Ingestion of a lipid-rich meat matrix blunts the postexercise increase of myofibrillar protein synthesis rates in healthy adults: a randomized controlled trial

American Journal of Clinical Nutrition · 2025-09-07 · 1 citations

Characterizing differences in the muscle transcriptome between cattle with alternative LCORL-NCAPG haplotypes

BMC Genomics · 2025-05-14 · 4 citations

BACKGROUND: The LCORL-NCAPG locus is a major quantitative trait locus (QTL) on bovine chromosome 6 (BTA6) that influences growth and carcass composition in cattle. To further understand the molecular mechanism responsible for the phenotypic changes associated with this locus, twenty-four Charolais-sired calves were selected for muscle transcriptome analysis based on alternative homozygous LCORL-NCAPG haplotypes (i.e., 12 "QQ" and 12 "qq", where "Q" is a haplotype harboring variation associated with increased growth). At 300 days of age, a biopsy of the longissimus dorsi muscle was collected from each animal for RNA sequencing. RESULTS: Gene expression analysis identified 733 genes as differentially expressed between QQ and qq animals (q-value < 0.05). Notably, LCORL and genes known to be important regulators of growth such as IGF2 were upregulated in QQ individuals, while genes associated with adiposity such as FASN and LEP were downregulated, reflecting the increase in lean growth associated with this locus. Gene set enrichment analysis demonstrated QQ individuals had downregulation of pathways associated with adipogenesis, alongside upregulation of transcripts for cellular machinery essential for protein synthesis and energy metabolism, particularly ribosomal and mitochondrial components. CONCLUSIONS: The differences in the muscle transcriptome between QQ and qq animals imply that muscle hypertrophy may be metabolically favored over accumulation of fat in animals with the QQ haplotype. Our findings also suggest this haplotype could be linked to a difference in LCORL expression that potentially influences the downstream transcriptional effects observed, though further research will be needed to confirm the molecular mechanisms underlying the associated changes in phenotype.

Low-fat pork ingestion promotes greater postexercise myofibrillar protein synthesis compared to high-fat pork and carbohydrate beverage in young adults

Physiology · 2025-05-01

The nutrient-nutrient interactions within a food matrix may alter the postprandial stimulation of myofibrillar protein synthesis rates (MPS). We have previously shown that a protein- and lipid-rich food matrix has greater anabolic potential compared to the ingestion of a low-fat, protein-rich food matrix. Objectives: Thus, this study aimed to investigate the effects of consuming a high-fat pork (HFP) compared to low-fat pork (LFP) product and a carbohydrate control drink (CHO) on postexercise stimulation of MPS. Hypothesis: We hypothesized that the ingestion of HFP and LFP would increase MPS compared to CHO. We further hypothesize that the ingestion of HFP will further potentiate the stimulation of MPS than the LFP condition. Methods: In a semi-crossover design, 16 physically-active adults (25±5; BMI: 25.0 ± 2.3 kg·m -2 ; 12M, 4 F) underwent primed constant infusions of L-[ ring - 13 C 6 ]phenylalanine and performed an acute bout of resistance exercise. Following resistance exercise, participants ingested either HFP (81% lean; 266 kcal, 20 g protein, and 20.6 g fat), LFP (95% lean; 120 kcal, 20 g protein, 4.4 g fat), or CHO (266 kcal, 0 g protein, 0 g fat, 73.3 g carbohydrate; Gatorade). During their second trial, participants were randomly assigned to one of the two remaining conditions in a counterbalanced fashion (resulting in n = 10 per condition). Repeated blood and muscle samples were collected at rest and throughout the 5 h postexercise recovery period for measurement of plasma amino acid concentrations and MPS. Data were analyzed using linear fixed effects models with time and group as fixed factors and Bonferroni post hoc analysis when significant ( P &lt; 0.05) differences were detected. Results: Plasma essential amino acid (EAA) and leucine concentrations increased after ingestion of HFP and LFP (both P &lt; 0.001), with greater peak plasma EAA and leucine concentrations in LFP treatment compared to HFP ( P = 0.018 and P = 0.027, respectively) and CHO (both P &lt; 0.001). Incremental area under the curve (iAUC) for plasma EAA and leucine concentrations did not differ between LFP and HFP ( P = 0.350 and P = 0.361, respectively), however, both conditions resulted in significantly higher iAUC as compared to CHO treatment (both P &lt; 0.001). Both HFP and LFP stimulated MPS above resting values ( P = 0.028 and P &lt; 0.001, respectively). Postexercise MPS was significantly greater in LFP (0.095 ± 0.029 %·h -1 ) compared to HFP (0.065 ± 0.024 %·h -1 ; P = 0.030) and CHO (0.052 ± 0.033 %/h -1 ; P &lt; 0.001). Conclusions: LFP ingestion immediately after resistance exercise results in greater stimulation of MPS than HFP and CHO. Our findings indicate that the nutrient profile of protein-rich foods uniquely modulates postexercise muscle anabolism compared to the protein content alone in healthy adults. This study was funded by the National Pork Board (project no. #22-040). This abstract was presented at the American Physiology Summit 2025 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.

Effects of maternal inflammation on growth performance, carcass characteristics, and meat quality of offspring pigs

Journal of Animal Science · 2024-01-01 · 4 citations

The objective of this research was to determine the effects of mid-gestational maternal inflammation on performance, carcass characteristics, and meat quality of offspring. Pregnant gilts were administered either lipopolysaccharide (LPS; n = 7) or saline (CON, n = 7) from days 70 to 84 of gestation. Gilts assigned to the LPS treatment were administered an intravenous injection of reconstituted LPS every other day with a beginning dose of 10 μg LPS/kg body weight and subsequent doses increasing by 12%, while CON gilts received intravenous injections of comparable volumes of saline. Gilts farrowed naturally, and at day 66 of age, a total of 59 pigs, both barrows and gilts began a 3-phase feeding regimen designed to meet or exceed nutrient requirements for growing-finishing pigs. Pigs were weighed on days 0, 35, 70, and 105 of the finishing trial to determine average daily gain, average daily feed intake, and gain-to-feed ratio (G:F). On day 106, pigs were slaughtered under the supervision of the U.S. Department of Agriculture Food Safety Inspection Service. Ending live weight, hot carcass weight, and dressing percentage were determined. The left side of carcasses was weighed and fabricated to determine carcass cutting yields. The semitendinosus was collected for histological samples. Fresh belly characteristics and loin quality were measured. Two chops were collected for Warner-Bratzler shear force and proximate analysis. No differences (P ≥ 0.13) between LPS and CON pigs were observed for growth performance in phases 1, 2, 3, or overall (days 0 to 105) performance with the exception of overall G:F reduced in CON pigs compared with LPS pigs (P = 0.03). There was a tendency for carcass yield to be reduced (P = 0.06; 0.82% units) in LPS pigs compared with CON pigs. Additionally, longissimus muscle area tended to be reduced (P = 0.10) 2.27 cm2 in LPS compared with CON pigs. Loin chop quality traits including instrumental color, subjective color, marbling, firmness, pH, and drip loss were not different (P ≥ 0.09) between LPS and CON pigs. Fresh belly characteristics were not different (P ≥ 0.22) between LPS and CON pigs. There were no differences in primal and subprimal weights, except that LPS pigs tended to have a reduction (P ≥ 0.07) in tenderloin and Canadian back weights compared with CON pigs. Furthermore, LPS pigs had no differences (P ≥ 0.25) in muscle fiber composition or size; however, LPS pigs tended (P = 0.10) to have a 13% reduction in estimated muscle fibers number compared with CON pigs. In summary, mid-gestational inflammation did not result in reduced meat quality, growth performance, or carcass yields of offspring.

PSV-8 Investigation of a haplotype and eQTL analysis of the LCORL-NCAPG locus associated with increased lean growth in beef cattle

Journal of Animal Science · 2024-09-01 · 1 citations

Abstract Numerous studies have shown genetic variation at the LCORL-NCAPG locus is strongly associated with growth traits in beef cattle. However, a causative molecular variant has yet to be identified. To define all possible candidate variants, Charolais-sired calves (n = 34) were whole genome sequenced including 17 homozygous for a long-range haplotype associated with increased growth (QQ), and 17 homozygous for potential ancestral haplotypes for this region (qq). The Q haplotype was refined to an 814-kb region between chr6:37,199,897-38,014,080 and contained 218 variants not found in qq individuals. These variants include an insertion in an intron of NCAPG, a previously documented mutation in NCAPG (rs109570900), two coding sequence mutations in LCORL (rs109696064 and rs384548488), and 15 variants located within ATAC peaks that were predicted to affect transcription factor binding. Notably, rs384548488 is a frameshift variant likely resulting in loss of function for long isoforms of LCORL. To test the association of the coding sequence variants of LCORL with phenotype, 405 cattle from five populations were genotyped. The two variants were in complete linkage disequilibrium. Statistical analysis of the three populations that contained QQ animals revealed significant (P &amp;lt; 0.05) associations with genotype and birth weight, body weight, carcass weight, hip height, and average daily gain. Additionally, an RNAseq analysis was performed using 22 of the Charolais-sired calves. This, in conjunction with the WGS data, was used to run an eQTL analysis, which revealed 256 genes whose expression were impacted by eQTL in the region (FDR &amp;lt; 0.05). These findings affirm the link between this locus and growth in beef cattle and describe DNA variants that define the haplotype. However, further studies will be required to define the true causative mutation.

The effect of chronic, non-pathogenic maternal immune activation on offspring postnatal muscle and immune outcomes

Journal of Animal Science · 2024-01-01 · 3 citations

The objective was to determine the effects of maternal inflammation on offspring muscle development and postnatal innate immune response. Sixteen first-parity gilts were randomly allotted to repeated intravenous injections with lipopolysaccharide (LPS; n = 8, treatment code INFLAM) or comparable volume of phosphate buffered saline (CON, n = 8). Injections took place every other day from gestational day (GD) 70 to GD 84 with an initial dose of 10 μg LPS/kg body weight (BW) increasing by 12% each time to prevent endotoxin tolerance. On GD 70, 76, and 84, blood was collected at 0 and 4 h postinjection via jugular or ear venipuncture to determine tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1β concentrations. After farrowing, litter mortality was recorded, and the pig closest to litter BW average was used for dissection and muscle fiber characterization. On weaning (postnatal day [PND] 21), pigs were weighed individually and 2 barrows closest to litter BW average were selected for another study. The third barrow closest to litter BW average was selected for the postnatal LPS challenge. On PND 52, pigs were given 5 μg LPS/kg BW via intraperitoneal injection, and blood was collected at 0, 4, and 8 h postinjection to determine TNF-α concentration. INFLAM gilt TNF-α concentration increased (P < 0.01) 4 h postinjection compared to 0 h postinjection, while CON gilt TNF-α concentration did not differ between time points. INFLAM gilt IL-6 and IL-1β concentrations increased (P = 0.03) 4 h postinjection compared to 0 h postinjection on GD 70, but did not differ between time points on GD 76 and 84. There were no differences between INFLAM and CON gilts litter mortality outcomes (P ≥ 0.13), but INFLAM pigs were smaller (P = 0.04) at birth and tended (P = 0.09) to be smaller at weaning. Muscle and organ weights did not differ (P ≥ 0.17) between treatments, with the exception of semitendinosus, which was smaller (P < 0.01) in INFLAM pigs. INFLAM pigs tended (P = 0.06) to have larger type I fibers. INFLAM pig TNF-α concentration did not differ across time, while CON pig TNF-α concentration peaked (P = 0.01) 4 h postinjection. TNF-α concentration did not differ between treatments at 0 and 8 h postinjection, but CON pigs had increased (P = 0.01) TNF-α compared to INFLAM pigs 4 h postinjection. Overall, maternal immune activation did not alter pig muscle development, but resulted in suppressed innate immune activation.

Characterizing differences in the muscle transcriptome between cattle with alternative LCORL-NCAPG haplotypes

Research Square · 2024-11-06

PSIII-8 CRISPR editing of IGF2 and MSTN to enhance productivity

Journal of Animal Science · 2024-09-01 · 1 citations

Abstract The ability to modify the genomes of livestock species has previously been limited by low efficiency and the high cost associated with reagents and the generation of edited live animals (e.g., via somatic cell nuclear transfer). However, the CRISPR/Cas9 system has shown promise by improving specificity and efficacy, while decreasing costs associated with reagent acquisition and potentially live animal production (e.g., via direct editing of embryos). Given these potential improvements there are still a limited number of well-characterized genes for targeting. Nonetheless, there are two genes where molecular variation in different species has shown highly significant effects on increased lean growth and reduced adiposity, insulin-like growth factor 2 (IGF2) and myostatin (MSTN). In pigs, a G-to-A substitution in intron 3 of IGF2 (g.3072G &amp;gt;A) disrupts a conserved binding site for the transcriptional repressor ZBED6 allowing for increased postnatal IGF2 expression. This increased expression is associated with increased lean muscle yield and intramuscular fat deposition, while decreasing backfat. In livestock species other than the pig, numerous loss-of-function mutations in MSTN have been reported. MSTN is a known early regulator of myoblast differentiation, negatively regulating myoblast fusion into myotubes. This results in muscle hyperplasia causing the commonly referred to “double-muscling” phenotype. Animals of this phenotype have significantly increased skeletal muscle mass, improved feed conversion, and decreased fat deposition. These mutations have the potential to act synergistically as demonstrated by generation of a mouse line possessing both IGF2 overexpression and MSTN loss-of-function mutations. Within this line, wild-type (WT) mice have an average body weight (BW) of 19.64 ± 1.89 g at 11 wk of age. In comparison, IGF2 overexpression, MSTN loss-of-function, and the combination of both mutations have average BW of 23.54 ± 2.31 g, 26.14 ± 2.35 g, and 31.43 ± 2.39 g, respectively (P &amp;lt; 0.0001). Based on these results in mice we have initiated editing of both genes in cattle. Two male fetal fibroblast cell lines were generated from d 75 fetuses from high genetic merit Angus matings. Four CRISPR guide RNAs have been designed for both genes and assayed for their in vitro cleavage efficiencies. All guide RNAs exceeded 60% cleavage efficiency. CRISPR/Cas9 ribonuclear protein complexes were electroporated into each cell line. Targeted modifications will be confirmed through sequencing, and successfully modified cell lines will undergo somatic cell nuclear transfer to produce live animals.

Effects of supplemental methionine sources in finishing pig diets on growth performance, carcass characteristics, cutting yields, and meat quality

Translational Animal Science · 2024-01-01 · 2 citations

Abstract Supplemental methionine (Met) is widely used within the swine industry; however, data are limited regarding the effect of Met sources on carcass cutability and meat quality. The objective was to determine the effects of L-Met (LM, 99%), DL-Met (DLM, 99%), or calcium salt of DL-Met hydroxyl analog (MHA, 84%) in finishing pig diets on carcass characteristics and meat quality. At 9 weeks of age, pigs (N = 240) were allocated to 60 single-sex pens for a four-phase finishing trial that lasted 104 d. Pigs were fed a common grower diet until day 56 where pens were randomly allotted to one of the three experimental diets. For the remaining 7 wk of the finisher phase, pigs (BW = 79.9 ± 0.80 kg) were fed diets containing LM, DLM, or MHA, with the supplemental Met source providing 25% of standardized ileal digestible (SID) Met + cysteine (Cys) requirement based on 65% bioefficacy for MHA in comparison with LM or DLM. One pig per pen was slaughtered at the study conclusion (on day 104), and the left sides of carcasses were fabricated into subprimal cuts to determine carcass-cutting yields. Loin quality including proximate composition and shear force were measured. Hot carcass weight was not different (P = 0.34) between treatments (LM 104.5 kg; DLM 103.0 kg; MHA 101.5 kg), moreover, loin eye area was not different (P = 0.98) between treatments (LM 52.65 cm²; DLM 52.49 cm²; MHA 52.81 cm²). Boneless carcass-cutting yield was not different (P = 0.56) between treatments (LM 54.97 kg; DLM 54.82 kg; MHA 54.52 kg). Loin pH was not different (P = 0.24) between treatments (LM 5.45; DLM 5.48; MHA 5.45). However, drip loss tended to be reduced (P = 0.11) by the DLM treatment (5.58%) compared with LM (7.03%) and MHA (6.68%) treatments. Shear force was not different (P = 0.85) between treatments (LM 3.03 kg; DLM 3.06 kg; MHA 3.10 kg). However, cook loss tended to be reduced (P = 0.06) by the DLM treatment (16.20%) compared with LM (18.18%) and MHA (18.50%) treatments. These data suggest that only minimal differences in carcass cutability and meat quality can be attributed to Met source in finishing pig diets when using 65% bioefficacy for MHA relative to L-Met or DL-Met.

Graded supplemental choline chloride fed throughout the grow and finish periods elicited minimal influence on growth performance and carcass characteristics of pigs in a commercial setting

Journal of Animal Science · 2024-12-23 · 1 citations

Choline is vital in a variety of physiological processes that influence brain development, growth, and carcass characteristics in birds and mammals. In this study, we investigated the influence of graded supplemental choline chloride on growth performance, carcass quality, and liver characteristics in grow-finish pigs. Pigs (672 barrows and 588 gilts) were obtained from a commercial nursery facility at 8 weeks of age and assigned to treatment based on body weight and sex, with 21 same-sex pigs comprising a replicate pen. Each dietary treatment was provided to 15 replicate pens, with 8 pens of barrows and 7 pens of gilts per each of 4 dietary treatments, which included: 1) C0, basal diet containing 0% of supplemental choline chloride; 2) C300, C0 + 0.06% supplemental choline chloride, to provide 300 mg/kg of choline ions; 3) C600, C0 + 0.12% supplemental choline chloride, to provide 600 mg/kg of choline ions; and 4) C900, C0 + 0.17% supplemental choline chloride, to provide 900 mg/kg of choline ions. Feed and water were provided ad libitum throughout the study, and pigs were managed using standard commercial practices. Data were analyzed by two-way ANOVA using the MIXED procedure of SAS, with factors including dietary treatment and sex. There was no dietary impact (P > 0.05) on growth performance. Pigs receiving intermediate levels of supplemental choline had higher (P < 0.05) tenderloin weights compared with other dietary treatments. Furthermore, and as expected, sex differences were denoted in both growth performance and carcass characteristics. Overall, graded supplementation of choline chloride did not significantly alter growth performance or carcass characteristics of pigs raised in a commercial setting.