Maja Maurić

Production performance, meat composition and oxidative susceptibility in broiler chicken fed with different phenolic compounds

BACKGROUND Various studies have been conducted to evaluate the effect of phenolic compounds on production animals. Supplementation of animal diets with phytogenic compounds, such as different essential oils and polyphenols, could improve animal productivity as well as the chemical composition and oxidative stability of food derived from those animals. RESULTS During the trial, 80 male broilers of the Ross 308 strain were allocated to four dietary groups: control and three groups supplemented with thymol, tannic acid and gallic acid. Feed utilisation was improved in all experimental groups and tannic acid also improved final body weight. Gallic acid significantly increased n-3 long-chain polyunsaturated fatty acids. A hypocholesterolaemic effect was noticed in all groups in liver, but not in muscle. The glucose lowering effect in serum was noticed in the tannic acid group in comparison to other experimental groups. Oxidative susceptibility was improved by tannic acid in liver and breast and by gallic acid in breast muscle. CONCLUSION The inclusion of phenolic compounds enhanced growth performance, decreased lipid oxidation, decreased cholesterol value and increased beneficial fatty acids content. Positive effects varied depending on phenolic compound used and, therefore, it would be interesting to further investigate synergistic effects of investigated phenolic compound.

Influence of meat type, sex and storage time on fatty acid profile of free range dalmatian turkey

Abstract Dalmatian turkey is a slow growing breed kept in free range systems. It is a type of “old fashioned poultry” whose meat is present on the market and accepted by consumers. However, no information about its meat quality and fatty acid profile is available. The chemical composition of the meat was influenced by gender and meat type and these differences could be important from the consumer’s point of view. Fatty acid composition was characterized by the predominance of n6 fatty acids, especially C18:2n6 and a high n6/n3 ratio. Increased time of storage strongly reduced the long chain polyunsaturated fatty acid (LC PUFA) and increased atherogenicity and thrombogenicity indices (AI and TI) in thigh tissue. The content of beneficial n3 PUFA was influenced by meat type, with lower values of C18:3n3 and higher values of LC PUFA in the breast compared to the thighs. The potential intake of LC PUFA of comercial turkey in the human diet was lower in comparison to poultry fed with complete feed mixtures. An interesting fact was the higher DHA values in comparison with DPA values in breast tissue, which is characteristic of old poultry breeds. The Dalmatian turkey is a highly valued traditional product and an important archaic breed for gene preservation and biodiversity. Nevertheless, Dalmatian turkey meat could be even further improved by minimal dietary manipulation to become a product with additional health promoting effects.

Cow colostrum and early milk enriched with eicosapentaenoic and docosahexaenoic fatty acid

The objective of the study was to explore whether it is possible to alter cow colostrum and early milk fatty acid composition with a low level of fat supplement, high in docosahexaenoic (DHA) and eicosapentaenoic (EPA) fatty acid. Diets included a control diet and a diet supplemented with DHA- and EPA-enriched fat supplement. Addition of fat supplement significantly decreased saturated fatty acids, C14:0 and C16:0 and increased the values of monounsaturated fatty acids, polyunsaturated fatty acids (PUFA), n3 fatty acids, EPA, DHA, C18:1n9cis and C18:1n11trans. The percentage of short-chain fatty acids significantly increased with the progress of lactation, while the percentage of PUFA, n3 and n6 significantly decreased. These results showed that fat supplement, high in DHA and EPA, modified the fatty acid profile of colostrum and milk fat and increased the proportion of beneficial fatty acids for human health.

Effects of different n6/n3 ratios and supplementation with DHA and EPA on the testicular histology and lipogenesis in streptozotocin treated rats

The aim of this study was to investigate the possible influence of different dietary n6/n3 ratios and DHA/EPA addition on the testis histology, antioxidative status and lipogenesis of streptozotocin‐treated rats. Diabetes was induced by a single intraperitoneal injection of streptozotocin (55 mg/kg). The rats were divided into five groups: CON (n6/n3 ratio, 7), CON‐DM1 (STZ; n6/n3 ratio, 7), N3‐DM1 (STZ; n6/n3 ratio, 1), N6‐DM1 (STZ; n6/n3 ratio, 60) and DHA‐DM1 (STZ; n6/n3 ratio, 1; added DHA/EPA). Antioxidative status was improved in the DHA‐DM1 group. Seminiferous tubule diameter, testicular pathohistological scoring and total lipid content were improved in the N6‐DM1 group compared to the other streptozotocin‐treated groups. Streptozotocin treatment induced changes in testis fatty acid profile depending on n6/n3 ratio. The fatty acid profile of N6‐DM1 group was characterised by similar or increased values for n6 fatty acids compared to the CON group, while the DHA‐DM1 group had the lowest content of n6 fatty acids. The content of n3 fatty acids was increased in the N3‐DM1 and DHA‐DM1 groups. These results suggest that a n6/n3 ratio could significantly influence testicular antioxidative status, histology and lipogenesis and that these effects vary depending on the supplemented fatty acid.