Carcass Composition Research Articles

Effect of dietary Anabaena supplementation on nutrient utilization, metabolism and oxidative stress response in Catla catla fingerlings

A 60-day feeding trial was conducted to evaluate the effects of dietary Anabaena blue-green algae (ABGA) meal on the growth performance, digestibility, and physio-metabolic responses of Catla catla fingerlings (initial average weight 9.45 ± 0.15 g). Six iso-nitrogenous (30% crude protein) and iso-caloric (378.09 Kcal. digestible energy/100 g) diets were formulated: a control diet (A0, 0% ABGA) and five experimental diets with varying ABGA inclusion levels (A3: 3%, A6: 6%, A9: 9%, A12: 12%, A15: 15%). The results demonstrated that there were no significant differences (P > 0.05) in percentage weight gain (PWG), specific growth rate (SGR), protein efficiency ratio (PER), and feed conversion ratio (FCR) among the experimental groups. Additionally, dietary ABGA did not significantly affect (P > 0.05) body carcass composition among different groups. However, amylase activity significantly decreased (P < 0.05) in the A12 and A15 fed groups, whereas lipase and protease activities remained insignificant (P > 0.05) across all groups. Notably, oxidative stress responses (SOD; superoxide dismutase and CAT; catalase), carbohydrate metabolic enzymes (LDH; lactate dehydrogenase and MDH; malate dehydrogenase), and serum glucose levels increased significantly (P < 0.05) with higher ABGA inclusion. Conversely, serum albumin content significantly decreased (P < 0.05) in the ABGA-fed groups. There were no significant differences (P > 0.05) observed in serum total protein, albumin/globulin (A/G) ratio, aspartate aminotransferase (AST), and alanine aminotransferase (ALT) activities among the experimental groups. Hematological parameters revealed that RBC (red blood cell) count, hemoglobin (Hb) concentration, and packed cell volume (PCV) significantly decreased (P < 0.05), while WBC (white blood cell) count significantly (P < 0.05) increased with higher dietary ABGA inclusion. In conclusion, the inclusion of dietary ABGA up to 15% did not impair nutrient utilization and supported normal growth performance in C. catla fingerlings. However, higher inclusion levels may have a detrimental effect on their growth, nutrient utilization, and physio-metabolic responses.

Accreditation of in-abattoir Dual Energy X-ray Absorptiometry scanning apparatus to predict lamb carcass composition in Australia

Dual Energy X-ray Absorptiometry (DXA) scanners operating at abattoir processing speeds are currently installed in six sheep meat abattoirs around Australia, predicting carcass composition as estimates of computed tomography (CT) determined fat %, lean %, and bone %. This study tested an updated bone-detection algorithm for these DXA scanners. This algorithm improved the precision of prediction for carcass fat% and lean%, but most notably for bone % (R2 = 0.92, RMSE = 0.61 %), compared to the previous algorithm (R2 = 0.51, RMSE = 1.57 %). This was due to improved allocation of bone-containing pixels, resulting from the inclusion of tissue thickness in the bone-detection equation. In a second experiment, the predictions from this new algorithm, along with an automated phantom calibration technique, were assessed relative to their ability to meet the AUS-MEAT accreditation accuracy standards required for predicting CT determined carcass fat%, lean%, and bone%. The DXA met these standards for predicting fat % (range 10.9 % - 37.1 %), lean % (range 49.0 % - 66.2 %), and bone % (range 11.6 % - 25.0 %), across three weight bands of light carcasses (<22 kg), mid-weight carcasses (22-28 kg), and heavy carcasses (>28 kg). This work allowed for the accreditation of DXA, enabling its predictions of carcass composition to be used for trading sheep carcasses in Australia. The accuracy of these predictions far exceed those provided by the historical industry measure of GR tissue depth, and hot carcass weight.

Effects of genotype and sex on carcass composition, meat quality, digestive tract morphometries and leg bone dimensions of spent parent Pekin ducks

The purpose of the present study was to analyze carcass composition, physicochemical properties, muscle texture, and structure, as well as morphometry of the digestive tract and leg bone dimensions of Cherry Valley ducks (SM3 Heavy hybrid) and Orvia ducks (ST5 Heavy hybrid) after laying. A total of 32 ducks were dissected, 8 females and 8 males from each breeding set. Analysis of meat quality (breast muscle, leg muscle) in terms of color (L*, a*, b*), acidity (pH24), electrical conductivity (EC24), and basic chemical composition (protein, water, fat, collagen) was performed. Analysis of the texture and structure of the pectoral muscle was also performed. The dimensions of the various lengths of the digestive tract and the dimensions of the tibia and femur were analyzed. Cherry Valley ducks after laying have better slaughter performance and a higher proportion of breast muscle in the carcass (P < 0.001). Also more favorable chemical composition (protein, fat, water) and physical properties (acidity, electrical conductivity, thermal loss) of muscle. In terms of texture characteristics, the pectoral muscle of Cherry Valley ducks was more elastic and cohesive, but also more flexible with higher viscosity, while the pectoral muscles of Orvia ducks in terms of structure were characterized by smaller values of the analyzed characteristics (cross-sectional area of fibers and smaller vertical and horizontal diameter). Analyzing the morphometry of the digestive system, Orvia ducks were characterized by longer sections of the digestive tract, which certainly has a beneficial effect on the absorption of nutrients. In terms of tibia and femur measurements taken, there were no differences between genotypes, while males were characterized by higher values of the analyzed traits compared to females.

Influence of genotype on carcass composition, metric traits of the digestive system and leg bones of laying hens after the egg-production season

Context The genotype of laying hens is one of the most important factors influencing their carcass composition and anatomical features. Aims The aim of the present study was to compare two genotypes of laying hens, Lohmann Brown and Lohmann White, after the laying period. Methods The experimental material consisted of 26 carcasses obtained after slaughtering spent laying hens at the age of 83 weeks. Key results The genotype of the birds had a significant (P &lt; 0.05) effect on carcass weight, and the proportion (%) of the breast muscle, leg muscle and gizzard weight. Significant correlations were also found between bodyweight and the weight of the stomach, proventriculus, liver and spleen. The origin of the laying hens also had a significant impact on the length of the sections on intestinal segments, namely, jejunum, ileum and colon. Significant differences in the correlations between bodyweight and length of duodenum, jejunum and rectum were also found. The compared hybrids of laying hens differed significantly in the dimensions of the femur and tibia. Lohmann Brown (LB) hens were characterized by higher greatest length, medial length, smallest breadth of the corpus, and greatest breadth of the distal end of the femur compared with Lohmann White (LW) hens. Dimensions of the tibia greatest length, axial length, smallest breadth of the corpus, greatest breadth of the distal end and greatest depth of the distal end in LB hens were also significantly (P &lt; 0.05) higher than those in LW hens. Conclusions The results showed that the genotype of laying hens tested after the laying period influenced carcass weight and muscle percentage, as well as differentiated the birds in terms of dimensions of individual segments of the digestive tract, femur, and tibia bones. Implications The results of this research may be useful for consumers of laying hen carcasses and people interested in poultry anatomy.

Comparative growth, production, carcass characteristics and reproduction performance of Naked Neck, Black Australorp and their crossbred chicken

This study evaluated the phenotypic and genetic parameters of indigenous Naked Neck (NN), exotic Black Australorp (BA), and their crossbred (NNBA) chickens. A total of 270 day-old chicks (30 per group) were raised under identical conditions from day 1 to 48 weeks of age. Growth performance, including body weight, daily and total gain, feed consumption, and feed conversion ratio (FCR), was highest in BA, followed by NNBA, and lowest in NN. Carcass composition also varied significantly, with BA and NNBA having higher dressing percentages (62.98% and 62.68%, respectively) compared to NN (60.60%). BA produced the heaviest eggs (54.0 g), followed by NNBA (50.9 g) and NN (47.93 g). BA also had the best egg quality, hatchability, and FCR (3.15), with NNBA showing intermediate results. NN had the poorest performance in all traits. Age at sexual maturity was earlier in NNBA (161.23 days) compared to NN and BA. The study concluded that NNBA crossbreds outperformed NN in growth, carcass traits, and egg production, indicating their potential for enhancing rural poultry farming.

Intramuscular fat % in the loin of Australian pork demonstrates a stronger relationship with computed tomography lean and fat % than abattoir measures of P2 and lean.

Intramuscular fat (IMF) % is an important measure of pork eating quality, with reduced IMF % linked to the selection of pigs with low backfat P2 thickness and more muscular genotypes over several decades. This experiment tested the association of IMF % from the M. longissimus thoracis et lumborum of 345 pigs at three abattoirs (Sites) with computed tomography (CT) determined carcass composition (% lean or fat), accredited abattoir measures of P2 backfat (mm) (Hennessy Grading Probe, AutoFom III and PorkScan Lite) and the lean % output from abattoir devices (Hennessy Grading Probe, AutoFom III and PorkScan Plus). There was a negative relationship between carcass CT lean % with IMF % at all Sites (P < 0.05), with the strength of this relationship varying between Sites. The strongest relationship was demonstrated at Site 1 (R2 0.30, RMSE 0.59), and across a 4 standard deviation range in the carcass lean % at each Site, resulted in a decrease in loin IMF % of 1.56, 0.44 and 0.80. There was a positive relationship of carcass CT fat % with IMF %, with similar, albeit slightly stronger relationship to IMF than with CT lean %. In contrast, only one of the three Sites with an accredited P2 measurement device demonstrated a significant association (P < 0.05) with IMF %. This is the first time the associations of IMF % with carcass CT composition has been assessed alongside that of P2 backfat measures from commercially deployed abattoir devices. Given P2 backfat is the key industry measure on which carcass value is determined in Australia, this experiment demonstrates the limitations that P2 has in measuring and monitoring the associations of carcass lean and fat % with IMF. Ideally, an independent measure of IMF % would allow for independent selection for lean % and IMF %, however there is currently no commercial device that can measure pork IMF %.

Body weight optimization of broiler breeder hens. 1. Pullet growth, feed efficiency, carcass composition, and sexual maturation

This study aimed to evaluate the effect of early growth (EG) and time of maximum pubertal growth peak (I2) on development, feed efficiency, carcass composition, and sexual maturation of broiler breeder females. Target BW trajectories were designed by changing coefficients of a 3-phase Gompertz model fit to the recommended BW target of Ross 308 breeders, BW=∑i=1i=3giexp(−exp(−bi(t−Ii))). In each phase i, biologically relevant coefficients describe the amount of BW gain (gi), the rate of growth (bi), and the inflection point (Ii), which is the time when the growth rate for that phase is at its maximum rate. The study consisted of a 6 × 2 factorial arrangement, with six I2 levels (I from phase 2) and two EG levels. The I2 coefficients were 15, 17, 19, 21 (standard), 22, and 23 in wk. The EG treatments were: EG0, where g1 and g2 coefficients estimated from the standard from the breeder recommended BW were unchanged; and EG20, where 20% of the gain (g2) in phase 2 (pubertal phase) was shifted to phase 1 (g1; prepubertal phase). Two-hundred-eighty-eight Ross 308 pullets were randomly assigned to the twelve BW growth trajectories and fed using a precision feeding system from 0 to 28 wk of age. Body composition variables were submitted to three-way ANOVA, with EG, I2, and age as fixed sources of variation. Analysis of covariance was conducted on the remaining dependent variables with EG as fixed effect, I2 as a continuous fixed effect, and age as continuous random effect. Differences were reported at P ≤ 0.05. The BW of females followed their target BW, and ADFI differed depending on the amount of feed required to achieve their respective BW targets. Breast fleshing score was 0.2 greater in the EG20 compared to EG0. The number of juvenile primary wing feathers and age at first egg decreased by 0.4 and 0.9 d, respectively, per wk of earlier I2. Advancing I2 resulted in birds with increased carcass fat deposition from 16 to 28 wk of age. Carcass fat was 1.3- to 1.6-fold greater in the EG20 only from 4 to 16 wk of age. Early growth increased mostly pullet muscle and skeletal characteristics whereas advancing I2 advanced sexual maturity and increased carcass fat deposition around sexual maturation time.

Age-related changes in carcass composition, physicochemical properties, texture and microstructure of meat from White King pigeons

ABSTRACT 1. An experiment was conducted to explore the age-related changes in carcass composition, physicochemical properties, texture and microstructure of meat from White King pigeons. The study used 32 carcasses collected from White King pigeons (16 aged 4 weeks and 16 aged 180 weeks). 2. The 180-week-old White King pigeons had a higher percentage of eviscerated carcass characteristics. The 4-week-old pigeons were characterised by higher percentage of skin with subcutaneous fat and carcass remainders. There were significant differences in chemical and physicochemical characteristics as well as in texture and microstructure parameters amongst White King pigeons of different ages. 3. In conclusion, the study demonstrated that the age of White King pigeons has a considerable impact on carcass composition, physicochemical properties, meat texture and microstructure. Older pigeons had higher percentages of eviscerated carcass components, which may reflect maturation, while younger pigeons had greater proportions of fat and carcass remainders. These findings suggest that age-related changes should be considered when evaluating meat quality and composition, as each age group presented distinct characteristics.

Stocking density affects growth, feed utilisation, metabolism, welfare and associated mRNA transcripts in liver and muscle of rainbow trout more pronouncedly than dietary fish meal inclusion level

In aquaculture, stocking density and diet composition are critical factors that influence the performance and welfare of the farmed animal. However, there is limited information on their interactive effects. In this context, applying a 2 × 2 factorial design, we conducted a 12-week feeding trial to evaluate the effect of stocking density (low, LSD: 3.3–15 kg m−3 and high, HSD: 5.8–25 kg m−3; initial-final values) and dietary fish meal content (high, HFM: 30 % and low, LFM: 15 %) on growth, feed utilisation, metabolic oxygen consumption, tissue indices, carcass composition, plasma metabolites, and transcriptional regulation of growth, metabolism and welfare-related biomarker mRNAs in liver and muscle of the juvenile rainbow trout. At the whole-animal level, the HSD group showed significantly higher routine metabolic rate and feed intake indicating higher energy demand; but growth and feed efficiency was lower in HSD than the LSD group. Morpho-anatomically, HSD fish had lower relative gut length and higher intra-peritoneal fat index than LSD fish. Lower plasma free amino acids and glucose levels reiterated high energy expenditure in HSD, and elevated albumin levels indicated potential oxidative stress in the HSD group. Correspondingly, at the transcriptional level, hepatic mRNA levels of antioxidative enzymes (sod, cat, gst, g6pd) and stress-related molecular chaperone hsp90 were up-regulated in HSD; while the transcript abundance of growth-axis markers (ghr, igf1 igf2) and nutrient-sensor mtor were decreased. In muscle, proteolytic pathway components fbx32 and murf1 were upregulated in HSD, and concurrently mtor was also upregulated suggesting higher protein turnover in this group. With respect to the effect of dietary fish meal inclusion levels, LFM showed decrease in growth, hepatic igf2 expression, and lower plasma triglycerides and free amino acid levels than HFM group. However, the sensory appearance of flesh was found to be slightly better in LFM. Significant diet-husbandry interactions were not observed phenotypically, but the mRNA abundance of hepatic markers (ampk1, hsp70, mhc1 and tnfa) linked to energy-sensing, stress and immune response were differentially regulated. Overall, the study shows that high stocking density has a greater degree of impact on fish growth and welfare than reduction in dietary fishmeal inclusion, with limited interactional effects.

Antioxidant and Immunological Properties of Dracocephalum moldavica Extract in Penaeus vannamei

Objectives: The effects of different concentrations of Dracocephalum moldavica extract (DME) supplement on growth, survival, antioxidants, some biochemical parameters and innate immunity of White leg shrimp (Penaeus vannamei) juveniles investigated. Methods: For 56 days, shrimp (4.5-5 g) received diets that were enhanced with 0 (control), 50, 100, 200 mg DME/kg feed to attain apparent satiety. Results: The results revealed that feeding shrimp with DME significantly improved Feed efficiency and Feed conversion ratio with an optimum level of 200 mg/kg diet. Dietary DME supplementation had no significant effects on their carcass composition. Total albumin and protein higher (P &gt; 0.05) in DME-fed particularly at 200 mg/kg treatment On the other hand, shrimp fed 200 mg DME/kg feed experienced significant decreases in aspartate and alanine aminotransferase levels. As dietary extract levels increased, there was a significant (P &lt; 0.05) increase in SOD and CAT activities, as well as LYZ and PO levels, so that treatments with 100 and 200 mg DME/kg feed had the highest values, and Significant (P &lt; 0.05) reductions in MDA and NO levels were observed at high dietary extract levels of 100 and 200 mg DME/kg. Conclusion: P. vannamei's growth, antioxidant capacity and innate immunity were boosted by diets that contained 200 mg DME/kg feed.

Effects on the productivity, haematological indices, and carcass quality of Nile tilapia reared at different stocking densities in a hybrid biofloc-RAS

The performance at varied over-stocking of Oreochromis niloticus was evaluated in a hybrid biofloc-recirculating aquaculture system (HBR) viz., 150 fish/m3 (HBR-SD150), 200 fish/m3 (HBR-SD200), 250 fish/m3 (HBR- SD250), and 300 fish/m3 (HBR- SD300) along with 150 fish/m3 (BFT-SD150) and 150 fish/m3 (RAS-SD150) each maintained in triplicate. Tapioca flour was used to maintain the carbon to nitrogen ratio of 15:1 within the HBR and BFT units throughout the experimental period of 120 days. At the conclusion of the experiment, assessments were made of productivity, biological and haematological indices; and proximate composition of the fish and the floc. Evern though significantly higher productivity was observed in HBR-SD200, a quadratic regression model applied to the productivity as a function of stocking density {Stocking density (fish/m3) = −21.008 × 2 + 532.15× - 3090.2, R2 = 0.6929} and the optimum productivity for O. niloticus (Nile tilapia) found to be 13.2 Kg/m3 at 229.89 fish/m3. Notably, HBR-SD150 groups exhibited significantly higher levels of haematological indices including NBT. The Proximate composition of the floc revealed that a significantly higher quantity of protein and ash was found in HBR-SD150 and HBR-SD300, respectively. There was no significant difference in carcass composition of Nile tilapia across the treatments except for that of crude protein levels. Profitability analysis demonstrated that low stocking density groups achieved greater profits than high stocking density HBR and control. The findings of present study indicate that the maximum production that can be accomplished from the HBR culture system is 13.2 Kg/m3 at a density of 229.89 fish/m3 without affecting the growth, immunity, and survival of Nile tilapia.

Combined genomic evaluation of Merino and Dohne Merino Australian sheep populations.

The Dohne Merino sheep was introduced to Australia from South Africa in the 1990s. It was primarily used in crosses with the Merino breed sheep to improve on attributes such as reproduction and carcass composition. Since then, this breed has continued to expand in Australia but the number of genotyped and phenotyped purebred individuals remains low, calling into question the accuracy of genomic selection. The Australian Merino, on the other hand, has a substantial reference population in a separate genomic evaluation (MERINOSELECT). Combining these resources could fast track the impact of genomic selection on the smaller breed, but the efficacy of this needs to be investigated. This study was based on a dataset of 53,663 genotypes and more than 2 million phenotypes. Its main objectives were (1) to characterize the genetic structure of Merino and Dohne Merino breeds, (2) to investigate the utility of combining their evaluations in terms of quality of predictions, and (3) to compare several methods of genetic grouping. We used the 'LR-method' (Linear Regression) for these assessments. We found very low Fst values (below 0.048) between the different Merino lines and Dohne breed considered in our study, indicating very low genetic differentiation. Principal component analysis revealed three distinct groups, identified as purebred Merino, purebred Dohne, and crossbred animals. Considering the whole population in the reference led to the best quality of predictions and the largest increase in accuracy (from 'LR-method') from pedigree to genomic-based evaluations: 0.18, 0.14 and 0.16 for yearling fibre diameter (YFD), yearling greasy fleece weight (YGFW) and yearling liveweight (YWT), respectively. Combined genomic evaluations showed higher accuracies than the evaluation based on the Dohne reference only (accuracies increased by 0.16, 0.06 and 0.07 for YFD, YGFW, and YWT, respectively). For the combined genomic evaluations, metafounder models were more accurate than Unknown Parent Groups models (accuracies increased by 0.04, 0.04 and 0.06 for YFD, YGFW and YWT, respectively). We found promising results for the future transition of the Dohne breed from pedigree to genomic selection. A combined genomic evaluation, with the MERINOSELECT evaluation in addition to using metafounders, is expected to enhance the quality of genomic predictions for the Dohne Merino breed.

Effect of Azolla meal-based diet on growth performance, haematological profile and proximate composition of common carp (Cyprinus carpio) fry

Optimising the cost of nutrients in fish diets is crucial for aquaculture production, as feed accounts for 50% of operational expenses in intensive aquaculture. The rising demand for mustard oil cake (MOC), a commonly used feed ingredient in Indian aquaculture, has led to a significant increase in its price due to its diverse applications. Azolla (Azolla pinnata), a free-floating freshwater plant, has attracted researchers in fish feed formulation due to its rich nutrient profile. The present study was conducted to evaluate the effects of replacement of MOC with Azolla meal in the diet of common carp (Cyprinus carpio) fry. Pelleted feed was formulated with Azolla meal replacing MOC at levels of 0, 10, 20, 30 and 40% and fed to fish. Growth performance, feed conversion ratio (FCR), haematological parameters and proximate composition in fish carcass were assessed after 90 days of experimental feeding. Simultaneously, a control feed without supplementing of Azolla meal was also prepared. Fish were fed daily with the experimental diets at 8, 6 and 4% of their body weight during the first, second and third months respectively, in the morning hours (10:00 hrs). Principal component analysis (PCA) was performed to assess the effect of formulated diets on fish carcasses composition and haematological parameters. The results showed that replacing 30% of MOC with Azolla meal in the diet, led to significantly (p≤0.05) higher specific growth rate (SGR) and percentage weight gain and significantly (p≤0.05) lower feed conversion ratio (FCR) at this concentration. Fish survival rate ranged from 80.00 to 93.33% among different treatments. Further, significant (p≤0.05) differences were observed in both haematological parameters of fish and the proximate composition of fish carcass. among the different treatments. These findings suggest that MOC can be effectively replaced with 30% Azolla meal in the diet for rearing common carp fry to fingerling stage, without compromising the growth performance. Keywords: Aquaculture, Feed conversion ratio, Health status, Mustard oil cake, Principal component analysis, Specific growth rate, Survival

Ameliorating effects of natural herbal supplements against water-borne induced toxicity of heavy metals on Nile tilapia, (Oreochromis niloticus)

The efficacy of herbal supplements in mitigating heavy metals (HMs) toxicity was investigated using a widely grown fish, the Nile tilapia (Oreochromis niloticus). The experiment was conducted over two phases: during the stress phase, the experimental fishes were exposed to sub-lethal concentrations of HMs, including lead, cadmium, zinc, and copper for 15 days; following which during the feeding phase, herbal supplements were given for 70 days to ameliorate their effects. Seven groups were established: the control negative group (CON−ve), control positive group (CON+ve, without any treatment), and five groups with supplementation of 1% turmeric (TUR), cinnamon (CIN), ginger (GIN), garlic (GAR), and their mixture (MIX), respectively. A total of 315 fishes were distributed evenly in experimental tanks (15 fishes per tank, in triplicates). The results revealed that exposure to HMs led to significant (p < 0.05) alterations in all the tested parameters, i.e., liver damage and growth reduction. The herbal supplements, especially the MIX groups, ameliorated the harmful effects of HMs and restored fish growth, digestibility, carcass composition, and liver health. In conclusion, the study demonstrated that the herbal supplements were effective in reducing the HMs-linked toxicity in Nile tilapia. Future studies pertaining to the mechanisms facilitated by the various herbal bioactive substances-linked tolerance to HMs in fishes are warranted.

Assessing the Effects of Phytogenic Feed Additives on Broilers during a Necrotic Enteritis Challenge

Subclinical necrotic enteritis (NE) is an enteric disease that inflicts significant economic losses in the poultry industry, primarily by reducing performance in commercial flocks but without significant mortality. This study evaluated the effects of a variety of phytogenic blends on broilers’ performance and carcass composition during an induced NE challenge. In this study, 1120 day (d)-old male broilers were allocated to four treatments groups (14 replicate floor pens, 20 birds/pen): the control (CONT) group, fed a basal corn-soybean diet, and three phytogenic blend dietary additives (PHYTO1, PHYTO2, and PHYTO3) added to the basal diet at 150, 250, and 500 mg/kg feed, respectively. Subclinical NE was induced by spraying a concentrated coccidiosis vaccine onto the feed and litter 24 h post-placement. On day 8, two birds/pen were necropsied for NE lesions. On days 8, 14, 28, and 42, the average daily gain (ADG), feed intake (ADFI), and feed conversion ratio (FCR) were calculated. On day 42, two birds/pen were euthanized to assess carcass composition using dual-energy X-ray absorptiometry (DXA). Statistical analyses for all data were performed using the ANOVA procedure (JMP, Pro 16) and significance (p ≤ 0.05) between treatments was determined by the LSD test. There was no effect of treatment on NE lesions. PHYTO1, PHYTO2, and PHYTO3 significantly improved FCR from days 9 to 14, 0 to 14, and 0 to 42 and resulted in greater ADG from days 9 to 14, 29 to 42 and cumulatively on days 0 to 42. Carcass composition data revealed a numerically higher lean-to-fat ratio in the PHYTO groups compared to the CONT group. These results indicate that the dietary supplementation of phytogenic blends could alleviate the adverse effects of NE challenge on broilers’ performance and carcass composition.

A review of porcine skeletal muscle plasticity and implications for genetic improvement of carcass and meat quality*

Skeletal muscle is characterized by a remarkable plasticity to adapt to stimuli such as contractile activity, loading conditions, substrate supply or environmental factors. The existing knowledge of muscle plasticity along with developed genetic and genomic technologies, have enabled creating animal breeding strategies and allowed for implementing agriculturally successful porcine genetic improvement programs. The primary focus of this review paper is on pig skeletal muscle plasticity as it relates to genetic improvement of desirable carcass composition and pork quality traits. Biological constraints between practically realized breeding objectives, pig skeletal muscle biology, and pork quality are also discussed. Future applications of genetic and genomic technologies and plausible focus on new breeding objectives enhancing pork production sustainability are proposed as well.

Research Note: The infectious bursal disease (Gumboro disease) vaccination scheme affects the quantitative and qualitative carcass characteristics and the immune response of Ross 308 broiler chickens

After different vaccinations, the study aimed to assess carcass composition, meat quality, and the level of the infectious bursal disease antibody titers in broiler chickens. In the experiment, 4 (30 chicks per group, 120 total) groups of Ross 308 broiler chickens (males and females) were included. Then, they were vaccinated at the hatchery. Group I was immunized against infectious avian bronchitis (IB) and Newcastle disease (ND) using vaccine A (20 mL/100 birds) and vaccine B (20 mL/100 birds), respectively, with injectable vaccine C (0.2 mL/each) targeting Infectious bursal' and Marek's diseases (MD). Group II received the same vaccinations for IB and ND, with separate injectable D vaccines for MD (0.2 mL/unit) and E for infectious bursal' disease (0.2 mL/each). Group III was similarly vaccinated for IB and ND; however, they received only vaccine D (0.2 mL/each) for MD, and on d 23, vaccine F was administered via drinking water against Gumboro disease (0.05 mL/each). Group IV served as the control and was not vaccinated. Ten carcasses from each group on d 42 were taken for carcass composition analysis and meat quality, including pH, color, and water-holding capacity (WHC). During rearing, on d 14, 28, and 42, blood was collected to determine the level of antibodies against infectious bursal' disease. Additionally, hematocrit (HCT), hemoglobin (HGB), and red blood cells were analyzed. In group I, a higher bursa of Fabricius weight than in the other groups was found (P < 0.001), and the liver weight was lower compared to group II (P = 0.020). In breast muscle, the pH24 was higher in the control group than in group I (P = 0.036). Lightness (L*) in breast and leg muscles from group I was higher than in group II (P < 0.05). WHC was higher in group I than in group II (P = 0.025). The antibody titers of infectious bursal' disease was higher in group I on d 28 than in other groups (P < 0.05). Vaccine C (1 dose 0.2 mL/1 bird) of the reconstituted vaccine with the live recombinant virus strain vHVT013-69, not less than 3.6 - 5.0 log10 PFU) had a beneficial effect.

PSLBI-21 Interactive effects of dietary betaine supplementation and soybean hulls inclusion on growth performance and carcass composition of young growing pigs

Abstract Growing barrow pigs [n = 24; Large White x Landrace x Duroc; 29.51 ± 3.24 kg initial body weight (BW)] were assigned to 4 treatments in a 2 x 2 factorial design to evaluate the synergistic effects of dietary levels of betaine (BET; 0 and 0.1%) and soybean hulls (SBH; 0 and 15%) on growth performance and carcass composition. Pigs were blocked by initial BW and housed in individual pens with ad libitum access to feed and water for a 28-d feeding period. Pigs were weighed and feed intake was recorded at 14-d intervals. Real-time ultrasonic (RTU) measurements of the 10th-rib longissimus dorsi muscle area (LMA) and off-midline backfat thickness (BF) were obtained initially and on d 28 for all pigs. Prediction equations were used to estimate total fat tissue (TOFAT) and fat-free total lean (FFTOLN) from the measurements. All data were analyzed using the MIXED procedure of the SAS software. Growth performance data were analyzed as repeated measures on time and carcass data were analyzed as single measures with the respective baseline values used as covariate in the statistical model. There were no SBH x BET interactions for growth response variables. Pig growth was not affected by dietary BET supplementation. During the first 14 d of the study, pigs fed 15% SBH had decreased average daily gain (ADG; P = 0.01), average daily feed intake (ADFI; P = 0.02), and feed efficiency [gain:fee; (G:F;P = 0.04)] when compared with pigs fed diets without SBH. From d 15 to 28, dietary addition of 15% SBH reduced ADFI (P = 0.01), whereas no significant effects on the other growth performance variables were observed. Overall, when compared with pigs fed diets without SBH, pigs fed diets with 15% SBH had reduced feed intake (P = 0.01) and ADG (P = 0.04), which resulted in lighter pigs (P = 0.03) at the completion of the feeding trial. A SBH x BET interaction (P = 0.04) was observed for LMA, with decreased values (P &amp;lt; 0.05) detected for BET-supplemented pigs only when SBH was not included in the diet. No additional carcass composition traits were altered by BET supplementation. Including 15% SBH to the diet decreased BF (P = 0.05) and TOFAT (P = 0.04) in growing pigs. Neither BET supplementation nor SBH inclusion affected FFTOLN. In conclusion, adding supplemental BET to diets with SBH did not synergistically alter nutrient partitioning of young growing pigs. Although no beneficial effects of BET supplementation on growth and carcass composition traits were observed, feeding pigs diets containing 15% SBH resulted in slower growth rates with less fat deposition.

DIFFERENCES IN CARCASS COMPOSITION OF MALE, CASTRATED, AND IMMUNOCASTRATED PIGS: A narrative literature review

The quality of pork is dependent on factors of retail and consumer interest, including appearance, shelf life, as well as tenderness and flavor. One of the factors determining the quality of the animal concerns its castration. Castration of pigs is a procedure carried out to control the odor of the meat and to guarantee the complete quality of the animal for consumption. Therefore, understanding its effects on pig production is essential to have a quality animal and increasingly higher production levels. In this sense, the general objective of this study is to carry out an analysis of the differences in the composition of the pig carcass: male, castrated and immunocastrated through a bibliographical review. The specific objectives were to elucidate the carcass characteristics of male, castrated and immunocastrated pigs and verify the impact of castration on the quality of the animal carcass. Through this study it was possible to conclude that immunocastrated pigs stand out in terms of carcass yield compared to surgically castrated males and intact males, due to the sexual odor, the quality of the meat, the thickness of the bacon and in its entirety.

43 Approaches for improving nitrogen utilization efficiency and environmental sustainability of pork production systems

Abstract Nitrogen (N) is an essential element for life, but due to its inefficient utilization, N waste and emissions generated have exceeded the planetary boundaries and ability of the Earth to effectively overcome these environmentally detrimental effects. Global food animal production contributes 29 to 34% of total global N emissions, with pork supply chains contributing about 16% of these emissions. Life cycle N use efficiency (NUE) of U.S. pork production is only about 56%, which is similar to broiler (55%) and egg (50%) production, but greater than beef (10%) and milk (31%) production. However, only about 10 to 44% of dietary N is converted into edible pork products. While genetic improvement has increased NUE associated with improved lean growth rate, improvement in litter size has led to an increased proportion of low-birth-weight pigs that have reduced NUE. Although metabolic modifiers including porcine somatotropin, ractopamine, and immunocastration improve NUE, they are not feasible or acceptable to consumers in many countries. Separate sex feeding and reducing market weight can also improve NUE. Ultimately feeding program design and implementation have the greatest potential to improve NUE because feed is associated with 70% of N emissions in pork production systems. Multi-objective feed formulation using Life Cycle Assessment environmental impact data of feed ingredients, precision feed formulation and feeding practices to overcome variability in digestible nutrient content of feed ingredients and nutritional requirements of pigs fed in groups, feed processing to enhance energy and nutrient digestibility, and minimizing feed wastage offer the greatest opportunity to improve NUE and environmental sustainability. There are substantial differences in greenhouse gas emissions and embedded water and land use associated with growing-finishing feeding programs depending on the dietary proportions of corn, soybean meal, distillers dried grains with solubles (DDGS), and crystalline amino acids among U.S. geographic regions. Furthermore, addition of thermally processed supermarket food waste to corn-soybean meal (CSBM) diets can significantly reduce environmental impacts and diet cost without compromising growth performance and carcass composition compared with current commercial feeding programs. Although growing-finishing feeding programs using CSBM diets with minimal crystalline amino acids result in greater N intake, N retained, and urinary N excretion compared with feeding low protein, crystalline amino acid supplemented (LP) diets, and diets containing 30% DDGS, growth performance and carcass composition are optimized and impacts on climate change, marine and freshwater eutrophication, and fossil resource are reduced by feeding CSBM diets compared with feeding LP or DDGS diets. Sourcing and using feed ingredients with reduced environmental impact metrics along with precision diet formulation and feeding practices to ensure “getting the right amount of energy and nutrients in the right feed fed to the right pigs at the right time” can improve NUE and environmental sustainability of pork production systems.