Arachidonic acid (AA) content, long-chain n-3 polyunsaturated fatty acid (PUFA) equivalent [LCE; calculated as 0.15 x linolenic acid (LA) + eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA)], and PUFA n-6/PUFA n-3 ratio were determined in meat [breast meat (BM), thigh meat (TM), and fillets (F), respectively] within four sets of chickens, five sets of turkeys, one set of common carp, and four sets of rainbow trout, fed either commercial diet or diets with manipulated PUFA n-3 and PUFA n-6 contents. AA content was within the range of 20 mg/100 g (F of rainbow trout fed the diet with linseed oil, LO) to 138 mg/100 g (TM of chickens fed restrictively the diet based on maize to the age of 90 days). AA content in BM of turkeys fed the diet with LO or fish oil (FO) did not differ (P > 0.05) from that of rainbow trout F. LCE was in the range of 16 mg/100 g (BM of turkeys fed a commercial feed mixture) to 681 mg/100 g (F of rainbow trout fed a commercial feed mixture). With regard to BM, only turkeys fed the diet with LO deposited more (P < 0.01) LCE (71 mg/100 g) as compared to all other poultry sets except turkeys fed the diet with FO (123 mg/100 g). Apart from all fish samples, also both BM and TM of turkeys fed the diet with either LO or FO met the recommended value of the PUFA n-6/PUFA n-3 ratio (<4). AA content in the tissue increased significantly (P < 0.001) with increasing dietary LA in both all chicken tissues and all turkey tissues, which is contrary to the suggested strong metabolic regulation of the AA formation. When all tissues within all animal species were taken as a one set, both AA percentage and EPA + DHA percentage in the tissue (Y, %) decreased (P < 0.001) with increasing fat content in the tissue (X, %), according to the equation Y = 4.7 - 0.54X (R (2) = 0.41) and Y = 6.0 - 0.33X (R (2) = 0.35), respectively. AA content in chicken BM, chicken TM, and turkey BM, respectively, decreased linearly (P < 0.01) with increasing live weight reached at the slaughter age.

Total cholesterol content in 24 fillets (F) of males and females of common carp, 35 samples of male chicken breast meat (BM) and thigh meat (TM), and 48 samples of male turkey BM and TM, respectively, was determined by high-performance liquid chromatography after total lipid (TL) extraction using n-hexane/2-propanol mixture. Cholesterol content in male carp fillets (77.6 mg/100 g) was higher (P < 0.001) in comparison with females (69.4 mg/100 g). Irrespective of the sex differences, cholesterol content increased (P < 0.01) in the sequence chicken BM (53.0 mg/100 g) = turkey BM (53.0) < turkey TM (61.5) < carp F (73.5) < chicken TM (82.9 mg/100 g). Cholesterol content in chicken TM decreased (P < 0.05) with increasing live weight reached at the age of 43 days, but did not change (P > 0.05) in other tested tissues. Cholesterol concentration in TL of all five tested tissues within three animal species decreased sharply (P < 0.001) with increasing TL content reached in a given tissue at the fixed age. It follows from the results of the study that a two hundred gram portion of carp F and chicken TM without skin represents 49 and 55% of the upper limit of daily cholesterol intake, respectively.

No abstract

ABSTRACT:The aim of the study was to compare parameters of passage of nylon capsules and digesta represented by Cr-labelled maize silage through the digestive tract of dairy cows. The capsules were made of nylon cloth (42 µm pore size, 10 mm outside diameter) and applied orally. The evaluation was carried out in dairy cows with milk yield of 19.0 kg/day. The diet (17.6 kg DM/day) consisted of maize silage, lucerne hay and concentrate. Total mean retention time (TMRT), delay time (τ), summarised compartmental mean retention time (CMRTS), and mean individual compartmental retention times (CMRT1 and CMRT2) were calculated. TMRT, τ, CMRTS, CMRT1 and CMRT2 values of nylon capsules and Cr-labelled silage were 36.2 and 45.4 h (P < 0.01), 16.2 and 8.3 h (P < 0.01), 20.1 and 37.2 h (P < 0.01), 7.8 and 8.5 h, 12.2 and 28.7 h (P < 0.05), respectively. The calculated mean retention time of nylon capsules in the reticulo-rumen (CMRTS) was shorter and in the intestines (τ) was longer than that of digesta. For this reason the estimation of digestibility using the nylon capsule method can be questionable.

ABSTRACT:The effect of age upon iron retention in cockerels of laying and meat type hybrids was examined within 46 subsequent balance periods. Chickens were fed ad libitum a diet with the content of 312 mg Fe per 1 kg. The dependence of Fe utilisation upon age from Day 3 to Day 100 was expressed by the second degree parabolas with minimum values in the tenth week of age. The dependence of Fe content in weight gains on age was highly significant (P < 0.01). The course of this dependence was expressed by parabolas with minimum values on Day 38 and Day 28 in slow and fast growing chickens, resp. The growth rate of total amount of Fe in the body was by 6 per cent lower (P < 0.01) than that of live weight of chickens.