Comparative analysis of productive performance and fattening efficiency of commercial pigs in China for two consecutive years

Combined metabolome and transcriptome analysis provides molecular insights into reproductive process in Chuanxiang Black and Landrace pigs

Testes are crucial for male reproduction, and transcriptomic and metabolomic analyses can help identify genes and pathways linked to reproductive performance differences in pig breeds. The present study was conducted to identify the differentially expressed genes and differentially accumulated metabolites (DAMs) through transcriptomic and metabolomic analyses of testicular tissues in Chuanxiang Black and Landrace pigs. Six testis tissue samples from each pig breed were used for transcriptomic analysis. Further liquid chromatography-mass spectrometry analysis was performed for targeted metabolomic analysis to identify differential metabolites in both breeds. RNA-sequencing data identified a total of 6,233 DEGs, including 3,417 upregulated and 2,816 downregulated genes in Chuanxiang Black compared to Landrace pigs. Comparative pathway enrichment analyses revealed that many DEGs and DAMs were associated with critical reproductive pathways, especially those related to male gametogenesis, spermatogenesis, sexual reproduction, development, and reproductive processes. Three major pathways related to signal transduction (PI3K-Akt, Rap1, and MAPK signaling pathways), lipid metabolism (linoleic acid and arachidonic acid metabolism), and cytokine-cytokine receptor interaction were identified as differentially enriched pathways in Chuanxiang Black pigs. Differential circRNA target gene enrichment analysis revealed 4,179 DEGs, including 3,022 genes involved in biological processes, 477 in cellular components, and 680 in molecular functions. Differential analysis of miRNA between the two groups revealed 2,512 DEGs, including 1,628 upregulated and 884 downregulated genes. Both miRNA and circRNA were involved in enriched KEGG pathways mainly including signaling pathways (cAMP signaling pathways, calcium signaling pathways), endocrine secretion (aldosterone synthesis and secretion and GnRH secretion), and signaling molecules and interaction (ECM-receptor interaction). These findings revealed that both circRNA and miRNA play a crucial role in regulating the differential gene expression related to reproductive processes in Chuanxiang Black compared to Landrace pigs.

Characterization of Lung Microbiome in Subclinical Pneumonic Thai Pigs Using 16S rRNA Gene Sequencing

Bacterial respiratory disease is one of the major concerns in the modern pig industry. To address the limitations of culture-based methods, 16S rRNA sequencing was employed to characterize the pig lung microbiome to gain a better understanding of microbial physiology and their population genetics. A batch of 510 slaughtered pigs from a farm located in Lampang province, Thailand, was selected. Individual pig weight was recorded. A total of 24 lungs (10 normal and 14 pneumonic lungs) were sampled for gross lesion examination and lung microbial communities were investigated. Poor growth performance and weight uniformity were denoted in this batch. Several pathogenic bacteria were detected in both normal and pneumonic lungs. Microbial diversity was decreased in the pneumonic group. PCoA and NMDS analysis showed a clear separation between the groups. Stenotrophomonas spp. (42.12%) was the dominant genus identified in normal lungs, while Mycoplasma hyopneumoniae (71.97%) was the most abundant in pneumonic lungs, correlating with the commonly observed consolidation lesions. The slaughterhouse serves as a key checkpoint for gathering comprehensive information on pig respiratory health, and lung is representative of the lower respiratory tract for microbiomics. Monitoring of lung lesions should be implemented routinely to gain a better understanding of regional pig respiratory health.

Daily feeding frequency impacts muscle characteristics and fat deposition in finishing pigs associated with alterations in microbiota composition and bile acid profile

Introduction

Feeding frequency has been shown to affect growth and body composition of the host associated with gut microbiota. It remains unknown whether adjusting feeding frequency could effectively regulate both skeletal muscle development and whole-body lipid metabolism and thus affect carcass composition and feed conversion efficiency. Therefore, this study aimed to explore the effects of feeding frequency on muscle growth, fat deposition, cecal microbiota composition, and bile acid composition in finishing pigs.

Methods

Sixteen Sichuan-Tibetan black pigs, with an initial weight of 121.50 ± 1.60 kg, were divided into two groups and fed either two meals (M2) or four meals (M4) per day. The trial lasted 30 days. The muscle fiber characteristics, lipid metabolism in adipose tissue, and cecal microbiota and bile acid composition were determined.

Results

The present study revealed that pigs fed four meals exhibited a lower feed-to-gain ratio, abdominal fat weight, and average backfat thickness (p < 0.05), as well as a higher loin eye area (p = 0.09) and myofiber diameter in the longissimus muscle than their counterparts. The mRNA expression of slow-twitch fiber and myogenesis-associated genes in the longissimus muscle was upregulated, while lipid metabolism-related genes in the backfat were downregulated in the M4 group compared to the M2 group (p < 0.05). The M4 pigs exhibited higher abundances of Firmicutes, Actinobacteriota, Bacillus, Clostridium_sensu_1, and Romboutsia, and lower abundances of Spirochaetota, Verrucomicrobiota, Treponema, and Muribaculaceae in the cecal content than the M2 pigs (p < 0.05). A higher feeding frequency increased the levels of primary bile acids and decreased the concentrations of taurine-conjugated bile acids in the cecal content of pigs (p < 0.05).

Conclusion

Our research suggested that the M4 feeding pattern, compared to the M2 pattern, promoted muscle growth and reduced fat deposition by enhancing fast- to slow-twitch fiber conversion and myogenesis in the muscle and repressing lipid metabolism in adipose tissue, associated with altered microbiota composition and bile acid profiles.

Identifying slow-growing commercial pigs using growth performance and health indicators

This study aimed to evaluate the growth performance and health status of commercial pigs in different body weight (BW) groups and develop methods for identifying slow-growing pigs. The research observed 79 commercial pigs grouped from 104 to 202 days of age, collecting data on BW, feed intake, and body condition score (BCS) from caliper. Results showed that BCS were highly correlated with BW (r > 0.85, P < 0.001), providing a simple method for assessing commercial pig BW. Commercial pigs with slaughter BWs below 114 kg at approximately 200 days old were identified as slow-growing individuals. White blood cell count, insulin-like growth factor binding protein-3, and blood urea nitrogen were identified as potential biomarkers for identifying slow-growing pigs. Economic analysis revealed that profitability across all BW groups was highly sensitive to market conditions, with feed costs being the most significant factor. Low BW groups performed better in low-price markets but reach break-even points later under medium to high-price scenarios.

Identification of factors affecting fattening efficiency of commercial pig herds and analysis of their impact at different performance levels

Improving fattening efficiency is an important goal of breeding commercial pigs, especially for the large-scale pig farms. Fattening efficiency index (FEI) can be used to evaluate the fattening efficiency. The aim of this study was to identify the factors affecting the fattening efficiency of commercial pigs in large-scale pig farms and further study the impact of these factors on the production performance of commercial pig batches at different production levels. The data of 9,570 batches was mainly consisted of four parts (farm facilities, general information of piglets, production performance of nursery pigs and finishing pigs). A total of 28 variables were evaluated by the multi-variable linear regression models. The differences in production factors significantly correlated with FEI at piglets-finishing stage were compared among high-performing (HP), moderate-performing (MP), and low-performing (LP) batches of commercial pigs during the nursery and finishing stage. Among the 28 variables, 18 were significantly correlated with fattening efficiency (P < 0.05), including 11 continuous variables and seven discrete variables. The significant differences among the 11 consecutive variables in the HP, MP, and LP batches of commercial pigs mostly persisted from the piglets-nursery stage to the growing-finishing stage, ultimately affecting the FEI at piglets-finishing stage. For the seven significant discrete variables, the HP batches had a lower proportions in owned source of piglets, number of the purchasing piglets in spring and winter, number of batches in the East and North regions and five-way crossbred pigs, while a higher proportions in the use of closed circuit television video (CCTV) and wastes treatment system. The fattening efficiency of commercial pigs in large-scale pig farms was comprehensively affected by farm facilities, piglets, and production performance at nursery and finishing stage. The low fattening efficiency may have started at the end of nursery stage.

Seasonal Effects on the Performance of Finishing Pigs' Carcass and Meat Quality in Indoor Environments

Most retailers in EU countries pay pig breeders for their animals' lean meat percentage, which does not align fully with measures of pork quality (such as colour). In this study, we investigated the effects of season (summer vs. autumn) on finishing pigs' performance, carcass characteristics, and meat quality parameters in 24 slaughter pigs. Growing performance traits (live weights, average daily weight gain), slaughter values (warm and cold carcass weights, trunk length, fat thickness) and meat quality parameters (pH at 45 min and 24 h postmortem, colour, drip loss, thawing loss, cooking loss, shear force, and meat composition) were recorded. Seasonal differences were more pronounced for the initial age, the number of days in the growing-finishing phase, and the average daily gain. There was also a significant difference in the trunk length between groups, the fat thickness on withers and loin, and also in mean fat thickness. A significant difference was found in the case of pH, total drip loss, and meat colour (L*). The intramuscular fat and collagen content of meat was significantly higher in summer; in contrast, the protein content of meat samples was considerably lower in summer. In conclusion, seasonal effects on finishers' performance, lean meat values, and several meat quality parameters highlight the importance of more profound seasonal settings of climate control to fulfil the progressively changing quantitative and qualitative requests of pork sector participants from farm to fork.