Meat Weight Research Articles

Physical and Chemical Properties of Meat in Relation to Wooden Breast Myopathies in Male Broiler Chickens Raised in Evaporative Cooling Systems

Background: There are few scientific reports of the occurrence of wooden breast (WB) in Thailand. This study aimed to evaluate the incidence and effect of WB on the physical and chemical properties of meat from chickens reared under an evaporative cooling system (EVAP). Methods: A total 124 broiler chickens (BW = 2721.27±273.40 g) were selected from a group of 588 male broiler chickens (at 36 days of age). The WB meat (left site) score of each chicken was identified as being normal, moderate or severe. In order to compare the effect of the WB score on meat quality, based on the number of chickens in the normal group, the number of chickens in the moderate and severe groups were equalised (19 birds/group). The effects of the WB score on pH, colour, drip loss, thawing loss and cooking loss of the meat were observed. Result: The body weight of normal meat, moderate WB and severe WB was 2525.26±221.49, 2683.53±273.17 and 2883.78±211.90 g, respectively. The severe WB score occurred when the body weight (g) was heavier than the normal meat group for 14.19% (P less than 0.01). At 24 hours, the pH, drip loss, cooking loss and water content of the severe WB group was significantly higher, while the protein content in the severe WB group was lower than the normal meat group (P less than 0.01). Moreover, the severe WB group presented higher lightness, redness and yellowness values compared to the normal meat group (P less than 0.01). In conclusion, a larger body of broiler chickens, greater than 14% of the strain’s recommendation induced a severe WB score, which caused poor meat quality.

Detection of genetic variation in bovine CRY1 gene and its associations with carcass traits

The biological clock (also known as circadian clock) is closely related to growth and development, metabolism, and diseases in animals. As a part of the circadian clock, the cryptochrome circadian regulator 1 (CRY1) gene is involved in the regulation of biological processes such as osteogenesis, energy metabolism and cell proliferation, however, few studies have been reported on the relationship between this gene and animal carcass traits. Herein, a total of four insertion/deletion (InDel) loci within the CRY1 gene were detected in Shandong Black Cattle Genetic Resource (SDBCGR) population (n = 433). Among them, the P1-6-bp-del locus was polymorphic in population of interest. Moreover, the P1-6-bp-del locus showed two genotypes, with a higher insertion/insertion (II) genotype frequency (0.751) than insertion/deletion (ID) genotype frequency (0.249). Correlation analysis showed that the P1-6-bp-del locus polymorphisms were significantly associated with twenty carcass traits (e.g., slaughter weight, limb weight, and belly meat weight). Individuals with II genotype were significantly better than those with ID genotype for eighteen carcass traits. Therefore, the P1-6-bp-del locus of the CRY1 gene can be used as a molecular marker for beef cattle breeding.

Can Bioelectrical Impedance Analysis (BIA) Be Used to Predict Pig’s Meat Quality In Vivo?

The aim of the current study was to evaluate the possibility of application of bioelectrical impedance analysis (BIA) in order to estimate pork quality. The BIA measurements were tested on 18 living animals for the prediction of the meat quality. The absolute resultant electrical resistance (Rz) and reactance (Xc) of the body was measured with a set of disposable surface electrodes at the frequency of 50 kHz and the current intensity of 400 µA. The characteristics of meat quality, pH measured 1 h and 24 h after slaughter, meat color parameters represented in CIE L*a*b* system, glycolytic potential, intramuscular fat, and natural drip loss, were assessed on the samples of the Longissimus dorsi (LD) muscle. The slaughter value of pigs was characterized on the basis of hot carcass weight (HCW) and percent of meat in carcass. The results showed a significant Pearson correlation between bioelectrical impedance parameter Rz and pH1 (r = 0.48*, p < 0.05). A significant Spearman correlation was showed between color b* value and the Rz/Xc/HCW ratio (r = −0.62*, p < 0.05) and Xc (r = −0.51*, p < 0.05), as well as between the Rz/Xc ratio with pH1 (r = 0.48*, p < 0.05). The multivariate statistical method (principal component analysis and cluster analysis) showed that bioimpedance measurements combined with meat quality traits make it possible to distinguish groups with different quality parameters. However, the relationships between them are complex and still require analysis.

Heat-Treated Meat Origin Tracing and Authenticity through a Practical Multiplex Polymerase Chain Reaction Approach.

Meat adulteration have become a global issue, which has increasingly raised concerns due to not only economic losses and religious issues, but also public safety and its negative effects on human health. Using optimal primers for seven target species, a multiplex PCR method was developed for the molecular authentication of camel, cattle, dog, pig, chicken, sheep and duck in one tube reaction. Species-specific amplification from the premixed total DNA of seven species was corroborated by DNA sequencing. The limit of detection (LOD) is as low as 0.025 ng DNA for the simultaneous identification of seven species in both raw and heat-processed meat or target meat: as little as 0.1% (w/w) of the total meat weight. This method is strongly reproducible even while exposed to intensively heat-processed meat and meat mixtures, which renders it able to trace meat origins in real-world foodstuffs based on the authenticity assessment of commercial meat samples. Therefore, this method is a powerful tool for the inspection of meat adulterants and has broad application prospects.

Mining of chicken muscle growth genes and the function of important candidate gene RPL3L in muscle development

The birth weight of chickens does not significantly affect the weight at slaughter, while the different growth rate after birth was one of the important reasons for the difference in slaughter weight. Also, the increase in chickens' postnatal skeletal muscle weight is the main cause of the slaughter weight gain, but which genes are involved in this biological process is still unclear. In this study, by integrating four transcriptome datasets containing chicken muscles at different developmental times or different chicken tissues in public databases, a total of nine candidate genes that may be related to postnatal muscle development in chickens were obtained, including RPL3L, FBP2, ASB4, ASB15, CKMT2, PGAM1, YIPF7, PFKM, and LDHA. One of these candidate genes is RPL3L, whose 42bp insertion/deletion (indel) mutation significantly correlated with multiple carcass traits in the F2 resource population from Xinghua chickens crossing with White Recessive Rock (WRR) chickens, including live weight, carcass weight, half eviscerated weight, eviscerated weight, breast meat weight, wing weight, leg muscle shear force, and breast muscle shear force. Also, there was a very significant difference between different genotypes of the RPL3L 42bp indel mutation in these trains. Further experiments showed that RPL3L was highly expressed in chicken skeletal muscle, and its overexpression could promote the proliferation and inhibit the differentiation of chicken myoblasts by regulating ASB4 and ASB15 expression. Our findings demonstrated that the RPL3L 42bp indel may be one of the molecular markers of chicken weight-related traits.

Characteristics of Beef Rendang with the Addition of Red Ginger (Zingiber officinale var. Rubrum) During Storage at Room Temperature

The addition of red ginger in the making of rendang was expected to increase antioxidants to prevent rancidity and increase the shelf life of rendang. This study aimed to analyze the physicochemical, organoleptic and antioxidant activity of beef rendang with the addition of red ginger at different levels based weight of meat (0%, 15%, and 30%). The tested rendang was stored in a tightly closed jar and left at room temperature. The results showed that the interaction of the addition of red ginger and storage period had a significant effect (p<0.05) on the pH value, water activity, moisture, protein content, TBARS value, and antioxidant activity, but has no significant effect on ash content, fat content, and tenderness. Ash and fat content as well as tenderness of beef rendang added red ginger were not different from beef rendang not added red ginger (control). Based on sensory test the addition of red ginger did not affect the preference of the panelists. The addition of red ginger to the manufacture of beef rendang has a positive effect on physicochemical characteristics and increases antioxidant activity. Generally, red ginger addition as much as 30% resulted the best result.

Meat yield and meat quality characteristics of indigenous, Hilly♂×Sonali♀ crossbred and commercial broiler chicken of similar weight at different storage time

The experiment was conducted to investigate meat yield and quality characteristics of indigenous, crossbred Hilly♂ × Sonali♀ and commercial broiler chickens at similar live weight. For this purpose male and female indigenous chickens were purchased from local market, while Hilly♂ × Sonali♀ crossbred was reared up to 12 weeks at Bangladesh Agricultural University (BAU) poultry farm. Sexed male and female of Ross 308 broiler chicks were also reared BAU poultry farm up to 30 days. Six male and six female chickens from each of indigenous, Hilly♂  Sonali♀ and commercial broiler were slaughtered, eviscerated and dissected to compare meat yield and meat quality characteristics during 0, 15 and 30 days of storage period at 1000 g (±50 g) body weight. The eviscerated and defeathered carcasses were stored at -18°C for 0, 15 and 30 days .Considering Indigenous, Hilly♂ ×Sonali ♀ and Broiler chickens of both sexes, shank, neck, carcass yield, dressed weight, breast meat weight were significantly (p<0.05) higher in commercial broiler while wing meat and thigh meat were higher in Hilly♂ × Sonali♀ chicken. The dry matter, crude protein were significantly higher in indigenous chicken while cooking loss, ether extract, ash, peroxide value, free fatty acid value and thiobarbituric acid value were found significantly higher in commercial broiler during different storage time in both sexes. The meat yield parameters did not differ significantly among three storage time. However, cooking loss, pH and crude protein decreased, while dry matter, ether extract, ash, peroxide vale, free fatty acid value, thiobarbituric acid value, increased with the increasing of storage time.

Penambahan Tepung Kulit Pisang Terfermentasi Dalam Ransum Terhadap Komposisi Karkas Ayam Kampung

This study aims to determine the effect of adding fermented banana peel flour in the ration to the physical composition of native chicken carcasses. Design used in this study was a Completely Randomized Design (CRD) consisting of 5 treatments and 3 replications, while. The treatments were R0 (Native Chicken that was not given fermented banana peel flour), R1 (Native chicken fed a ration containing 2.5% of fermented banana peel flour), R2 ( Native Chicken fed a ration containing 5% fermented banana peel flour) R3 (Native chickens were given a ration containing 7.5% fermented banana peel flour) and R4 (Native chickens were given a 10% fermented banana peel flour). Ration fermented banana peel flour had a significant effect (P<0.05) on meat weight, skin and subcutaneous fat on the thigh chart, while the effect was not significant (P>0.05) on the weight of meat, bone, skin and subcutaneous fat of the chest and thigh bones

Effects of the dietary zinc source and vitamin E level on live weight and carcass yield and meat quality in male broilers reared under chronic cyclic heat stress conditions in the finisher phase.

The objective of this study was to evaluate the effect of the interaction of the zinc source (ZnSO4 vs. zinc amino acid complex) and vitamin E level (50 IU/kg vs. 100 IU/kg) on meat yield and quality in broilers subjected to chronic cyclic heat stress in the finisher phase. A total of 1224 one-day-old male Ross 308 broilers were randomly distributed among four dietary treatments. Each treatment contained nine replicates of 34 birds, housed in floor pens in a temperature- and lighting-controlled room. Treatments were organized in a 2 × 2 factorial arrangement: two sources of zinc, 60 mg/kg of Zn as ZnSO4 or 60 mg/kg of Zn as zinc amino acid complexes (ZnAA), combined with two levels of vitamin E (50 or 100 IU/kg). From day 28 until day 37 (finisher phase), all birds were subjected to chronic cyclic heat stress (32 ± 2°C for 6 h daily). In the present study, it was observed that replacing ZnSO4 with ZnAA increased breast meat weight and yield of broilers reared under chronic cyclic heat stress conditions, whereas total slaughter yield was not affected. Moreover, it was observed that replacing ZnSO4 with ZnAA resulted in breast meat with a lower drip and thawing loss and a higher marinade uptake. In conclusion, replacing ZnSO4 with more readily available ZnAA can improve breast meat yield and increase the water-holding capacity of breast meat of broilers exposed to chronic cyclic heat stress at the end of the production cycle. However, as no thermoneutral group was included in the present study, the observed effects of the zinc source cannot be generalized as a solution for heat stress. Moreover, the beneficial effects of ZnAA on breast meat yield and quality seem to be independent of the vitamin E level, and increasing vitamin E level has no additional beneficial effects.

Identification of quantitative trait loci for growth-related traits in the blood clam (Tegillarca granosa)

The blood clam (Tegillarca granosa) is an economically important marine shellfish in the southeast coastal area of China. In T. granosa breeding practice, growth-related traits are most important phenotypic selection index. In order to increase the breeding efficiency, we used a previously published genetic linkage map of T. granosa to map quantitative trait loci (QTL) for growth-related traits in a single full sibling F1 family. Eight growth-related traits including shell length (SL), shell height (SH), shell width (SW), shell weight (Swi), shell umbo width (SUW), as well as outer ligament length (OLL), meat weight (MW) and total weight (TW) of T. granosa were measured for QTL mapping. The estimated phenotypic correlations between any 2 of the 8 growth-related traits were significant (P < 0.001). Twenty-nine QTL were identified for growth-related traits, including 13 QTL with the phenotypic variance of 4.20–15.63% in the female map and 16 QTL of 3.99%–14.58% in the male map. Thirteen amplification fragment length polymorphism (AFLP) markers were validated to closely link to seven QTL except the shell height. This is the first report of QTL mapping on growth-related traits in T. granosa. These QTL and their tightly linked markers present the initial step towards the goal of marker-assisted selection in T. granosa.

PSXIII-B-10 Effects of Termite (Hodotermopsis Sjostedti) Meal Supplement in Broiler Chicken Diets on Growth and Intake

Abstract Effects of partial replacement of fishmeal with termite (Hodotermopsis sjostedti) meal in chicken diets on BW, ADG, intake, and organ and meat weight were tested with Chunky broiler female chickens in two experiments. In Exp.1, 20 chickens (8 d of age and 239 ± 3.0 g BW initially) were allocated in individual pens and assigned one of the four diet treatments; commercial diet with fishmeal supplement (0.0%) and replacement of fishmeal with freeze-dried ground termite meal of 0.5%, 2.5%, and 5.0%. In Exp.2, 18 chickens (9 d of age and 309 ± 3.8 g BW initially) were assigned one of the three diet treatments; commercial diet (COM), 2.5% fishmeal supplement (FM), and 2.5% termite meal supplement (TM). At 21 d old, chickens were slaughtered, and meat and organ weight were measured. Treatment diet CP concentrations resulted in 29.7 and 27.9% DM for Exp.1 and Exp.2, respectively. There was no treatment effect (P&amp;gt;0.05) on BW, ADG, intake, feed conversion rate, meat (i.e., thigh, breast fillet, and inner breast fillet) weights, or organ (i.e., liver, heart, spleen, gizzard, proventriculus, and intestine) weight in both experiments. In Exp.1, empty cecum weight was greater (P=0.03) when termite meal was not included (0.37, 0.33, 0.31, and 0.31 % per shrunk BW for 0.0%, 0.5%, 2.5%, and 5.0%, respectively; SE=0.022). Similarly, whole cecum weight (0.38, 0.54, and 0.40 % per shrunk BW for COM, FM, and TM, respectively; SE=0.043) and cecum fill (0.08, 0.21, and 0.09 % per shrunk BW for COM, FM, and TM, respectively; SE=0.037) were greater (P=0.05) for FM than COM and TM in Exp.2. In conclusion, termite meal supplements did not have either favorable or adverse effects on the growth or weight of meat and organs except cecum weight. Further investigation is needed for cecum function and meat quality.

Detection and characterization of meat adulteration in various types of meat products by using a high-efficiency multiplex polymerase chain reaction technique.

Identification of meat authenticity is a matter of increasing concerns due to religious, economical, legal, and public health reasons. However, little is known about the inspection of eight meat species in one tube reaction due to technological challenge of multiplex polymerase chain reaction (PCR) techniques. Here, a developed multiplex PCR method can simultaneously authenticate eight meat species including ostrich (753 bp), cat (564 bp), goose (391 bp), duck (347 bp), chicken (268 bp), horse (227 bp), dog (190 bp), and sheep (131 bp). The detectable deoxyribonucleic acid (DNA) contents for each target species was as low as 0.01 ng in both raw and heat-treated meat or target meat down to 0.1% (w/w) of total meat weight reflecting high stability of the assay in heat processing condition, indicating that this method is adequate for tracing meat origin in real-world meat products, which has been further validated by authenticity assays of commercial meat products. Overall, this method is a powerful tool for accurate evaluation of meat origin with a good application foreground.

The Effect of Different Natural Antioxidants on Meat Quality of Broiler Chickens

An experiment was conducted to assess the effect of natural antioxidants (black pepper, green tea, roselle and their combinations) on meat quality of broiler chickens. A total of 270 1 - day old Arbor Acre broiler chicks were randomly distributed into nine treatments of three replicates each (10 birds in each replicate) in a 2 x 5 factorial arrangement for 2 inclusion levels (0.5g and 1.0g per kg of feed) of natural antioxidants (Control (CT), Green tea (GT), Roselle (RS), Black pepper (BP) and combination (CM) of the 3 antioxidants). At the end of the feeding trial (at 8 weeks), nine birds per treatment were immobilized, slaughtered, dressed, weighed and cut into primal cuts. The growth (initial and final body weight gain, average daily feed intake and weight gain, and feed conversion) and blood assay (haematology and serum biochemistry) of the birds were monitored while the breast and thigh meat cuts were subjected to physico-chemical and sensory analysis. The result indicated that, among examined natural antioxidants, BP improved the bird’s live weight. High Density Lipoprotein value was highest (p&lt;0.05) in control and closely followed by birds on GT, CM, BP and RS. The lowest blood (p&lt;0.05) cholesterol was recorded in RS which was closely followed by GT and CM. Carcass evaluation showed that birds fed BP had better (p&lt;0.05) live weight (2.05kg) and highest acceptability (p&lt;0.05) for organoleptic properties. The breast meat weight was also highest (p&lt;0.05) in BP. It was concluded that the natural antioxidants increased live weight, improved performance and reduced abdominal fat. RS reduced blood cholesterol while RS, CM (GT + RS + BP) inclusion improved serum total protein of broiler chickens. Inclusion of natural antioxidant in the diets of broiler is hereby advocated for achieving optimum broilers performance and meat quality.

Evolution of Sensory Properties of Beef during Long Dry Ageing.

Ageing is an essential step in obtaining meat with satisfactory sensory properties. Dry-ageing, although being a niche practice, is increasingly being developed to enhance the taste experience of meat consumers. In this work, we studied the kinetics of the evolution of muscle properties with increasing ageing time, in order to propose an optimal duration, allowing a compromise between quality and meat weight loss reduction. Our study was performed on 32 samples from 8 animals for which the Longissimus thoracis sensory properties were analysed at different stages of ageing (7, 16, 35 and 60-days post-slaughter). This work showed an increase in the dry matter content of meat with increasing ageing duration, concomitant with a slight increase in pH. Although the luminance of the meat is stabilized after 14-days, the red and yellow indices decrease until 35-days of ageing. Iron content also decreases with ageing duration. Finally, the kinetic evolution of muscle rheological properties indicates that the toughness decreases at least up to 35-days on raw meat. Cooking seems to homogenise the tenderness of the samples, no difference was noticed between the different ageing durations when meat was cooked. These first experimental data need to be confirmed with different animal types.

Two variants of AUTS2 gene are associated with high lean meat percentage in Pekin ducks

Duck meat is starting to receive more attention due to its unique meaty characteristics. Pekin duck is an important breed resource of meat duck, which has been used in meat production and product research. However, the study about whole genome resequencing analysis of ducks for meat production has not been reported and the underlying mechanisms of meat production remain undefined. Here, lines with high lean meat percentage (S, n = 30) and low lean meat percentage (Z, n = 30) were used to analyze. The values of body weight, breast meat weight and leg meat weight in S line (body weight: 3,071 ± 26.83 g), breast meat: 391.3 ± 6.670 g; leg meat: 121.1 ± 2.184 g) were significantly higher than those in Z line (body weight: 2,584 ± 38.53 g, breast meat: 263.9 ± 6.984 g; leg meat: 110.1 ± 3.645 g). The values of body size in Z line (26.47 ± 0.1571 cm) were significantly higher than that in S line (25.38 ± 0.2475 cm). A total of 14,220,037 SNPs were obtained from 19 individuals by whole-genome resequencing, and the separate analyses of FST (range from 0.30 to 0.52) and log2θπ ratio (range from 5.8 to 8.1) revealed 50 and 124 candidate genes in the top 0.1% regions respectively, which involved in 209 and 298 candidate regions. The integration of two approaches resulted in 7 overlapping genes. Notably, AUTS2 gene is related to activator of developmental regulator. As expected, we found that in the chr29:2.29–2.30 Mb region of AUTS2, the FST value is 0.32, and the S line (π = 7.3 × 10 -5) shows a very low level of π value compared with Z line (π = 8.8 × 10 -3). Genotyping and GWAS analysis showed that 2 candidate SNPs (chr29:2,296,787 and chr29:2,296,832) were associated with high meat percentage, which were verified by Sanger sequencing. Taken together, lean meat percentage was much higher in S line individuals by comparing with Z line. The integration of FST and θπ resulted in only 7 overlapping genes that in the top 0.1% candidate regions of them. The chr29:2,296,787 and chr29:2,296,832 in the AUTS2 gene could be important molecular markers for high lean meat adaptation selection in S line.

Increased Sulphur Amino Acids Consumption as OH-Methionine or DL-Methionine Improves Growth Performance and Carcass Traits of Growing-Finishing Pigs Fed under Hot Conditions.

Simple SummaryOur results suggest that increased methionine consumption by growing- finishing pigs leads to improvement of performance and carcass quality. Moreover, supplementation with OH-methionine improved the loin depth. Taken together, our findings indicate that it might be necessary to update the recommendations for methionine for growing-finishing pigs raised under tropical conditions. This study aimed to evaluate the impact of DL-Methionine (DL-Met) or OH-Methionine (OH-Met) when supplemented beyond the usually accepted requirements in sulfur amino acids (SAA) on the performance and carcass traits of growing-finishing pigs. Two hundred mixed sex pigs were distributed in a randomized block (body weight and sex), under a 2 × 2 factorial design with two methionine sources, DL-methionine, or OH-Methionine and two methionine doses (100% SAA or 120% of the SAA level present in the control). Diets were formulated to meet amino acids recommendations of the Brazilian Tables for Poultry and Swine (2017), except for SAA, which varied with the methionine doses. Daily feed intake, daily weight gain, and feed conversion were evaluated. Moreover, the carcasses were measured electronically for fat thickness (FT), longissimus dorsi muscle depth (LD), and lean meat (%). During the growing phase II (92 till 122 days of age), daily feed intake (p < 0.001) and daily weight gain (p < 0.05) increased with the high SAA levels. High SAA levels also provided greater daily weight gain during the entire period of the trial (0.90 versus 0.86 kg; p < 0.05) No significant interaction was observed between the methionine source and the SAA level for any carcass traits. However, animals that received OH-Met had greater (p < 0.05) loin depth (58.37 versus 55.21 mm) and those that received higher doses of methionine presented heavier (p < 0.05) carcass weight (78.16 versus 74.70 kg), and more (p < 0.05) lean meat weight (43.69 versus 41.90 kg). Taken together, these results demonstrated that supplementation of high sulfur amino acids levels under hot conditions provided heavier carcasses and more lean meat.

Modeling the relationships of growth and morphometrics to dress-out traits in the oriental river prawn, Macrobrachium nipponense

Macrobrachium nipponense is a crustacean species of economic importance. The dress-out traits in this species cannot be directly selected for improvement due to their failure to be reliably measured. In this study, the path analysis approach was used to make clear how much dress-out traits were determined by growth (body weight at harvest) and morphometrics (body length, chela length, abdominal length, cephalothorax width, second abdominal segment width, second abdominal segment height). Then efforts were made to establish reliable prediction models of dress-out traits in both sexes. Results showed that abdominal meat weight was 0.69 (± 0.17) g for females, and 0.75 (± 0.25) g for males; abdominal meat percentage was 34.67 (± 4.21) %, and 33.94 (± 4.85) %. Body weight was the only determinant of abdominal meat weight in both sexes (P < 0.01), whereas the coefficients of determination of growth and morphometrics on abdominal meat percentage were all nonsignificant in both sexes (P > 0.05). According to the results of path analysis, models of abdominal meat weight on body weight were established, with R2 value reaching 0.952 for females, and 0.949 for males. Residuals analysis showed the adequacy of the abdominal meat weight models. The shrinkage on cross-validation of the abdominal meat weight was 0.004 for females, and 0.006 for males, showing the applicability of the models. Growth and morphometrics were not able to be used for predicting abdominal meat percentage. In practical breeding program of this species, direct selection of abdominal meat weight can be pursued through predictions using the reliable models established in our study, alternatively indirect improvement of abdominal meat weight through direct selection for growth. Abdominal meat percentage is not suggested for the target of improvement in M. nipponense.

Effect of amaranth leaf meal on performance, meat and bone characteristics of Boschveld indigenous chickens

This study aimed to determine the effect of amaranth leaf meal inclusion on the performance, meat, and bone characteristics of indigenous Boschveld chickens. A total of 200, day-old, indigenous Boschveld chicks were randomly allocated to five dietary treatment levels in a completely randomised design, with each treatment having four replicates and each replicate having ten chicks. Amaranth leaf meal (ALM) inclusion levels used in this study were 0, 5, 10, 15, and 20%. Bodyweight and feed intake were measured weekly to calculate the feed conversion ratio. Meat and bone characteristics were measured, and the general linear model of statistical analysis software was used to analyse collected data. Chickens which were offered diets with 0 and 10% ALM inclusion levels had higher (p < .05) breast meat weights than those which were offered diets with 5, 15, and 20%. Chickens that were offered diets with 15% ALM levels had higher (p < .05) abdominal fats weights than those offered diets with 0, 5, 10, and 20%. Chickens which were offered 20% ALM in their diets, had higher (p < .05) meat tenderness than those offered 0, 5, 10, and 15%. Chickens which were offered diets with 15% ALM had a lighter and redder (p < .05) breast meat colour than those offered 0, 5, 10, and 15% ALM inclusion levels. At the age of 21 and 42 days, chickens which were offered diets containing 5, 15, and 20% ALM had higher (p < .05) tibia calcium and phosphorus contents than those on diets having 0, and 10% ALM inclusion levels. Highlights Amaranth leaf meal inclusion in diets has no adverse effect on indigenous Boschveld chickens performance Amaranth leaf meal inclusion in diets increase meat tenderness and shear force of chickens Amaranth leaf meal showed to favour bone physical characteristics and more bone minerals deposition of indigenous Boschveld chickens.

Evolution of antioxidant peptides and their proteomic homology during processing of Jinhua ham

This study aimed to clarify the evolution of antioxidant peptides and their proteomic homology during a continuous period of Jinhua ham processing. The peptide content increased during the process, reaching a value of 1.92% (weight %, based on meat weight) in ham at the end of dry-ripening, which was approximately 8-fold higher than that prior to salting. From scavenging effects on 1,1-diphenyl-2-picrylhydrazyl radical (DPPH•) and hydroxyl radical (•OH) and chelating ability on Fe2+, it was suggested that peptides generated at the end of dry-ripening had the highest level of antioxidant activity. Size-exclusion chromatography indicated that the antioxidation of peptides might be related to their MWs, where more fractions with small MWs result in higher antioxidant activity. The results of endogenous protease activities showed 22.33% of the initial activities of Cathepsin B were retained, suggesting that Cathepsin B plays a key role in the formation of antioxidant peptides. Homology-based proteomics showed that peptides primarily arose from myosin (32.37%), followed by actin (16.91%), troponin T (12.08%) and others.

Using TD-NMR relaxometry to assess the effects of diet type and stocking rate on the incidence and degree of severity of myopathies in broilers

This study aimed to evaluate different feeding strategies and stocking rates (SR) on the occurrence and severity of broiler myopathies. Additionally, a second aim was to test the potential use of Time-Domain Nuclear Magnetic Resonance (TD-NMR) relaxometry for assessing white striping (WS) and wooden breast (WB) incidence and the degree of severity in broiler chicken breasts. Treatments were arranged in a 2 × 2 factorial design and consisted of two nutritional levels (regular and superior diets) and two different SR (high 47 kg/m2 or regular 59 kg/m2). Infrared thermography (IRT) images were recorded on three different days to determine the average, minimum and maximum temperatures. After 49 days of rearing, birds were slaughtered, and 75 breasts were weighed and classified according to the absence (normal breast, without the occurrence of myopathy – NB) or occurrence and severity of WB and WS. The whole breasts were analysed by TD-NMR relaxometry using the Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence and Continuous Wave-Free Precession (CWFP-T1) pulse sequence. There was no effect of diet and diet*SR interaction on the weight of breast meat; however, chickens raised at the higher density presented a lower breast weight (P < 0.0001; 490 vs. 539 g). The incidence and severity of myopathies was not influenced by the treatments (P = 0.9467); the frequencies of WB and WS were similar in the different treatments. For CPMG and CWFP-T1, three and two relaxation populations were noted, respectively. The sPLS-DA model optimisation showed a significant separation between WS and NB in terms of occurrence and severity. In conclusion, changes in diet and SR did not mitigate the occurrence or severity of WS and WB. Additionally, TD-NMR relaxometry showed to be a promising technology for evaluating and segregating breasts according to myopathy incidence and severity.