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The study was conducted on 90 thirty-week-old Messa H-43 layers divided into 3 groups. The control group was fed a diet without oil seeds, while the RLP and RLP+E groups were given a diet containing a mixture of 00 rapeseed, linseed, and evening primrose seed. Vitamin E, 200 mg/kg, was added to the RLP+E diet. After 4 weeks, egg quality, fatty acid content, and the lipid oxidation level were determined. Half of the collected eggs were examined the next day and the second half, after 20 days of storage at 12°C. No effect of feeding was found on egg quality. Eggs from groups RLP and RLP+E had less saturated fatty acids and more polyunsaturated fatty acids. Egg weight and albumen quality decreased and yolk content increased during storage, irrespective of the diet. Changes in fatty acid content in yolk during storage were found. Diet and the storage had insignificant effect on oxidation of yolk lipids.KEY WORDS: rape seed, linseed, evening primrose seed, egg quality, TBA, fatty acids INTRODUCTIONThe subject of many current studies is improving the nutritional value of hen's eggs. One of the methods is increasing egg-yolk polyunsaturated fatty acids (PUFA) content, which can be done by feeding hens diets with oil seeds. Rape 00, linseed and evening primrose seeds can be used for this purpose in Poland. Many authors (Aymond and Van Elswyk, 1995;Brettschneider et al., 1995;Roth-Maier and Kirchgessner, 1995;Niemiec et al, 1997) confirmed the favourable effect of these seeds in diet for layers on PUFA content in egg-yolk. The aim of the presented study was to determine the effect of storage on the quality and fatty acid content of PUFAenriched eggs.

From the fourth week of life, 1200 ISA Vedetta chicks were fed with one of four feed mixtures with similar protein and energy contents, to which were added: 8.0% rape seeds (diet I), 4.0% lard (diet II), 5.5% by-product fat (diet III) or 3.5% sunflower oil (diet IV). The highest body weight achived broilers fed diets with lard (P^O.Ol); feed utilization per kg gain was the best in this group too.The cholesterol content of meat from broilers receiving the sunflower oil-containing diet was the lowest, and the linolenic and linoleic acid contents in breast and thigh meat were the highest in chickens fed the rape seeds-containing diet.

In two series of experiments plasma thyroxine and triiodothyronine concentration were examined in 56 adult hens and 139 meat type chickens of Biała Brwinowska strain fed up to 7 weeks of age a diet containing "OO" rape seeds, wheat and barley (diet B) or maize, soyabean meal and wheat (diet C). Relationship between reproductive performance of adult hens and plasma thyroid hormone concentration was assessed.At the age of 7 weeks, chickens fed diet B had significantly lower body weight (except of males in 1994) and, despite of its low (0.7-0.9 /rniol/g) glucosinolate content, significantly higher plasma thyroxine concentration than control birds. No significant diet-related difference was found in their plasma T 3 level and T 3 /T 4 ratio. Also no differences were found in reproductive perfomance of one year old hens related to the diet fed in the first 7 weeks of life. In addition, in both series of experiments plasma T 4 concentration was positively correlated with egg fertility (P ;£ 0.05) while T, negatively to the hatchability rate (P^O.01).