, nor body weight gain, while the feed conversion ratio was 6% better, on average, in birds fed diets with cultivars of lower viscosity (Zebra, Vinjett, Torka and Turnia) in comparison with diets based on the remaining cultivars (P<0.05).

The objective of the study was to determine the nutritive value of grain of different maize cultivars for broiler chickens. The study involved 45 Ross 308 broilers (9 groups with 5 chickens per group) aged 42 to 49 days. Chickens were fed the grain of maize cultivars Pioneer PR39H84, Smok, Arobase, Moncada, Pioneer PR39G12, Eurostar, Opoka, Boruta, and Nysa ad libitum. The cultivars of maize differed in basic chemical composition, contents of amino acid and fibre fractions, as well as fatty acid profiles. Variations in chemical composition among different maize cultivars had an effect on the extent of basic nutrient digestion and on the energy value of grain in broiler chickens. For practical utilization of maize in broiler feed mixtures it will be important to determine the content of insoluble fibre, as it is negatively correlated with nutrient digestibility and the AME N value of grain (r=-0.69; P<0.05).

The effects of dietary linseed cultivars, traditional (Opal, Omega) or the new Linola cultivar with an increased content of linoleic acid, on the performance and chemical composition of lamb meat and liver were investigated. The animals were fed meadow hay and concentrate. The control group received no linseed in concentrate, whereas the experimental groups received 10% crushed linseed of different cultivars. There was no significant effect of linseed, irrespective of cultivar, on daily weight gains of the lambs, feed conversion, dressing percentage and chemical composition of leg muscle and liver. However, significant (PO.05) changes were shown in the fatty acid profile of meat and liver.