GSK3 regulation Wnt/β-catenin signaling affects adipogenesis in bovine skeletal muscle fibro/adipogenic progenitors

Clarifying the cellular origin and regulatory mechanisms of intramuscular fat (IMF) deposition is crucial for improving beef quality. Here, we used single-nucleus RNA sequencing to analyze the structure and heterogeneity of skeletal muscle cell populations in different developmental stages of Yanbian cattle and identified eight cell types in two developmental stages of calves and adults. Among them, fibro/adipogenic progenitors (FAPs) expressing CD29 (ITGA7)pos and CD56 (NCAM1)neg surface markers were committed to IMF deposition in beef cattle and expressed major Wnt ligands and receptors. LY2090314/XAV-939 was used to activate/inhibit Wnt/β-catenin signal. The results showed that the blockade of Glycogen Synthase Kinase 3 (GSK3) by LY2090314 promoted the stabilization of β-catenin and reduced the expression of genes related adipogenic differentiation (e.g., PPARγ and C/EBPα) in bovine FAPs, confirming the anti-adipogenic effect of GSK3. XAV-939 inhibition of the Wnt/β-catenin pathway promoted the lipid accumulation capacity of FAPs. Furthermore, we found that blocking GSK3 enhanced the paracrine effects of FAPs-MuSCs and increased myotube formation in muscle satellite cells (MuSCs). Overall, our results outline a single-cell atlas of skeletal muscle development in Yanbian cattle, revealed the role of Wnt/GSK3/β-catenin signaling in FAPs adipogenesis, and provide a theoretical basis for further regulation of bovine IMF deposition.

Effects of adding ruminal propionate on dry matter intake and glucose metabolism in steers fed a finishing ration

The objective of this experiment was to determine if supplying additional propionate to the rumen alters dry matter intake (DMI), feeding behavior, glucose metabolism, and rumen fluid metabolites in steers fed a finishing diet. Ruminally cannulated steers (n = 6) were fed a finishing diet ad libitum. Steers were randomly assigned to one of three treatments in a 3 × 6 Latin rectangle design with three 15 d periods. Treatments of no Ca propionate (Control), 100 g/d (Low), or 300 g/d (High) were ruminally dosed twice daily. Individual intake was measured using an Insentec feeding system. Pre-feeding blood samples were collected on day 7 and rumen fluid samples were collected on day 13. An intravenous glucose tolerance test (IVGTT) was conducted on day 14 and liver biopsies were collected on day 15. Liver samples were analyzed for expression of genes involved in gluconeogenesis. Data were analyzed using a mixed model with period, treatment, day, and their interaction included, with day and minute within period as a repeated measure and steer as a random effect. Meal size (P = 0.049), meal frequency (P = 0.046), and DMI (P < 0.001) were decreased in High steers. Day 7 plasma glucose (P = 0.23) and lactate (P = 0.47) were not affected by treatment, but insulin was decreased (P = 0.008) and non-esterified fatty acids were increased (P = 0.044) in the High treatment compared with the Control. Rumen fluid lactate was decreased (P = 0.015) in the High treatment compared with the Low treatment. Total VFA concentrations did not differ (P = 0.88) between treatments. There was treatment × time interaction for proportions of acetate and propionate (P < 0.001) and the acetate:propionate ratio (P = 0.005). The effect on acetate was due to a decrease in the High treatment 2 h after dosing the treatment. Propionate proportions were greater in the High treatment than the Control at all time points and differed from the Low except at 0 h. Propionate treatments had no major effects on the glucose and insulin parameters observed in the IVGTT other than a tendency (P = 0.09) for an increased insulin time to peak. These data indicate that exogenous propionate decreases DMI but the decrease in propionate from fermentation due to reduced DMI might negate the supply of exogenous propionate in VFA supply to the animal. Mechanisms other than hepatic oxidation of propionate might be responsible for DMI regulation.

Live and carcass production traits for progeny of purebred sires in comparison with the clone of a USDA prime yield grade one carcass

Cloning is a technology by which an animal's tissue can be salvaged and replicated. Carcasses that grade USDA prime-yield grade 1 (P1) represent a rare and antagonistic outcome and are a goal for terminal sire selection in the United States. A terminal sire progeny test generated offspring for a crossbred bull (14% Zebu, 86% Angus; ALPHA), born in 2012 via somatic cell nuclear transfer (SCNT) from a carcass that graded P1. ALPHA progeny (steers and heifers) were compared against progeny of three purebred (Angus; Charolais; Simmental) reference sires. Live production traits included weaning weight, morbidity, mortality, and days on feed; carcass traits included abscessed liver frequency and lung lesion frequency, individual quality and yield grade (YG) parameters, and carcass value. Observed carcass traits for progeny from the Angus, Charolais, and Simmental sires were reflective of the carcass outcomes expected for each sire's respective breed. Calves sired by the Angus were the earliest maturing indicated by the youngest chronological age at harvest (P ≤ 0.02) concomitant with the most backfat (P < 0.01), and the greatest marbling scores (P < 0.01). Calves sired by the Charolais had the heaviest carcass weight (P = 0.04), greatest cutability as assessed by USDA calculated YG (P < 0.01) and were the heaviest muscled based on "longissimus" muscle area (P < 0.01). ALPHA-sired calves were the most similar in carcass outcomes to calves sired by the Simmental, combining advantageous quality and yield parameters to produce an intermediate for carcass quality and yield. The economic value of moderate carcass outcomes is reflected in the carcass value per century weight, in which ALPHA-sired steers tended (P = 0.07) to be of the greatest value compared to other sire groups. ALPHA progeny performed comparably to high-performing reference sires for terminal sire production traits and the P1 genetics in which ALPHA was cloned have economical and biological value in modern U.S. beef production.

The effects of varying levels of trace mineral supplementation on performance, carcass characteristics, mineral balance, and antibody concentrations in feedlot cattle

The objective of this experiment was to determine the effects of increasing trace mineral (TM) supplementation on finishing cattle performance, carcass characteristics, TM balance, and antibody concentrations. Commercial Angus steers (n = 240; body weight, BW = 291 kg ± 27.4) were stratified by arrival BW and source and randomly assigned to 1 of 4 experimental treatments in a randomized complete block design (12 pens/treatment; 5 steers/pen). All steers underwent a TM depletion period for a minimum of 42-d prior to the administration experimental treatments. Treatments included a negative control (CON) in which cattle received no additional TM supplementation or TM supplementation treatments in which cattle received added Co, Cu, I, Mn, Se, or Zn from inorganic TM sources at 2016 Nutrient Requirements of Beef Cattle (NASEM) requirement levels (1X), at 2 times NASEM requirements (2X), or at 4 times NASEM requirements (4X). Selenium was included at 0.1, 0.2, and 0.3 mg/kg for 1X, 2X, and 4X respectively, based on federal law. There was no difference in overall BW, average daily gain (ADG), dry matter intake (DMI), or gain to feed (G:F) due to TM supplementation (CON vs. SUPP P ≥ 0.47). There was no difference in hot carcass weight, rib eye area, fat thickness, dressing percentage, marbling score, or USDA Yield Grade due to TM supplementation (CON vs. SUPP P ≥ 0.30). One steer was chosen at random from each pen to be evaluated for serum and liver TM status and antibody concentrations to common respiratory viruses. There was a treatment × day interaction for serum Co and liver Cu and Se (P < 0.0001). Serum Co was greatest for the 4X treatment from d 28 through harvest. Liver Cu was greatest for the 2X and 4X treatments from d 56 through harvest. Liver Se was greatest for 2X and 4X from d 28 through harvest. Serum Zn was greatest for the 4X treatment (P = 0.02). There was an effect of day on liver Co, Fe, Mn, Mo, and Zn (P ≤ 0.0001) and serum Cu, Mn, Mo, Se, and Zn (P ≤ 0.002). Individual TM concentrations differed over time; however, none were ever considered deficient or toxic based on published reference ranges. There was an effect of time on bovine viral diarrhea virus Type 1A, bovine herpesvirus type 1, and bovine parainfluenza 3 virus antibody concentrations (P ≤ 0.0001). Supplementation of TM above NASEM requirements did not affect overall cattle performance, carcass characteristics, or antibody concentrations, but did affect the storage and circulation of certain TM.

Nutritional Benefits from Fatty Acids in Organic and Grass-Fed Beef

Livestock production is under increasing scrutiny as a component of the food supply chain with a large impact on greenhouse gas emissions. Amidst growing calls to reduce industrial ruminant production, there is room to consider differences in meat quality and nutritional benefits of organic and/or pasture-based management systems. Access to forage, whether fresh or conserved, is a key influencing factor for meat fatty acid profile, and there is increasing evidence that pasture access is particularly beneficial for meat’s nutritional quality. These composition differences ultimately impact nutrient supply to consumers of conventional, organic and grass-fed meat. For this review, predicted fatty acid supply from three consumption scenarios were modelled: i. average UK population National Diet and Nutrition Survey (NDNS) (<128 g/week) red meat consumption, ii. red meat consumption suggested by the UK National Health Service (NHS) (<490 g/week) and iii. red meat consumption suggested by the Eat Lancet Report (<98 g/week). The results indicate average consumers would receive more of the beneficial fatty acids for human health (especially the essential omega-3, alpha-linolenic acid) from pasture-fed beef, produced either organically or conventionally.

Screening out important substances for distinguishing Chinese indigenous pork and hybrid pork and identifying different pork muscles by analyzing the fatty acid and nucleotide contents

Fatty acids and nucleotides are major contributors of pork flavor, which are key quality traits influencing consumers' preference. In this study, we investigated the contents of nucleotides (inosinic acid, inosine, and hypoxanthine) and 26 fatty acids by high-performance liquid chromatography and gas chromatography in longissimus dorsi and semimembranous muscle of four breeds (Dongbei Min pig, Beijing Black pig, Wuzhishan pig, and DLY pigs). Combining with multivariate statistics, we found significant differences in the nucleotides and fatty acids compositions among the breeds and muscles. Furthermore, the content of total unsaturated fatty acids and DHA were higher in native pigs than crossbred pigs. This study provides a theoretical basis for understanding the composition of flavor precursor substances, as well as for the identification of different muscles.

Nutritional properties of organic and conventional beef meat at retail

BACKGROUND

Consumers perceive that organic meat has superior nutritional properties compared to conventional meat, although the available evidence from commercial samples is very scarce. The present study compared the nutritional composition of organic and conventional beef meat sold at retail, including, for the first time, the bioactive compounds coenzyme Q₁₀ , carnosine, anserine, creatine and taurine. Sampling comprised two muscles: longissimus thoracis and supraspinatus.

RESULTS

Organic beef had 17% less cholesterol, 32% less fat, 16% less fatty acids, 24% less monounsaturated fatty acids, 170% more α-linolenic acid, 24% more α-tocopherol, 53% more β-carotene, 34% more coenzyme Q₁₀ and 72% more taurine than conventional beef. Differences between organic and conventional samples were clearly dependent on the muscle because longissimus thoracis and supraspinatus showed different patterns of compound accumulation.

CONCLUSION

To our knowledge, a higher amount of bioactive compounds in organic beef meat is reported for the first time in the present study. Retail organic beef had a higher nutritional value than retail conventional beef, which resulted from better-balanced lipid and bioactive compound contents. © 2019 Society of Chemical Industry.

Prediction of beef carcass and meat quality traits from factors characterising the rearing management system applied during the whole life of heifers

In this study, four prediction models were developed by logistic regression using individual data from 96 heifers. Carcass and sensory rectus abdominis quality clusters were identified then predicted using the rearing factors data. The obtained models from rearing factors applied during the fattening period were compared to those characterising the heifers' whole life. The highest prediction power of carcass and meat quality clusters were obtained from the models considering the whole life, with success rates of 62.8% and 54.9%, respectively. Rearing factors applied during both pre-weaning and fattening periods influenced carcass and meat quality. According to models, carcass traits were improved when heifer's mother was older for first calving, calves ingested concentrates during pasture preceding weaning and heifers were slaughtered older. Meat traits were improved by the genetic of heifers' parents (i.e., calving ease and early muscularity) and when heifers were slaughtered older. A management of carcass and meat quality traits is possible at different periods of the heifers' life.

Analysis of meat flavor compounds in pedigree and two-strain Yangzhou geese

In this study, we evaluated the meat flavor compounds of Yangzhou geese, including one group of pedigree strain (AA group) and 4 groups of 2-strain crossbreds (KA, KB, CA, and SA). Each group consisted of 100 geese comprised of 5 replicates of 10 males and 10 females each. Inosine 5'-monophosphate (IMP), amino acid (AA), and fatty acid (FA) levels in breast and thigh muscle were determined. Results showed that AA group had the highest levels of total amino acid (TAA) and dissolved free amino acids (DFAA) in breast muscle and of polyunsaturated fatty acids (PUFA) in thigh muscle (P<0.05). In SA group, the levels of C17:1, C22:0, C22:1, C20:4, and C24:1 in breast muscle were significantly higher in SA than in other groups (P<0.05). KB group had the lowest glycine levels in breast muscle (P<0.05) while MUFA levels were significantly higher in KB than in other groups (P<0.05). In KA, the levels of C18:3 in breast muscle in were higher than in CA and KB (P<0.05). CA had relevant higher IMPc levels in breast muscle than SA (P<0.05) and other groups (P>0.05); however, no significant differences were obtained in thigh muscle (P>0.05). In conclusion, Yangzhou AA goose has high levels of meat flavor compounds than its crossbreeds. Future efforts should focus on assessing meat flavor through measurement of sensory characteristics of Yangzhou geese.