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The Slovenian Krškopolje pig is the only preserved local autochthonous breed, appreciated mainly for its good meat quality and considered more appropriate for processing into dry-cured products. However, the biological characteristics of the skeletal myofibers of the Krškopolje breed, specifically the heavy myosin chain-based contractile and metabolic phenotypes that could affect meat quality, have not been established under different husbandry systems. The breed is generally maintained in either conventional indoor or organic systems. In the present study, the morphological, contractile, and metabolic properties of myofibers of the longissimus dorsi muscle were compared between animals reared in either an organic or a conventional indoor system. The myofibers were studied using immunohistochemical and succinate dehydrogenase (SDH) activity-based classification, histomorphometric assessment, and qPCR. Results revealed that the organic production system influenced the composition of the longissimus dorsi myofiber type, characterized by a smaller myofiber cross-sectional area, a shift toward oxidative (SDH-positive) myofiber types, increased relative expression of myosin heavy chain (MyHC) isoforms I, IIa, and IIx, and downregulation of MyHC IIb. On the contrary, no apparent effect was observed on the metabolic phenotype of the myofiber as assessed through relative mRNA expression of energy metabolism-related genes [peroxisome proliferator-activated receptor gamma, coactivator 1 alpha (PGC-1α), peroxisome proliferator-activated receptor gamma (PPARγ), lipoprotein-lipase (LPL), carnitine palmitoyltransferase 1B (CPT1B), glycogen synthase 1 (GYS1), hexokinase 2 (HK2), and fatty acid synthase (FASN)]. Differences in MyHC expression were largely corroborated by the histochemical classification, indicating that the contractile protein content is directly regulated by the MyHC genes. A correlation between the muscle contractile and metabolic phenotypes was not established, except for that between the HK2 and MyHC I genes. In conclusion, the present study showed an evident effect of rearing on the longissimus dorsi myofiber contractile phenotype but not the metabolic phenotype. Moreover, obtained data suggest that rearing the Krškopolje pig breed in a conventional system would result in an increased fiber size and a greater proportion of type IIb myofibers, which are known to be negatively correlated with some meat quality traits.

Simple Summary Intensive selective breeding and genetic improvement of relatively few pig breeds led to the abandonment of many low productive local pig breeds. However, local pig breeds are more highly adapted to their specific environmental conditions and feeding resources, and therefore present a valuable genetic resource. They are able to deposit more fat and have a distinct lipogenic capacity, along with a better fatty acid composition than modern breeds. Physiological, biochemical and genetic mechanisms responsible for the differences between fatty and lean breeds are still not fully clarified. The present paper highlights important associations to better understand the underlying mechanisms of lipid deposition in subcutaneous and intramuscular fat between fatty and lean breeds. Abstract Modern pig breeds, which have been genetically improved to achieve fast growth and a lean meat deposition, differ from local pig breeds with respect to fat deposition, fat specific metabolic characteristics and various other properties. The present review aimed to elucidate the mechanisms underlying the differences between fatty local and modern lean pig breeds in adipose tissue deposition and lipid metabolism, taking into consideration morphological, cellular, biochemical, transcriptomic and proteomic perspectives. Compared to modern breeds, local pig breeds accumulate larger amounts of fat, which generally contains more monounsaturated and saturated fatty acids; they exhibit a higher adipocyte size and higher activity of lipogenic enzymes. Studies using transcriptomic and proteomic approaches highlighted several processes like immune response, fatty-acid turn-over, oxidoreductase activity, mitochondrial function, etc. which differ between local and modern pig breeds.

Effect of reduced salting and pig sex on the quality of Slovenian dry-cured ham Kraški pršut was studied. A total of 48 hams from 24 crossbred pigs (12 gilts, 12 castrates) were submitted to two different salting regimes ; standard salting for 18 days (HS hams, n = 24) and shortened salting (LS hams, n = 24) for 10 days. Reduced salting time effectively reduced salt content but resulted also in higher extent of proteolysis of LS hams which was associated with differences in texture and colour of biceps femoris muscle. Lower fat oxidative stability was observed in HS hams. With regard to sex effect, the hams originating from gilts were more proteolysed which was associated with differences in texture and colour. Lipid oxidation was similar in gilts and castrates.

The EU is supporting measures that stimulate enhanced value-added products in order to conserve local and threatened livestock breeds. Several Traditional Pork Products (TPP) and Innovative Traditional Pork Products (ITPP) with health innovations from four untapped pig breeds in Spain (Porc Negre Mallorquí), Croatia (Turopolje), Italy (Cinta Senese) and Slovenia (Krškopolje) were analysed. Consumers' “Non-hypothetical” willingness to pay (WTP) and hedonic evaluation were investigated. An integrated experimental approach using two Non-Hypothetical Discrete Choice Experiment (NH-DCE) was carried out before and after a hedonic evaluation test. Results showed that the health innovative products (ITPP) received similar and even lower WTP than the “control” products (TPP) from the untapped pig breeds. The TPP outperformed products enriched with healthy ingredients or with reduced undesirable compounds. The potential demand for traditional and “unaltered” product from the rustic pig breeds could contribute to their conservation. A market niche exists, where consumers appreciate these high-quality products and where no “add-ons” are required to enhance their uptake. info:eu-repo/semantics/acceptedVersion

Traits of interest concerning reproductive performance, growth performance, carcass and meat quality of local pig breeds involved in H2020 project TREASURE were collected from the available literature, unpublished data available to partners or results recorded in the experiments within the project. The survey revealed great variability in the availability and quality of information. Reproductive performance of local pig breeds is lower than in conventional modern pig breeds, not only due to their genetic background but also due to the management. Data on growth rates reflect the heterogeneity of different production systems and feeding regimes used. The growth potential of the majority of local pig breeds is not well exploited, and their nutritional requirements are not known. Generally, local pig breeds show low muscular development and high potential for fat tissue deposition and are slaughtered at older age and weight, which results in higher intramuscular fat and more intense colour of meat. However, considerable differences exist between them and their potentials, not only in their production systems. For many local pig breeds studied in the project, the collected information provides the first in-depth overview of their productive performance in their preserved, present-day phenotype., The research was conducted within the project TREASURE, which received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 634476. The content of this chapter reflects only the authors’ view and the European Union Agency is not responsible for any use that may be made of the information it contains. Core financing of Slovenian Research Agency is acknowledged (grant P4-0133 for MČP, NBL, UT and MŠ).

Environmental assessment of pig production systems using local breeds remains poorly documented in the literature. So far, studies did not account for specificities of outdoor rearing which is quite common in such systems. The present study aimed at evaluating the environmental impacts of pig production systems using local breeds in Europe, while accounting for emissions associated to consumption of grass and mitigation of impacts through soil-C sequestration. Environmental impacts were estimated for 48 farms using local pig breeds: 25 in France (Gascon breed), eight in Italy (Mora Romagnola breed) and 15 in Slovenia (Krskopolje breed). Assessment was performed with and without accounting for pasture-intake emissions and potential soil-C sequestration. The data were obtained from on-farm surveys. Systems with Gascon pigs had the lowest impacts per kg of live weight for global warming and cumulative energy demand, due to lower impacts of feeds. Acidification potential was higher for Krskopolje pigs due to high dietary crude protein content and high AP of feeds, while eutrophication potential was higher for Gascon pigs due to higher phosphorus content of feeds (28% higher than the mean of the other farms). When impacts were expressed per ha of land use, pig production in Gascon farms had the lowest impacts due to more available area per pig, except for eutrophication. Low contribution of soil-C sequestration to climate change mitigation was observed (4.7% on average). However, it may have a substantial contribution for the most extensive pig systems using large land surfaces. Emissions resulting from grazing had a rather low contribution to Global Warming Potential (4%) and Eutrophication (3%), but a substantial one to Acidification impact (9% on average). In the frame of our study, the contribution of emissions related to grazing is moderate because commercial feed supply for outdoor pigs was higher than in extensive systems studied in literature. This study highlighted that main hotspots include feed composition and supply and the origin of feed ingredients. It also suggests that future assessments of extensive pig systems relying on pig foraging on grasslands or rangelands should account for soil-C sequestration and emissions associated to grazing and foraging.

There are indications of reduced meat quality in entire male pigs (EMs) in comparison to surgically castrated pigs (SCs), however, the differences are not strongly confirmed, and the etiology is not clarified. In the present study, samples of the longissimus dorsi, pars lumborum muscle (LL) from EMs (n = 12) and SCs (n = 12) of the same age and weight were evaluated at the physico-chemical and proteomic level. EMs exhibited lower intramuscular fat content, higher collagen content with higher solubility, a higher level of protein carbonyl groups (indicating higher protein oxidation), lower water holding capacity, and tougher meat than SCs. Proteomic analysis revealed differences in heat shock proteins expression, while a greater abundance of several other identified proteins (malate dehydrogenase, Na/K-transporting adenosintriphosphatase (ATP-ase) subunit alpha-1, and blood plasma proteins) indicates that EMs have a more oxidative metabolic profile than that of SCs. More abundant protein fragments (mainly actin and myosin heavy chain) suggest a higher degree of proteolysis in EMs, which was not followed by lower meat toughness.

Oxidation is one of the major reasons for impaired quality of meat and meat products but can be prevented by the addition of antioxidants. In the present study, the effect of dietary sweet chestnut wood extract and hop cones on the quality and oxidative stability of meat and dry-cured products was investigated. Control pigs (N = 11) were fed a commercial diet (13.1 MJ metabolizable energy, 15.5% crude protein), while the other two experimental groups were supplemented with 3% of sweet chestnut wood extract (Tannin, N = 12) or 0.4% of hop cones (Hops, N = 11). The quality of meat and dry-cured products was evaluated by means of chemical composition, water holding capacity, objective color, and lipid and protein oxidation. No major effects of sweet chestnut wood extract or of hops supplementation were observed, nevertheless, some indications of improved water holding capacity could be attributed to antioxidants supplementation. The color evolution of dry-cured bellies from Tannin and Hops groups of pigs during refrigerated storage was also indicative of an improved oxidative stability.

Data on production traits of the only Slovenian autochthonous pig breed, the Krškopolje pig, is very scarce. Krškopolje pigs are reared in conventional and organic production systems, which were compared in the present study. After weaning, 24 barrows were assigned within litter to either conventional (CON) or organic (ECO) rearing system. Group CON (n=12) was housed indoors in two pens (7.5 m2) with partly slatted floor. Group ECO (n=12) was held in a sty with sheltered area (concrete floor, bedded with straw, 16 m2) and outdoor paddock area (100 m2). The trial started when pigs had 68±8 kg BW and 157±6 days of age. Two diets were formulated with equivalent ingredients and composition. For ECO diet the ingredients used were ecological. Group ECO received a diet with 12.4 MJ metabolisable energy (ME) per kilogram and 12.9% CP and group CON a diet with 12.7 MJ ME/kg and 13.6% CP. Feed distribution was limited to 3.5 kg per pig daily. In line with the rules for organic production, ECO pigs were additionally given alfalfa hay ad libitum. After 73 days on trial, the pigs were slaughtered and carcass, meat and fat quality was evaluated. Meat quality traits (pH, colour, water holding capacity), fatty acid composition, lipid and protein oxidation, collagen content and solubility were analysed in longissimus lumborum (LL) muscle. Fatty acid composition, lipid oxidation, and vitamins A and E concentrations were determined in backfat. There were no significant differences in growth rate and carcass traits between ECO and CON pigs, however, ECO pigs tended (Plt;0.10) to have higher daily gain and lower dressing percentage, higher (Plt;0.001) pH 45 min and lower (Plt;0.01) pH 24 h postmortem, affecting (Plt;0.10) also water holding capacity and objective colour parameters (Plt;0.05) of LL muscle. There were no differences in intramuscular fat (IMF) content of LL muscle, however, IMF of ECO pigs had lower (Plt;0.05) proportion of saturated and higher (Plt;0.01) proportion of monounsaturated fatty acids accompanied by higher (Plt;0.001) values of thiobarbituric reactive substances (TBARS). In backfat, ECO pigs showed lower (Plt;0.05) vitamin E content, higher (Plt;0.001) TBARS, higher (Plt;0.01) degree of unsaturation (percentage of polyunsaturated fatty acids), and also higher (Plt;0.05) vitamin A concentration than CON pigs, which can be related to alfalfa hay supplementation of ECO pigs. In brief, organic rearing of Krškopolje pigs did not affect performances but had an effect on meat and fat quality.

The effect of dietary fibre content on intestinal production of indolic compounds was studied in immunocastrated pigs (IC). In addition, entire males (EM) and IC were compared on control diet (with low fibre content). For the study 32 crossbred pigs were assigned, within a litter to 4 treatment groups; 24 pigs were immunocastrated (at the age of 77 and 112 days) and 8 pigs were kept as entire males (EM). IC were split into three groups (IC_H, IC_M and IC_L) fed three diets differing in crude fibre (34, 60 and 80 g/kg dry matter, respectively) and net energy (NE) (10.0, 9.3, 8.5 MJ NE/kg/DM, respectively). EM were fed high NE i.e. low fibre diet. The experiment started when pigs were 84 days old and finished at the age of 172 days, when pigs were sent to slaughter. Skatole and indole concentrations were determined in the samples of intestinal content taken from caecum (CE), ascending (AC) and descending colon (DC). The concentration of indole was the highest in CE and proximal part of the colon, while skatole concentration increased in the distal parts of the large intestine. Concentrations of indolic compounds did not differ between EM and IC that were fed the same diet. Lowering dietary NE by inclusion of high fibre ingredients reduced the production of indole in the intestinal content of IC pigs, whereas the production of skatole was not affected.

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.

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., The research has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 634476 (Project acronym TREASURE). The content of this paper reflects only the authors’ view and Research Executive Agency is not responsible for any use that may be made of the information it contains. Authors also acknowledge the financial support of the Slovenian Research Agency (grants P4-0133 and V4-1417) and the Ministry of Agriculture, Food and Forestry (V4-1417), from AGL2015-64673-R (MINEICO, Spain) and FEDER funds.

α-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 γ-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 γ-tocopherol's 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 (α- and γ-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, Tα (N = 10) was supplemented with 67 mg/kg RRR-α-tocopherol, Tγ (N = 8) with 67 mg/kg RRR-γ-tocopherol, and Tαγ (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. α-Tocopherol alone and in combination with γ-tocopherol was able to prevent lipid oxidation, which was also supported by transcriptome analysis. The effect of γ-tocopherol was evident in the expression of genes involved in inflammatory processes and immune response, while α-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.

The objective of the present study was to determine the effect of linseed oil supplementation on performance, fatty acid composition and oxidative status of rabbits. Twelve male SIKA rabbits were divided into two groups. The control group (n = 4) received commercial diet and the linseed group (n = 8) received commercial diet containing 9% of linseed oil, which was sprayed onto the pellet. Rabbits were slaughtered at 115 days of age, 52 dazs after the start of the experiment. Live weight, weight gain, feed intake and feed efficiency were recorded. The fatty acid composition of muscle, adipose tissue and liver was determined by the in situ transesterification method and gas chromatography-flame ionisation detection (GC-FID). In order to evaluate the oxidative status of rabbits, the malondialdehyde (MDA) concentration in plasma, liver and muscle were measured. The results show that it is possible to enhance proportion of n-3 polyunsaturated fatty acids (PUFA) in rabbit's muscle, adipose tissue and liver by adding linseed oil in the diet without detrimental effect on productive performance. Linseed oil addition improved fatty acid composition in all tissues by increased PUFA proportion and decreased proportion of saturated and monounsaturated fatty acid. Linseed oil also reduced n-6/n-3 PUFA ratio in all tissues. However, linseed oil addition led to significantly higher MDA concentrations in plasma, liver and muscle. Since PUFA are highlz susceptible to oxidation, further research is needed to focus on protecting animal and their products from lipid oxidation by adding various natural antioxidants to the diet. V poskusu smo preučevali vpliv dodatka lanenega olja v krmo na proizvodne lastnosti, maščobnokislinsko sestavo in oksidacijski status kuncev. Dvanajst kuncev slovenske mesne linije SIKA smo razdelili v dve skupini. Kontrolna skupina (n = 4) je uživala standardno krmo, poskusna skupina (n = 8) pa standardno krmo z dodatkom 9 % lanenega olja, ki smo ga nanesli na pelete. Kunce smo zaklali pri starosti 115 dni, 52 dni po začetku poskusa. V času poskusa smo zapisovali maso živali, prirast, zauživanje in izkoristek krme. Maščobnokislinsko sestavo mišic, maščobnega tkiva in jeter smo določili z in situ transesterifikacijo in kapilarno plinsko kromatografijo. Za določitev oksidacijskega statusa kuncev smo izmerili koncentracijo malondialdehida (MDA) v plazmi, jetrih in mišici. Rezultati so pokazali, da lahko z dodatkom lanenega olja v krmo kuncev povečamo dele n-3 večkrat nenasičenih maščobnih kislin (VNMK) v mišici, maščobnem tkivu in jetrih brez negativnih učinkov na proizvodne lastnosti. Dodatek lanenega olja je izboljšal maščobnokislinsko sestavo s povečanjem deleža VNMK in zmanjšanjem deleža nasičenih in enkrat nenasičenih maščobnih kislin, kar je znižalo tudi razmerje n-6/n-3 VNMK v vseh tkivih. Dodatek lanenega olja je značilno povečal koncentracijo MDA v plazmi, jetrih in mišici. Ker so VNMK zelo podvrene oksidaciji, so potrebne nadaljnje raziskave, v katerih se bo potrebno osredotočiti na zaščito živali in njihovih produktov pred lipidno oksidacijo z dodajanjem različnih naravnih antioksidantov v krmo.

The only Slovenian autochthonous pig breed (krškopolje) reared in very diverse conditions. Many small-scale breeders are rearing these pigs in extensive conditions, often using a combination of indoor and outdoor system, while some breeders are dealing with a more intensive production.

Local pig breeds are adapted to specific local environment and fed various locally available feedstuffs. So, besides their genetic merit for agro-biodiversity, they represent the basis for sustainable local pork chains.