Identify known and novel candidate genes associated with backfat thickness in Duroc pigs by large-scale genome-wide association analysis

Backfat thickness (BFT) is complex and economically important traits in the pig industry, since it reflects fat deposition and can be used to measure the carcass lean meat percentage in pigs. In this study, all 6,550 pigs were genotyped using the Geneseek Porcine 50K SNP Chip to identify SNPs related to BFT and to search for candidate genes through genome-wide association analysis in two Duroc populations. In total, 80 SNPs, including 39 significant and 41 suggestive SNPs, and 6 QTLs were identified significantly associated with the BFT. In addition, 9 candidate genes, including a proven major gene MC4R, 3 important candidate genes (RYR1, HMGA1 and NUDT3) which were previously described as related to BFT, and 5 novel candidate genes (SIRT2, NKAIN2, AMH, SORCS1 and SORCS3) were found based on their potential functional roles in BFT. The functions of candidate genes and gene set enrichment analysis indicate that most important pathways are related to energy homeostasis and adipogenesis. Finally, our data suggests that most of the candidate genes can be directly used for genetic improvement through molecular markers, except that the MC4R gene has an antagonistic effect on growth rate and carcass lean meat percentage in breeding. Our results will advance our understanding of the complex genetic architecture of BFT traits, and laid the foundation for additional genetic studies to increase carcass lean meat percentage of pig through marker-assisted selection and/or genomic selection.

Chromium and energy restriction as substitutes for ractopamine in finishing gilts diet

ABSTRACT: This study evaluated chromium supplements and energy restriction as substitutes for ractopamine in the diets of late finishing gilts. Sixty gilts were used, with initial weights of 98.87 ± 0.25 kg and final weights of 122.69 ± 10.97 kg, distributed in a randomized block design with five diets: control; yeast chromium (0.8 ppm); chromium picolinate (0.48 ppm); ractopamine (20 ppm) and energy restriction (reduction of 150 kcal of EM kg-1 of feed), with six replicates and two animals per experimental unit. Feeding diet containing ractopamine enabled better (P<0.05) feed conversion and greater weights of the hot carcass of the gilts. The diet containing ractopamine exhibited a lower (P<0.05) cost of feed per kilogram of gain and higher economic efficiency, when compared to diets containing chromium and energy restriction; these exhibited better outcomes, compared to the control diet. Diets supplemented with chromium and ractopamine resulted in a higher (P<0.05) percentage and quantity of lean meat and a higher rate of carcass bonus, when compared to the control diet and energy restriction. The energy reduction did not harm the gilts’ responses, compared to the control diet. Ractopamine supplementation allowed for a better feed conversion, lower feed cost per kilogram of gain, and a higher economic efficiency index. Supplements of chromium and ractopamine increased the percentage and quantity of lean meat and the bonus index of the carcasses. Therefore, chromium picolinate and chromium yeast are potential substitutes for ractopamine for optimizing the gilts carcass characteristics.

MAGRARIO: A NEW GENOTYPE TO PRODUCE QUALITY SHEEP MEAT

Generally there is poor tradition to produce and to commercialize heavy lean lamb carcasses. To achieve a better product for the ovine meat market Ideal (Polwarth) breed ewes were backcrossed to Texel breed rams (breed recognized to reduce carcass fat). Ideal breed (I) is one of the most ordinary breeds in Argentina. However, when their lambs are reared in feed-lot conditions, a high fat content is found in their lamb carcasses. After three generations of backcrosses followed by a breeding program for increase male lamb weaning weight and female fertility a new genotype was obtained for the local ovine meat production systems. This new genotype registered as Magrario (M) was obtained at Villarino Field Station of UNR (Zavalla, Santa Fe, 33º S, 61º W). It was verify that M produced more lean meat than I breed under feet lot conditions. M rams were introduced in flocks of Hampshire Down (HD) breed to evaluate lamb crosses with lean meat. Genotype M was compared under feed lot conditions with HD lambs during two months in the post weaning. Also crosses (MxHD), (MxI) and (IxHD) were evaluated in the same conditions. At the end of the experiment ultrasonic methods were used to evaluate fat depot on Longissimus dorsi. The (MxHD) showed a reduction of 20% respecting to HD. These results suggested that M genotype could be a useful paternal genotype to reduce fat depots when the aim is to produce lamb crosses under feed lot conditions in a short period of time. Key words: ovine, lean meat, feed lot, crossing.

Hunting and raising livestock are associated with meat-related attitudes, norms and frequent consumption: implications for dietary guidance to rural residents

PurposeMeat consumption is higher than health recommendations, but little is known about potential moderating factors in rural areas. Informed by the theory of planned behaviour (TPB), this paper explored potential moderators amongst rural residents.Design/methodology/approach The authors summarized meat-related attitudes (importance, taste preference, healthfulness perceptions), social norms, controls (availability, affordability, self-efficacy) and frequency of consumption (overall, lean meat, wild game) in a cross-sectional survey of rural, adult, US volunteers (n = 572). The authors examined correlations and differences by gender, connection to hunting and to livestock raising.Findings These rural residents had positive attitudes toward meat, high family expectations to consume meat and daily consumption. Half of the meat consumed was lean but was infrequently wild game. Respondents with connections to hunting or raising livestock reported more positive meat-related attitudes, norms and self-efficacy, and more frequent meat consumption. Those with a connection to hunting also had higher perceived availability, affordability and consumption of wild game.Research limitations/implications Strong meat preferences and expectations may hamper moderation amongst rural residents, particularly in households connected to hunting or raising livestock. Dietary advice can be tailored to respect meat consumption, emphasize the identification and selection of lean meats and highlight wild game as a lean meat that is moderately available and affordable. Future research should disentangle hunting and livestock raising as potential factors in food choice and examine wild game consumption in jurisdictions where it can be sold legally.Originality/value This study was novel in examining meat-related practices amongst rural residents, separately examining lean meats and wild game, and identifying hunting and livestock raising as important predictors.

Preliminary Study of Slaughter Value and Meat Characteristics of 18 Months Ostrich Reared in Hungary

The study aimed to evaluate the slaughter value and meat characteristics of ten ostrich females reared and slaughtered at the age of 18 months in Hungary. The ratio of selected body parts, the main organs and the lean meat parts were examined. The nutritive composition, the colour, the technological and organoleptic characteristics of five valuable meat parts (outside strip—M. flexor cruris lateralis, oyster—M. iliofemoralis externus, tip—M. femorotibialis medius, outside leg—M. gastrocnemius pars externa, medal—M. ambiens) and the amino acid, fatty acid and mineral composition of outside strip (M. flexor cruris lateralis) were also evaluated. The ratio of body parts and the main organs as the percentage of live weight, and the lean meat part as the percentage of carcass weight showed 16.74 ± 0.01%, 6.16 ± 0.01% and 57.29 ± 0.59%, respectively. The dry matter content of the examined valuable meat parts ranged between 24.89 ± 0.08 and 26.23 ± 0.13%, the protein ratio took on values between 18.40 ± 0.09 and 20.62 ± 0.16%, the fat content showed values between 2.36 ± 0.07 and 4.50 ± 1.09% and the hydroxyproline content ranged between 0.01 ± 0.001 and 0.08 ± 0.001%. The amino acid content of the outside strip showed a range between 0.15 and 3.33%. The ratio of SFA, MUFA and PUFA was 35.10 ± 0.53, 37.37 ± 1.52 and 27.54 ± 1.01. The n-6/n-3 ratio showed 3.91 ± 0.43 and the SFA/UFA ratio was 0.54 ± 0.02. Among the examined minerals, the content of Ca, K, Mg, Na and P was the highest in the meat. In the case of the colour, regarding L* value, we could reveal no significant difference between the examined meat parts. For a* and b* values, the outside leg had the lowest data of all. We could not reveal a significant difference between the pH values of the meat parts. Regarding technological parameters, meat differed only in thawing loss. The significantly lowest thawing loss could be detected in the outside leg (2.72 ± 0.01%) and in the medal (2.32 ± 0.01%). The results of the organoleptic evaluation showed that the outside strip and the tip had the best flavour and tenderness. In comparison with the younger birds (10–14 months of age) in the literature, the 18-month-old ostriches in our study showed similar or slightly lower slaughter weight, skin weight and head ratio, greater liver weight, lighter meat, lower protein and higher fat content, higher essential amino acid and lower non-essential amino acid content and higher SFA content in some cases. However, data on nutrition and population size were not always available. In comparison with other ratites (emu and rhea), ostrich meat has lower dry matter and protein, but higher fat, SFA, MUFA and PUFA content and lower n-6/n-3 ratio.

Characteristics of pig carcasses of two genetic breeds / Características de carcaças suínas de duas linhagens genéticas

The production of good quality carcasses is the main goal of modern commercial and industrial pig farming.The genetic potential of commercial breeds has changed considerably, especially in terms of deposition rates of lean meat and lard thickness. By morphology and analysis of the small intestine one can evaluate the utilization of nutrients for the deposition of fat and meat in swine carcasses.This study aimed to evaluate the quality of carcasses from two commercial genetic breeds, using quantitative traits, and to investigate if there is difference in length and absorptive surface of the intestine, verifying if these data are correlated with the yield of lean meat on the carcass. 60 animals from each breed were slaughtered and evaluations made for the characteristics: hot carcass weight (HCW), carcass length (CL), lard thickness (LT), percentage of lean meat (LM%), intramuscular fat (IMF) and intestinal length (IL). For the analysis of intestinal absorption (IA) were used only 62 of the animals previously studied, being 31 animals of each genotype.The average values of CL and IMF presented differences between breeds. The meat of the swines studied presented a low IMF content, existing correlation between the LM% and LT. The breeds had statistically equal IC, AI and LM%. There was also correlation between LM% and LT.

Variation in Red Meat Categories Meaningfully Influences Red Meat Intake Estimates of the U.S. Population Aged 2 + Years

Objectives Limitations in dietary assessment methodology lead to broad and inconsistent red meat intake categories. For example, red meat is often combined with processed meat, which includes processed poultry. Our objective was to quantitatively assess how these limitations influence red meat intake estimates of the U.S. population. Methods Three distinct red meat categories were identified from a series of systematic literature reviews. By systematically disaggregating and reaggregating meat variables (lean meat oz-eq) from the USDA's Food Pattern Equivalents Database, the following categories were created: 1) ‘unprocessed red meat’, 2) ‘total red meat’ [unprocessed red meat + processed red meat], and 3) ‘mixed red and processed meat’ [unprocessed red meat + total processed meat which includes processed poultry]. The 2015–16 and 2017–18 cycles of NHANES (n = 15,039) were combined to estimate and compare mean intakes across these three categories as well as the proportion of the population that exceeded age- and sex-specific red meat allotments in the Dietary Guidelines for Americans recommended eating patterns for those aged 2 + years. The two-part correlated model of the NCI Usual Intake method in SAS was used. Estimates were adjusted for age, sex, race, and ethnicity and pairwise comparisons were made across categories; P &lt; 0.05. Results Mean intake estimates (lean meat oz-eq/day) differed by red meat category (pairwise comparisons P &lt; 0.00,001): 1.5 ± 0.04 for unprocessed red meat, 2.2 ± 0.05 for total red meat, 2.4 ± 0.05 for mixed red and processed meat. The % of the population exceeding their respective age-sex red meat allotment in the DGA eating patterns also differed by category (pairwise comparisons P &lt; 0.00,001): 18.3 ± 1.9% for unprocessed red meat, 45.1 ± 1.8% for total red meat, 55.2 ± 1.8% for mixed red and processed meat. Conclusions Our results emphasize the importance of accurate and transparent red meat categories in nutrition epidemiology when estimating population intakes. Future research should examine how differences in these intake categories can influence associations between red meat intake and chronic disease. Funding Sources Not applicable.

Application of the Modified Cytosine Base-Editing in the Cultured Cells of Bama Minipig

Bama minipig is a unique miniature swine bred from China. Their favorable characteristics include delicious meat, strong adaptability, tolerance to rough feed, and high levels of stress tolerance. Unfavorable characteristics are their low lean meat percentage, high fat content, slow growth rate, and low feed conversion ratio. Genome-editing technology using CRISPR/Cas9 efficiently knocked out the myostatin gene (MSTN) that has a negative regulatory effect on muscle production, effectively promoting pig muscle growth and increasing lean meat percentage of the pigs. However, CRISPR/Cas9 genome editing technology is based on random mutations implemented by DNA double-strand breaks, which may trigger genomic off-target effects and chromosomal rearrangements. The application of CRISPR/Cas9 to improve economic traits in pigs has raised biosafety concerns. Base editor (BE) developed based on CRISPR/Cas9 such as cytosine base editor (CBE) effectively achieve targeted modification of a single base without relying on DNA double-strand breaks. Hence, the method has greater safety in the genetic improvement of pigs. The aim of the present study is to utilize a modified CBE to generate MSTN-knockout cells of Bama minipigs. Our results showed that the constructed “all-in-one”-modified CBE plasmid achieved directional conversion of a single C·G base pair to a T·A base pair of the MSTN target in Bama miniature pig fibroblast cells. We successfully constructed multiple single-cell colonies of Bama minipigs fibroblast cells carrying the MSTN premature termination and verified that there were no genomic off-target effects detected. This study provides a foundation for further application of somatic cell cloning to construct MSTN-edited Bama minipigs that carry only a single-base mutation and avoids biosafety risks to a large extent, thereby providing experience and a reference for the base editing of other genetic loci in Bama minipigs.