Effects of feeding and rearing systems on growth, carcass composition and meat quality in pigs

Towards a 'One quality' approach of pork: A perspective on the challenges and opportunities in the context of the farm-to-fork continuum - Invited review

A substantial amount of research on pork production and consumption highlights an interplay between the intrinsic qualities that are inherent to the product and the extrinsic qualities related to how it is produced, which together contribute to the perception and evaluation of fresh pork. However, studies have emphasised difficulties in defining their relative importance depending on the countries, consumers' knowledge, experience and personal beliefs, as well as their dynamic changes over time. A joint and multidimensional consideration of the intrinsic and extrinsic quality dimensions is critical to achieve sustainable development goals that ensure healthy, nutritious, fair and environmentally friendly pork produced in a profitable manner. However, very few studies have investigated the synergies and antagonisms between the multiple dimensions of intrinsic and extrinsic qualities of pork. This perspective aims to define and promote the concept of 'One Quality' pork, as an approach to meeting the multiple and divergent expectations of stakeholders in the pork value chain, while jointly considering pork quality and sustainability. It aims to discuss how the changing expectations of consumers, citizens and public action including policy makers are currently promoting a holistic definition and evaluation of pork quality. It also seeks to explore how the multiple dimensions of pork quality, including their intrinsic and extrinsic dimensions, can be considered simultaneously. The opportunities and challenges of implementing a 'One Quality' approach to pork for an integrated sustainability assessment of the farming systems, i.e., by jointly addressing the intrinsic quality attributes, ensuring sustainable farming practices, economic viability for stakeholders, and alignment with consumer and citizen expectations, are then discussed along the farm-to-fork continuum.

Effects of Dietary Protein Levels on Meat Quality, Serum Antioxidant Capacity, and Intestinal Microorganisms in Ningxiang Pigs

This study aimed to evaluate the impact of five different dietary protein levels on meat quality, serum antioxidant capacity, and intestinal microorganisms of Ningxiang pigs, thus providing new insights into their nutritional needs. One hundred and twenty-five healthy Ningxiang barrows with an average body weight of 53.19 ± 2.12 kg were randomly divided into five groups with five replicates and five pigs per replicate. The diet was formulated using corn, soybean meal, and rice bran meal as raw materials based on net energy. Following the nutritional requirements outlined in the Nutrient Requirements of Swine in China (2020), diets with five different protein levels (crude protein: 11.09%, 12.09%, 13.09%, 14.09%, 15.09%) were formulated. The amino acid levels of lysine, threonine, tryptophan, methionine, valine, isoleucine, and other amino acids were standardized to meet the recommended values, as were other essential amino acids. The experiment lasted for 62 days. The results indicated a linear decrease in the redness and yellowness values of the Longissimus dorsi muscle with increased dietary protein, alongside a quadratic decrease in intramuscular fat (p < 0.01). Notably, muscles from pigs fed with 13.09%, 14.09%, and 15.09% protein diets exhibited significantly lower redness and yellowness than those on a 12.09% protein diet (p < 0.05). Additionally, higher dietary protein levels linearly enhanced the presence of specific fatty acids (C17:0, C17:1, C18:3n3, and C18:3n6) and certain amino acids in the Longissimus dorsi muscle, following a quadratic trend (p < 0.01). The serum GSH-Px content increased linearly with greater dietary protein levels (p < 0.05). Significant variations in cecal and colonic metabolites were observed across different protein levels, affecting the contents of putrescine, cadaverine, spermine, spermidine, and short-chain fatty acids (p < 0.05). Additionally, the increase in dietary protein levels correlates with the growth performance and amino acid profile of the Longissimus dorsi muscle in Ningxiang pigs, presenting a quadratic relationship. Concurrently, the serum antioxidant capacity and cecal bioamine content demonstrate a linear increase. Despite a balanced inclusion of six essential amino acids, both excessively high and low protein levels adversely affect growth and intestinal health. Notably, dietary protein levels of 12.09% and 13.09% yield the optimal growth performance under the specified experimental conditions.

Effect of Selection for Litter Size Variability on Growth, Carcass and Meat Quality in Rabbits

This study aimed to analyze the effect of reducing litter size variability on growth rate, carcass traits, and meat quality in rabbits. Two divergent lines selected by litter size variability were compared: a line selected to reduce litter size variability (HO) and one selected to increase litter size variability (HE). All animals were fed the same commercial diet and kept under identical rearing conditions. The HO line had lower live weight at weaning compared to the HE line (p ≤ 0.05), but the growth rate was higher in the HO line than in the HE line (p ≤ 0.05). Carcass weight and composition were similar between the lines. No differences in meat pH at 45 min and 24 h post-mortem were found between lines. However, the HO line had a higher lightness (L*) value at 45 min post-mortem than the HE line (p ≤ 0.05). The HO line showed higher Ca concentrations than the HE line (p ≤ 0.05). The HO line also had higher protein content and lower saturated fatty acid content than the HE line (p ≤ 0.05). No differences in fat oxidation were observed among the lines. In conclusion, the selection to reduce litter size variability did not negatively impact growth rate and had a favorable effect on protein content, as well as a reduction in saturated fatty acid content in carcass.

Effect of Passiflora Edulis Sims Peel Feed on Meat Quality of Finishing Pigs

Passiflora edulis Sims peel (Chinese name Baixiangguo, BXG) is a by-product with a high nutritional and economic value of Passiflora edulis Sims. In this study, corn was partly replaced with BXG to make feed for finishing pigs and the effects on the carcass traits, meat quality, muscle amino acid profile, and gene expression of finishing pigs were evaluated. A total of 20 healthy finishing pigs (Duroc × Landrace × Large) were randomly divided into two groups. The control group (CON) was fed the basal diet, and the experimental group (BXG) was fed a basal diet with BXG instead of 10% corn for a period of 43 d. Compared to the CON group, the carcass weight, intramuscular fat content, and marbling score were significantly increased, while the drip loss, b* value, and shear force of the BXG group were significantly reduced (p < 0.05). Gene expression analysis showed that the mRNA expression of lipid synthesis and oxidative-type fiber related genes was significantly increased in the BXG group (p < 0.05). Proteomic research revealed that the metabolic pathways of the BXG and CON groups differed significantly. A total of 36 differentially expressed proteins were identified, mainly related to energy metabolism, fatty acid degradation, and endocrine regulation pathways. However, the contents of glutamine, glutamate, proline, and other amino acids in the BXG group were significantly reduced (p < 0.05). Overall, this study has a positive effect on improving meat quality, but the specific mechanism needs to be further explored, which offers practical guidance for the application of BXG in producing higher-quality pork and further promotes its commercial application.

Growth Performance, Carcass Quality, and Lipid Metabolism in Krškopolje Pigs and Modern Hybrid Pigs: Comparison of Genotypes and Evaluation of Dietary Protein Reduction

This study compared the performance, meat quality and adipose tissue characteristics of Krškopolje pigs and modern hybrid pigs under identical rearing conditions, besides examining the effects of dietary protein reduction in both genotypes. A total of 29 pigs (14 Krškopolje and 15 hybrids) were assigned to litter into two dietary groups (high and low protein). The low-protein diet for hybrid pigs corresponded to the high-protein diet for Krškopolje pigs. All diets were iso-energetic. Dietary protein reduction decreased growth rate and muscle development in modern hybrids but had no significant impact on performance, quality or metabolic traits in Krškopolje pigs. Genotype differences revealed that Krškopolje pigs had lower growth rates, less lean and more fat deposition, as reflected in thicker subcutaneous and higher intramuscular fat compared to modern hybrids. Krškopolje pigs also exhibited higher myoglobin concentration and fatty acid saturation. Lipogenic enzyme activity and histo-morphological traits behaved in a tissue-specific manner but still indicated a greater lipogenic potential in Krškopolje pigs. This study provides valuable insights into breed-specific responses to dietary changes and highlights the unique characteristics of Krškopolje pigs.

Role of Metabolomics and Metagenomics in the Replacement of the High-Concentrate Diet with a High-Fiber Diet for Growing Yushan Pigs

The objective of this study was to investigate the regulatory effects of a high-fiber content feed on the productive performance, meat quality, and fat acid composition. A total of 18 120-day-old Yushan pigs with similar initial body weight were randomly allotted into high-concentrate diet (high energy, HE) and high-fiber diet (low energy, LE) treatments for the determination of regulatory effects on productive performance, meat quality, and fatty acid content. Further, blood metabolomic, gut microbiota, and liver energy-related gene expression measurements were used to investigate the underlying mechanisms. Results showed that the LE treatment significantly increased ADFI while decreasing carcass weight, fat percentage, and IMF. Metabolomic results showed that the high-fiber treatment significantly down-regulated metabolites that participated in lipid metabolism such as cyclic ADP-ribose and hippuric acid, while up-regulated metabolites were mainly enriched in nitrogen metabolism such as DL-arginine and propionylcarnitine (p < 0.05). Microbial results showed relative abundances of Lactobacillus and Bifidobacterium are significantly proliferated in the high-fiber feeding treatments (p < 0.05). Transcriptomic results showed that genes mainly enriched into the lipid metabolism are significantly up-regulated under the high-fiber dietary treatment (p < 0.05). Conclusion: higher dietary fiber significantly reduced dietary energy provision, effectively decreased the backfat and abdominal fat content of Yushan pigs through proliferating intestinal fiber-degradable bacteria, and up-regulating the hepatic lipolysis-related gene expression.

Exploring the multifaceted factors affecting pork meat quality

The significance of pork meat quality extends far beyond mere consumer satisfaction, encompassing crucial aspects such as health and nutrition, economic impact, reputation and branding, food safety, and sustainability within the global food system. Influenced by a multitude of factors, each playing a pivotal role in shaping its sensory attributes and consumer appeal, pork meat quality stands as a cornerstone of the meat industry. Thus, understanding these factors are imperative for ensuring consistent high-quality pork production, aligning with consumer preferences, and elevating overall satisfaction levels. In this review, we provide a comprehensive overview of the diverse factors affecting pork meat quality, including genetic characteristics, rearing systems, feed composition, gender differences, pre-slaughter handling, and meat aging processes.

Rearing hogs on pasture minimally impacts pork composition

Managing swine on pasture is increasing in popularity for both the consumer and producer. This interest appears to be driven by an effort to create an improved perception of environmentally sustainable practices and increased animal welfare, while keeping start-up costs low. However, evidence-based guidance on pasture management practices that support quality pork production and environmentally sustainable procedures is lacking. The objective of this work was to quantify the impact of pasture rearing on pig growth efficiency and pork quality. In this pilot study, 20 pigs similar in genetics, age, weight, and sex ratio were divided across indoor (n = 10) and Outdoor (n = 10) housing environments. Pigs were weighed every 14 d and harvested upon reaching an average weight of 113 kg. Average starting body weights were similar between both groups (P = 0.98). Carcass quality was evaluated by measuring pH, loin eye area (LEA), back fat (BF) thickness, subjective color and marbling scores, and colorimetry (CIE color space [L*, a*, b*]) at the 10th rib. Final body weights at slaughter also showed no significant variation between housing groups (P = 0.98). No differences were observed in pork quality: pH 0 h (P = 0.53), 6 h (P = 0.29), 12 h (P = 0.80), and 24 h (P = 0.07) postmortem, LEA (P = 0.44), color (P = 0.73), and marbling (P = 0.40). However, hogs raised indoors had an increase in BF thickness (P = 0.04). Based on this pilot study, outdoor rearing conditions did not have significant impacts on pork quality. Further research will help to determine the impact that rearing scheme has on pH and BF.

Re-domestication of feral pigs in Martinique: first results of growing-finishing trials to test meat consumption and consumers' perceptions

In Martinique, pig production satisfies less than 20% of demand for pork, with traditional pig farming and wild pig hunting covering only a small proportion. This study has three parts: (i) for the first time, it analyses the performance of domesticated descendants of Creole feral pigs of Martinique based on a 29-day finishing test on two farms (A vs. B) with the same fibre-rich diet on a total of 40 pigs; (ii) it evaluates consumers' tastes based on a sensorial test by an untrained panel of 61 consumers who tasted pork prepared as a fricassee from either farm A or farm B; and (iii) evaluates willingness to pay (WTP) for Creole pork products and of the design of a future niche market. The average daily gain (ADG) of the finishing pigs was higher on farm A than on farm B (256 vs. 100 g/d, P < 0.001) resulting in a higher hot carcass weight on farm A than farm B (41.3 vs. 33.5 kg, P < 0.01), and better hot carcass yield on farm B than farm A (74.0 vs 68.8 %, P < 0.01). In the sensorial test, the consumers gave a higher score to the meat originating from the youngest pigs (Farm B), especially scores for tenderness and juiciness (+0.94 and +0.55 points, P < 0.05 and P=0.10, respectively). The 61 respondents were willing to pay more for processed products (sausage, pâté, ham) than for fresh meat. They considered that Creole pork has a better taste and is of better quality than industrial meats originating from mainstream genotypes. According to the majority of respondents, Creole pork should be rich in intra-muscular fat (100% of respondents) and low in inter-muscular fat (60% of respondents). Based on the survey, the main desirable future for Martinique's Creole pig production correspond to a low-carbon system with feed based on local resources, with on-farm slaughtering and short-distance sales (direct-to-consumer farm gate sale, sale at the butcher's or at the pig cooperative).

Exploring effects of organic selenium supplementation on pork loin: Se content, meat quality, antioxidant capacity, and metabolomic profiling during storage

This research was conducted to study the effects of organic selenium (Se) supplements at different levels on pork loin quality during storage. Fifteen pork loins were procured randomly from three groups, Con (fed basal diet), Se15 (fed 0.15 ppm organic Se along with 0.10 ppm inorganic Se), and Se45 (fed 0.45 ppm organic Se along with 0.10 ppm inorganic Se). Each sample was analyzed for Se contents, antioxidant properties (glutathione peroxidase [GPx] activity, 2,2'-azinobis-[3-ethylbenzothiazoline-6-sulfonic acid] [ABTS] and 2,2-diphenyl-1-picrylhydrazyl [DPPH] radical scavenging activities, 2-thiobarbituric acid reactive substances), physicochemical properties (water holding capacity, pH, color), and metabolomic analysis during 14-day storage period. Se45-supplemented group showed significantly higher Se contents and GPx activity than the other groups throughout the storage period. However, other antioxidant properties were not significantly affected by Se supplementation. Selenium supplementation did not have an adverse impact on physicochemical properties. Nuclear Magnetic Resonance-based metabolomic analysis indicated that the selenium supply conditions were insufficient to induce metabolic change. These results suggest that organic Se (0.15 and 0.45 ppm) can accumulate high Se content in pork loins without compromising quality.

Seasonal Variations on Testicular Morphology, Boar Taint, and Meat Quality Traits in Traditional Outdoor Pig Farming

Traditional outdoor pig farming is renowned for its emphasis on animal welfare and the production of highly valued, quality meat. While seasonality is known to impact certain animals, particularly those raised outdoors, there is a lack of research on Bísaro boars, a native Portuguese breed. This research study was conducted on a total of 20 male entire Bísaro pigs, reared in outdoor pens from 4 to 13 months old, and subsequently slaughtered. The animals were divided into two groups: one slaughtered in winter (Wi, n = 9), and the other in summer (Su, n = 11). The objective was to evaluate testicular morphometry, boar taint compounds, and meat quality traits, including sensory analysis and fatty acid profile. Testicles from the Su group exhibited reduced volume, indicating diminished functionality during that season. While no significant differences were observed in the boar taint compound analysis, panelists could discern a more intense aroma and flavor of boar taint in the Su meat. Other meat quality traits showed no significant variations, but the fatty acid profile displayed higher values in the Wi group. This study reveals that Bísaro boars experience reproductive seasonality, leading to variations in boar taint compounds across the seasons. This information is crucial for farm planning.

The color of fresh pork: Consumers expectations, underlying farm-to-fork factors, myoglobin chemistry and contribution of proteomics to decipher the biochemical mechanisms

The color of fresh pork is a crucial quality attribute that significantly influences consumer perception and purchase decisions. This review first explores consumer expectations and discrimination regarding pork color, as well as an overview of the underlying factors that, from farm-to-fork, contribute to its variation. Understanding the husbandry factors, peri- and post-mortem factors and consumer preferences is essential for the pork industry to meet market demands effectively. This review then delves into current knowledge of pork myoglobin chemistry, its modifications and pork discoloration. Pork myoglobin, which has certain peculiarities comparted to other meat species, plays a weak role in determining pork color, and a thorough understanding of the biochemical changes it undergoes is crucial to understand and improve color stability. Furthermore, the growing role of proteomics as a high-throughput approach and its application as a powerful research tool in meat research, mainly to decipher the biochemical mechanisms involved in pork color determination and identify protein biomarkers, are highlighted. Based on an integrative muscle biology approach, the available proteomics studies on pork color have enabled us to provide the first repertoire of pork color biomarkers, to shortlist and propose a list of proteins for evaluation, and to provide valuable insights into the interconnected biochemical processes implicated in pork color determination. By highlighting the contributions of proteomics in elucidating the biochemical mechanisms underlying pork color determination, the knowledge gained hold significant potential for the pork industry to effectively meet market demands, enhance product quality, and ensure consistent and appealing pork color.

Effects of lysine concentration of the diet on growth performance and meat quality in finishing pigs with high slaughter weights

The present study aimed to investigate the feasibility of using a diet low in lysine content as a means for increasing the intramuscular fat (IMF) content and pork muscle quality of finishing pigs. Thirty-two crossbred gilts and barrows weighing approximately 80 kg were fed either a low-lysine diet (0.60%; Low-lys) or a control diet (0.80% lysine; Med-lys) under a 2 × 2 factorial arrangement of treatments. The animals were slaughtered at a 132-kg body weight (BW) on average, followed by physicochemical analyses and sensory evaluation on Longissimus lumborum (LL) and Semitendinosus (ST) muscles. The average daily gain (ADG) did not differ between the Med-lys and Low-lys groups. However, ADG exhibited a tendency of sex × diet interaction (p = 0.09), being greater for barrows vs. gilts on the Low-lys diet (p < 0.05), but not on the Med-lys diet. Backfat thickness adjusted for 132-kg BW also exhibited the interaction; it was greater for the Low-lys vs. Med-lys group within gilts but tended to be less for the former in barrows (p = 0.08). The IMF content was not influenced by the diet or sex in either LL or ST. The a*, b*, and Warner-Bratzler Shear Force values and fatty acid composition were influenced by the sex or diet in either or both of the muscles, but the treatment effects did not apparently influence the meat quality. Sensory scores for the flavor, juiciness, tenderness, umami, and palatability of cooked muscle were not influenced by the diet in either LL or ST. When the LL and ST data were pooled, scores for those sensory attributes were positively correlated with the IMF content, which was associated with overall greater IMF contents and greater sensory scores for ST vs. LL. Collectively, the Low-lysine diet seemingly elicited the intended lysine deficiency in gilts as indicated by the increased BFT due to the diet. However, the Low-lys diet was not effective for increasing the IMF deposition or eating quality of the pork muscle of finishing pigs slaughtered at high BW probably because its lysine content was not low enough to elicit either outcome.

Early Colonization of the Intestinal Microbiome of Neonatal Piglets Is Influenced by the Maternal Microbiome

The intestinal microbiome plays a crucial role in animal health and growth by interacting with the host, inhibiting pathogenic microbial colonization, and regulating immunity. This study investigated dynamic changes in the fecal microbial composition of piglets from birth through weaning and the relationship between the piglet fecal microbiome and sows. Feces, skin, neonatal oral cavity, and vaginal samples were collected from eight sows and sixty-three piglets, and 16S genome sequencing was performed. The results revealed that Firmicutes, Bacteroidetes, and Proteobacteria dominated the piglet microbiome in the early stages, and Firmicutes and Bacteroidetes were crucial for maintaining a balance in the intestinal microbiome during nursing. The abundance of Christensenellaceae_R-7_group, Succinivibrio, and Prevotella increased in weaned piglets fed solid feed. Analysis of the microbiome from sows to piglets indicated a shift in the microbiome colonizing piglet intestines, which became a significant constituent of the piglet intestinal microbiome. This study supports the theory that the neonatal intestinal microbiome is vertically transmitted from the mother. Further research is required to integrate factors related to sows, piglets, and their environments to gain a better understanding of the early establishment of the intestinal microbiome in piglets.

Effect of a Co-Feed Liquid Whey-Integrated Diet on Crossbred Pigs' Fecal Microbiota

This study assessed the potential effect of a co-feed liquid whey-integrated diet on the fecal microbiota of 14 crossbred pigs. The experimental design was as follows: seven pigs were in the control group, fed with a control feed, and seven were in the experimental group, fed with the same control feed supplemented daily with liquid whey. The collection of fecal samples was conducted on each animal before the dietary treatment (T0) and one (T1), and two (T2) months after the beginning of the co-feed integration. In addition, blood samples were collected from each pig at the same time points in order to evaluate the physiological parameters. Taxonomic analysis showed a bacterial community dominated by Firmicutes, Bacteroidetes, Spirochaetes, and Proteobacteria phyla that populated the crossbred pig feces. The diversity metrics suggested that the co-feed supplementation affected some alpha diversity indexes of the fecal microbiota. In addition, the differential abundance analysis at the genus level revealed significant differences for various genera, suggesting that the liquid whey supplementation potentially influenced a part of the bacterial community over time. Spearman's correlations revealed that the differential abundant genera identified are positively or negatively correlated with the physiological parameters.

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.

Are biters sick? Health status of tail biters in comparison to control pigs

BACKGROUND

Tail biting is a multifactorial problem. As the health status is one of the factors commonly linked to tail biting, this study focuses on the health of identified biters. 30 (obsessive) biters are compared to 30 control animals by clinical and pathological examination as well as blood and cerebrospinal fluid samples. In that way, altogether 174 variables are compared between the groups. Moreover, connections between the variables are analysed.

RESULTS

In the clinical examination, 6 biters, but only 2 controls (P = 0.019) were noticeably agitated in the evaluation of general behaviour, while 8 controls were noticeably calmer (2 biters, P = 0.02). Biters had a lower body weight (P = 0.0007) and 13 biters had overlong bristles (4 controls, P = 0.008). In the pathological examination, 5 biters, but none of the controls had a hyperceratosis or inflammation of the pars proventricularis of the stomach (P = 0.018). However, 7 controls and only 3 biters were affected by gut inflammation (P = 0.03). In the blood sample, protein and albumin levels were below normal range for biters (protein: 51.6 g/l, albumin: 25.4 g/l), but not for controls (protein: 53.7 g/l, albumin: 27.4 g/l), (protein: P = 0.05, albumin: P = 0.02). Moreover, 14 biters, but only 8 controls had poikilocytosis (P = 0.05). Although not statistically different between groups, many animals (36/60) were affected by hypoproteinemia and hyponatremia as well as by hypokalemia (53/60) and almost all animals (58/60) had hypomagnesemia. For hypomagnesemia, significant connections with variables linked to tail damage and ear necrosis were detected (rs/V/ρ ≥ 0.4, P ≤ 0.05).

CONCLUSION

The results suggest that behavioural tests might be helpful in identifying biters. Moreover, cornification and inflammation of the pars proventricularis is linked to becoming a biter. Furthermore, the results highlight the need for appropriate and adjusted nutrient and mineral supply, especially with regard to magnesium.

Utilizing NUtrack to Access the Activity Levels in Pigs with Varying Degrees of Genetic Potential for Growth and Feed Intake

Feed cost accounts for over two-thirds of the variable cost of production. In order to reduce feed costs without sacrificing production numbers, feed efficiency must be improved. Calorie expenditure has been difficult to quantify in the past but is understood to impact residual feed intake (RFI) greatly. The objective of this work was to utilize an advanced computer vision system to evaluate activity levels across sex and sire groups with different expected breeding value combinations for growth and feed intake. A total of 199 pigs from four different sire groups (DNA Genetics Line 600) High Feed Intake/High Growth (HIHG), Low Feed Intake/High Growth (LIHG), High Feed Intake/Low Growth (HILG), and Low Feed Intake/Low Growth (LILG) were utilized at the UNL ENREC farm over 127 days. The NUtrack system allowed for individual monitoring of pigs in group housing to track daily activity traits. In total, HIHG pigs travelled less (p < 0.05; 139 vs. 150 km), spent more time lying (p < 0.05; 2421 vs. 2391 h), and less time eating (p < 0.05; 235 vs. 243 h) when compared to LILG pigs across time. The results suggest variation in activity occurs across the progeny of the sire groups selected to differentiate in growth and feed intake.

Barley, Triticale, or Rye? The Type of Grain Can Affect the Growth Performance and Meat Quality of Sustainable Raised Pigs

The effect of high level of barley, triticale, or rye as base of complete mixtures for growing-finishing pigs on growth performance, carcass traits, meat quality, and fatty acid profile in meat and backfat was investigated. The 100-day experiment involved 72 pigs, assigned into three groups (24 animals each). Pigs of each group were kept in six pens (two gilts and two barrows per pen). Diets offered to pigs differed in the proportion of cereals as the leading ingredients in the mixture formulation: I-barley, II-triticale, III-rye. The results showed diversified grain influence on the production results and meat quality. Triticale- and barley-based diets ensured better weight gain and lower carcass fatness than rye (p ≤ 0.05). The basic nutrients digestibility of mixtures containing triticale was comparable to that containing barley and higher than that of rye (p ≤ 0.05). The meat and backfat of pigs receiving diet with triticale or barley was characterized by more favorable fatty acids profile in respect to the health-promoting indicators (atherogenicity and thrombogenicity indexes; hypocholesterolemic/hypercholesterolemic ratio). The cholesterol level in various tissues was the lowest in pigs fed with rye diet, and their meat characterized by better water holding capacity and more SFA. Higher fat saturation indicate better resistance to oxidation during storage and longer meat shelf life. It seems that the supplementation of triticale to diet may improve the growth efficiency of pigs and the health-promoting value of meat, while the supplementation of rye may be better for the production of traditional or long-matured meat products.

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.

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.

Stress levels of mangalita, large white, and pietrain pigs reared in different housing systems in south eastern Europe

ABSTRACT Cortisol is a steroid hormone that regulates a wide range of vital processes throughout the body, including metabolism and the immune response. It also has a very important role in helping the body respond to stress. Numerous studies have been conducted around the world to compare the development rates of pigs raised indoors to those raised outdoors, but the results have been ambiguous and, in many cases, conflicting. The objective of this study was to determine the effects of various housing systems (indoors with no free access to outdoor runs or indoors with free access to outdoor runs) on stress levels and slaughter value in growing-finishing pigs.

Gut microbiota and meat quality

Sustainable meat production is important to providing safe and quality protein sources for humans worldwide. Intensive artificial selection and high energy input into the diet of many commercial animals for the last decade has significantly increased the daily gain of body weight and shortened the raising period, but unexpectedly decreased the meat quality. The gastrointestinal tract of animals harbors a diverse and complex microbial community that plays a vital role in the digestion and absorption of nutrients, immune system development, pathogen exclusion, and meat quality. Fatty acid composition and oxidative stress in adipose and muscle tissue influences meat quality in livestock and poultry. Recent studies showed that nutraceuticals are receiving increased attention, which could alter the intestinal microbiota and regulate the fat deposition and immunity of hosts to improve their meat quality. Understanding the microbiota composition, the functions of key bacteria, and the host-microbiota interaction is crucial for the development of knowledge-based strategies to improve both animal meat quality and host health. This paper reviews the microorganisms that affect the meat quality of livestock and poultry. A greater understanding of microbial changes that accompany beneficial dietary changes will lead to novel strategies to improve livestock and poultry meat product quality.

Modifying the Quality of Pig Carcasses, Meat, and Dry Fermented Sausage from Black Slavonian Pigs by Selecting the Final Body Weight and Nutrition

A total of 96 Black Slavonian pigs were subjected to the research, in which they were split into 6 groups. Three groups (100, 120, and 130 kg) were fed a higher level (HL) of crude protein in fodder mixtures (CPFM), and three groups (100, 120, and 130 kg) were fed a lower level (LL) of CPFM. After the pigs were slaughtered, pig carcasses were dissected and the meat and halves quality indicators were determined. According to the influence of the final body weight (BW) and nutrition of pigs on the quality of their halves, meat, and dry fermented sausages (kulens), it was concluded that feeding an HL of CPFM increased the proportion of loin, belly rib part, and chin and increased the muscle tissue in the ham, loin, shoulder, neck, and belly rib parts. However, the chemical composition of the meat and the sensory properties of the kulen were not significantly affected by feeding the pigs an HL of CPFM. It was concluded that, by selecting the final BW and adjusting the feeding strategies for pigs, it is possible to modify the conformation and composition of pig carcasses and the quality of meat and kulens produced from the Black Slavonian pig, which is important because consumers prefer products with certain characteristics and of a standard quality and are ready to pay for them.

Influence of Slaughter Weight and Sex on Growth Performance, Carcass Characteristics and Ham Traits of Heavy Pigs Fed Ad-Libitum

Simple Summary

In recent years, pigs involved in the dry-cured ham production system have suffered from excessive leanness. This has led to the increase of slaughter weight (SW) to achieve greater carcass and ham fatness statuses to compensate for the loss in dry-curing aptitude. The production guidelines for the production of Italian dry-cured ham are currently under revision and an extension of the range of carcass weights from 126 to 168 kg, corresponding to about 146 to 210 kg of SW, has been proposed. However, little is known about the influence of SW in the range of 140–200 kg on growth performance, feed efficiency, carcass quality and ham curing aptitude. We hypothesized that an increased SW could exert a positive influence on ham characteristics. Data from 159 pigs fed ad libitum with diets, unlimiting for nutrient contents, up to 8 or 9 months of age (140–200 kg SW) were used. Greater SWs were linearly and positively associated with the growth performance of the pigs and with better ham quality traits. Greater SW increased ham weight, muscularity, and greater fat covering, according to the dry-cured ham industry’s expectations. Barrows produced hams with greater weight and marbling than gilts.

Abstract

Slaughter weight (SW) is critical for dry-cured ham production systems with heavy pigs. A total of 159 C21 Goland pigs (gilts and barrows) at 95 ± 9.0 kg body weight (BW) from three batches were used to investigate the impact of ad libitum feeding on SW, growth performance, feed efficiency, and carcass and green ham characteristics. Diets contained 10 MJ/kg of net energy and 7.4 and 6.0 g/kg of SID-lysine. Slaughter weight classes (SWC) included <165, 165–180, 180–110 and >210 kg BW. In each batch, pigs were sacrificed at 230 or 258 d of age. Left hams were scored for round shape, fat cover thickness, marbling, lean colour, bicolour and veining. Data were analyzed with a model considering SWC, sex and SWC × Sex interactions as fixed factors and the batch as a random factor. The linear, quadratic and cubic effects of SWC were tested, but only linear effects were found. Results showed that pigs with greater SWC had greater average daily gain and feed consumption, with similar feed efficiency and better ham quality traits: greater ham weight, muscularity, and fat coveringin correspondence of semimembranosus muscle. Barrows were heavier and produced hams with slightly better characteristics than gilts.

Beef from Calves Finished with a Diet Based on Concentrate Rich in Agro-Industrial By-Products: Acceptability and Quality Label Preferences in Spanish Meat Consumers

Conjoint analysis was used to estimate the relative importance of some of the main extrinsic attributes and quality labels of beef in three Spanish cities (Córdoba, Marbella, and Santa Pola) in a study performed with 300 individuals. Consumers were segmented according to their frequency of consumption. Willingness to pay for different meats was also calculated from the conjoint analysis results. Consumer liking of beef that had been finished with an alternative concentrate rich in agro-industrial by-products and aged for three different durations as compared to conventionally finished beef was also evaluated using the same consumers. The most important attribute for Spanish consumers was the price (28%), followed by origin (25%), animal welfare certification (19%), protected geographical indication (14%), and organic agriculture certification (14%). Most consumers preferred beef from Spain at the lowest possible price and with the highest number of quality labels. Consumers were willing to pay a premium of 1.49, 3.61, and 5.53 EUR over 14 EUR/kg for organic certification, protected geographical indication, and animal welfare certification, respectively. Sensory analysis revealed that, for regular consumers, beef finished with an alternative concentrate rich in agro-industrial by-products offered several hedonic advantages (color, flavor, and tenderness) when compared to beef finished using a conventional diet, while occasional consumers did not find any difference between the two kinds of meat.

Consequences of a low protein diet on the liver and longissimus dorsi transcriptome of Duroc × Iberian crossbred pigs

Low protein diets supplied during the growing period of pigs can diminish their growth rate and increase the intramuscular fat (IMF) content which affects the sensorial and technological characteristics of the products. In the present study, the effects of a low protein diet supplied during the growing period of Duroc × Iberian crossbred pigs on several phenotypic traits and on liver and longissimus dorsi transcriptome were analysed at the beginning (EARLY) and at the end (LATE) of the growing period. Two experimental groups of 10 crossbred pigs each were fed two isocaloric diets with different protein content: control diet (C) with 16.5% protein and 0.8% lysine and low protein diet (LP) with 11% CP and 0.6% lysine. Animals fed LP diet have a slower growth than those fed C diet, but no effect of LP diet was observed on the IMF content. The transcriptomes of liver and longissimus dorsi were characterised and quantified through RNA-sequencing (RNA-seq). In liver, 134 and 480 differentially expressed annotated genes and new isoforms (DEGs) were detected between C and LP diets for EARLY and LATE animals, respectively. In muscle, 128 and 68 DEGs were detected at EARLY and LATE time-points. Functional interpretation revealed that LP diet may inhibit immune system molecules and processes in both tissues at EARLY stage. In liver, the DEGs mainly affect lipid and cholesterol metabolic processes, while in muscle, the expression changes would be involved in growth, development and meat quality. In conclusion, a low protein diet supplied during the growing period seems to slow down the growth of Duroc × Iberian crossbred pigs, but it also seems to affect multiple biological processes that could compromise the immune system of Duroc × Iberian crossbred pigs. Therefore, these results question the adequacy of this type of regime in Duroc × Iberian pigs that must be studied in greater depth before being implemented.

Review: Quality and authentication of organic animal products in Europe

The 'organic' label guarantees a production process that avoids the use of synthetic fertilisers, pesticides and hormones and minimises the use of veterinary drugs; however, consumers are demanding guarantees regarding food quality. This article reviews the current state of knowledge on the quality of organic animal products, including the authentication of their organic origin. Quality has been considered as an integrative combination of six core attributes: commercial value, and nutritional, sensory, technological, convenience and safety attributes. The comparison of these attributes between organic and conventional animal products shows high heterogeneity due to variability in farming pratices in both organic and conventional systems. To overcome this, we pinpoint the farming practices underlying the differences observed. This enables light to be shed on the consequences of possible trajectories of organic farming, if specifications are relaxed or tightened up on commitments concerning farming practices that impact product quality. Two recent meta-analyses showed better nutritional attributes in organic milk and meat linked to their higher poly-unsaturated fatty acid (PUFA) content, particularly n-3 PUFAs. Regarding safety, we point to a lack of integrated studies quantifying the balance between positive and negative effects. Organic farming reduces the risk of drug residues and antibiotic resistance, but both outdoor rearing and a frequently longer rearing period increase the animals' exposition to environmental contaminants and the risk of their bioaccumulation in milk, eggs, meat and fish flesh. We highlight antagonisms between quality attributes for certain animal products (lamb, pork). In general, attributes are more variable for organic products, which can be explained by lower genetic selection (poultry), lower inputs and/or greater variability in farming conditions. However, the literature does not address the implications of this greater variability for the consumers' acceptability and the necessary adaptation of manufacturing processes. Further research is needed to document the impacts on human nutritional biomarkers and health. Methods used to authenticate organic origin are based on differences in animal diet composition between organic and conventional systems, but their reliability is hampered by the variability in farming practices.

Review: Pork quality attributes from farm to fork. Part I. Carcass and fresh meat

This work considers all factors along the production chain from farm to fork influencing the quality of fresh pork and processed products. Pork quality is multidimensional and comprises various attributes: commercial value of carcasses, meat organoleptic, nutritional, technological (i.e. suitability for processing and storage) properties, convenience, and societal image. The latter denotes cultural, ethical (including animal welfare) and environmental dimensions related to pork production, including geographical origin, all of which influence societal perceptions for pork. This review covers the impact of production factors, slaughter methods, carcass processing, and post mortem ageing on fresh meat quality. The impact on pork quality from some of these factors are now well documented and clearly established (e.g. genetics and pork technological attributes; diet and lipid profile; preslaughter and slaughter conditions and pork technological or organoleptic attributes…). Gaps in scientific knowledge are also identified, including the need for a better understanding of regulatory pathways for oxidative stress in vivo and post mortem that can contribute to optimise pork organoleptic and nutritional attributes and its suitability for processing and storage. This review highlights the strong interactions between primary production factors on pork quality attributes. Interactions are particularly marked in alternative production systems, in which synergies between factors can lead to specific quality characteristics that can be used to market pork at a premium as branded products. There are also antagonisms between quality attributes, namely between carcass commercial value and pork technological and organoleptic properties, between nutritional attributes and processing and storage suitability of fat tissues, between societal image and pork technological attributes in outdoor production systems, and between societal image (better welfare) and organoleptic attributes (risk for boar taint) in entire male production. Further research is needed to better understand the effects of some specific production factors and their interactions on quality attributes. A holistic approach with the use of multicriteria analyses can help to work out the trade-offs between pork quality attributes and between stakeholders (farmer, slaughterhouse or processing plant, consumers, citizens …) whose priorities may differ.

Review: Pork quality attributes from farm to fork. Part II. Processed pork products

Pork is often consumed in a very wide variety of products, processed from integral cuts or minced meat using different conservation methods (curing, smoking, cooking, drying, fermenting). Quality of pork products results from a combination between the properties of the raw material and the processing conditions to elaborate the final products. The influence of primary production factors, slaughtering and carcass processing on the quality of fresh pork has been reviewed (part 1), considering quality as an integrative combination of various attributes: commercial, organoleptic, nutritional, technological, convenience, and societal image, the latter denotes cultural, ethical (including animal welfare) and environment dimensions related to the way pork is produced, processed, and its geographical origin. This review (part 2) focuses on the influence of primary production factors and processing techniques on the quality of two important and economically significant processed pork products issued from contrasting processing techniques: cooked ham and dry-cured ham. As with fresh pork, many factors influence the quality of processed products, and one factor can affect several attributes. Moreover, in the case of processed products, numerous factors in both animal production and processing steps interact to determine their quality attributes. The quality of cooked ham depends on the properties of the raw material (in particular pH, colour, water holding capacity, presence of destructured meat defect, etc.) which are determined by pig husbandry practices (especially the genotype), pre-, postslaughter and processing conditions including the composition of curing mixture (ingredients, additives), salting, mixing and heat treatment. Processing techniques of cooked ham aim at homogenising the product quality within a given quality category (e.g. 'standard' or 'superior') or brand. Therefore, the variability of raw material is problematic for the cooked ham processing industry, which generally seeks uniformity and homogeneity of fresh hams. Likewise, pig husbandry conditions exert even greater impact on dry-cured ham quality. Indeed, the properties of raw material (including weight of fresh ham, fat thickness, pH, intramuscular fat and antioxidants content, fatty acid profile, etc.) that result from combined effects of primary production factors (genotype, feeding, production system, etc.) interact with processing conditions (salting, drying, ripening conditions and duration, etc.) to elaborate the quality attributes of the final products. Synergies can be sought between the primary production factors and processing techniques leading to specific organoleptic characteristics (texture, taste, aroma, flavour, etc.) that can be valued by quality labels. Quality of products is thus built along the whole chain from farm to fork.

The Impact of Zn, Cu and Fe Chelates on the Fatty-Acid Profile and Dietary Value of Broiler-Chicken Thigh Meat

Simple Summary

Poultry meat is deemed a product with a dietary value. The chemical composition of meat can be altered by modifying animals’ diets. Our objective was to show the impact of the addition of glycine chelates of minerals (Zn, Cu, Fe) to broiler chickens’ feed on the fatty-acid profile and dietary value of thigh meat. A positive effect was most frequently noted for Zn chelate, especially in a larger dose. The lowest levels of saturated fatty acids and atherogenic and thrombogenic indices but the highest content of polyunsaturated fatty acids n−3 and polyunsaturated fatty acids/saturated fatty acid ratios and hypocholesterolemic/hypercholesterolemic indices were noticed. The use of Cu and Fe glycine chelates was worse than Zn but did not meet the levels from the control group. These types of treatments are important in order to ensure correct functions of the body and can mitigate or even prevent the occurrence of many diseases.

Abstract

This study aimed to compare the effect of Zn, Cu and Fe glycine chelates on the proximate composition, cholesterol levels, fatty-acid profile and dietary value of the thigh meat of broiler chickens. The experiment involved three hundred and fifty Ross 308 chickens divided into seven groups. The chickens were administered Zn, Cu and Fe glycine chelates in an amount corresponding to 50% of the requirement or 25% of the requirement for 42 days. It was found that the use of Zn, Cu and Fe glycine chelates did affect the fatty acid profile and dietary value of meat. A positive impact was most frequently (p < 0.05) noted in chickens receiving Zn chelate in an amount covering 50% of the requirement: the lowest levels of SFA and atherogenic and thrombogenic indices, the highest content of PUFA n−3 and PUFA/SFA ratios and hypocholesterolemic/hypercholesterolemic indices. Positive effects were more often recorded for chickens receiving Zn in an amount corresponding to 50% of the requirement. The results did not show that the use of Cu and Fe glycine chelates can reduce the dietary value of thigh meat in broiler chickens since, generally, the outcomes were not worse than those in the control group. It should be highlighted that due to ambiguous results, it is impossible to determine a dose of Cu and Fe glycine chelate which would be more efficient for broiler chickens. However, chickens receiving chelates in amounts corresponding to 25% of the requirement showed far better results.

Effects of two dietary crude protein levels on finishing performance, meat quality, and gene expression of market lambs

Seventeen crossbred lambs were assigned randomly to low-protein (LP; 8% crude protein [CP]; n = 9) and high-protein (HP; 13% CP; n = 8) diets for 9 weeks. The final body weight, average daily feed intake (ADFI), and average daily gain (ADG) of the HP lambs were significantly higher (P < 0.05) than the LP lambs; however, gain to feed ratio (G:F) for the LP lambs was significantly higher (P < 0.05) than the HP lambs. Hot carcass weight (HCW), adjusted fat thickness, and drip loss of longissimus dorsi (LD) muscle were significantly higher (P < 0.05) for the HP than LP lambs. In contrast, instrumental color values L*, a*, b*, C*, and hue angle (H) of meat from the LP lambs scored significantly higher (P < 0.05) than the HP lambs. The LD muscle from HP lambs had significantly greater CLA of cis-9 trans-11 isomer (P < 0.05) than the LP lambs. The gene expression of metabolism and meat quality-related genes of LP was significantly higher than HP (P < 0.05). These results suggest that a higher dietary CP level promotes growth performance for finishing lambs, whereas lower dietary CP level is beneficial for meat quality, especially when evaluating color characteristics in the final product.

Finishing season and feeding resources influence the quality of products from extensive-system Gascon pigs. Part 1: Carcass traits and quality of fresh loin

Consumers perceive pork products from local breeds reared in extensive systems positively because of their specific quality properties and regional identity. The sensory, nutritional and technological qualities of these products depend, among other things, on pig production, especially its climatic conditions and the availability of feed resources, which can influence traits of muscle and fat tissue. The present study (part 1) was part of a larger project that assessed the influence of the finishing season and feeding resources on carcass and tissue traits and the quality of meat and dry-cured ham from Gascon pigs in an extensive system. Following the specifications of the Protected Designation of Origin "Noir de Bigorre", castrated Gascon males were reared on rangelands (grassland and forest areas) and received a supplementary diet from 5 to 6 months of age until slaughter at a minimum of 12 months of age and ca. 170 kg live weight. Three finishing seasons were considered as follows: Winter (n = 18), Spring (n = 22) and Autumn (n = 23). To estimate specific effects of season on productive and quality traits and avoid bias due to effects of genes known to influence these traits, polymorphisms in the RYR1, PRKAG3, MC4R and LEPR genes were included in the analysis models. The finishing season did not influence growth rate. Compared to Winter pigs, Spring and Autumn pigs had slightly lower carcass fatness (P < 0.05), higher ultimate pH and redder and darker color of the Longissimus muscle (LM) (P < 0.01). Loin drip loss was low overall, but was higher for Spring pigs, whereas cooking loss and shear force were similar among seasons. Spring pigs tended to have the lowest LM lipid content, whereas LM myoglobin content remained unaffected. Autumn pigs had lower potential of lipid oxidation in LM than Winter and Spring pigs (P < 0.01), but muscle metabolic traits assessed via glycolytic and oxidative enzyme activities did not differ among seasons. The finishing season modified the backfat fatty acid (FA) profile, with a lower polyunsaturated FA percentage in Autumn pigs than Winter or Spring pigs (P < 0.001), even though the saturated and monounsaturated FA percentages did not differ. In particular, Spring pigs had the lowest n-6:n-3 and C18:2:C18:3 ratios (P < 0.001), as a result of grazing. Overall, Spring and Autumn finishing seasons seem more favorable to technological and sensory pork attributes, with an additional positive effect of Spring finishing on pork nutritional value.

Pork Quality of Two Lithuanian Breeds: Effects of Breed, Gender and Feeding Regimen

Simple Summary

A few highly selected commercial pig breeds have been developed and many different local breeds have been replaced by these modern breeds. With the aim to preserve rare local breeds, the necessity has arisen to find and create the conditions under which local breeds could be more widely used. Therefore, the performance and production qualities of local breeds should be evaluated and highlighted. As the quality of pig production is associated with breeds and effects of other different conditions, the objective of this experiment was to investigate the effects of breed, gender, and feeding level in the finishing phase on the carcass and meat quality of Lithuanian White and Lithuanian Indigenous Wattle pigs reared indoors. Feed restriction during the finishing phase and gender both affected the growth and fatness of pigs. The breed and gender appeared to have an effect on the parameters of meat quality including fatty acid composition. The breed and gender effects on fatty acid composition showed more favorable lipid indices in relation to healthy nutrition in the ham muscles of Lithuanian White pigs compared with Lithuanian Indigenous Wattle pigs and also in the ham muscle and backfat of females compared with castrated males.

Abstract

The diversity of breeds is an important factor influencing carcass and meat quality traits that are also associated with other different effects. The objective of this study was to investigate the effects of breed, gender, and feeding level in the finishing phase on the carcass and meat quality of Lithuanian White and Lithuanian Indigenous Wattle pigs reared indoors. After 60 kg weight, half of the animals from both breeds were fed a restricted diet of approximately 82% of average ad libitum feeding intake, and the other half of pigs were further fed ad libitum to the end of the experiment. Feed restriction during the finishing phase decreased daily gain and weight of pigs at slaughter, and backfat thickness at the tenth rib (p ˂ 0.001, p ˂ 0.01, and p ˂ 0.05, respectively). Lithuanian White pigs demonstrated higher (p ˂ 0.001) growth rate, live body weight at slaughter and carcass weight, and had a higher (p ˂ 0.01) length of carcass and loin area and lower (p ˂ 0.05) backfat thickness at the last rib and at two points at the lumbar area compared with Lithuanian Indigenous Wattle pigs. The semimembranosus muscle of Lithuanian White pigs had relatively (8.1%) lower (p ˂ 0.001) proportions of saturated and 41.2% higher (p ˂ 0.001) proportions of polyunsaturated fatty acids compared with the pigs of the Lithuanian Indigenous Wattle breed, whereas in the longissimus muscle and subcutaneous tissue, the breed only affected the n-6/n-3 ratio (p ˂ 0.01 and p ˂ 0.001, respectively). Gender showed an effect on saturated fatty acids in all the studied tissues, however, the effects on polyunsaturated fatty acids were found in the semimembranosus muscle and subcutaneous tissue (p ˂ 0.05 and p ˂ 0.001) and the effects on monounsaturated fatty acids was found only in the semimembranosus muscle (p ˂ 0.01). These differences in the fatty acid composition of the semimembranosus muscle and subcutaneous tissue of females exhibited more favorable lipid quality indices compared with castrated males (p ˂ 0.001). The semimembranosus muscle of Lithuanian White pigs also showed more favorable lipid quality indices in relation to healthy nutrition compared with Lithuanian Indigenous Wattle pigs (p ˂ 0.001). This study is one of the steps toward the development and utilization of endangered breeds. The obtained information can be used to increase choice in pork production and consumption, and provides new insights for research into the conservation of local breeds.

The Quality and Health-Promoting Value of Meat from Pigs of the Native Breed as the Effect of Extensive Feeding with Acorns

Simple Summary

Modern society is paying more attention to the quality of meat and its production system. Therefore, in this study, we analyzed the possibility of using a native pig breed—Złotnicka Spotted. This breed’s popularity has increased in Poland as it may be a good source of valuable meat. Compared to the meat frompigs of the same breed following intensive fattening, the meat from free-range pigs extensively fed on silage and small amounts of acorns is characterized by a higher content of fat, which acts as a carrier for flavor and, indirectly, juiciness. Moreover, rearing systems with traditional feeding, e.g., with the use of acorns, may have a positive effect on meat quality, dietetic value, and, therefore, consumer acceptance of the product.

Abstract

The popularity of meat from animals of native breeds is growing all over the world, due to consumer belief regarding its higher quality compared to meat from industrial farm animals. In addition, the living conditions (welfare) are of great importance for consumers. We observed the effect of different ways of keeping and feeding pigs of the same conservative breed on the quality of meat and its health benefits. The aim of the study was to compare the meat quality from pigs of the native Złotnicka Spotted breed, fattened intensively or extensively (with conventional farm-produced compound feed and acorns). The meat from free-range pigs extensively fed on silage and small amounts of acorns was characterized by a higher content of fat, which acts as a carrier for flavor and juiciness, as well as higher monounsaturated fatty acid (MUFA) content (p ≤ 0.05) and lower atherogenic, thrombogenic, and peroxidability indices (p ≤ 0.05). It may be stated that the meat quality of the native pig breed is significantly dependent on the housing and feeding method. A more beneficial effect on the quality of meat and its dietetic value, as well as its susceptibility to rancidity, can be obtained throughextensive pig feeding with roughage and the addition of acorns.

Physical Activity Effects on Blood Parameters, Growth, Carcass, and Meat and Fat Composition of Portuguese Alentejano Pigs

Simple Summary

Outdoor farming systems are associated with health, animal welfare, sustainability, and food security, making them highly desirable for consumers. In this trial, it was possible to confirm that pig physical activity, a major factor in the traditional and extensive production systems of the Alentejano pig, influences animal welfare and the results of biochemical and zootechnical parameters. In this perspective, breeding pig breeds that perform spontaneous physical activity has greater advantages for producers, as pigs can reach the same slaughter weight in less time and with lower feed costs than animals reared in individual pens. Based on these results, the negative impacts that system intensification (with the consequent reduction in the vital space of each animal and the physical activity performed) may have on animal welfare, animal performance and on the quality of the meat obtained, should be considered.

Abstract

This study evaluated the effects of physical activity on blood, growth, carcass, and meat quality of finishing Alentejano (AL) pigs. Pigs, reared from ~87 to 160 kg in individual pens (no exercise area, NE group, n = 9) or in an outdoor park (with exercise area, WE group, n = 9), were fed commercial diets (85% ad libitum). WE pigs were in a park (~400 m²) with a feeding area separated from the drinking area with an automatic waterer, forcing pigs to walk at least 800 m daily. Blood samples were obtained during the trial (weeks 2, 11, and 18) and at slaughter. The left-side carcass was submitted to commercial cuts, and samples from loin, tenderloin, and dorsal subcutaneous fat (DSF) were analyzed. Plasma urea in WE pigs was higher in weeks 2 and 11, while cholesterol, LDL-cholesterol, cholesterol to HDL-cholesterol and LDL- to HDL-cholesterol ratios, and cortisol were lower in weeks 11 and 18. Final weight and average daily gain were higher and feed conversion ratio lower in WE pigs. DSF thickness and carcass weight were higher in WE pigs, leading to higher carcass yield. Finally, loin and tenderloin from WE pigs presented higher total protein content. These data show that allowing physical activity affects metabolism, growth, and carcass and meat quality of AL pigs.

Effect of Excessive or Restrictive Energy on Growth Performance, Meat Quality, and Intramuscular Fat Deposition in Finishing Ningxiang Pigs

This study investigated the effects of excessive or restrictive energy on growth performance, meat quality, intramuscular fat (IMF) deposition, and related gene expression in finishing Ningxiang pigs. A total of 36 Ningxiang pigs (43.26 ± 3.21 kg) were randomly assigned to three treatments (6 pens of 2 piglets per treatment) and fed by one of three dietary treatments until the pigs of each treatment weighed approximately 75 kg equally. The three treatments were control diet (digestible energy, DE:13.02 MJ/kg, CON), excessive energy diet (DE 15.22 MJ/kg, EE), and restrictive energy diet (DE 10.84 MJ/kg, RE). Results showed that EE improved average daily gain (ADG) and feed conversion ratio (FCR) (p < 0.01), while nothing significantly changed by RE except FCR increasing (p < 0.01). EE increased the content of IMF and triglycerides (TG) (p < 0.05), L*24h and b*45min (p < 0.01), while decreasing cooking loss and meat tenderness in longissimus thoracis (LT) (p < 0.05). b*24h was significantly increased with the increase of energy level (p < 0.01). Meanwhile, EE increased the cross-sectional area (CSA) of muscle fiber and the mRNA expression of myosin heavy chain (MyHC) IIb, acetyl CoA carboxylase (ACC), fatty acid synthase (FAS), and adipocyte fatty-acid binding protein (FABP4) (p < 0.05). In addition, throughout: A diet supplemented with excessive energy promoted IMF deposition by positively changing lipogenic potential while decreasing tenderness by increasing glycolytic muscle fibers, which together affected meat quality. In terms of growth performance and meat quality, the present study suggests that the low-energy diet is suitable for finishing Ningxiang pigs.

Strategies to Meet Nutritional Requirements and Reduce Boar Taint in Meat from Entire Male Pigs and Immunocastrates

This paper reviews the current knowledge on the nutritional requirements of entire male and immunocastrated pigs to obtain an efficient growth, low boar taint level, and good carcass and meat quality. We present the reasons for offering entire males ad libitum access to the diets in order to optimize their protein deposition potential. Boar taint is one of the major issues in the production of entire males; therefore, the impact of various skatole- and indole-reducing feed ingredients is discussed regarding their efficiency and the possible mechanism affecting skatole and indole production in the hindgut. Entire males have lean carcasses, so their intramuscular fat content can be lower than that of surgical castrates or females and the adipose tissue can be highly unsaturated. The possible nutritional strategies to counteract these effects are summarized. We conclude that immunocastrates can be fed similarly to entire males until the second vaccination. However, due to the metabolic changes occurring shortly after the second vaccination, the requirements for essential amino acids are markedly lower in immunocastrates than in entire males.

Free-Range and Low-Protein Concentrated Diets in Iberian Pigs: Effect on Plasma Insulin and Leptin Concentration, Lipogenic Enzyme Activity, and Fatty Acid Composition of Adipose Tissue

The purpose of this study was to investigate the effect of diets with different protein contents on carcass traits, plasma hormone concentration, lipogenic enzyme activities, and fatty acid (FA) composition in the adipose tissue of Iberian pigs. Twenty-four castrated male Iberian pigs (eight per feeding diet) were fed under free-range conditions with acorns and grass (FR), and in confinement with concentrated diets with standard (SP) and low-protein contents (LP) from 116.0 to 174.2 kg live weight. Backfat thickness was not affected by diet. The plasma leptin concentration was higher (p < 0.001) in the FR group than in the LP and SP groups, while insulin concentration was higher in the SP group than in the LP and FR groups. The lipogenic enzyme activities of glucose-6-phosphate dehydrogenase, malic enzyme, and glycerol-3-phosphate dehydrogenase were lower in the FR group compared to the LP and SP pigs. The activities of these enzymes were adipose-tissue-specific. No differences were found in FA composition of adipose tissue between the SP and LP groups, while the FR pigs had lower proportions of saturated FA and higher proportions of monounsaturated and polyunsaturated FA than the SP and LP pigs. In conclusion, feeding low-protein diets in Iberian pigs does not seem to affect adipose carcass traits, strengthening previous findings that indicate that this is a good strategy to improve meat and dry-cured product quality.

Carcass Characteristics and Primal Pork Cuts of Gilts, Boars, Immunocastrates and Barrows Using AutoFOM III Data of a Commercial Abattoir

Simple Summary

Male piglets designated for pork production have been surgically castrated for centuries. The fattening of intact boars is more environmentally friendly due to anabolic effects, but entails a higher risk of aggressive and sexual behavior, and some boar carcasses may exhibit boar taint, which reduces pork quality. Immunocastration as a further alternative to surgical castration is considered as a reliable and animal welfare-friendly method, but currently still has a very small market share. A crucial factor for the period following surgical castration is that pork production, either with boars or immunocastrates, is competitive and produces valuable carcasses with regard to lean meat content and the respective amounts of primal pork cuts. In this study, we therefore evaluated AutoFOM III data from a commercial abattoir. The results show that carcasses from immunocastrates were of similar quality to those of barrows, with carcass characteristics that lay between the values of gilts and barrows. Boar carcasses are leaner in comparison to barrows, but produce the same amount of valuable pork per carcass. Boars and immunocastrates are therefore suitable for the processing industry and both techniques are able to compete with pork production with barrows in terms of carcass characteristics and primal pork cuts.

Abstract

The surgical castration of male piglets as a routine procedure in modern pig production is facing increasing societal criticism. Pork production with boars and immunocastrates are available alternatives, but both have low market shares as it is so far uncertain how the carcass characteristics and primal pork cuts of boars and immunocastrates will be estimated in comparison to barrows and gilts. This article therefore evaluates the impact of sex group (gilts, boars, immunocastrates and barrows) on carcass characteristics and primal pork cuts using AutoFOM III data from a commercial abattoir. In our study, weekly slaughter data from a total of n = 36,994 pigs between 2018 and 2019 were analyzed. The results show that gilts had the highest amount of pork per carcass of all sex groups, whereas non-significant differences between boars, immunocastrates and barrows could be observed. Boars had the highest lean meat content, followed by gilts, immunocastrates and finally barrows with the lowest lean meat content. These results suggest that both immunocastration and pork production with boars are sustainable techniques that can replace pork production with barrows without affecting carcass quality.

Transcriptome analysis reveals the genetic basis of skeletal muscle glycolytic potential based on a pig model

Glycolytic potential (GP) calculated based on glucose, glycogen, glucose-6-phosphate, and lactate contents is a critical factor for multiple meat quality characteristics. However, the genetic basis of glycolytic metabolism is still unclear. In this study, we constructed six RNA-Seq libraries using longissimus dorsi (LD) muscles from pigs divergent for GP phenotypic values and generated the whole genome-wide gene expression profiles. Furthermore, we identified 25,880 known and 220 novel genes from these skeletal muscle libraries, and 222 differentially expressed genes (DEGs) between the higher and lower GP groups. Notably, we found that the Lactate dehydrogenase B (LDHB) and Fructose-2, 6-biphosphatase 3 (PFKFB3) expression levels were higher in the higher GP group than the lower GP group, and positively correlated with GP and lactic acid (LA), and reversely correlated with pH value at 45 min postmortem (pH_45min). Besides, LDHB and PFKFB3 expression were positively correlated with drip loss measured at 48 h postmortem (DL_48h) and drip loss measured at 24 h postmortem (DL_24h). Collectively, we identified a serial of DEGs as the potential key candidate genes affecting GP and found that LDHB and PFKFB3 are closely related to GP and GP-related traits. Our results lay a solid basis for in-depth studies of the regulatory mechanisms on GP and GP-related traits in pigs.

Potential Use of Near-Infrared Spectroscopy to Predict Fatty Acid Profile of Meat from Different European Autochthonous Pig Breeds

Autochthonous pig breeds provide products of differentiated quality, among which quality control is difficult to perform and insufficient for current market requirements. The present research evaluates the predictive ability of near-infrared (NIR) spectroscopy, combined with chemometric methods as a rapid and affordable tool to assure traceability and quality control. Thus, NIR technology was assessed for intact and minced muscle Longissimus thoracis et lumborum samples collected from 12 European autochthonous pig breeds for the quantification of lipid content and fatty acid composition. Different tests were performed using different numbers of samples for calibration and validation. The best predictive ability was found using minced presentation and set with 80% of the samples for the calibration and the remaining 20% for the external validation test for the following traits: lipid content and saturated and polyunsaturated fatty acids, which attained both the highest determination coefficients (0.89, 0.61, and 0.65, respectively) and the lowest root mean square errors in external validation (0.62, 1.82, and 1.36, respectively). Lower predictive ability was observed for intact muscles. These results could contribute to improve the management of autochthonous breeds and to ensure quality of their products by traditional meat industry chains.

Modeling host-microbiome interactions for the prediction of meat quality and carcass composition traits in swine

BACKGROUND

The objectives of this study were to evaluate genomic and microbial predictions of phenotypes for meat quality and carcass traits in swine, and to evaluate the contribution of host-microbiome interactions to the prediction. Data were collected from Duroc-sired three-way crossbred individuals (n = 1123) that were genotyped with a 60 k SNP chip. Phenotypic information and fecal 16S rRNA microbial sequences at three stages of growth (Wean, Mid-test, and Off-test) were available for all these individuals. We used fourfold cross-validation with animals grouped based on sire relatedness. Five models with three sets of predictors (full, informatively reduced, and randomly reduced) were evaluated. 'Full' included information from all genetic markers and all operational taxonomic units (OTU), while 'informatively reduced' and 'randomly reduced' represented a reduced number of markers and OTU based on significance preselection and random sampling, respectively. The baseline model included the fixed effects of dam line, sex and contemporary group and the random effect of pen. The other four models were constructed by including only genomic information, only microbiome information, both genomic and microbiome information, and microbiome and genomic information and their interaction.

RESULTS

Inclusion of microbiome information increased predictive ability of phenotype for most traits, in particular when microbiome information collected at a later growth stage was used. Inclusion of microbiome information resulted in higher accuracies and lower mean squared errors for fat-related traits (fat depth, belly weight, intramuscular fat and subjective marbling), objective color measures (Minolta a*, Minolta b* and Minolta L*) and carcass daily gain. Informative selection of markers increased predictive ability but decreasing the number of informatively reduced OTU did not improve model performance. The proportion of variation explained by the host-genome-by-microbiome interaction was highest for fat depth (~ 20% at Mid-test and Off-test) and shearing force (~ 20% consistently at Wean, Mid-test and Off-test), although the inclusion of the interaction term did not increase the accuracy of predictions significantly.

CONCLUSIONS

This study provides novel insight on the use of microbiome information for the phenotypic prediction of meat quality and carcass traits in swine. Inclusion of microbiome information in the model improved predictive ability of phenotypes for fat deposition and color traits whereas including a genome-by-microbiome term did not improve prediction accuracy significantly.

Effect of an Outdoor Access System on the Growth Performance, Carcass Characteristics, and Longissimus lumborum Muscle Meat Quality of the Prestice Black-Pied Pig Breed

Simple Summary

The conservation of indigenous animal breeds is important, in terms of global food security and agricultural sustainability. The Prestice Black-Pied pig is a Czech breed which is maintained under the National Program for the Conservation and Utilization of Genetic Resources. Compared to improved breeds, the Prestice pig is characterized by a lower growth performance and higher carcass fatness; and is therefore not competitive under large-scale rearing conditions. On the other hand, so-called “primitive” characteristics, such as hardiness and adaptability, have been preserved in this breed. Thus, they are suitable for extensive rearing conditions similar to other indigenous European breeds. Despite this, most of the Prestice pig population is kept within a conventional indoor system. No research has been performed on the performance of this genotype within extensive conditions and their subsequent meat quality. Based on the results of the present study, the Prestice pig is able to utilize local protein feed (white lupin seeds/pea seeds) well, with regards to growth and feed efficiency, and it is possible to fatten them extensively using an outdoor-access system. An in-depth assessment of the breed’s production potential and market potential could assist in the conservation of the breed; through the promotion of higher value products.

Abstract

The effect of an outdoor-access vs. conventional indoor system on the growth, carcass characteristics, and longissimus lumborum muscle (LL) meat quality was evaluated in 24 Prestice Black-Pied pigs, during the growing-finishing period. Two groups received the same complete diet and were housed separately under conventional indoor conditions, with only one group having full access to pasture (350 m²/pig). The animals showed acceptable growth rates (outdoor vs. indoor, average of 740 g/d vs. 700 g/d), feed intake (average of 2700 g/d), and feed conversion ratios (FCR) (average of 3.3 vs. 3.5). The rearing system significantly affected the fatty acid composition of the LL. Outdoor pigs had lower ratios of n − 6/n − 3 polyunsaturated fatty acids, saturation indexes, atherogenic indexes, and thrombogenic indexes, compared with indoor-raised pigs. No differences were recorded in carcass characteristics, physical meat quality traits (pH₄₅, pH₂₄, drip loss, water holding capacity), or the chemical composition of the meat (crude protein, cholesterol, intramuscular fat, hydroxyproline, and tocopherol). The sensory analysis of grilled LL muscle found that outdoor pigs received lower evaluation scores for tenderness, juiciness, and chewiness, but had a better overall acceptance compared to pigs reared indoors.

Effects of Early and Current Environmental Enrichment on Behavior and Growth in Pigs

Enriched environments are known to beneficially affect the behavior of pigs, as compared with barren pens. The influence of enrichment may, however, depend on pigs' early life housing experiences. The aim of this study was to investigate the long-term effects of early and later life environmental enrichment on behavior and growth in pigs with different coping styles. Pigs were housed in either barren pens or in larger pens enriched with rooting substrates from birth, and half of them experienced a housing switch, i.e., a loss or gain of enrichment, at 7 weeks of age, creating four treatment groups. Home pen behavior and body weight were recorded until 19 weeks of age. Pigs were classified as reactive or proactive based on a backtest at 2 weeks of age. Enrichment increased time spent exploring, chewing, and play and decreased oral manipulation of penmates and pen-directed exploring and chewing. Behavior of pigs that switched from barren to enriched pens or vice versa reflected not only their actual environment, but also their early life housing. As early and later life enrichment affected most behaviors in opposite directions, effects of enrichment, or lack thereof, after the switch were more pronounced in pigs that had experienced a different early life condition. For instance, pigs experiencing an upgrade from barren to enriched pens seemed to "catch-up" by showing more exploration and play. Conversely, pigs exposed to a downgrade displayed more oral manipulation of penmates than ones kept barren throughout, which particularly held for pigs with a reactive coping style. Effects of early life and current housing on several other behaviors depended on coping style too. Pigs housed in enriched conditions appeared better able to cope with weaning than barren housed pigs, as they gained more weight and had higher feed intake post-weaning. Barren housed pigs had a lower body weight than enriched pigs just before the switch, after which growth was mainly determined by actual housing, with enriched kept pigs having a higher feed intake and body weight. Thus, not only current housing conditions, but also a (mis)match with the early life environment may affect behavior and growth of pigs.

Application of extended feed withdrawal time preslaughter and its effects on animal welfare and carcass and meat quality of enriched-housed pigs

A total of 144 barrows were distributed into four treatment groups. One group was housed conventionally and fasted for 16 h preslaughter, while the other three groups were housed in enriched conditions (straw-bedding and low density) and fasted for 16, 24 and 32 h preslaughter. When compared with conventionally-housed pigs, enriched-housed pigs were heavier (P < .05) and fatter (P < .01), but easier to handle at loading (P < .05) and produced less exudative pork (P < .05) possibly resulting from a lower post-mortem muscle glycolytic potential (P = .10). Extending fasting time up to 32 h reduced dressing yield (P < .001) and increased skin lesion scores (P < .01), but did not result in any clear or major effect on muscle metabolism and meat quality. In conclusion, given the beneficial effects of enriched housing conditions on stress response and pork quality, the application of an extended fasting time (32h) preslaughter is not required for this production.