Fattening of Polish Holstein-Friesian × Limousin Bulls under Two Production Systems and Its Effect on the Fatty Acid Profiles of Different Fat Depots.

This study was designed to compare the fatty acid (FA) profiles of four types of fat depots from crossbred bulls (Polish Holstein-Friesian × Limousin, PHF × LM) fattened semi-intensively (SI) and intensively (I). Intramuscular fat was most abundant in total polyunsaturated fatty acids (PUFAs), n-3 and n-6 PUFAs, and functional fatty acids C 18:2, C 18:3, C 20:4 and C 20:5 in comparison with the remaining fat types. Furthermore, note that external fat was more abundant in conjugated linoleic acid (CLA) than other fat types. Grass silage fed to cattle during fattening had a beneficial influence on the FA profile of beef, and an increase in the amount of concentrate in the ration did not decrease beef quality.

Fatty acid profile as affected by fat depot and the sex category of Polish Holstein-Friesian × Limousin fattening cattle fed silage ad libitum.

This study was designed to compare the fatty acid profiles of four types of fat depots from bulls, steers, and heifers. All animals were Polish Holstein-Friesian and Limousin crossbreds fattened semi-intensively-silage at libitum and concentrate in the amount corresponding to 30% of their net energy requirements. The fatty acid profile in intramuscular, intermuscular, and external and internal fat was determined. The intramuscular fat of bulls was most abundant in total PUFAs and n-6 PUFAs, and functional fatty acids C 18:2, C 20:4, and C 22:5 in comparison with steers and heifers. Regardless of sex category, intramuscular and external fat were characterized by higher levels of UFAs and a more desirable MUFA/SFA ratio than the remaining fat types. It should also be noted that external fat was more abundant in CLA than other fat types, and that the highest CLA content was found in bull fat, compared with the remaining sex categories of cattle.

The effect of slaughter season on the Fatty Acid profile in four types of fat deposits in crossbred beef bulls.

The objective of this study was to determine the effect of slaughter season on the fatty acid profile in four types of fat deposits in crossbred (Polish Holstein Friesian Black-and-White×Limousine) beef bulls. The percentage share of fatty acids was determined by gas chromatography and were divided into the following categories of fatty acids: saturated (SFAs), unsaturated (UFAs), monounsaturated (MUFAs), polyunsaturated (PUFAs), desirable hypocholesterolemic (DFAs) and undesirable hypercholesterolemic (OFAs), n-3 and n-6. Perinephric fat was characterized by the highest SFA concentrations (59.89%), and subcutaneous fat had the highest MUFA content (50.63%). Intramuscular fat was marked by a high percentage share of PUFAs and the highest PUFA/SFA ratio. The slaughter season had a significant effect on the levels of C18:3, C20:4 (p≤0.01) and conjugated linoleic acid (p≤0.05). There was an interaction between the slaughter season and fat type for the content of C20:4 (p≤0.01) and C20:5 (p≤0.05). The results of this study show that beef from cattle slaughtered in the summer season has a higher nutritional value and more health-promoting properties.

The Effect of Body Energy Reserve Mobilization on the Fatty Acid Profile of Milk in High-yielding Cows.

We investigated the effect of the amount of body condition loss in the dry period and early lactation in 42 high-yielding Holstein-Friesian cows on milk yield and the share of fatty acids in milk fat. Energy reserves were estimated based on the body condition scoring (BCS) and backfat thickness (BFT). Milk yield and milk composition were determined over 305-d lactation. From d 6 to 60 of lactation, the concentrations of 43 fatty acids in milk fat were determined by gas chromatography. Cows were categorized based on body condition loss from the beginning of the dry period to the lowest point of the BCS curve in early lactation into three groups: low condition loss group (L) ≤0.5 points (n = 14); moderate condition loss group (M) 0.75 to 1.0 points (n = 16) and high condition loss group (H) >1.0 points (n = 12). Cows whose body energy reserves were mobilized at 0.8 BCS and 11 mm BFT, produced 12,987 kg ECM over 305-d lactation, i.e. 1,429 kg ECM more than cows whose BCS and BFT decreased by 0.3 and 5 mm, respectively. In group H, milk yield reached 12,818 kg ECM at body fat reserve mobilization of 1.3 BCS and 17 mm BFT. High mobilization of body fat reserves led to a significant (approx. 5%) increase in the concentrations of monounsaturated fatty acids-MUFA (mostly C18:1 cis-9, followed by C18:1 trans-11), a significant decrease in the levels of fatty acids adversely affecting human health, and a drop in the content of linoleic acid, arachidonic acid and docosahexaenoic acid in milk fat. In successive weeks of lactation, an improved energy balance contributed to a decrease in the concentrations of unsaturated fatty acids (UFA) and an increase in the conjugated linoleic acid (CLA) content of milk fat.

Chromosome banding studies by replication and restriction enzyme treatment in vendace (Coregonus albula) (Salmonidae, Salmoniformes).

Chromosome banding studies were performed in vendace, Coregonus albula. Original data on distribution of early and late replication regions, restriction sites (AluI, DdeI, HinfI and HaeIII) on chromosomes in this coregonid fish have been used to analyse karyotype heterochromatin differentiation. Heterochromatic bands (C-positive and not digested by restriction enzymes) have been identified as late replicating regions. Extra bands produced by the applied methods have permitted the identification of several homologous pairs. The centromeres were differentially digested by the restriction enzymes. The studied population seems to be homogenic regarding karyotype characteristics.