The use of partially slatted floor designs as an alternative to littered systems in broiler chickens. I. The effects on the performance, slaughter and carcass traits.

In this study, the effects of fully littered, slatted and their varying combinations on growth, performance, carcass and meat quality characteristics in broiler chickens were investigated. In the experiment, five treatment groups were formed as fully littered (FL), fully slatted (FS), 1/3 littered + 2/3 slatted (2/3 SF), 1/2 littered + 1/2 slatted (1/2SF), 2/3 littered + 1/3 slatted (1/3 SF). Each treatment group included 5 replicates (24 chicks in each) and a total of 600 male-female mixed fast growing broiler chicks (Ross-308) were used during 6 weeks. Weekly body weight (BW, g), feed intake (FI, g), feed conversion ratio (FCR, g.feed intake/g.weight gain), livability (%) and EPEF (European Production Efficiency Factor) were determined as performance characteristics. Carcass yield (CY, %), and the percentages of abdominal fat (AFP, %), edible internal organs (EIOP, %), gizzard (GP, %), breast (BRP, %) and thigh (TP, %) meat were the carcass characteristics. Meat quality measured by pH and color (L*: lightness, a*: redness, b*: yellowness) of breast and thigh meat, and occurrence of white striping and hemorrhaging in breast meat. The weekly BW differences among the floor treatments were significant (P < 0.01), and 1/3SF broilers were the heaviest at slaughter age (3311.6 g). The 6-week FCR in FS broilers was significantly worse than the others (1.471), but FI, livability and EPEF were similar among treatments. AFP tended to be higher in FL birds (P = 0.066), while CY, EIOP, GP, BRP and TP did not differ between groups. Breast pH was similar between treatments, with 1/2SF showing the highest (6.34) and FL the lowest (6.24) breast pH (P < 0.01). The partially slatted systems caused lighter, redder and yellower color values in breast meat (P < 0.01) than the fully littered or slatted systems, but did not change the color of the thigh meat. White striping and hemorrhaging in breast meat were not affected by the floor treatments. This study suggests that the use of partially slatted systems in broiler chickens improves meat color without compromising performance traits (body weight, feed efficiency, EPEF), litter moisture and slaughter traits and these systems could be an alternative to fully littered systems.

Productive, internal organ and intestinal histomorphological characteristics of broiler chickens in response to dietary rapeseed meal: A meta-analysis.

The use of rapeseed as a source of protein in broiler chicken diets has been highlighted. However, there are inconsistent findings on the performance data of broiler chickens fed rapeseed meal (RSM). Therefore, this meta-analysis aimed to resolve the inconsistent findings on the effect of RSM on growth performance, carcass characteristics, internal organs, and intestinal histomorphology of broiler chickens, identify knowledge gaps and create new insights using published data. Fourteen studies on the topic were identified via a systematic search performed on bibliographic databases, and the data generated was analysed using OpenMEE software. A random-effects model was used, and effect sizes were presented as standardised mean difference (SMD) at a 95% confidence interval (CI). Sources of heterogeneity were evaluated using broiler strains, inclusion levels, processing methods, rearing phases and sex as moderators. In comparison with the controls, the results showed that RSM decreased feed intake (SMD = -0.29; 95% Cl: -0.41, -0.18; p < 0.001), average daily gain (SMD = -0.48; 95% Cl: -0.63, -0.32; p < 0.001), and liver weight (SMD = 1.24; 95% Cl: 0.78, 1.71; p < 0.001), but had no effect on feed conversion ratio (SMD = 0.10; 95% Cl: -0.05, 0.23; p = 0.19). Likewise, broiler chickens fed RSM had significantly reduced carcass yield, weights of thigh, abdominal fat and heart when compared with the control. Results indicate that duodenum villus height (DVH) and jejunum villus height (JVH)/crypt depth (CD) ratios were improved in broiler chickens fed RSM. Meta-regression revealed that the analysed moderators are significant predictors of feed intake, average daily gain and feed conversion ratio in broiler chickens. In conclusion, dietary RSM negatively influenced growth performance, liver weight and carcass characteristics in broiler chickens, but improved aspects of intestinal histomorphology traits. Therefore, innovative research on processing methods that will improve the feeding value of rapeseed meal in broiler chickens is recommended.

Characterization of Post-Mortem pH Evolution and Rigor Mortis Process in Botucatu Rabbit Carcasses of Different Categories.

The aim of the present study was to evaluate the characteristics of carcasses, monitor their pH evolution during the first 24 h post-mortem, and determine the time required for the establishment and resolution of rigor mortis in different categories of Botucatu rabbits. Live weight at slaughter, carcass weight, and yield were higher in 12-month-old animals compared to 3-month-old rabbits, regardless of sex. There was an effect of muscle type, age, and sex on the kinetics of muscle acidification, with the Biceps femoris showing a significantly higher pH than the Longissimus lumborum from 4 h post-mortem onward. The establishment of rigor mortis occurred at 5 h post-mortem in young rabbits and bucks and at 6 h post-mortem in does, along with pH stabilization, while the resolution of rigor occurred at 18 h post-mortem for all types of carcasses evaluated. In conclusion, Botucatu rabbit carcasses should be chilled continuously at 4 °C for a minimum of 18 h to ensure efficient rigor mortis progression and muscle-to-meat transformation throughout the carcass.

Assessing the Influence of Cumulative Chlorella vulgaris Intake on Broiler Carcass Traits, Meat Quality and Oxidative Stability.

The impacts of cumulative Chlorella vulgaris intake (proportion of microalga in the diet multiplied by the total feed consumed by each bird) on broiler carcass traits, meat quality and oxidative stability were reviewed to identify the optimal intake levels for maximising benefits. Our findings indicate that a cumulative intake of 8.73 g/bird significantly enhances thigh yield, while levels ranging from 8.73 to 401 g/bird optimise carcass weight and overall meat quality. However, higher cumulative levels may reduce carcass dressing percentage due to metabolic inefficiencies. Furthermore, C. vulgaris intake improves the oxidative stability of broiler meat by increasing antioxidant levels and balancing pro- and antioxidants. Including C. vulgaris in broiler diets boosts total carotenoid content, and antioxidant assays confirm that it enhances meat oxidative stability, with low to moderate cumulative intake levels (8.73 to 401 g/bird) providing the best balance of benefits. Optimal oxidative stability and antioxidant properties were observed at a cumulative intake level of 401 g/bird, showing significant improvements in meat antioxidant capacity. Higher levels may lead to diminishing returns or potential negative effects due to the digestibility issues of the microalga. Future research should refine intake models, understand the bioavailability of C. vulgaris nutrients and explore cost-effective methods to enhance its digestibility, to ensure its viability and sustainability as a feed additive.

Effects of GH L127V and TG5 C422T polymorphisms on the hormonal profile, slaughter traits, and meat quality of Hereford bulls.

Background and Aim: The creation of objective methods for the evaluation and improvement of quantitative and qualitative indicators of meat productivity in farm animals should be based on a comprehensive analysis of the genetic, physiological, and biochemical parameters of the animal. This study aimed to investigate the effects of growth hormone (GH) and thyroglobulin (TG5) gene polymorphisms on the hormonal status, slaughter traits, and chemical, amino acid, and fatty acid composition of meat in Hereford bulls. Materials and Methods: Hereford bulls (n = 9) were reared under the same feeding and housing conditions until the age of 21 months, after which they were slaughtered. Polymerase chain reaction-restriction fragment length polymorphism was performed for genotyping GH L127V and TG5 C422T polymorphisms. The experimental animals were evaluated to determine slaughter traits (including pre-slaughter weight, carcass, and internal fat weight and yield), chemical, fatty acid, and amino acid composition of ground beef, and hormonal status using serum concentrations of GH, triiodothyronine, and thyroxine. Results: Animals with the valine homozygous (VV) genotype of GH had the maximum serum GH level of 9.33 mIU/mL (p = 0.10) higher than leucine homozygous (LL) genotype carriers. Individuals with the LL genotype outperformed V-allele carriers in serum thyroxine (T4) concentration by 21.3-30.5 nmol/L (16.15%-24.86%; p < 0.01-0.05). Genetic differentiation induced by TG5 C422T polymorphism was determined to a lesser extent by the hormonal status of the Hereford animals. The V-allele was associated with increased carcass weight, with VV homozygotes significantly outperforming LL individuals by 45.0 kg (13.61%; p < 0.05). The T allele at the TG5 gene polymorphism was associated with more intense lipogenesis and less protein synthesis in muscle tissue and these effects were enhanced in the homozygous state. Young animals with the TT variant of the TG5 gene exhibited a significantly superior polyunsaturated fatty acid/saturated fatty acid ratio of 0.012 units (p < 0.01). Carriers of the LL genotype were characterized by minimum amino acid content in muscle tissue. Heterozygous bulls exceeded LL homozygotes in the sum of essential amino acids by 3.09% (p = 0.10) and non-essential amino acids by 1.9% (p < 0.05). Conclusion: The development of breeding programs for the Hereford breed should be carried out considering genetic features that determine the formation of economic traits in animals. Analysis of polymorphisms in the TG5 gene is a promising method for the early diagnosis of the fatty acid composition of beef. Identification of polymorphisms in the GH gene allows the prediction of higher productivity potential and amino acid composition of meat. The different effects of the GH and TG5 genes on the development of various economic traits allowed us to determine further vectors for scientific research on their complex associations in Hereford cattle, which will be useful for planning effective breeding schemes.

Cull guinea pigs: carcass and non-carcass traits in males and females compared to their fattening counterparts.

Culling of guinea pigs can provide a large number of animals per year for meat production, but little information is available in the scientific literature on the carcass characteristics and non-carcass components of these animals. The objective of this study was to evaluate the carcass and non-carcass characteristics of cull guinea pigs in comparison to their fattening counterparts. Forty-eight fattening (3 months-age, 24 females and 24 males) and forty-eight cull (14 months-age, 24 females and 24 males) guinea pigs were slaughtered and carcass yield, linear measurements, tissular composition, and non-carcass components were evaluated. In general, cull guinea pigs had higher carcass, tissue, and non-carcass component weights. Cull male and both female guinea pig groups had similar carcass yields. Cull animals had higher carcass and hind leg lengths, lumbar and thoracic circumferences, and carcass compactness than their young counterparts. However, a sex effect was found for leg compactness depending on whether they were fattened or cull. Tissue percentages values were similar between fattening and culling animals of the same sex. However, females had a higher percentage of fat tissue than males. Fattening females had the best muscle to bone ratio, followed by cull males. The non-carcass elements were more represented in fattening animals than in culls, probably due to an allometric growth of the viscera in relation to the rest of the body. In commercial and cooking terms, this information is valuable for producers and researchers who need to understand the factors that influence carcass characteristics of guinea pigs.

Correlation analysis of primal cuts weight, fat contents, and auction prices in Landrace × Yorkshire × Duroc pig carcasses by VCS2000.

Currently, in pork auctions in Korea, only carcass weight and backfat thickness provide information on meat quantity, while the production volume of primal cuts and fat contents remains largely unknown. This study aims to predict the production of primal cuts in pigs and investigate how these carcass traits affect pricing. Using the VCS2000, the production of shoulder blade, loin, belly, shoulder picnic, and ham was measured for gilts (17,257 pigs) and barrows (16,365 pigs) of LYD (Landrace × Yorkshire × Duroc) pigs. Single and multiple regression analysis were conducted to analyze the relationship between the primal cuts and carcass weight. The study also examined the correlation between each primal cut, backfat thickness (1st thoracic vertebra backfat thickness, grading backfat thickness, and Multi-brached muscle middle backfat thickness), pork belly fat percentage, total fat yield, and auction price. A multiple regression analysis was conducted between the carcass traits that showed a high correlation and the auction price. After conducting a single regression analysis on the primal cuts of gilt and barrow, all coefficients of determination (R2) were 0.77 or higher. In the multiple regression analysis, the R2 value was 0.98 or higher. The correlation coefficient between the carcass weights and the auction price exceeded 0.70, while the correlation coefficients between the primal cuts and the auction prices were above 0.65. In terms of fat content, the backfat thickness of gilt exhibited a correlation coefficient of 0.70, and all other items had a correlation coefficient of 0.47 or higher. The correlation coefficients between the Forequarter, Middle, and Hindquarter and the auction price were 0.62 or higher. The R2 values of the multiple regression analysis between carcass traits and auction price were 0.5 or higher for gilts and 0.4 or higher for barrows. The regression equations between carcass weight and primal cuts derived in this study exhibited high determination coefficients, suggesting that they could serve as reliable means to predict primal cut production from pig carcasses. Elucidating the correlation between primal cuts, fat contents and auction prices can provide economic indicators for pork and assist in guiding the direction of pig farming.

Estimation of genetic correlations and genomic prediction accuracy for reproductive and carcass traits in Hanwoo cows.

This study estimated the heritabilities (h2) and genetic and phenotypic correlations between reproductive traits, including calving interval (CI), age at first calving (AFC), gestation length (GL), number of artificial inseminations per conception (NAIPC), and carcass traits, including carcass weight (CWT), eye muscle area (EMA), backfat thickness (BF), and marbling score (MS) in Korean Hanwoo cows. In addition, the accuracy of genomic predictions of breeding values was evaluated by applying the genomic best linear unbiased prediction (GBLUP) and the weighted GBLUP (WGBLUP) method. The phenotypic data for reproductive and carcass traits were collected from 1,544 Hanwoo cows, and all animals were genotyped using Illumina Bovine 50K single nucleotide polymorphism (SNP) chip. The genetic parameters were estimated using a multi-trait animal model using the MTG2 program. The estimated h2 for CI, AFC, GL, NAIPC, CWT, EMA, BF, and MS were 0.10, 0.13, 0.17, 0.11, 0.37, 0.35, 0.27, and 0.45, respectively, according to the GBLUP model. The GBLUP accuracy estimates ranged from 0.51 to 0.74, while the WGBLUP accuracy estimates for the traits under study ranged from 0.51 to 0.79. Strong and favorable genetic correlations were observed between GL and NAIPC (0.61), CWT and EMA (0.60), NAIPC and CWT (0.49), AFC and CWT (0.48), CI and GL (0.36), BF and MS (0.35), NAIPC and EMA (0.35), CI and BF (0.30), EMA and MS (0.28), CI and AFC (0.26), AFC and EMA (0.24), and AFC and BF (0.21). The present study identified low to moderate positive genetic correlations between reproductive and CWT traits, suggesting that a heavier body weight may lead to a longer CI, AFC, GL, and NAIPC. The moderately positive genetic correlation between CWT and AFC, and NAIPC, with a phenotypic correlation of nearly zero, suggesting that the genotype-environment interactions are more likely to be responsible for the phenotypic manifestation of these traits. As a result, the inclusion of these traits by breeders as selection criteria may present a good opportunity for developing a selection index to increase the response to the selection and identification of candidate animals, which can result in significantly increased profitability of production systems.

Analysing the Impact of Spirulina Intake Levels on Performance Parameters, Blood Health Markers and Carcass Traits of Broiler Chickens.

This systematic review examines the impact of varying Spirulina (Limnospira platensis) intake levels on broiler chickens, focusing on growth performance, blood health markers and carcass traits. The data revealed cumulative Spirulina intakes from 3.13 g to 521 g per bird (total feed consumed multiplied by its proportion in the diet) establish a cubic relationship between dosage and growth outcomes. Initial benefits peak and diminish with increased intake, with the optimal threshold for growth performance identified at 45 g per bird. Lower intakes between 14 g and 29 g per bird enhance blood health markers, improving lipid profiles and antioxidant capacity. Similarly, cumulative intakes of 14 g to 37 g per bird optimise meat quality, resulting in better dressing percentages, breast and thigh yields and meat tenderness while minimizing undesirable traits like abdominal fat and cooking loss. These findings underscore the importance of precisely calibrated Spirulina supplementation strategies to maximise growth, health and meat quality benefits while avoiding adverse effects at higher doses. Future research should focus on identifying optimal dosage and duration, assessing long-term implications, elucidating mechanisms of action and ensuring safety and regulatory compliance. Comparative studies with other feed additives could further establish Spirulina's effectiveness and economic viability in poultry production.

A meta-analysis of the meat physicochemical parameters of broiler chickens fed insect-based diet.

A total of 23 studies were identified in a literature search performed in the Scopus, Science Direct and Google Scholar databases for meta-analysis. The criteria used include studies that were published from 2015 to 2023 and those reporting the effects of insect meal utilisation in poultry diets. Data on live weight (LW), carcass weight (CW), moisture, meat pH, lightness (L*), redness (a*), yellowness (b*), proximate composition (protein, fat and ash content) and shear force in broilers were subjected to OpenMEE software, and data were pooled using a random-effect model. Subgroup analysis and meta-regression were performed to ascertain the influence of dietary insect meals on the response of meat aspects and the source of heterogeneity, respectively, using the following moderators (insect species, dosage level, feeding duration and age at slaughter). The results indicated that dietary insect meal did not affect LW, CW, meat L*, pH, shear force, moisture, fat and ash content. In contrast, dietary insect meal increased the a* of the meat (standardised mean differences (SMDs) = 1.03; 95% confidence intervals (CIs) = 0.484-1.578; p ≤ 0.001), b* (SMD = 1.117; 95% CI = 0.334-1.90; p = 0.005), and meat protein content (SMD = 0.365; 95% CI = 0.031-0.7; p = 0.032). The subgroup analysis showed that insect meal dosage of ≤10% and age at slaughtered ≤35 days had improved the LW, CW and meat L*. In addition, the meat a*, protein and ash content were also influenced by insect species, dosage levels and age at slaughter. In conclusion, ≤10% of either Hermetia illucens or Tenebrio molitor can be included in broiler diets without compromising the LW, CW, meat pH, colour, shear force, moisture, fat and ash content in broilers. The study therefore indicated that insect meals have a bright future as an alternative protein source in poultry diets.

Effect of different bedding depths of rice hulls on growth performance and carcass traits of White Pekin ducks.

Duck meat is recognized as a healthier poultry product that contains higher amounts of unsaturated and essential fatty acids, iron, and excellent amounts of protein. It has been found to possess the ability to reduce low-density lipoprotein cholesterol and subsequently, blood pressure in the human body; and improve the immunity system. The current study investigated the appropriate bedding depths of rice hulls as a preferred bedding material by evaluating the growth performance and carcass traits of White Pekin ducks raised for 42 days. A total of 288 one-day-old White Pekin ducklings were randomly allotted to floor cages with one of four bedding depths at 4 cm, 8 cm, 12 cm, and 16 cm. Ducklings were fed standard duck starter (days 1-21) and finisher (days 22-42) diets. The birds were stocked at a rate of 6 birds/m2 with 6 replicates per treatment. Growth performance evaluation for the body weight, average daily gain, and average daily feed intake were measured to calculate the weekly feed conversion ratio. Breast, leg, and carcass yield were assessed as carcass traits. The muscle color and proximate composition were also analyzed for meat quality. Footpad dermatitis was also evaluated on day 42. Ducks reared on 16 cm bedding depth over the 42 days recorded higher (p < 0.05) body weight, average daily, average daily feed intake, and improved feed conversion ratios compared to other groups. The crude fat in breast meat also lowered (p < 0.05) in ducks reared at 16 cm (1.02%) when compared to ducks raised at 4 cm bedding depth (2.11%). Our results showed improved redness (p < 0.05) when the depth of bedding materials was elevated. Except for the breast meat fat, the dissimilar bedding depths did not affect (p < 0.05) the breast and leg meat composition, footpad dermatitis, and mortality for the current study. In conclusion, this study indicated that the bedding depths would directly or indirectly affect the growth performance and meat color of White Pekin ducks; and the bedding depth of rice hulls at 16 cm improved the growth performance of White Pekin ducks for 42 days.

The effects of Artemisia annua nutritional supplementation at varying concentrations on broiler growth, economic yield, and gene expression levels of certain antioxidant, inflammatory, and immune genes.

Background and Aim: Artemisia annua (AA), used as a growth promoter in poultry, lowers feed costs and enhances economic efficiency. This study aimed to assess the impact of varying AA concentrations on broiler chicken growth, gene expression, and profitability. Materials and Methods: Two hundred 1-day-old male Cobb chicks were randomly allocated into four treatment groups, each containing five replicates and 10 birds. The experimental groups consisted of G1 (basal diet), G2 (basal diet with 0.3% AA), G3 (basal diet with 0.6% AA), and G4 (basal diet with 0.9% AA). The birds had continuous access to feed and water throughout the study. The experiment lasted for 42 days. We measured the growth performance (Feed intake, Life weight), carcass traits (weight after slaughter, dressed carcass, heart, gizzard, spleen, giblet and thymus weight), liver and spleen antioxidants (CAT, GSH, SOD), and gene expression of anti-inflammatory and immune- related genes. Results: The primary findings revealed that the addition of 0.6% AA had a positive impact (p < 0.05) on all investigated variables compared with the control and other groups. Dietary supplementation with 0.6% AA led to increased breast, giblet, skeleton, and total yield, and net return compared with the control group. Supplementation with AA exhibited antioxidant, anti-inflammatory, and immunological effects through improved levels of antioxidant superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in tissue homogenates of the liver and spleen. It also upregulated the relative messenger RNA levels of anti-inflammatory interleukin (IL)-10, SOD, CAT, and GSH-Px, whereas IL-1ß and tumor necrosis factor-alpha were downregulated. Conclusion: The study found that AA is a promising replacement for antibiotics in poultry farming as a growth promoter for chickens. 0.6% AA in the broiler diet yielded the best results, striking a balance between superior performance and robust economic benefits.

Comparative assessment of growth performance, heat resistance and carcass traits in four poultry genotypes reared in hot-humid tropical environment.

This study investigated the impact of heat stress on growth and carcass traits in four poultry genotypes-Giriraja, Country chicken, Naked Neck and Kadaknath reared in a hot and humid tropical environment. Birds from all genotypes had ad libitum access to feed and water while being challenged with consistently high environmental temperatures in the experimental shed. Daily diurnal meteorological data were recorded inside and outside the shed. The study specifically examined growth variables and carcass characteristics. Significant differences (p < 0.01) were observed in body weight and average daily gain at various intervals. Notably, feed intake showed significant differences (p < 0.01) across weeks, indicating interactions between genotypes and time intervals. The feed conversion ratio (FCR) varied significantly (p < 0.01), with the highest FCR recorded in the Kadaknath breed. Livability percentages were similar across groups, except for Giriraja, which had significantly lower livability (p < 0.01). Carcass traits, including dressing, wings, feathers and giblet percentages, showed significant differences among genotypes (p < 0.01). Hepatic mRNA expression of growth-related genes revealed numerical variations, with Naked Neck displaying the highest (p < 0.05) fold change in IGF-1 expression compared to other genotypes. The study recognized in the Naked Neck genotype to possess higher resilience in maintaining homoeostasis and uncompromised growth under heat stress, providing valuable insights for sustainable poultry farming in challenging environmental conditions.

Genome-wide identification of quantitative trait loci and candidate genes for seven carcass traits in a four-way intercross porcine population.

BACKGROUND: Carcass traits are essential economic traits in the commercial pig industry. However, the genetic mechanism of carcass traits is still unclear. In this study, we performed a genome-wide association study (GWAS) based on the specific-locus amplified fragment sequencing (SLAF-seq) to study seven carcass traits on 223 four-way intercross pigs, including dressing percentage (DP), number of ribs (RIB), skin thinkness (ST), carcass straight length (CSL), carcass diagonal length (CDL), loin eye width (LEW), and loin eye thickness (LET). RESULTS: A total of 227,921 high-quality single nucleotide polymorphisms (SNPs) were detected to perform GWAS. A total of 30 SNPs were identified for seven carcass traits using the mixed linear model (MLM) (p < 1.0 × 10- 5), of which 9 SNPs were located in previously reported quantitative trait loci (QTL) regions. The phenotypic variation explained (PVE) by the significant SNPs was from 2.43 to 16.32%. Furthermore, 11 candidate genes (LYPLAL1, EPC1, MATN2, ZFAT, ZBTB10, ZNF704, INHBA, SMYD3, PAK1, SPTBN2, and ACTN3) were found for carcass traits in pigs. CONCLUSIONS: The GWAS results will improve our understanding of the genetic basis of carcass traits. We hypothesized that the candidate genes associated with these discovered SNPs would offer a biological basis for enhancing the carcass quality of pigs in swine breeding.

Genome-wide association study comparison analysis based on Hanwoo full-sib family.

Objective: The improvement of carcass traits is essential for the Hanwoo industry because of the Hanwoo grade determination system, and Genome-Wide Association Study (GWAS) analysis is an instrumental tool for identifying the genetic factors that impact these traits. While GWAS analysis utilizing family data offers advantages in minimizing genetic bias, research on family-based GWAS in Hanwoo is currently lacking. Methods: This study classified Group A using both parental and offspring genetic information, and Group B based solely on offspring genetic information, to compare GWAS analysis results of Hanwoo carcass traits. Results: 16 significant SNP markers (carcass weight (CWT) 7, back fat thickness (BFT) 3, marbling score (MS) 6) were identified in Group A, and 7 significant SNP markers (CWT 3, eye muscle area (EMA) 1, BFT 1, MS 2) were identified in Group B. Functional annotation analysis revealed only one common function related to carcass traits between the groups, while Protein-protein interaction (PPI) analysis indicated more gene interactions in Group A. The reliability of estimated values for common SNP markers identified between the groups was higher in Group A. Conclusion: GWAS analysis utilizing parental genetic information holds greater potential for application, owing to its higher reliability of estimated values and the ability to explore numerous candidate genes.

Cattle, carcass, economic, and estimated emission impacts of feeding finishing steers lubabegron or ractopamine hydrochloride.

Lubabegron (Experior; Elanco, Greenfield, IN, USA) is the first U.S. Food and Drug Administration approved feed additive for reducing gas emissions from feedlot animals or their waste; it does not have live or carcass performance claims. Our primary objective was to determine the effect of lubabegron on feedlot performance and carcass traits in finishing beef steers compared to ractopamine hydrochloride (Optaflexx; Elanco, Greenfield, IN, USA). A commercial feedlot trial using cross-bred beef steers (n = 2,117; 373 ±â€…15 kg initial body weight [BW]) was completed with a randomized complete block design. Treatments consisted of two feed additives: (1) OPT targeted to deliver 300 mg/animal/d of ractopamine hydrochloride for 28 ±â€…7 d out from harvest and (2) EXP targeted to deliver 36 mg/animal/d of lubabegron 56 ±â€…7 d out from harvest and a 4-d preslaughter withdrawal period. Twenty 70 to 142 hd pens with 10 pens per treatment were used. Cattle were weighed at arrival processing and at harvest and fed for an average of 167 d. Data were used to calculate production metrics, partial budgets, and estimated greenhouse gas emissions using published methods, and were analyzed using linear mixed models with pen as the experimental unit and block as a random intercept. A statistical significance threshold of α = 0.05 was determined a priori. There was no evidence for statistically significant differences between treatments for initial BW (P = 0.70), health-related outcomes (P values ≥ 0.43), or mobility scores (P = 0.09). Cattle-fed EXP had increased final BW, ADG, G:F, and decreased dry matter intake (P values ≤ 0.01) compared to OPT. Carcasses were 11 ±â€…1.76 kg (hot carcass weight) heavier in EXP group (P < 0.01), and differed between treatments for both yield grades (YG) and quality grades distributions (P values ≤ 0.01). Cattle-fed EXP had a shift toward more YG 1 and 2, select and sub-select carcasses compared to OPT, which had as shift toward more YG 3, 4, 5, prime and choice carcasses. With increased beef production and efficiency compared to OPT, the estimated CO2 equivalent emissions from production were reduced by 6.2% per unit of carcass weight for EXP (P ≤ 0.01). Estimated net returns/animal shipped were $56.61 ±â€…9.37 more for EXP than OPT (P ≤ 0.01). In conclusion, when cattle were fed for the same total number of days, feeding EXP compared to OPT increased net returns, feedlot performance, and efficiency, but resulted in carcass yield and quality characteristics that may impact marketing programs.

Does transport stress have any effect on carcass quality of Nellore cattle (Bos taurus indicus) in Brazil? - A case study.

With the increasing concomitant demands for Brazilian beef and in particular high-quality beef, there is a need for observational studies of the effects of pre- and post-slaughter practices on beef carcass traits. We hypothesized in our case study that pre-slaughter transport of bovines over significant distances would induce stress in animals, and that this would reduce carcass quality because of higher pH resulting from long-distance transportation. To test this hypothesis, 30,230 Nellore carcasses from a private slaughterhouse were evaluated 24 h postmortem. Analysis showed correlations between animal maturity, ultimate pH, distance, and carcass weight. More precisely, there was a slight positive correlation between ultimate pH and weight (but not with transportation distance) and a slight positive correlation between maturity and weight. A linear regression model (R2 = 0.016) failed to show distance having a significant effect on ultimate pH (P = 0.63), while carcass weight significantly affected ultimate pH (P < 0.001) with a low coefficient of 0.0003. Maturity negatively affected ultimate pH also (P < 0.001) but with also a small effect (-0.0008). Results (from 95% confidence intervals of variance of the random effects and of the random errors) showed that the variability within farms was higher than between farms. The linear mixed model showed that maturity had a significant effect on carcass weight value (P < 0.001) with a large coefficient of 2.90. The R2 of the linear mixed model was 46.03%. In conclusion, while weight and maturity both affect ultimate pH, long distances did not significantly impact ultimate pH and therefore the beef quality from Nellore cattle. This could be because of low stress during transport, as well as the physical characteristics of the Nellore breed that favor greater resistance to tropical climatic conditions.

Large-scale transcriptomic and genomic analyses reveal a novel functional gene SERPINB6 for chicken carcass traits.

BACKGROUND: Carcass traits are crucial indicators of meat production efficiency. However, the molecular regulatory mechanisms associated with these traits remain unclear. RESULTS: In this study, we conducted comprehensive transcriptomic and genomic analyses on 399 Tiannong partridge chickens to identify key genes and variants associated with carcass traits and to elucidate the underlying regulatory mechanisms. Based on association analyses with the elastic net (EN) model, we identified 12 candidate genes (AMY1A, AP3B2, CEBPG, EEF2, EIF4EBP1, FGFR1, FOXD3, GOLM1, LOC107052698, PABPC1, SERPINB6 and TBC1D16) for 4 carcass-related traits, namely live weight, dressed weight, eviscerated weight, and breast muscle weight. SERPINB6 was identified as the only overlapping gene by 3 analyses, EN model analysis, weighted gene co-expression network analysis and differential expression analysis. Cell-level experiments confirmed that SERPINB6 promotes the proliferation of chicken DF1 cells and primary myoblasts. Further expression genome-wide association study and association analysis indicated that rs317934171 is the critical site that enhances SERPINB6 expression. Furthermore, a dual-luciferase reporter assay proved that gga-miR-1615 targets the 3'UTR of SERPINB6. CONCLUSIONS: Collectively, our findings reveal that SERPINB6 serves as a novel gene for chicken carcass traits by promoting fibroblast and myoblast proliferation. Additionally, the downstream variant rs317934171 regulates SERPINB6 expression. These results identify a new target gene and molecular marker for the molecular mechanisms of chicken carcass traits.

Heavy Pigs Reared for Italian Dry-Cured Products: Does Immunocastration Influence the Fatty Acid Profile of Loins and Backfat?

The Italian pig sector requires heavy pigs (raised for at least nine months and slaughtered at >160 kg). In order to avoid boar taint and lower the impact on welfare, immunocastration provides an alternative to surgical castration. This study investigated the effects of immunocastration compared to surgical castration on the chemical composition and fatty acid profile of loins (longissimus dorsi muscle) and adipose tissue in Italian heavy pigs raised for dry-cured ham. Twenty-four male pigs were subjected to surgical castration (n = 12) or immunocastration (n = 12). Carcass parameters were monitored at slaughter, and samples of longissimus dorsi muscle and subcutaneous fat were analysed. This study showed no significant differences in carcass characteristics and proximate composition of fresh meat. However, variations were observed in the fatty acid profiles of meat and adipose tissue between groups. Notably, saturated fatty acids, particularly stearic acid (18:0), were higher in the intramuscular fat (IMF) of the immunocastrated pigs compared to the surgically castrated pigs. Conversely, monounsaturated fatty acids, predominantly oleic acid (18:1n-9), were higher in the IMF from the surgically castrated pigs compared to the immunocastrated pigs. While immunocastration may offer benefits in terms of animal growth and carcass composition, it could lead to unfavourable lipid changes in fresh loin meat for Italian heavy pigs.

Effects of Zilpaterol Hydrochloride with a Combination of Vitamin D3 on Feedlot Lambs: Growth Performance, Dietary Energetics, Carcass Traits, and Meat Quality.

This study evaluated the impact of supplementing ZH in combination with D3 on the growth performance, energy efficiency, carcass traits, and meat quality of feedlot lambs. Thirty-two Dorper × Katahdin cross lambs (37.3 ± 5.72 kg) were utilized in a 29 d experiment in a completely randomized block design with a 2 × 2 factorial structure consisting of two levels of ZH for 26 d (0 and 0.20 mg/kg PV-1) and two levels of D3 for 7 d (0 and 1.5 × 106 IU/d-1). ZH improved (p ≤ 0.05) the average daily gain (ADG) and feed efficiency by 9.9% and 17.8%, respectively, as well as hot carcass weight (HCW) and dressing carcass by 4.3% and 2.6%, respectively. (p ≤ 0.03). However, ZH increased (p < 0.01) muscle pH and Warner-Bratzler shear force (WBSF) (2.5 and 23.0%, respectively). D3 supplementation negatively affected (p ≤ 0.02) dry matter intake (DMI) (last 7 d) and ADG by 15.7% and 18.1%. On the other hand, D3 improved the pH of the longissimus thoracis muscle by 1.7% (p = 0.03) without affecting WBSF. When D3 was supplemented in combination with ZH, it was observed that meat quality was improved by reducing muscle pH compared to lambs treated only with ZH. However, D3 did not improve the meat tenderness negatively affected by ZH supplementation.