Effects of Animal Diet and Processing Methods on the Quality Traits of Dry-Cured Ham Produced from Turopolje Pigs.

The Turopolje pig (TP) is a local Croatian pig breed that almost became extinct in the second half of the 20th century. Today, the TP is still endangered, and a new conservation strategy based on products with higher added value is needed to preserve the breed. There is little information on the quality of TP meat products such as smoked and dry-cured ham, including the impact of natural feeds or processing innovations such as smoke reduction. This study, therefore, investigated the effects of the animal's diet (either conventionally fed or acorn-supplemented) and the processing method (standard or lightly smoked) on the quality traits of dry-cured TP ham. Twenty hams, evenly distributed among the treatments, were processed for 15 months and then analysed for physicochemical and textural traits, volatiles and sensory profile. The hams from acorn-supplemented pigs lost less weight during processing (p ≤ 0.05). Otherwise, the diet had no significant effect on most examined ham traits. The exceptions were protein content and the texture parameter hardness, which decreased (p ≤ 0.05), and the degree of proteolysis and colour parameters, which increased (p ≤ 0.05) as a result of acorn supplementation. However, these effects were generally small and varied between the inner (m. biceps femoris) and outer (m. semimembranosus) muscles. Furthermore, acorn supplementation was associated with less typical ham odour and lower sensory scores for sweetness and colour uniformity (p ≤ 0.05). The smoke reduction had no effect on the physicochemical and colour properties but resulted in a significant reduction (p ≤ 0.05) in the volatile phenolic compounds and an improved texture to the hams. This was reflected both in reduced (p ≤ 0.05) hardness, identified in the instrumental analysis, and in an increased (p ≤ 0.05) softness, solubility and moistness, identified in the sensory evaluation. To summarize, the quality of the TP ham under the conditions studied was only slightly affected by acorn supplementation, whereas reduced smoking had a more significant effect, which was mainly reflected in an improved texture.

A meta-analysis of genetic and phenotypic diversity of European local pig breeds reveals genomic regions associated with breed differentiation for production traits.

BACKGROUND: Intense selection of modern pig breeds has resulted in genetic improvement of production traits while the performance of local pig breeds has remained lower. As local pig breeds have been bred in extensive systems, they have adapted to specific environmental conditions, resulting in a rich genotypic and phenotypic diversity. This study is based on European local pig breeds that have been genetically characterized using DNA-pool sequencing data and phenotypically characterized using breed level phenotypes related to stature, fatness, growth, and reproductive performance traits. These data were analyzed using a dedicated approach to detect signatures of selection linked to phenotypic traits in order to uncover potential candidate genes that may underlie adaptation to specific environments. RESULTS: Analysis of the genetic data of European pig breeds revealed four main axes of genetic variation represented by the Iberian and three modern breeds (i.e. Large White, Landrace, and Duroc). In addition, breeds clustered according to their geographical origin, for example French Gascon and Basque breeds, Italian Apulo Calabrese and Casertana breeds, Spanish Iberian, and Portuguese Alentejano breeds. Principal component analysis of the phenotypic data distinguished the larger and leaner breeds with better growth potential and reproductive performance from the smaller and fatter breeds with low growth and reproductive efficiency. Linking the signatures of selection with phenotype identified 16 significant genomic regions associated with stature, 24 with fatness, 2 with growth, and 192 with reproduction. Among them, several regions contained candidate genes with possible biological effects on stature, fatness, growth, and reproductive performance traits. For example, strong associations were found for stature in two regions containing, respectively, the ANXA4 and ANTXR1 genes, for fatness in a region containing the DNMT3A and POMC genes and for reproductive performance in a region containing the HSD17B7 gene. CONCLUSIONS: In this study on European local pig breeds, we used a dedicated approach for detecting signatures of selection that were supported by phenotypic data at the breed level to identify potential candidate genes that may have adapted to different living environments and production systems.

Analysis of Early Growth of Piglets from Hyperprolific Sows Using Random Regression Coefficient.

Management of hyperprolific sows is challenging when it comes to controlling birth weight variability and piglet survival in large litters. The growth of low birth weight piglets can be compromised and have a negative impact on production efficiency. The objective of the study was to apply a random regression coefficient model to estimate the main effects of the growth of piglets of highly prolific sows. The dataset contained growth data for 360 piglets from 25 Pen Ar Lan Naima sows. In addition to routine procedures after farrowing, piglets were weighed five times: on day 1 after farrowing, on day 14 of life, at weaning on day 28, on day 30 of nursery period, and at the end of the nursery period when piglets were 83 days old. Data were treated as longitudinal, with body weight as the dependent variable. Fitting age as a quadratic regression within piglets in the random part of the model helped to determine the significant effect of birth weight, litter size, and parity on the growth of the piglets. Since the piglets from large litters often have non-uniform birth weights and this can affect further growth, the use of a random regression coefficient model is practical for analysing the growth of such piglets due to the ability to describe the individual growth pattern of every individual.

Prediction of fatty acid composition in intact and minced fat of European autochthonous pigs breeds by near infrared spectroscopy.

The fatty acids profile has been playing a decisive role in recent years, thanks to technological, sensory and health demands from producers and consumers. The application of NIRS technique on fat tissues, could lead to more efficient, practical, and economical in the quality control. The study aim was to assess the accuracy of Fourier Transformed Near Infrared Spectroscopy technique to determine fatty acids composition in fat of 12 European local pig breeds. A total of 439 spectra of backfat were collected both in intact and minced tissue and then were analyzed using gas chromatographic analysis. Predictive equations were developed using the 80% of samples for the calibration, followed by full cross validation, and the remaining 20% for the external validation test. NIRS analysis of minced samples allowed a better response for fatty acid families, n6 PUFA, it is promising both for n3 PUFA quantification and for the screening (high, low value) of the major fatty acids. Intact fat prediction, although with a lower predictive ability, seems suitable for PUFA and n6 PUFA while for other families allows only a discrimination between high and low values.

Admixture and breed traceability in European indigenous pig breeds and wild boar using genome-wide SNP data.

Preserving diversity of indigenous pig (Sus scrofa) breeds is a key factor to (i) sustain the pork chain (both at local and global scales) including the production of high-quality branded products, (ii) enrich the animal biobanking and (iii) progress conservation policies. Single nucleotide polymorphism (SNP) chips offer the opportunity for whole-genome comparisons among individuals and breeds. Animals from twenty European local pigs breeds, reared in nine countries (Croatia: Black Slavonian, Turopolje; France: Basque, Gascon; Germany: Schwabisch-Hällisches Schwein; Italy: Apulo Calabrese, Casertana, Cinta Senese, Mora Romagnola, Nero Siciliano, Sarda; Lithuania: Indigenous Wattle, White Old Type; Portugal: Alentejana, Bísara; Serbia: Moravka, Swallow-Bellied Mangalitsa; Slovenia: Krskopolje pig; Spain: Iberian, Majorcan Black), and three commercial breeds (Duroc, Landrace and Large White) were sampled and genotyped with the GeneSeek Genomic Profiler (GGP) 70 K HD porcine genotyping chip. A dataset of 51 Wild Boars from nine countries was also added, summing up to 1186 pigs (~ 49 pigs/breed). The aim was to: (i) investigate individual admixture ancestries and (ii) assess breed traceability via discriminant analysis on principal components (DAPC). Albeit the mosaic of shared ancestries found for Nero Siciliano, Sarda and Moravka, admixture analysis indicated independent evolvement for the rest of the breeds. High prediction accuracy of DAPC mark SNP data as a reliable solution for the traceability of breed-specific pig products.

Genetic diversity and population structure of six autochthonous pig breeds from Croatia, Serbia, and Slovenia.

BACKGROUND: The importance of local breeds as genetic reservoirs of valuable genetic variation is well established. Pig breeding in Central and South-Eastern Europe has a long tradition that led to the formation of several local pig breeds. In the present study, genetic diversity parameters were analysed in six autochthonous pig breeds from Slovenia, Croatia and Serbia (Banija spotted, Black Slavonian, Turopolje pig, Swallow-bellied Mangalitsa, Moravka and Krskopolje pig). Animals from each of these breeds were genotyped using microsatellites and single nucleotide polymorphisms (SNPs). The results obtained with these two marker systems and those based on pedigree data were compared. In addition, we estimated inbreeding levels based on the distribution of runs of homozygosity (ROH) and identified genomic regions under selection pressure using ROH islands and the integrated haplotype score (iHS). RESULTS: The lowest heterozygosity values calculated from microsatellite and SNP data were observed in the Turopolje pig. The observed heterozygosity was higher than the expected heterozygosity in the Black Slavonian, Moravka and Turopolje pig. Both types of markers allowed us to distinguish clusters of individuals belonging to each breed. The analysis of admixture between breeds revealed potential gene flow between the Mangalitsa and Moravka, and between the Mangalitsa and Black Slavonian, but no introgression events were detected in the Banija spotted and Turopolje pig. The distribution of ROH across the genome was not uniform. Analysis of the ROH islands identified genomic regions with an extremely high frequency of shared ROH within the Swallow-bellied Mangalitsa, which harboured genes associated with cholesterol biosynthesis, fatty acid metabolism and daily weight gain. The iHS approach to detect signatures of selection revealed candidate regions containing genes with potential roles in reproduction traits and disease resistance. CONCLUSIONS: Based on the estimation of population parameters obtained from three data sets, we showed the existence of relationships among the six pig breeds analysed here. Analysis of the distribution of ROH allowed us to estimate the level of inbreeding and the extent of homozygous regions in these breeds. The iHS analysis revealed genomic regions potentially associated with phenotypic traits and allowed the detection of genomic regions under selection pressure.

Proteolysis and protein oxidation throughout the smoked dry-cured ham process.

During the five stages of smoked dry-cured ham processing, proteolysis and protein oxidation were simultaneously detected in the Biceps femoris (BF) and Semimembranosus (SM) muscles. Proteolysis was more advanced in BF than in SM throughout the process of production. The total FAA increased significantly (p < 0.05) throughout the processing, resulting in higher total FAA content in BF than in SM muscle. SDS-PAGE revealed progressive degradation of sarcoplasmic proteins of investigated muscles, with the pronounced changes for the 69.9-41.7 kDa region. SDS-PAGE of BF showed more intense degradation of myofibrillar proteins due to greater proteolysis in BF. Electrophoresis of myofibrillar proteins evidenced the marked degradation of 130 kDa, 96.7 kDa and 27-20.7 kDa bands in both muscles. A similar trend was observed for protein oxidation in BF and SM, with the final values of 26.36 and 23.7 nmol carbonyls/mg proteins, respectively. The Pearson correlation revealed a strong relationship between protein oxidation and proteolysis.

Describing variability in pig genes involved in coronavirus infections for a One Health perspective in conservation of animal genetic resources.

Coronaviruses silently circulate in human and animal populations, causing mild to severe diseases. Therefore, livestock are important components of a "One Health" perspective aimed to control these viral infections. However, at present there is no example that considers pig genetic resources in this context. In this study, we investigated the variability of four genes (ACE2, ANPEP and DPP4 encoding for host receptors of the viral spike proteins and TMPRSS2 encoding for a host proteinase) in 23 European (19 autochthonous and three commercial breeds and one wild boar population) and two Asian Sus scrofa populations. A total of 2229 variants were identified in the four candidate genes: 26% of them were not previously described; 29 variants affected the protein sequence and might potentially interact with the infection mechanisms. The results coming from this work are a first step towards a "One Health" perspective that should consider conservation programs of pig genetic resources with twofold objectives: (i) genetic resources could be reservoirs of host gene variability useful to design selection programs to increase resistance to coronaviruses; (ii) the described variability in genes involved in coronavirus infections across many different pig populations might be part of a risk assessment including pig genetic resources.

The survival rate and efficiency of non-encapsulated and encapsulated native starter cultures to improve the quality of artisanal game meat sausages.

This study addresses the application of native, multiple strain starter cultures for standardization of game meat sausages production. The designed starter cultures consisting of two indigenous Lactobacillus sakei and one Leuconostoc mesenteroides strains. These strains were used in both, the encapsulated and non-encapsulated form, in the game meat dough, individually or in combination, with eight treatments in total. Microbiological and physicochemical characteristics of the sausages were monitored throughout the manufacturing process, while sensory properties, biogenic amine content, and volatile compounds were evaluated in the final products. As revealed by rep-PCR, native starter cultures, encapsulated or non-encapsulated, had survived the whole sausage production process; however, to varying degrees. The application of indigenous decarboxylase negative Lb. sakei strains significantly (P < 0.05) reduced tyramine content, rapidly decreased pH and promoted the number reduction of Enterobacteriaceae and elimination of E. coli, L. monocytogenes and coliforms in ready-to-eat products. A total of 84 volatile compounds were identified by SPME-GC-MS in the eight treatment batches of game meat sausages, with only minor differences between the treatments. No significant differences in sensory traits (P > 0.05) between tested treatments were found, although treatment with the Lb. sakei strains received the highest scores for the sensory traits including cross-section, odour, hardness, aroma, and overall acceptability. Combination of multi-strain Lb. sakei starter cultures resulted in growth prevention of undesirable microbiota, reduction of tyramine content and increased the acceptability parameters of full-ripened sausages, which make them good candidates for industrial as well as artisanal application.

Influence of Immunocastration on Slaughter Traits and Boar Taint Compounds in Pigs Originating from Three Different Terminal Sire Lines.

The aim of the research was to investigate the influence of terminal sire line (TSL) and male category (MC) on carcass and meat quality of commercial fatteners. The study was performed on 180 pigs originating from three terminal sire lines: A (Pietrain × Large White), B (pure Pietrain), and C (Pietrain × Duroc × Large White), being assigned to three groups according to MC: immunocastrates (IC, n = 60), surgical castrates (SC, n = 60) and entire males (EM, n = 60). TSL affected most of the carcass and meat quality traits, together with the androstenone concentration. At the same time, MC had a significant effect on fat thickness, ham circumference, drip loss, cooking loss and androstenone and skatole concentrations. A significant interaction effect was observed for carcass length and ham circumference, as well as for most of the measured meat quality traits (except cooking loss, CIE L*, CIE b*, and Warner Bratzler Shear Force (WBSF)). Among the three investigated sire lines, immunocastration was shown to be most beneficial for fatteners sired by the TSL C. However, if deciding to raise EM, fatteners from the TSL B are recommended in terms of carcass and meat quality, although strategies for avoiding boar taint in their carcasses must be taken into consideration.

Erratum: Aluwé, M. et al. Exploratory Survey on European Consumer and Stakeholder Attitudes towards Alternatives for Surgical Castration of Piglets. Animals 2020, 10, 1758.

The authors wish to make the following corrections to this paper [...].

Exploratory Survey on European Consumer and Stakeholder Attitudes towards Alternatives for Surgical Castration of Piglets.

Surgical castration of piglets without pain relief is still common practice in many countries. Possible alternatives for surgical castration are application of pain relief or anaesthesia or production of boars (entire males) and immunocastrates. Each of these alternatives faces advantages and disadvantages which may result in different citizen attitudes and consumers acceptability. Understanding which practice is acceptable to whom and why may further stimulate implementation. Consumer (n = 3251) and stakeholder (n = 1027) attitudes towards surgical castration without pain relief, surgical castration with anaesthesia, immunocastration, and production of boars were surveyed from April to June 2020 via an online questionnaire in 16 countries (>175 respondents per country). Surgical castration without pain relief was separated from each of the alternatives due to animal welfare and showed the lowest acceptability (32%). Within the alternatives, a further partitioning between the alternatives was based on perceived quality and food safety, with an acceptance of 85% for applying anaesthesia, 71% for immunocastration, and 49% for boar production. Differences depending on professional involvement and familiarity with agriculture could be observed, mainly for the acceptance of surgical castration without anaesthesia, immunocastration, and boars. Castration with anaesthesia was highly accepted by all types of respondents.

Whole-genome sequencing of European autochthonous and commercial pig breeds allows the detection of signatures of selection for adaptation of genetic resources to different breeding and production systems.

BACKGROUND: Natural and artificial directional selection in cosmopolitan and autochthonous pig breeds and wild boars have shaped their genomes and resulted in a reservoir of animal genetic diversity. Signatures of selection are the result of these selection events that have contributed to the adaptation of breeds to different environments and production systems. In this study, we analysed the genome variability of 19 European autochthonous pig breeds (Alentejana, Bísara, Majorcan Black, Basque, Gascon, Apulo-Calabrese, Casertana, Cinta Senese, Mora Romagnola, Nero Siciliano, Sarda, Krskopolje pig, Black Slavonian, Turopolje, Moravka, Swallow-Bellied Mangalitsa, Schwäbisch-Hällisches Schwein, Lithuanian indigenous wattle and Lithuanian White old type) from nine countries, three European commercial breeds (Italian Large White, Italian Landrace and Italian Duroc), and European wild boars, by mining whole-genome sequencing data obtained by using a DNA-pool sequencing approach. Signatures of selection were identified by using a single-breed approach with two statistics [within-breed pooled heterozygosity (HP) and fixation index (FST)] and group-based FST approaches, which compare groups of breeds defined according to external traits and use/specialization/type. RESULTS: We detected more than 22 million single nucleotide polymorphisms (SNPs) across the 23 compared populations and identified 359 chromosome regions showing signatures of selection. These regions harbour genes that are already known or new genes that are under selection and relevant for the domestication process in this species, and that affect several morphological and physiological traits (e.g. coat colours and patterns, body size, number of vertebrae and teats, ear size and conformation, reproductive traits, growth and fat deposition traits). Wild boar related signatures of selection were detected across all the genome of several autochthonous breeds, which suggests that crossbreeding (accidental or deliberate) occurred with wild boars. CONCLUSIONS: Our findings provide a catalogue of genetic variants of many European pig populations and identify genome regions that can explain, at least in part, the phenotypic diversity of these genetic resources.

Consumers' expectations and liking of traditional and innovative pork products from European autochthonous pig breeds.

The aim of the study was to ascertain the acceptability of Traditional (T) and Innovative (IT) pork products by European consumers considering also the influence of the sensory properties. The tests were performed in Barcelona, Bologna, Toulouse and Zagreb, with products from autochthonous pig breeds Porc Negre Mallorquí (patties), Cinta Senese (dry-fermented sausages), Gascon-Noir de Bigorre (dry-cured hams) and Turopolje (dry-cured hams), respectively. The methodological approach relied on the expectancy-disconfirmation model and the assimilation theory (blind, expected and informed tests). All consumers had a similar behaviour: higher expectations of T and IT differentiating them significantly from the remaining products, except in Barcelona test, because consumers in this city were not acquainted with the production system. Innovation in T products focusing on healthy and process innovation highlighted the need to provide information about the breed and the production system, but we can conclude that the sensory quality had a significant role on the preferences of consumers.

The effect of salting time and sex on chemical and textural properties of dry cured ham.

Effect of reduced salting and pig sex on the quality of Slovenian dry-cured ham Kraski prsut 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.

Diversity across major and candidate genes in European local pig breeds.

The aim of this work was to analyse the distribution of causal and candidate mutations associated to relevant productive traits in twenty local European pig breeds. Also, the potential of the SNP panel employed for elucidating the genetic structure and relationships among breeds was evaluated. Most relevant genes and mutations associated with pig morphological, productive, meat quality, reproductive and disease resistance traits were prioritized and analyzed in a maximum of 47 blood samples from each of the breeds (Alentejana, Apulo-Calabrese, Basque, Bísara, Majorcan Black, Black Slavonian (Crna slavonska), Casertana, Cinta Senese, Gascon, Iberian, Krskopolje (Krskopoljski), Lithuanian indigenous wattle, Lithuanian White Old Type, Mora Romagnola, Moravka, Nero Siciliano, Sarda, Schwäbisch-Hällisches Schwein (Swabian Hall pig), Swallow-Bellied Mangalitsa and Turopolje). We successfully analyzed allelic variation in 39 polymorphisms, located in 33 candidate genes. Results provide relevant information regarding genetic diversity and segregation of SNPs associated to production and quality traits. Coat color and morphological trait-genes that show low level of segregation, and fixed SNPs may be useful for traceability. On the other hand, we detected SNPs which may be useful for association studies as well as breeding programs. For instance, we observed predominance of alleles that might be unfavorable for disease resistance and boar taint in most breeds and segregation of many alleles involved in meat quality, fatness and growth traits. Overall, these findings provide a detailed catalogue of segregating candidate SNPs in 20 European local pig breeds that may be useful for traceability purposes, for association studies and for breeding schemes. Population genetic analyses based on these candidate genes are able to uncover some clues regarding the hidden genetic substructure of these populations, as the extreme genetic closeness between Iberian and Alentejana breeds and an uneven admixture of the breeds studied. The results are in agreement with available knowledge regarding breed history and management, although largest panels of neutral markers should be employed to get a deeper understanding of the population's structure and relationships.