Lean Meat Content Research Articles

Organic rearing of non-castrated male pigs: welfare indicators, carcass traits, pork quality and boar taint in Duroc and Pietrain crossbreds

The main principles of organic farming as presented by the European organisation for organic food and farming are health, ecology, fairness and care, but the intrinsic quality of products is also important for consumers. Pig genotype was tested as a lever to improve animal welfare and pork quality (meat tenderness, processing ability) of organic, non-castrated males while controlling the risk for boar taint. Non-castrated Large White × Duroc (D, n = 47) or Large White × Pietrain NN (P, n = 34) males were involved in two batches, each including one group of pigs per genotype. Each group was reared in a pen from the same building on deep straw bedding (1.3 m2/pig), with a feeding zone (0.2 m2/pig) and an outdoor area (1.0 m2/pig), from 28 kg BW until slaughter at ca. 125 kg BW. All pigs received ad libitum the same growing and finishing diets, and hay. Overall, health and welfare indicators showed few problems, but the proportions of pigs with skin scratches, and tail lesions at the end of the finishing period, were lower in D than in P pigs (P < 0.05). Growth rate and final BW did not differ between genotypes. The D pigs had lower carcass lean meat content (P < 0.001) and relative proportions of ham and loin (P ≤ 0.01), and higher proportions of belly and backfat (P ≤ 0.001) than P pigs. Compared to P, loin (Longissimus muscle) of D pigs was less light and exudative and had higher chroma (P < 0.05), but pH 24 h and glycolytic potential did not differ. Loin meat of D pigs had higher intramuscular fat content (P < 0.001) and tended to have a lower shear force (P = 0.09), but cooking loss did not differ. In the ham muscles, D pigs had higher chroma than P pigs in the Gluteus medius, whereas pH 24 h did not differ in the Gluteus medius and Semimembranosus. D pigs had higher backfat concentrations of androstenone (P < 0.001), and skatole and indole (P < 0.05) than P pigs, suggesting a higher risk of rejection by consumers due to boar taint. However, only one D carcass was detected as tainted by human nose test. Altogether, organic farming of non-castrated Duroc crossbred males appears to be favourable for animal welfare, technological and several sensory pork properties provided that the risk of undesirable odours is limited through management practices.

Genome-Wide Association Study for Meat Quality Traits in a Multi-Breed Pig Population

Abstract This study aimed at identifying genomic regions that affect nine pork quality traits in purebred and crossbred fatteners. A total of 259 fatteners represented by six purebreds/crosses were genotyped for 45556 SNP markers by Illumina Porcine SNP60 BeadChip. The following traits were recorded: glycogen potential (GP), glycogen content (GC), lactate content (LC), pH35, pH24, pH48, drip loss after 48 hours (DL48), colour lightness (L *) and lean meat content (LMC). Multi-Locus Mixed Model methodology was applied to find associations between SNP markers and recorded traits. Several SNPs were found to be significantly associated with some pork quality traits: four SNPs (located on SSC7, SSC10 and SSC14) with GP, three SNPs (SSC10, SSC14) with GC, one SNP (SSC15) with DL48 and one SNP with pH48. Genetic variation explained by significant SNPs ranged from 7.6% to 9.1%. Moreover, some genes (e.g. CAPN10, ALDH5A1, PASK, SNITA1 and MYH7B) located in the close vicinity to significant markers are proposed to be candidate genes explaining the genetic background of the traits studied.

Feeding strategy in organic pig farming as a lever to improve various quality dimensions of pork

Since 2022, European specifications for organic pig farming have evolved to distribute 100 % organic feed and to reinforce the link to the soil with feed resources that should primarily be obtained from the farm or the same region. Feeding strategy acts as a lever to improve various quality dimensions of organic (as well as conventional) pork, including intrinsic dimensions (carcass composition, nutritional, organoleptic, technological, sanitary qualities) and extrinsic dimensions related to animal farming (image). Diet may also influence the risk of undesirable odours or flavours that may be found in pork from non-castrated male pigs. This study aimed at evaluating the effects of a specific feeding strategy on several quality dimensions of organic meat from non-castrated male pigs. The experiment was conducted with 77 organic non-castrated male pigs (Piétrain NN × Large White) reared according to organic specifications and distributed in two batches. Within litters, male littermates were allocated at around 33 kg of live weight to either a Control group which received a Control feed (C) corresponding to the organic specifications or in a Bio+ group which received an organic test feed based mainly on French raw materials and which contained more fibres (faba bean and access to forages) and omega-3 fatty acids (linseed, camelina). All pigs were reared in the same building on deep straw bedding (1.3 m2/pig) with free outdoor access (1.0 m2/pig) using one pen per experimental group. Pigs were fed ad libitum until slaughter at about 125 kg live weight. Average daily gain, carcass weight and lean meat content did not differ significantly between C and Bio+ pigs. Compared to C, Bio+ pigs had higher (P < 0.05) ultimate pH in the loin (Longissimus muscle) and ham (Gluteus medius, and Semimembranosus) muscles, associated with a lower Longissimus muscle glycolytic potential (P < 0.001). Loin and ham meat from Bio+ vs. C pigs was lighter (P < 0.05) and had a more intense red colour (P < 0.10). The Bio+ strategy led to a lower Longissimus muscle n-6:n-3 fatty acid ratio (P < 0.001), indicating an improvement in pork nutritional value. Backfat skatole concentration was lower in Bio+ than in C pigs whereas backfat androstenone was higher in Bio+ than in C pigs (P < 0.05). Altogether, we demonstrated that the Bio+ strategy had positive impacts on several qualities of organic pork from non-castrated male pigs.

Properties and physiological effects of dietary fiber-enriched meat products: a review

Meat is a rich source of high biological proteins, vitamins, and minerals, but it is devoid of dietary fiber, an essential non-digestible carbohydrate component such as cellulose, hemicellulose, pectin, lignin, polysaccharides, and oligosaccharides. Dietary fibers are basically obtained from various cereals, legumes, fruits, vegetables, and their by-products and have numerous nutritional, functional, and health-benefiting properties. So, these fibers can be added to meat products to enhance their physicochemical properties, chemical composition, textural properties, and organoleptic qualities, as well as biological activities in controlling various lifestyle ailments such as obesity, certain cancers, type-II diabetes, cardiovascular diseases, and bowel disorders. These dietary fibers can also be used in meat products as an efficient extender/binder/filler to reduce the cost of production by increasing the cooking yield as well as by reducing the lean meat content and also as a fat replacer to minimize unhealthy fat content in the developed meat products. So, growing interest has been observed among meat processors, researchers, and scientists in exploring various new sources of dietary fibers for developing dietary fiber-enriched meat products in recent years. In the present review, various novel sources of dietary fibers, their physiological effects, their use in meat products, and their impact on various physicochemical, functional, and sensory attributes have been focused.

Effect of the Inclusion of Extruded Flaxseed in the Diet of Fattening Pigs on Performance Parameters and Blood Parameters

Abstract The aim of the study was to determine the effect of the inclusion of 2%, 4% and 6% extruded flaxseed in the diet of fattening pigs on their growth performance parameters, carcass parameters, and selected blood parameters. The experiment was conducted on 160 weaners (from about 30 kg to about 110 kg BW) assigned to four experimental groups of 40 animals each (5 replicates with 8 individuals each). The animals in control group received a diet in which the source of fat was soybean oil. The other groups received extruded flaxseed (FE) in place of soybean meal in the amount of 2% (group 2FE); 4% (group 4FE) and 6% (group 6FE). Soybean oil was added to the diets in the experimental treatments to obtain equal amounts of fat. The inclusion of 2% and 4% extruded flaxseed in the diet of fatteners in place of soybean meal significantly improved the digestibility of basic nutrients, i.e. ether extract (by about 5%) and dietary fibre (by more than 20%) and led to better growth performance (higher BW by about 11%; higher ADG by about 20% and lower FCR by about 12%) vs group C. In the groups with 2% and 4% extruded flaxseed there was also an increase in the lean meat content of the carcasses (by about 6%) and the thickness of the backfat (by about 6.5%) vs group C. The inclusion of extruded flaxseed did not affect the animals’ condition, as indicated by the haematological and biochemical parameters of the blood, which were within reference ranges. The results for production, nutrient digestibility and carcass analysis between groups 2FE and 4FE were similar, and at this stage of research indicate that the use of 2% extruded flaxseed is economically more justified.

Integrated analysis of genome-wide association studies and 3D epigenomic characteristics reveal the BMP2 gene regulating loin muscle depth in Yorkshire pigs.

The lack of integrated analysis of genome-wide association studies (GWAS) and 3D epigenomics restricts a deep understanding of the genetic mechanisms of meat-related traits. With the application of techniques as ChIP-seq and Hi-C, the annotations of cis-regulatory elements in the pig genome have been established, which offers a new opportunity to elucidate the genetic mechanisms and identify major genetic variants and candidate genes that are significantly associated with important economic traits. Among these traits, loin muscle depth (LMD) is an important one as it impacts the lean meat content. In this study, we integrated cis-regulatory elements and genome-wide association studies (GWAS) to identify candidate genes and genetic variants regulating LMD. Five single nucleotide polymorphisms (SNPs) located on porcine chromosome 17 were significantly associated with LMD in Yorkshire pigs. A 10 kb quantitative trait locus (QTL) was identified as a candidate functional genomic region through the integration of linkage disequilibrium and linkage analysis (LDLA) and high-throughput chromosome conformation capture (Hi-C) analysis. The BMP2 gene was identified as a candidate gene for LMD based on the integrated results of GWAS, Hi-C meta-analysis, and cis-regulatory element data. The identified QTL region was further verified through target region sequencing. Furthermore, through using dual-luciferase assays and electrophoretic mobility shift assays (EMSA), two SNPs, including SNP rs321846600, located in the enhancer region, and SNP rs1111440035, located in the promoter region, were identified as candidate SNPs that may be functionally related to the LMD. Based on the results of GWAS, Hi-C, and cis-regulatory elements, the BMP2 gene was identified as an important candidate gene regulating variation in LMD. The SNPs rs321846600 and rs1111440035 were identified as candidate SNPs that are functionally related to the LMD of Yorkshire pigs. Our results shed light on the advantages of integrating GWAS with 3D epigenomics in identifying candidate genes for quantitative traits. This study is a pioneering work for the identification of candidate genes and related genetic variants regulating one key production trait (LMD) in pigs by integrating genome-wide association studies and 3D epigenomics.

The effect of feeding fattener pigs with hybrid rye on selected growth and carcass traits and on meat quality characteristics

Abstract Modern hybrid varieties of rye can be successfully used for feeding pigs. The aim of the research was to determine the effects of different levels (20%, 40% and 60%) of hybrid rye in diet on the growth, slaughter value, chemical composition, physical and sensory traits and the fatty acids profile in pork meat. The experiment was performed with 100 Polish Landrace pigs that were randomly allocated into 4 groups: control, without rye, and experimental with hybrid rye addition. After slaughter lean meat content estimation, carcass traits, quality characteristics and the fatty acids profile of the longissimus lumborum muscle were determined. No significant influence on the growth performance, carcass traits and the majority of physical traits, basic composition, cholesterol content and sensory features of the longissimus lumborum muscle was found. The type and levels of cereals significantly change the FA profile. More favorable values for PUFA and the ratio of n-6/n-3 acids were obtained in pigs fed with hybrid rye than with a mix of wheat with barley. In conclusion, feeding pigs with hybrid rye at the level of 20–60% in the diet results in positive effects in the fatty acids profile, without compromising daily gain, feed intake, carcass traits, physicochemical and sensory attributes of pork meat.

Short-term supplementation of zinc nanoparticles in weaned piglets affects zinc bioaccumulation and carcass classification

High doses of zinc have been used as a prevention against weaned piglets' diarrhea for many years. Nevertheless, since 2022 high doses of zinc oxide have been banned in EU. Currently, there are several studies about the potential of zinc nanoparticles in lower doses which could maintain a preventive effect. Several concerns about nanoparticles' toxicity and bioaccumulation have been raised in many other fields of research. The aim of this short follow-up study is focused on the impact of zinc nanoparticles used as a prevention of diarrhea for weaned piglets, on the classification of slaughtered pigs’ carcasses and on zinc retention in muscle tissue. Seventy piglets (10 groups of 7 piglets) were fed a standard diet. The treated groups’ diets were supplemented with zinc oxide (ZnO), and phosphate-based nanoparticles: spherical- shaped type A (ZnA) and irregular-shaped: type C (ZnC), at the doses of 500, 1000 and 2000 mg Zn equivalent per kilogram of diet. The control group´s diet was not treated with zinc in any form. The feed experiment started when the piglets were 28 days old and lasted for 10 days. Experimental animals were grown to the final weight 120 ± 10 kg and slaughtered in a slaughterhouse. The pig carcasses were evaluated according to S/EUROP standards: the pigs’ weight, back fat thickness and lean meat content were monitored. Moreover, zinc concentrations in M. longissimus dorsi et thoracis were analyzed. The results have not proved significant changes in S/EUROP standard classification and zinc bioaccumulation in muscle tissue. This follow-up experiment was carried out as part of maintaining a precautionary approach to the use the nanoparticles in piglet fattening. In our study we did not confirm their effect on the assessment of carcass classification and their bioaccumulation in muscle tissue.

Effect of feeding Alphitobius diaperinus meal on fattening performance and meat quality of growing-finishing pigs

ABSTRACT A total of 48 piglets with an average weight of 26 kg were allocated to 4 experimental groups of 12 animals, balanced according to litter, sex and weight, and fattened on feed containing 0, 3, 6, or 9% of Alphitobius diaperinus meal (ADM) replacing soybean meal (SOY) as protein source. The control feed contained 10.7% SOY while in the 9% ADM feed SOY was completely replaced. Feed was accessible ad libitum in transponder-controlled feeders. Feed consumption and fattening performance records started when the animals reached 35 kg. The 3-way crossbred animals (Landrace x Large White sows mated to Duroc, Pietrain, or Large White sire line bores) were slaughtered at a target carcass weight of 86 kg. No linear effect of ADM on daily gain and feed consumption was found. No effect on lean meat content nor on any of the meat quality traits was observed. The content of polyunsaturated fatty acids (PUFA) in the backfat increased with increasing amount of ADM in the feed. It is concluded that ADM may replace SOY in pig feed without exerting detrimental effects on growth performance, carcass composition and meat quality except for a higher PUFA-content in the adipose tissue.

Pork quality traits and associated muscle metabolic changes in pigs under chronic prenatal and postnatal heat stress.

Chronic heat stress (HS) is a major concern affecting pig growth performance and metabolism, with potential consequences on carcass and meat quality traits. The objective of this study was to assess the influence of prenatal (PE) and growing (GE) thermal environments, and their combination, on muscle metabolism, carcass characteristics, and pork quality. From 6 to 109 d of gestation, 12 sows (1 per block) were kept under thermoneutral (TN) conditions (cyclic 18 to 24 °C; PTN) and 12 sows under chronic HS (cyclic 28 to 34 °C; PHS). Two female offspring per sow were selected based on body weight at weaning, for a total of 48 female pigs (12 blocks of 2 sisters from each PE), and one sister was placed in each GE. Gilts were housed from 82 to 140 d of age under cyclic GTN (18 to 24 °C; n = 24) or GHS (28 to 34 °C; n = 24) environments. Data were analyzed using a mixed model including PE, GE, and PE × GE interaction as main effects, and sire, sow within PE, pen within PE × GE, and slaughter day (for plasma, muscle, and meat traits) as random effects. No significant PE × GE interaction was found on any trait under study (P ≥ 0.05). Prenatal HS did not affect growth performance and carcass traits (P ≥ 0.05). Compared with GTN, GHS pigs had lower average daily feed intake, average daily gain, and hot carcass weight (P < 0.01), but similar carcass lean meat content (P ≥ 0.05). Prenatal HS had scarce effects on pork quality, with only higher a* and C* values (P < 0.05) in the Gluteus superficialis. Growing HS led to a higher pH 24 h (P < 0.05) in the Longissimus thoracis et lumborum (LTL) and ham muscles, and higher meat quality index in the ham muscles. In contrast, quality traits of the Semispinalis capitis (SC) were not affected by either PE or GE (P > 0.05). Except a tendency for a higher citrate synthase activity in the SC (P = 0.065), PHS did not affect muscle metabolism. Growing HS induced muscle-specific metabolic responses, with reduced glycolytic potential (P < 0.01) and metabolic enzyme activities (P < 0.05) in the glycolytic LTL, but not in the oxidative SC (P > 0.05). Plasma glucose content at slaughter was lower in the GHS compared with GTN pigs (P = 0.002), indicating an altered energy metabolism in pigs under GHS. Altogether, growing HS altered growth without affecting carcass traits, but improved technological quality of loin and ham. Prenatal HS, alone or combined with GHS, had limited or even no effect on carcass and pork quality.

Blood hormone concentrations as markers and predictors of porcine meat production and quality?

Context The applicability of hormones in the prediction of meat production in non-ruminant species has been poorly examined. Aims To examine the applicability of plasma concentrations of leptin, estradiol, progesterone and insulin-like growth-factor I (IGF-I) for characterisation and early prediction of the production and quality of meat in gilts. Methods Animals were compared at 150 days of age with below (‘low’) and above (‘high’) median hormone concentrations and their traits of meat production and quality at the age of 200 days. Key results Animals with a high leptin concentration in blood at the age of 150 days had higher slaughter and carcass weights and weight of ham, but a lower lean meat content at the age of 200 days, than did the gilts with a low leptin concentration. Animals with a high estradiol concentration had a higher carcass weight, weight of ham and backfat thickness and a lower electrical conductivity of musculus semimembranosus than did animals with a low estradiol concentration. High blood IGF-I concentration was associated with a higher slaughter weight, carcass weight and lean meat content. No significant differences between the animals with ‘high’ and ‘low’ progesterone concentration and meat characteristics have been found. Conclusions These observations confirm the involvement of leptin, IGF-I and estradiol in up-regulation of meat production in pigs. Furthermore, they suggest that leptin can be useful for characterisation and prediction of fat production, whereas IGF-I and estradiol (but not progesterone) could be both markers and predictors of porcine growth and meat production. Implications The blood concentrations of these hormones could help in characterisation and selection of pigs for meat production.

Possible effects of the MC4R Asp298Asn polymorphism on pig production traits under ad libitum versus restricted feeding.

The missense mutation Asp298Asn in the melanocortin 4 receptor (MC4R) is associated with daily gain or fatness in pigs (Sus scrofa domesticus). However, to the best of our knowledge, no study has directly compared the effects of the polymorphism between different feeding levels, even though diet plays a vital role in the swine industry. To explore possible differences, data from 439 mostly commercial hybrids fattened ad libitum and 119 commercial hybrids fattened with restricted feed ration were collected. The recorded traits were average daily gain (ADG), feed conversion ratio (FCR), carcass weight (CW), dressing percentage (DP), lean meat content (LM), backfat thickness (BFT), lean cuts weight, and meat quality parameters such as pH, temperature, drip loss, and CIELAB colour space. The general linear model revealed that the overall effect of MC4R was not statistically significant, but significant differences (p < 0.05) were found in ADG, FCR, CW, DP, LM, and BFT. In the ad libitum category, the AA genotype (298Asn/298Asn) tended to be the most favourable for growth-related traits, with the lowest LM, which is consistent with previous findings. In the restricted category, on the other hand, GA heterozygotes (298Asp/298Asn) achieved the best performance in terms of growth, whereas AA homozygotes showed the worst performance. Therefore, these results raise the possibility of an interaction between MC4R and the feeding level.

Productive traits of the Belarusian population of pigs of Yorkshire breed different selection and genetics groups

Breeding and genetic improvement of blood lines and families is carried out continuously through selection, mating and management of purebreeding, taking into account the individual characteristics of animals. This determines the relevance of scientifi c research in this area. The results of studying the productive traits of pigs of diff erent blood lines and families in the Belarusian population of Yorkshire breed, their evaluation and further use in pig breeding in the formation of herds have been presented in the article. The studies were carried out during 2011–2020. The object of the research was the purebred animals of diff erent lines of pigs of Yorkshire breed bred in OAO “Selection and Hybrid Center “Zapadny” in the Brest region. As a result of the evaluation, the best lines and families have been identifi ed that can be used in further breeding work with animals of Yorkshire breed. Boars of the lines HENNATI, Farad and Factor were recognized as the best in terms of reproductive traits. Young boars of the line HENNATI were the best in terms of their own productivity and reached a live weight of 100 kg for 152,8 days and had an average daily gain of 678,3 g. The content of lean meat in the body of boars of this line reached 59 %. According to the reproductive traits of sows, the best indicators were animals of the lines Friend, Farad, Duchess, so, the prolifi cacy was 11,6–12,1 piglets per farrowing. When analyzing the productive traits of blood families, the best indicator of milk capacity (60,3–62,6 kg) was shown by sows belonging to the families Catalina and Taiga. According to the litter weight at the weaning, animals of the families Taiga and Fortuna were recognized as the best – 78,7–80,1 kg. The novelty lies in the fact that in our study we propose to use promising blood lines and families of pigs of the Belarusian population of Yorkshire breed in the formation of breeding herds, and their use in breeding and industrial pig breeding.

Effects of Lactobionic Acid on Pig Growth Performance and Chemical Composition of Pork.

Simple SummaryCurrently, due to different beneficial properties of lactobionic acid (calcium absorption, prebiotic, antioxidant, and preservative) it may find application in animal feed. However, data about its effect on animal husbandry product quality are limited. Common interest about the effect of feed supplements on pig growth performance and the chemical composition of pork is growing, which is important for farmers, meat processors and consumers. The feed supplemented with lactobionic acid promotes better utilization of feed in the digestive tract of pigs, resulting in a higher bioavailability of nutrients and a significant increase of pig live weight gain. Pork obtained from pigs fed with lactobionic acid supplemented feed had higher essential amino acid content. Fatty acid composition revealed slightly higher proportion of saturated fatty acids over unsaturated fatty acids. Further analysis of fatty acid composition indicated that the control group had better nutritional quality of fat.Lactobionic acid is an innovative product obtained in the fermentation process of cheese or curd whey, and it has several beneficial properties. Therefore, it may have potential application in animal feeding. Currently, lactobionic acid is not widely used yet in feeding farm animals. Therefore, the aim of our study was to evaluate the effect of lactobionic acid (LBA) on pig growth performance and pork quality. Two groups of pigs (control and trial, 26 piglets each) were completed. The control group received compound feed, whereas the trial group’s feed was supplemented with LBA (0.17 kg per 100 kg of feed). Carcass weight and meat pH were determined. The subcutaneous fat layer S (mm) was measured. Lean meat content was determined using the SEUROP classification. Amino acids and fatty acids in pork were evaluated. The addition of LBA to pig feed significantly increased the live weight gain and slaughter yield of pigs, but the samples had a slightly thicker backfat layer. Results obtained showed higher concentration of amino acids in the trial group but slightly lower pork fat quality in the same group. Lactobionic acid has the potential for applications in pig feeding.

The effect of dietary Echium oil supplementation on the fatty acid profile, omega-3 fatty acid content and subcutaneous fat quality of pork

This study evaluated the effect of five dietary oils - palm (Control), soya, linseed, fish and Echium oil at a 1% inclusion level- on growth performance, feed efficiency, subcutaneous fat quality and fatty acid composition of subcutaneous fat. The trial consisted of 60 gilts, randomly allocated to ten groups with six animals per pen. Dietary treatment had no significant effect on growth performance, feed efficiency or lean meat content of pigs. All colour parameters, extractable fat content, fat free dry matter, and moisture content of subcutaneous fat were unaffected by dietary treatment. The only significant difference for fat firmness was between the control treatment containing palm oil (Bergafat HPL 106) and the linseed oil treatment (P = 0.049), with the control producing the hardest fat. The iodine value was significantly lower in the control treatment (P < 0.001). Both the Echium and linseed oil treatments increased the ratio of polyunsaturated fatty acid:saturated fatty acid (PUFA:SFA) and decreased the omega-6:omega-3 (n-6:n-3) ratio of subcutaneous fat. Stearidonic acid concentration of subcutaneous fat was the highest (P < 0.001) for the Echium oil treatment (0.21%). The fish oil treatment had significantly higher levels (P < 0.001) of eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA) and total EPA+DPA+DHA than all other treatments. The Echium oil treatment resulted in significantly (P < 0.001) higher EPA, DPA and EPA+DPA+DHA levels in subcutaneous fat than the linseed oil, soya oil and control treatments. The result suggests that Echium oil can be used in pig diets to improve the long chain n-3 fatty acid content of subcutaneous fat.

Effect of Changes in Dietary Net Energy Concentration on Growth Performance, Fat Deposition, Skatole Production, and Intestinal Morphology in Immunocastrated Male Pigs.

Nutritional requirements of heavy immunocastrated (IM) pigs and therefore appropriate feeding strategies have not yet been determined. Thus, the effects of changes in dietary net energy (NE) content were studied in 41 IM pigs, fed ad libitum diets with low, medium, and high NE content (LNE, MNE, and HNE diets, with 8.5, 9.3, and 10.0 MJ NE/kg, respectively), from 84 days of age until slaughter at an average age of 172 days and an average body weight of 122.5 kg. In the period from 143 to 170 days of age, there was a tendency for a greater NE intake (p = 0.08) in pigs fed the HNE diet along with greater (p < 0.01) backfat gain. Dietary treatment affected carcass composition, as lower backfat thickness (p = 0.01) and lower area of fat over the longissimus muscle (p = 0.05) were observed in the LNE and MNE pigs. In addition, greater lean meat content (p = 0.04) was observed in the LNE pigs. Reducing the NE of the diet by replacement of cereals and soybean meal with high-fiber ingredients resulted in lower indole production in the ascending colon (p < 0.01) and greater skatole production (p < 0.01) in the cecum. Greater villus area, width, height and perimeter, crypt depth, and thickness of the intestinal mucosa in the jejunum, ileum, ascending colon, and descending colon were found in the LNE group (p < 0.01) than in the HNE group, while those in the MNE group was intermediate. Cell proliferation was not affected by dietary treatment (p > 0.05). The present results show that a reduction in dietary NE concentration lowers lipid deposition, without affecting performance or energy efficiency in IM pigs. This technique provides an advantage in terms of improved leanness, without affecting growth rate in IM pigs after immunization, which is particularly important when the backfat thickness is a determinant of carcass value and IM pigs are fattened to higher weights (e.g., in heavy pig production) or when a longer delay between immunization and slaughter is practiced.

Grass/clover silage for growing/finishing pigs – effect of silage pre-treatment and feeding strategy on growth performance and carcass traits

ABSTRACT This study evaluated the influence of feeding strategy and grass/clover silage pre-treatment on pig growth performance and carcass traits. In total, 128 pigs weighing 30–110 kg were fed either a commercial control feed or received silage in a pellet (SP) or in a total mixed ratio (TMR) containing chopped silage (SC) or intensively treated silage (SE). Silage replaced 20% of dietary crude protein content (g/kg). Diet affected weight gain (P = 0.001), with pigs fed the SP diet showing best overall growth performance. Pigs fed the SC diet had the lowest weight gain (P = 0.001), while pigs fed the SE diet performed similarly to those fed the control diet. Carcass weight and dressing percentage differed between the diets (P = 0.016 and P = 0.018), but there was no difference in lean meat content (P = 0.832). The results show satisfactory growth performance and carcass traits, indicating that silage can replace other protein sources in growing/finishing pig diets.

The expression pattern, polymorphisms and association analyses of the porcine NREP gene.

NREP (neuronal regeneration related protein homolog) plays a role in the transformation of neural, muscle, and fibroblast cells and in smooth muscle myogenesis. The NREP gene was selected for detailed study as an expressional and functional candidate gene on the basis of data from the expression microarray, which detected the differences in gene expression between Czech Large White pigs and wild boars in the longissimus lumborum et thoracis and biceps femoris muscle tissues. Quantitative real-time PCR results confirmed that porcine NREP was expressed in both skeletal muscles and significantly overexpressed in Czech Large White pigs compared with wild boars (14.5- and 11.6-fold; p<.05). We identified 9 polymorphic sites in the genomic DNA of NREP. Six of these polymorphisms were in complete linkage disequilibrium, and therefore, only 4 loci were informative. The associations of the HF571253:g.103G>A, HF571253:g.134G>A, HF571253:g.179T>C and HF571253:g.402_409delT polymorphisms with backfat thickness, lean meat content and average daily gain were assessed in Czech Large White pigs. The GG genotypes HF571253:g.103G>A and HF571253:g.134G>A, the TT genotypes HF571253:g.179T>C and 67 HF571253:g.402_409delT genotypes had favourable effects on the studied traits. Our results indicate the possibility of utilizing the variability of the NREP gene in marker-assisted selection in order to improve meat production in pigs.

The Indigenous Prestice Black-Pied Pig Breed Differs from a Commercial Hybrid in Growth Intensity, Carcass Value and Meat Quality

The study was designed for the comparison of barrows and gilts of two contrasting genotypes in terms of growth ability, carcass value and meat quality. A total of 76 pigs (from 7 ± 1 kg to 95 ± 6 kg) of the indigenous breed Prestice Black-Pied (PB) and the commercial hybrid of Large White × Landrace × Large Whitesireline (CH) were included in this study. The groups were balanced regarding genotype and sex. Live weight at the age of 79 days (p &lt; 0.001), live weight at slaughter (p &lt; 0.01), average daily gain (p &lt; 0.001), weight of carcass and left carcass side (p &lt; 0.05) and ham proportion (p &lt; 0.001) were higher in the CH group. The values of the given parameters were higher in barrows than in gilts. The effect of genotype and sex interaction was observed in lean meat content (p &lt; 0.05) and backfat thickness (p &lt; 0.01). The CH gilts showed the highest lean meat content and the lowest backfat thickness compared to the lowest values in the PB barrows. The value of pH45 (p &lt; 0.01) and intramuscular fat content were higher in the PB group. The lightness (p &lt; 0.001), yellowness (p &lt; 0.01), drip loss (p &lt; 0.05) and protein content were lower in the PB group. Higher values of lightness (p &lt; 0.05), yellowness (p &lt; 0.05) and cholesterol content (p &lt; 0.05) were observed in the boars. Oxidative stability of the meat (malondialdehyde content) was more favorable in the PB pigs. The effect of genotype and sex interaction was confirmed for the pH24 value (the highest value was found in the PB barrows and the lowest in the CH barrows, p &lt; 0.001) and for the dry matter content (lowest in the PB gilts and highest in the CH barrows, p &lt; 0.05). Overall, the PB pigs were characterized by inferior growth and carcass parameters, however, with more favorable parameters for meat quality.

LEAN MEAT CONTENT OF PIG’S CARCASSES IN THE EIGHT SLAUGHTERHOUSES IN THE REGION OF VOJVODINA, SERBIA

The end product of the pig production is carcass. Lean meat content is a measure of the quality of the carcass. Serbia is one of only a few countries in Europe which has not yet adopted the practice of pig’s carcasses classification and failed to regulate this issue through legislation. The purpose of this work was to measure lean meat content in carcasses probed in several slaughterhouses in the Province of Vojvodina (northern Serbia) and to classify them according to the SEUROP classification. In total it was classified 65764 pig carcasses in eight different slaughterhouses. The lean mean content was measured on the slaughter line 45 minutes post mortem with the one-point puncture model. The measurement was carried out with the optoelectronic probe for the classification of pig carcasses CLASSPRO GmbH (Germany). The percentage of meat in the carcass was calculated using the mathematical model. In all eight slaughterhouses in which the measurements were done there was no poor quality (P class) pig carcass. The majority of carcasses were in the class E-excellent (35545 carcasses or 54.05% in total) and U-very good (25864 carcasses or 39.33% in total). However, a very small number of the carcasses were in the superior class with more than 60% of lean meat content, only 2072 carcases or 3.15% in total. Any future effort which the government would put in the implementation of the system of pricing of pigs based on the carcass characteristics would have enormous effect on the pig production in general. The pig producers would have the reason to invest in better farm management, selection in effort to improve the quality of the end products-pigs. In addition, the meat industry would certainly have benefits by having a higher quality raw material for further processing.