Production Performance Of Pigs Research Articles

Effects of Dietary Fiber and Copper on the Performance and Gut Microbiota of Finishing Pigs

This study aimed to investigate the effects of dietary fiber (DF) levels and copper concentrations on the production performance and cecal microbial diversity of finishing pigs. A 2 × 2 factorial experimental design was used, with different levels of dietary fiber (low [23% DF]: L and high [30% DF]: H) and copper concentrations (normal [25 mg/kg]: N and supplemented [45 mg/kg]: S) resulting in four diets (LN, LS, HN, and HS). Forty-eight hybrid barrows (Duroc × Landrace × Yorkshire), with an initial body weight of 76 kg ± 1.5 kg, were randomly assigned to four groups: LN, LS, HN, and HS, with 12 replicates per group and one pig per replicate. There was a 7-day adaptation period followed by a 56-day feeding trial, after which all pigs were slaughtered for sampling. Results indicated that in finishing pigs, the low dietary fiber group exhibited a higher final weight, a higher average daily gain, and a lower feed-to-gain ratio compared to the high fiber group (p < 0.05). The LS group showed higher digestibility of dry matter, crude protein, crude fiber, ash, neutral detergent fiber, and DF than the HN and HS groups (p < 0.05). Blood total protein levels were higher in the high fiber group, whereas blood Cu levels were higher in the supplemented copper group (p < 0.05). High dietary fiber increased the activities of colonic carboxymethylcellulase and β-glucanase (p < 0.05). Concentrations of acetic acid, propionic acid, and total volatile fatty acids were elevated in the high fiber group (p < 0.05). Microbial α-diversity indices (observed species, Chao 1, and Shannon indices) increased with fiber but decreased with copper supplementation (p < 0.05). The Firmicutes/Bacteroidetes ratio increased with fiber levels, with a higher relative abundance of Lactobacillus in the LS group. In conclusion, appropriate copper supplementation in diets can mitigate the negative effects of high fiber levels on finishing pig production performance by enhancing nutrient digestibility, fiber-degrading enzyme activity, regulating the microbial community, and its metabolic products.

Pediococcus pentosaceus RC007 and Saccharomyces boulardii RC009 as antibiotic alternatives for gut health in post-weaning pigs.

The aim of the present study was to evaluate a novel probiotic Pediococcus pentosaceus RC007 used alone and convined with Saccharomyces cerevisiae var. boulardii RC009, as in-feed additives to substitute the non-therapeutic use of antibiotics, and evaluate the different structural characteristics of intestinal bacterial populations between groups, correlated with pig production performance. The in vivo study was conducted on post-weaning pigs, from 21 to 56 days-old. Three dietary treatments were included: T1- basal diet (BD - Control group); T2- BD with P. pentosaceus RC007; and T3- BD with a mix of P. pentosaceus RC007 and S. boulardii RC009. The weight gain increase of pigs consuming non-therapeutic antibiotics was similar to those that did not consume antibiotics during the study (p=0.0234), but had better health indicators. The use of a probiotic combination increased carcass weight and significantly reduced the lumbar fat thickness. In terms of taxonomic composition, there was a tendency to modify the abundance of Proteobacteria, Cyanobacteria, Enterobacteriaceae and Lactobacillaceae in pigs that consumed the additives. The genus Butyricicoccus, Collinsella and Ruminococcus tended to be more abundant in the microbiota of pigs at T3. For the first time, the results of the present study indicate that P. pentosaceus RC007 and S. boulardii RC009, a probiotic combination, could be a good substitute for antibiotics in improving pig production performance, while also contributing to a healthier gut microbiota, especially with the reduced abundance of Proteobacteria and Cyanobacteria.

RSAD2 suppresses viral replication by interacting with the Senecavirus A 2 C protein

Senecavirus A (SVA), an emerging virus that causes blisters on the nose and hooves, reduces the production performance of pigs. RSAD2 is a radical S-adenosylmethionine (SAM) enzyme, and its expression can suppress various viruses due to its broad antiviral activity. However, the regulatory relationship between SVA and RSAD2 and the mechanism of action remain unclear. Here, we demonstrated that SVA infection increased RSAD2 mRNA levels, whereas RSAD2 expression negatively regulated viral replication, as evidenced by decreased viral VP1 protein expression, viral titres, and infected cell numbers. Viral proteins that interact with RSAD2 were screened, and the interaction between the 2 C protein and RSAD2 was found to be stronger than that between other proteins. Additionally, amino acids (aa) 43–70 of RSAD2 were crucial for interacting with the 2 C protein and played an important role in its anti-SVA activity. RSAD2 was induced by type I interferon (IFN-I) via Janus kinase signal transducer and activator of transcription (JAK-STAT), and had antiviral activity. Ruxolitinib, a JAK-STAT pathway inhibitor, and the knockdown of JAK1 expression substantially reduced RSAD2 expression levels and antiviral activity. Taken together, these results revealed that RSAD2 blocked SVA infection by interacting with the viral 2 C protein and provide a strategy for preventing and controlling SVA infection.

PSII-26 Effects of diquat injection on growth performance and blood and liver redox status in growing pigs

Abstract Oxidative stress, caused by excessive reactive oxygen species generation, impairs health and production performance of pigs. A number of nutrients and feed additives have antioxidative property. Our current research project is to study the antioxidative roles of methionine (a sulfur-containing amino acid) in pigs, and this abstract is to report our setup of an oxidative-stressed model by injection of diquat (dibromide monohydrate), a bipyridyl herbicide, to the pig. Barrows [n = 20, body weight (BW) = 21.5 ± 2.50 kg] were randomly allotted to two treatment groups fed a corn-and-soybean-meal-based diet that met or slightly exceeded the NRC (2012) recommended requirements of nutrients and energy. After 3 wk of feeding (Phase 1), while Group-1 pigs were intraperitoneally injected with 10 mL saline, Group-2 pigs were injected with 10 mg/kg BW diquat in 10 mL saline. After the injection, pigs were continually fed for 7 d more (Phase 2). At the end of Phases 1 and 2, average daily gain (ADG), average daily feed intake (ADFI), and gain to feed (G:F) ratios were respectively determined. Blood samples were collected on d 1, 22, and 29 of the experiment, and liver samples were collected on d 29. Commercial assay kits were used to determine the blood and liver redox status, for which the malondialdehyde (MDA) and glutathione (GSH) contents, the superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) activities, and the total antioxidant capacity (TAC) were measured. The data was statistically analyzed using Student’s t-test. During Phase 1, there were no differences (P > 0.10) in initial BW, final BW, ADFI, ADG, and G:F ratio. There were no differences (P > 0.10) in the serum MDA contents, the serum GPX, SOD, and CAT activities, and the serum TAC and GSH contents between the two dietary treatment groups. By the end of Phase 2, however, the AFDI and ADG in Group 2 were less (P < 0.001) than that in Group 1. The serum MDA content in Group 2 was greater (P < 0.05) than in Group 1, the serum GPX activity and liver SOD activity in Group 2 was less (P < 0.05) than in Group 1, and the liver GPX activity in Group 2 tended to be greater (P = 0.10) than in Group 1, although there were no differences (P > 0.10) in serum SOD activity, serum TAC, and serum and liver CAT activities between the two treatment groups. In conclusion, the results of this study confirmed that young growing pigs intraperitoneally injected with diquat can lead to oxidative stress and serve as a model for studying antioxidant nutrients or feed additives in pigs.

Heterosis formation mechanism, prediction methods, and their application and prospect in pig production.

Heterosis is the phenomenon that the hybrid offspring outperform two-parent population. Hybridisation has been widely used in plant and animal production as it effectively improves the growth and developmental performance, reproductive performance and disease resistance of the offspring. Hybridization can effectively improve the growth and development performance, reproductive performance and disease resistance of offspring, so it is widely used in animal and plant production. Researchers have used cross-breeding techniques to cultivate excellent new agricultural and animal husbandry strains and supporting lines such as super-excellent Chaoyou 1000 hybrid rice, Xiaoyan No.6 hybrid wheat, Dumeng sheep, and Shanxia black pigs. However, there are still some urgent problems in the current hybrid dominance research: the existing hybrid dominance theory can only partially explain the phenomenon of plant and animal hybrid dominance, and the theory of animal hybrid dominance is less researched, and the accuracy of the existing hybrid dominance prediction methods is limited. China is the world's largest pork production and consumption country. Heterosis can effectively improve the production performance of pigs, and its application in the pig industry has important economic and research value. However, the existing research on pig hybrid production is in its infancy and needs to be further studied. In this review, we summarize the existing heterosis theory, heterosis prediction methods, and their application in pig production, to provide a reference for the application of heterosis in pig breeding.

The Potential of Grape Polyphenols Additive in Pig Nutrition: Chemical Structure, Bioavailability and Their Effect on Intestinal Health of Pigs

The recognition of the necessity for employing natural additives in animal feed has grown alongside the ban on antibiotics in the animal feed sector. Grapes, as well as by-products of the wine-making industry (grape marc and seed extracts), possess biologically active chemical constituents that can be used to improve animal production by incorporating them into animal feed. Grapes are a valuable resource of polyphenols, especially flavonoids, stilbenes and phenolic acids, most of them showing therapeutic or health-promoting properties. The purpose of this review is to elucidate the impact of polyphenols on animal gut health. The first section of the review discusses the chemical structure of the major polyphenols in grapes and the polyphenols’ bioavailability and metabolism in pigs. The second and major part of the review reviews the results of investigations into the antioxidant, antimicrobial and prebiotic effects of grape polyphenols in pig diets, as well as their regulation of intestinal barrier functions through signalling pathways and intestinal responses. All of this is supported by previous research, findings and conclusions. There are fewer recorded pig studies, but the inclusion of up to 9% grape by-products resulted in improved performance with an increased mean daily gain. Ultimately, this analysis concluded that supplementation of pigs with grape phenolic compounds as natural feed additives enhanced their antioxidant capacity, improved humoral and cellular immune responses, and promoted gut ecosystem biodiversity and the overall production performance in pigs.

Effect of Sasa quelpaertensis Nakai extract on gut microbiota and production performance in pigs.

Different dietary patterns affect the gut microbial compositions and diversity. Consistently, microbiome alterations are linked to digestion, immunity, and productivity. Sasa quelpaertensis Nakai (SQ) is a perennial bamboo species rich in proteins and fiber. Previous studies have confirmed the health benefits of SQ; however, the effects of SQ supplementation on gut microbiome and production performance are unclear. Herein, Landrace pigs were supplemented with SQ extract (SQE) and gut microbial compositions as opposed to the control group were assessed using 16S rRNA sequencing. Additionally, the influences of SQE supplementation on average daily gain (ADG) and backfat thickness (BF) were assessed after slaughter. In the SQE group, Firmicutes and Actinobacteria phyla increased significantly, whereas Bacteroidetes and Spirochaetes phyla markedly decreased (p < 0.05). The expression level of Bifidobacterium and Lactobacillus genera increased, whereas that of Treponema, Prevotella, and Turicibacter decreased (p < 0.05). The microbial richness was similar between groups; however, microbial diversity decreased in the SQE supplementation group. Additionally, the SQE supplementation in pigs resulted in a slight increase in ADG. In contrast, BF in the SQE group decreased notably (p < 0.05). These results underscore the significant influence of SQE supplementation on the gut microbiota and demonstrate the potential of SQ as a valuable feed resource for enhancing animal productivity.

Enhancement of systemic virus-specific T lymphocyte responses in pigs supplemented with algae-derived β-glucan

Algae-derived β-glucan has been widely used as a feed additive in the swine industry. The supplementation of β-glucan aims to improve growth performance and modulate the immunity of pigs. However, the potential effects of supplementing β-glucan from algae on immune responses in pigs—specifically antigen-specific immunity—must be determined. In this study, the effects of algae-derived β-glucan supplementation on growth performance, virus neutralising antibody and virus-specific T lymphocytes responses were investigated in pigs. Piglets (n=112 per treatment) were assigned to three treatments including non-supplemented group (control), β-glucan 100 g/ton supplemented group (BG100), and β-glucan 200 g/ton supplemented group (BG200).In this study, production performance of pigs was not found to be different between the experimental groups. Pigs supplemented with β-glucan exhibited high levels of classical swine fever virus (CSFV)-specific producing T lymphocytes and neutralising antibody titer, compared to the control group. Interestingly, supplementation of β-glucan significantly enhanced porcine reproductive and respiratory syndrome virus (PRRSV)-specific interferon-gamma (IFN-γ) producing T lymphocytes, including CD4+, CD8+, and CD4+CD8+ T lymphocyte subpopulations. Moreover, PRRS modified live vaccine (MLV) viremia was reduced in earlier for β-glucan-supplemented pigs compared to the control group. The findings indicate that the algae-derived β-glucan possesses biological potential as an immunomodulatory substance to enhance antiviral immunity, which may contribute to disease resistance in pigs.

Prospects for the use of probiotics in pig breeding

This article analyzes the effectiveness of various groups of probiotics in the context of use in pig farming, based on real research. Aspects such as the effect of probiotics on the growth and development of piglets, the health and composition of the intestinal microflora, as well as the overall productivity of pigs, including sows, are considered. Based on the analysis, it can be concluded that different groups of probiotics have a diverse effect on the production performance of pigs. The use of various drugs, according to research, can help increase the fertility and safety of piglets. And some probiotics can be effective in rearing piglets, reducing feed costs and improving growth parameters. The article emphasizes the importance of choosing the optimal group of probiotics depending on the specific conditions and tasks of pig farming.

Modulation of Swine Gut Microbiota by Phytogenic Blends and High Concentrations of Casein in a Validated Swine Large Intestinal In Vitro Model.

Phytogenic feed additives are gaining popularity in livestock as a replacement for antibiotic growth promotors. Some phytogenic blends (PB) positively affect the production performance, inhibit pathogens within the gut microbiota, and improve the overall health of farm animals. In this study, a swine large intestine in vitro model was used to evaluate the effect of two PBs, alone or in combination with casein, on swine gut microbiota. As a result, the combination of casein with PB1 had the most beneficial effects on swine gut microbiota, as it increased the relative abundance of some commensal bacteria and two genera (Lactobacillus and Oscillospiraceae UCG-002), which are associated with greater production performance in pigs. At the same time, supplementation with PBs did not lead to an increase in opportunistic pathogens, indicating their safety for pigs. Both PBs showed fewer changes in swine gut microbiota compared to interventions with added casein. In contrast, casein supplementation significantly increased beta diversity and the relative abundance of commensal as well as potentially beneficial bacteria. In conclusion, the combination of casein with PBs, in particular PB1, had the most beneficial effects among the studied supplements in vitro, with respect to microbiota modulation and metabolite production, although this data should be proven in further in vivo studies.

Effect of Sasa quelpaertensis Nakai extract on gut microbiota and production performance in pigs

Effect of Sasa quelpaertensis Nakai extract on gut microbiota and production performance in pigs

Comparative Serum Proteome Analysis Indicates a Negative Correlation between a Higher Immune Level and Feed Efficiency in Pigs.

Identifying and verifying appropriate biomarkers is instrumental in improving the prediction of early-stage pig production performance while reducing the cost of breeding and production. The main factor that affects the production cost and environmental protection cost of the pig industry is the feed efficiency of pigs. This study aimed to detect the differentially expressed proteins in the early blood index determination serum between high-feed efficiency and low-feed efficiency pigs and to provide a basis for further identification of biomarkers using the isobaric tandem mass tag and parallel reaction monitoring approach. In total, 350 (age, 90 ± 2 d; body weight, 41.20 ± 4.60 kg) purebred Yorkshire pigs were included in the study, and their serum samples were obtained during the early blood index determination. The pigs were then arranged based on their feed efficiency; 24 pigs with extreme phenotypes were grouped as high-feed efficiency and low-feed efficiency, with 12 pigs in each group. A total of 1364 proteins were found in the serum, and 137 of them showed differential expression between the groups with high- and low-feed efficiency, with 44 of them being upregulated and 93 being downregulated. PRM (parallel reaction monitoring) was used to verify 10 randomly chosen differentially expressed proteins. The proteins that were differentially expressed were shown to be involved in nine pathways, including the immune system, digestive system, human diseases, metabolism, cellular processing, and genetic information processing, according to the KEGG and GO analyses. Moreover, all of the proteins enriched in the immune system were downregulated in the high-feed efficiency pigs, suggesting that a higher immune level may not be conducive to improving feed efficiency in pigs. This study provides insights into the important feed efficiency proteins and pathways in pigs, promoting the further development of protein biomarkers for predicting and improving porcine feed efficiency.

Probiotic Effects of Bacillus subtilis on Growth Performance and Intestinal Microecological Balance of Growing-to-Finishing Pigs

The present study investigated the growth performance, immune status, gut morphology, and gut microflora modulation in growing-to-finishing pigs (n = 72; 24 pigs/group) after dietary supplementation with Bacillus subtilis (B. subtilis; two groups (experiment 1 (E1) and experiment 2 (E2): 63 and 98 days, respectively) and control (Ct, basal diet). The results revealed that both 1–98 d and 1–63 d groups significantly improved growth performance, including an increase in midtest body weight (MBW) P = 0.0114 , final body weight (FBW) P &lt; 0.0001 , and average daily gain (ADG) P &lt; 0.0001 and a decrease in the ratio of feed to gain (F/G) P &lt; 0.0001 . There was an increase in serum IgG and SOD levels after supplementation with B. subtilis P = 0.0074 . Furthermore, B. subtilis potentiated the integrity of intestinal morphology (villus height (VH) P &lt; 0.0001 and villus height/crypt depth (VH/CD) P = 0.0009 ) in growing-to-finishing pigs. The LEfSe analysis identified 11 and 13 biomarkers in the fecal samples of the 1–63 d group and 1–98 d, respectively. The gut microflora alterations of growth-finishing pigs suggested that dietary B. subtilis could promote gut health by altering the relative abundances of different bacterial communities. A correlation analysis showed that B. subtilis could regulate the functional network of the intestine microflora and their interactions with its host. Taken together, dietary B. subtilis supplementation had a positive influence on the growth performance, gut health, and the composition of gut microorganisms, suggesting that B. subtilis can be used as a functional probiotic candidate for application in the production of growing-to-finishing pigs. Practical Applications. The addition of probiotics in the diet can modulate intestinal health, improve the digestibility of nutrients, and thus, help improve the nutrient utilization and production performance of pigs. It is one of the ideal substitutes for antibiotics. This study will help us understand the function of B. subtilis in the regulation of pig intestinal health, so as to provide scientific basis for the rational use of probiotics in the future pig industry.

Association of gut microbiota and SCFAs with finishing weight of Diannan small ear pigs.

Finishing weight is a key economic trait in the domestic pig industry. Evidence has linked the gut microbiota and SCFAs to health and production performance in pigs. Nevertheless, for Diannan small ear (DSE) pigs, a specific pig breed in China, the potential effect of gut microbiota and SCFAs on their finishing weight remains unclear. Herein, based on the data of the 16S ribosomal RNA gene and metagenomic sequencing analysis, we found that 13 OTUs could be potential biomarkers and 19 microbial species were associated with finishing weight. Among these, carbohydrate-decomposing bacteria of the families Streptococcaceae, Lactobacillaceae, and Prevotellaceae were positively related to finishing weight, whereas the microbial taxa associated with intestinal inflammation and damage exhibited opposite effects. In addition, interactions of these microbial species were found to be linked with finishing weight for the first time. Gut microbial functional annotation analysis indicated that CAZymes, such as glucosidase and glucanase could significantly affect finishing weight, given their roles in increasing nutrient absorption efficiency. Kyoto Encyclopedia of Genes and Genomes (KEGG) Orthologies (KOs) and KEGG pathways analysis indicated that glycolysis/gluconeogenesis, phosphotransferase system (PTS), secondary bile acid biosynthesis, ABC transporters, sulfur metabolism, and one carbon pool by folate could act as key factors in regulating finishing weight. Additionally, SCFA levels, especially acetate and butyrate, had pivotal impacts on finishing weight. Finishing weight-associated species Prevotella sp. RS2, Ruminococcus sp. AF31-14BH and Lactobacillus pontis showed positive associations with butyrate concentration, and Paraprevotella xylaniphila and Bacteroides sp. OF04-15BH were positively related to acetate level. Taken together, our study provides essential knowledge for manipulating gut microbiomes to improve finishing weight. The underlying mechanisms of how gut microbiome and SCFAs modulate pigs' finishing weight required further elucidation.

Effect of different odors on the fighting behavior of weaning piglets after merging into a large pen.

In intensive pig production, the fighting behavior of weaning piglets after merging pens is relatively common. Fighting behavior not only easily causes injury in pigs but also affects the production performance of pigs. To reduce fighting behavior in farms, this study aimed to explore the possible effect of odorous substances on piglet fighting behavior after merging into a large pen. Six different sprays were tested: original creamy, cheese flavor, orange flavor, truffle, vanilla and pigpen flavor. In each experiment, two groups were set (one odor-sprayed and no sprayed control), and 12 pigs were used per group. After mixing, the frequency of occurrence of various piglet behaviors in different pens was recorded. During this period, salivary cortisol levels and skin lesion scores were evaluated. As a result, the piglets sprayed with the original creamy, cheese flavor and vanilla substances obtained significantly higher average daily gain and feed intake and showed a significantly lower incidence of fighting behavior, and the skin lesion score and salivary cortisol of piglets were also reduced significantly. All the other odorous substances had no significant effects on the fighting behavior and production performance of piglets.

Low- and high-protein diets supplemented up to the fourth limiting amino acid for genetic lines of grower-finisher pigs

The protein contents in diets for grower-finisher pigs reflect directly on the pig industry, also allowing to verify the responses of modern genotypes according to the protein feeding regimen. Therefore, this study was conducted to assess low- and high-protein diets and 2 genetic lines on growth performance, plasma urea concentration (PUC), apparent digestible energy and nutrient digestibility, N balance, carcass traits and meat quality in grower-finisher pigs. In Exp. I, a total of 120 pigs (31.5 ± 5.2 kg BW) were assigned to a 2 × 2 factorial arrangement of treatments, 2 genetic lines (LI7600 and AGPIC 337) and 2 protein diets (low-protein, LP, and high-protein, HP), with 10 replicate pens per treatment and 3 pigs per pen in a randomized block design. In Exp. II, 24 entire male pigs (27.4 ± 2.9 kg BW) housed individually in metabolic cages were used in the same design as Exp. I with 6 replicates though. In Exp. I, pigs fed HP diet showed (P ≤ 0.05) greater ADG and ADFI than those fed LP diet. However, gain to feed ratio was lower (P < 0.05) in pigs fed LP diet during grower I, finisher II, and total period. Plasma urea concentration was lower (P < 0.05) in pigs fed LP diet during grower I and II and finisher I. Pigs fed HP diet had greater (P < 0.01) N intake, N absorbed, N retained, total N excreted and urine N than those fed LP diet. Fecal N was greater in AGPIC 337 pigs than in LI7600 pigs (P = 0.009). Pigs fed HP diet had greater (P ≤ 0.05) cold carcass weight, lean meat, and initial pH in L. dorsi when compared to pigs fed LP diet. However, meat color, marbling degree, drip loss, and cooking loss were lower (P ≤ 0.05) in pigs fed HP diet. LI7600 pigs showed greater (P ≤ 0.05) backfat thickness than AGPIC 337 pigs. However, lower lean meat and a* were observed (P ≤ 0.05) in LI7600 pigs. In Exp. II, LI7600 pigs showed greater (P = 0.048) ADC of gross energy and digestible energy than AGPIC 337 pigs. In conclusion, pigs fed HP diet showed optimal growth performance, meat attributes, and apparent digestibility of CP. However, HP diet did not reduce the N excretion with changes in PUC, and low CP diet without Val-and Ile-supplementation can compromise pig production performance. Furthermore, AGPIC 337 pigs showed optimal results on meat attributes compared with LI7600 pigs, but lower apparent energy digestibility.

"King of the forage"-Alfalfa supplementation improves growth, reproductive performance, health condition and meat quality of pigs.

As one kind of high-quality feed with rich nutrients, including high quality protein and amino acids, dietary fiber, enriched vitamins and mineral elements and bioactive molecules, alfalfa has been widely used in the production of ruminant livestock. As the understanding of alfalfa becomes more and more comprehensive, it is found that the high-quality nutrients in alfalfa could have positive effects on pigs. An increasing number of researches have shown that supplementing dietary alfalfa to the diet of gestating sows reduced constipation, alleviated abnormal behavior, improved satiety and reproductive performance; supplementing dietary alfalfa to the diet of piglets improved growth performance and intestinal barrier function, reduced intestinal inflammatory response and diarrhea; supplementing dietary alfalfa to the diet of growing-fattening pigs improved production performance and pork quality. Moreover, the mechanisms by which various nutrients of alfalfa exert their beneficial effects on pigs mainly including dietary fiber stimulating intestinal peristalsis, enhancing the activity of digestive enzymes, and promoting the colonization of beneficial bacteria in the intestinal tract through fermentation in the intestine, producing short-chain fatty acids and thus improving intestinal health; high quality protein and amino acids are beneficial to improve animal health condition; rich vitamins and mineral elements play an important role in various physiological functions and growth and development of the body; and bioactive molecules can improve the antioxidant and anti-inflammatory level. Therefore, alfalfa could be used as pig feed ingredient to alleviate various problems in the pig industry and to improve pig production performance. In this review, we detail the current application of alfalfa in pigs and discuss the potential mechanisms involved in how alfalfa improves growth and reproductive performance, pork quality, and intestinal health of the animals, thus laying the foundation for the increased application of high-quality forage in pig production.

Genome-Wide Association Study of Growth Traits in a Four-Way Crossbred Pig Population.

Growth traits are crucial economic traits in the commercial pig industry and have a substantial impact on pig production. However, the genetic mechanism of growth traits is not very clear. In this study, we performed a genome-wide association study (GWAS) based on the specific-locus amplified fragment sequencing (SLAF-seq) to analyze ten growth traits on 223 four-way intercross pigs. A total of 227,921 highly consistent single nucleotide polymorphisms (SNPs) uniformly dispersed throughout the entire genome were used to conduct GWAS. A total of 53 SNPs were identified for ten growth traits using the mixed linear model (MLM), of which 18 SNPs were located in previously reported quantitative trait loci (QTL) regions. Two novel QTLs on SSC4 and SSC7 were related to average daily gain from 30 to 60 kg (ADG30-60) and body length (BL), respectively. Furthermore, 13 candidate genes (ATP5O, GHRHR, TRIM55, EIF2AK1, PLEKHA1, BRAP, COL11A2, HMGA1, NHLRC1, SGSM1, NFATC2, MAML1, and PSD3) were found to be associated with growth traits in pigs. The GWAS findings will enhance our comprehension of the genetic architecture of growth traits. We suggested that these detected SNPs and corresponding candidate genes might provide a biological foundation for improving the growth and production performance of pigs in swine breeding.

Genome-Wide Association Studies Revealed Significant QTLs and Candidate Genes Associated with Backfat and Loin Muscle Area in Pigs Using Imputation-Based Whole Genome Sequencing Data.

Improvement of carcass features is an essential goal in pig genetic breeding programs. Backfat (BF) and loin muscle area (LMA) are important carcass production metrics and useful indicators of pig production performance and lean meat rate. However, the genetic architecture of BF and LMA traits remains elusive. To identify quantitative trait loci (QTLs) and genes associated with these traits, we performed a genome-wide association study (GWAS) using imputation-based whole genome sequencing data for four phenotypes (adjusted 100 kg BF and LMA, adjusted 100 kg BF EBV and LMA EBV) in 1131 pigs from 3 breeds (French Yorkshire, Landrace, and Duroc). After genotype imputation and quality control, 14,163,315 single nucleotide polymorphisms (SNPs) were retained for further analysis. For the adjusted 100 kg BF trait, using the 2-LOD drop method, a QTL with a 13.4 Kb interval (2.91 to 2.93 Mb on SSC2) and containing a SHANK2 gene was defined. In addition, two QTLs with 135.40 Kb (from 66.10 to 66.23 Mb) and 3.12 Kb (from 66.886 to 66.889 Mb) intervals containing CCND2 and TSPAN11 genes, respectively, were found on SSC5. For the BF-EBV trait, two QTLs (128.77 Kb from 66.10 to 66.23 Mb on SSC5 and 42.10 Kb from 2.89 to 2.93 Mb on SSC2) were identified. Notably, CCND2 and SHANK2 were the only candidate genes in their respective QTL interval. Furthermore, we detected a 3.33 Kb (66.106 to 66.110 Mb on SSC2) haplotype block which was detected as affecting the BF_EBV trait, which only contained the CCND2 gene. Thus, we suggested CCND2 and SHANK2 as strong candidate genes for regulating the BF trait for pigs. The empirical confidence intervals of the QTLs were 1.14 Mb (165.65 to 166.79 Mb on SSC6) for adjusted 100 kg LMA and 1.49 Mb (165.26-166.74 Mb on SSC6) for LMA-EBV. These two confidence intervals contained 13 and 28 annotated genes, respectively. Our results provide a deeper understanding of the genetic basis of pig carcass traits. The identified molecular markers will be useful for selecting breeding lines for breeding pigs with superior carcass traits.

Exploring a Possible Link between the Fecal Microbiota and the Production Performance of Pigs.

Simple SummaryThe aim of this study is to investigate the relationship between fecal microbiota and the backfat thickness of pigs by 16S rRNA gene sequencing. Our study found that there were significant differences in the composition of microbiota at the species level, characterized by a higher abundance of Lactobacillus reuteri (L. reuteri) in pigs with low-backfat thickness. Additionally, functional profiling of microbial communities indicated that the isoquinoline alkaloid biosynthesis, arachidonic acid metabolism, and styrene degradation were significantly different between low- and high-backfat thickness groups. Furthermore, feeding L. reuteri reduced the intake-to-gain ratio and had the potential to reduce backfat thickness. These findings show that microbiota could alter the production performance of pigs.The backfat thickness of pigs not only affects the physical properties and taste of meat, but it also closely relates to the reproduction performance of sows. Accumulating evidence indicates that, apart from genetic factors, gut microbiota can also modulate the fat deposition and muscle growth. However, the differential microbiota in pigs with different backfat thickness, and whether microbiota affects backfat thickness, remains elusive. Firstly, 16S ribosomal RNA (16S rRNA) gene sequencing was performed on 62 fecal samples from pigs with different backfat thicknesses, and the compositions of microbiota among different groups with different backfat thicknesses were different. The abundance of Lactobacillus. reuteri (L. reuteri) and Prevotella sp RS2 was significantly higher in pigs with low-backfat thickness than that in pigs with middle and high-backfat thickness; meanwhile, the abundance of Desulfovibrio piger was significantly lower (p < 0.05) in pigs with low-backfat thickness. Furthermore, the functional profiling of microbial communities suggested that the abundance of isoquinoline alkaloid biosynthesis and styrene degradation were significantly lower (p < 0.05) in the low-backfat thickness group than that in middle and high-backfat thickness groups. Finally, L. reuteri fed to Meishan piglets was capable of improving the production performance and had the potential to reduce backfat thickness. This study provides new evidence that microbiota can regulate the phenotype of the host, and dietary supplementation with L. reuteri can improve the production performance of piglets.