Urška Tomažin

Supplementing entire male pig diet with hydrolysable tannins: Effect on carcass traits, meat quality and oxidative stability

The purpose of the present study was to investigate the potential impact on carcass and meat quality of a sweet chestnut wood extract (SCWE)diet supplement for pigs, in particular on oxidative stability and fatty acid composition. Entire (non-castrated) male pigs (n=24) were assigned to treatment groups within litter and offered one of 4 finisher diets on an ad libitum basis: T0 (control), T1, T2 or T3, supplemented with 0, 1, 2 or 3% of commercially available SCWE, respectively. The highest SCWE supplementation reduced carcass fat deposition and water holding capacity of meat (higher thawing loss). In fresh meat, SCWE supplementation increased lipid (malondialdehyde) and protein oxidation (carbonyl groups in myofibril isolates). With regard to fat tissue, SCWE supplementation increased the proportion of polyunsaturated fatty acids.

Properties and aromatic profile of dry-fermented sausages produced from Krškopolje pigs reared under organic and conventional rearing regime

Krškopolje pig, the only Slovenian autochtonous breed is still relatively untapped, with almost no information available on the effect of rearing conditions or its aptitude for processing and meat product quality. In the present study, dry-fermented sausages were produced from Krškopolje pigs that were fed similar diets (with regard to ingredients, energy and protein content) but reared in either conventional (CON) or organic conditions (ECO). Sausage weight losses at the end of processing were recorded and their final pH, chemical composition (moisture, fat and protein content, proteolysis index, fat and protein oxidation, fatty acid and free fatty acid profile) were determined in addition to measurements of instrumental texture, sensory evaluation and volatile profile analysis. Compared with CON, ECO dry-fermented sausages had lower processing losses, lower pH, higher moisture, salt and thiobarbituric acid reactive substances content, less saturated fat and less free fatty acids. Volatile profile analysis showed that ECO dry-fermented sausages exhibited higher concentrations of compounds arising from lipid autooxidation and lower levels of volatile compounds resulting from microbial lipid β-oxidation, amino acid degradation and spices. Panellists perceived ECO dry-fermented sausages as saltier and less colour intensive, while both rheological and sensory analysis indicated that ECO sausages had softer texture than CON. The present results indicate that rearing of Krškopolje pigs according to organic standards induced differences in meat and fat properties which affected the quality of dry-fermented sausages, most distinctly in terms of softer texture and different volatile profile.

Crescimento de leitões Krškopolje nos períodos pré e pós desmame

The only Slovenian autochthonous pig breed (Krskopolje) is reared in very diverse conditions resulting in variable growth rates. As literature data on this breed is scarce, different growth phases were assessed within the TREASURE project. Growth in the pre-weaning period (n=156) was recorded on the farms of their origin (7 organic and 11 conventional), whereas the post-weaning period data originated from a subsample (n=42; piglets from 5 organic and 9 conventional farms). transferred to the experimental farm. There the piglets were assigned within litter to three pens; one pen (ECO; n=14) received organic feed mixture (12.8 MJ metabolizable energy, 17% crude proteins), while two pens (CON, n=28) received a conventional starter for 10 days (14 MJ metabolizable energy, 17.8% crude proteins) and thereafter a grower diet (13.6 MJ metabolizable energy, 16.8% crude proteins). Piglets were fed ad libitum and weighed at the average age of 38, 54 and 113 days. Prior to weaning, the piglets grew faster on conventional (app. 20%) than on organic farms (209±16 vs. 173±19 g/day, respectively), but the difference was not significant (P=0.17). Post-weaning, CON group had only 8% higher daily gain than ECO (391±31 vs. 361±41 g/day, respectively; P=0.60). The results suggest that no differences in between the systems are expected within similar rearing and feeding conditions.

Productive performance of Krškopolje pig breed – Review of preliminary results

Local pig breeds are adapted to specific local environment and fed with various locally available feedstuffs. Besides their genetic merit for agro-biodiversity, they represent the basis for sustainable local pork chains. The aim of the present study was to summarize data already available in the literature on production performance of Slovenian autochthonous pig breed - Krskopolje, which is one of the local pig breeds investigated in the project TREASURE. A collection and review of available literature data on productive traits (growth, carcass and meat quality) of Krskopolje pig breed was carried out. Literature review shows that growth rate of Krskopolje pigs from birth to slaughter is in average 492 g/day (339-637 g/day; n=6). In the studies described in the literature, slaughter was performed at the average age of 293 days (230-360 days; n=9) and 118 kg live weight (90-145 kg; n=7). Reported average dressing yield was 77.3% (71.7-80.2%; n=9) and lean meat content 43.5 % (37.5-47.8%; n=7). Backfat thickness measured at the level of the last rib was in average 38 mm (28-53 mm; n=11), whereas loin eye area and loin eye fat area were in average 32.6 and 33.0 cm2, respectively (23.2-41.7; n=5 and 27.7-42.2; n=4; respectively). In the studies reporting meat quality of Krskopolje pigs, pH 24 h post-mortem in Longissimus dorsi muscle was in average 5.46 (5.28-5.60; n=7), drip loss 48 h post-mortem reached 5.1% (3.9-6.7%; n=4) and intramuscular fat content averaged 3.5% (2.7-4.6%; n=6). Although studies on Krskopolje pig are scarce, current review gives the first insight on productive performance of this local pig breed.

Krskpolje pig in treasure project: from rearing to product

Krskopolje pig, a Slovenian autochthonous breed, is poorly researched and exploited, as is the case in many autochthonous (local) pig breeds. More knowledge about various aspects of breed characterisation, performances and socio-economic relevance is needed for the development of sustainable pork value chains. To answer these challenges, the studies are conducted within H2020 project TREASURE spanning from rearing to product evaluation. In this work, an overview of the first partial and preliminary results are presented for Krskopolje pig which concern the evaluation of growth performance in different rearing systems, effect of the incidence of RYR1 gene mutation and sensory quality and consumer acceptability of new traditional product (dry-cured sausage – salami type) from Krskopolje pigs.

The diverse effects of α- and γ-tocopherol on chicken liver transcriptome

&NA; &agr;‐Tocopherol is the form of vitamin E with the highest biological value and is almost exclusively considered as vitamin E in feed and feed supplements. Because &ggr;‐tocopherol, the predominant form of vitamin E naturally present in chicken feed, is not considered as a source of vitamin E, its re‐evaluation with newer methods might be important. Despite &ggr;‐tocopherols lower estimated biological value, it has been shown to be effective in reducing reactive nitrogen species, regulating immune and inflammatory processes, and diminishing the risk of metabolic perturbations and associated diseases. A 30‐day nutritional trial in broiler chickens (Ross 308) was conducted to investigate how specific forms of vitamin E (&agr;‐ and &ggr;‐tocopherol) and their combination impact liver gene expression when oxidative susceptibility of the organism is induced by high n‐3 polyunsaturated fatty acids (PUFA) intake (linseed oil). Thirty‐six one‐day‐old male broilers were fed a diet enriched with 5% linseed oil. A control group (Cont; N = 10) was used as a reference group, T&agr; (N = 10) was supplemented with 67 mg/kg RRR‐&agr;‐tocopherol, T&ggr; (N = 8) with 67 mg/kg RRR‐&ggr;‐tocopherol, and T&agr;&ggr; (N = 8) with a combination of 33.5 mg/kg of each tocopherol. Beside oxidative stress indicators, whole chicken genome microarray analysis was performed on liver RNA and selected differentially expressed genes were confirmed by real time quantitative PCR. &agr;‐Tocopherol alone and in combination with &ggr;‐tocopherol was able to prevent lipid oxidation, which was also supported by transcriptome analysis. The effect of &ggr;‐tocopherol was evident in the expression of genes involved in inflammatory processes and immune response, while &agr;‐tocopherol affected genes involved in lipid and cholesterol metabolism. Both isomers of vitamin E influenced the transcription of genes, which are related to improved fat oxidation and enhanced glucose sparing.