Breast Meat Weight Research Articles

DIETARY EFFECTS OF TULSI LEAVES AND BLACK PEPPER EXTRACT ON BROILER GROWTH PERFORMANCE AND CARCASS TRAITS

This study was conducted to determine the efficacy of the dietary effect of different levels of Tulsi leaves (Ocimum sanctum) and Black Pepper (Piper nigrum) Extract (TBE) on growth performance and carcass traits of commercial broiler. The study was conducted at the Poultry farm of Hajee Mohammad Danesh Science and Technology University, Dinajpur during the period from 11 April to 08 May, 2019. A total of 96 day old broiler chicks (Lohman Meat) were randomly and equally distributed to 4 groups having 3 replicates of 8 birds each. The birds were grouped as T0, T1, T2 and T3 group with normal water (control group), 1% TBE 1ml /L of drinking water, 2% TBE 2 ml/L of drinking water and 3% TBE 3ml /L of drinking water, respectively. Body weight gains, Feed Conversion Ratio (FCR), mortality (%) and meat yield traits were recorded. The collected data were analyzed by using ANOVA with SPSS version 22. Feed intake (g/bird) was almost similar (P>0.05) among the dietary treatment groups. Body weight gain (g) and FCR were significantly (P<0.05) differed among the dietary treatment groups. The highest body weight gain (g) was significantly (P<0.05) higher in T2 (1659.35g±2.19), followed by T1 (1631.05g±2.52), T3 (1590.67g±2.73) and T0 (1472.01g±4.58), respectively. The lowest FCR was found in T2 (1.41±0.00) and the highest FCR in T0 (1.52±0.01), the intermediate in T1 (1.45±0.01) and T3 (1.46±0.01), respectively. It was found that there was significant (P<0.05) difference among the dietary treatment groups in case of live weight (g), carcass weight (g),dressing percentage (%), breast weight (g), liver weight(g), but there was almost similar (P>0.05) among the dietary treatment groups in case of heart weight (g), spleen weight (g), gizzard weight (g), thigh weight (%), head weight (g), intestine weight (g) and shank weight (g). The carcass meat weight, Carcass yield (%), breast weight and breast meat weight (%) was significantly (P<0.05) higher in treatment T2 group compared to control group T0. Liver weight was significantly (P<0.05) higher in control group T0 compared to treatment group T2. No mortality was found among the dietary treatment groups during experimental period. Based on the result it could be concluded that 2% Tulsi leaves and Black Pepper Extract (TBE) 2 ml/L of drinking water may be used in broiler diet as growth promoter and it may also serve as an antioxidant.

Phenotypic and genomic characterisation of performance of tropically adapted chickens raised in smallholder farm conditions in Ethiopia.

In sub-Saharan Africa, 80% of poultry production is on smallholder village farms, where chickens are typically reared outdoors in free-ranging conditions. There is limited knowledge on chickens' phenotypic characteristics and genetics under these conditions. The present is a large-scale study set out to phenotypically characterise the performance of tropically adapted commercial chickens in typical smallholder farm conditions, and to examine the genetic profile of chicken phenotypes associated with growth, meat production, immunity, and survival. A total of 2,573 T451A dual-purpose Sasso chickens kept outdoors in emulated free-ranging conditions at the poultry facility of the International Livestock Research Institute in Addis Ababa, Ethiopia, were included in the study. The chickens were raised in five equally sized batches and were individually monitored and phenotyped from the age of 56days for 8weeks. Individual chicken data collected included weekly body weight, growth rate, body and breast meat weight at slaughter, Newcastle Disease Virus (NDV) titres and intestinal Immunoglobulin A (IgA) levels recorded at the beginning and the end of the period of study, and survival rate during the same period. Genotyping by sequencing was performed on all chickens using a low-coverage and imputation approach. Chicken phenotypes and genotypes were combined in genomic association analyses. We discovered that the chickens were phenotypically diverse, with extensive variance levels observed in all traits. Batch number and sex of the chicken significantly affected the studied phenotypes. Following quality assurance, genotypes consisted of 2.9 million Single Nucleotide Polymorphism markers that were used in the genomic analyses. Results revealed a largely polygenic mode of genetic control of all phenotypic traits. Nevertheless, 15 distinct markers were identified that were significantly associated with growth, carcass traits, NDV titres, IgA levels, and chicken survival. These markers were located in regions harbouring relevant annotated genes. Results suggest that performance of chickens raised under smallholder farm conditions is amenable to genetic improvement and may inform selective breeding programmes for enhanced chicken productivity in sub-Saharan Africa.

Genetic polymorphisms of calpain1 and calpain3 genes and their effects on growth, carcass, and meat quality traits in Betong chicken (KU line).

Betong chicken (KU line) is a slow-growing Thai native chicken used for meat production. The objectives of this study were to identify polymorphisms of the calpain1 (CAPN1) and calpain3 (CAPN3) genes and to investigate their effects on growth, carcass, and meat quality traits in Betong chickens (KU line). A sample of 252 Betong chickens (KU line) was screened for CAPN1 and CAPN3 polymorphisms. The polymorphisms of CAPN1 were detected using gel electrophoresis and DNA sequencing, whereas the polymorphisms of CAPN3 were identified using restriction fragment length polymorphism. Polymorphisms were detected in both CAPN1 (AA, AB, and BB genotypes) and CAPN3 (CC, CT, and TT genotypes). The frequency of the B allele was higher than for the A allele (0.78 and 0.22, respectively) in CAPN1, while the C allelic frequency was higher than for the T allele (0.54 and 0.46, respectively) in CAPN3. The CAPN1 genotype and the combination of the CAPN1 and CAPN3 genotypes could be used as genetic markers for meat lightness. The CAPN3 could be useful for increasing body weight, live weight, and breast meat weight in Betong chickens (KU line).

Body conformation, morphometry and meat yield characteristics of different genotypes of chicken

The aim of this study was to evaluate body conformation, morphometry and meat yield characteristics of broiler, Sonali, deshi and Fayomi chicken available in local market. Experiment was carried out at the poultry science laboratory of Jhenidah government veterinary college (JGVC), Jhenidah for a period of one month from February 2022 to March 2022. A total n u mb e r of 38 chicken (20 females and 18 males) were collected from different local market viz. broiler (10), Sonali (9), deshi (8) and Fayomi (11). The healthy birds were selected based on the availability and market demand. This study revealed that shank length, chest circumferences and digestive tract length were found highest in broiler. On the other hand, body length was recorded highest in Fayoumi and lowest in Sonali chicken. However, body conformation indices of male chicken showed higher value than their female counterparts. The findings indicated that broiler chicken had the highest body mass index (BMI), followed by Fayomi, Sonali, and deshi chicken. Similarly, broiler had the highest and Sonali had the lowest massiveness and compactness indices, whereas reverse feature was found for shape index. Sonali had the highest and broiler had the lowest shape index. Meat yield characteristics of male chicken were found higher than the female chicken among the genotypes. On the other hand, percentage of breast meat weight was found higher in female than male birds of all genotypes. However, both sexes of broiler had the highest and Sonali had the lowest percentage of dressed weight, breast meat and total meat weight. The study revealed that broiler chicken showed better meat yield performance when compared to deshi, Fayomi and Sonali chicken as meat bird available in local market of Bangladesh which provides an important message for consumer, producer and researcher.

Higher concentrations of folic acid reduced the dietary requirements of supplemental methionine for commercial broilers.

An experiment was conducted to study the effect of supplementing DL methionine (DL Met) at graded concentrations on performance, carcass variables, immune responses and antioxidant variables in broiler chicken fed folic acid (FA) fortified (4 mg/kg) lowmethionine diet. A basal diet (BD) without supplemental DL Met, but with higher level (4 mg/kg) of FA and a control diet (CD) with the recommended concentration of methionine (Met) were prepared. The BD was supplemented with DL Met at graded concentrations (0%, 10%, 20%, 30%, 40%, and 50% supplemental DL Met of CD). Each diet was fed ad libitum to 10 replicates of 5 broiler male chicks in each from 1 to 42 d of age. Body weight gain (BWG) reduced, and feed conversion ratio (FCR) increased in broilers fed low-Met BD. At 30% and 20% inclusion of DL met, the BWG and FCR, respectively were similar to those fed the CD. Similarly, supplementation of 10% DL Met to the BD significantly increased ready to cook meat yield and breast meat weight, which were similar to those of the CD fed broilers. Lipid peroxidation reduced, the activity of antioxidant enzymes (GSHPx and GSHRx) in serum increased and lymphocyte proliferation increased with increased supplemental DL Met level in the BD. The concentrations of total protein and albumin in serum increased with DL Met supplementation to the BD. Based on the data, it can be concluded that supplemental Met can be reduced to less than 50% in broiler chicken diets (4.40, 3.94, and 3.39 g/kg, respectively in pre-starter, starter and finisher phases) containing 4 mg/kg FA.

Sustainable Broilers Production Performance under High Stocking Condition through Colocynth Seed Supplementation

The negative impacts of high stocking density on the commercial poultry industry compromise sustainable birds’ productivity and welfare. Thus, we investigated the potential of colocynth seed (CC) supplementation in alleviating the negative impacts of high stocking density on broilers’ performance, immunity, inflammation, and redox status. A total of 648 one-day-old male Cobb 500 chicks were recruited and distributed into 2 × 2 factorial arrangements. The treatment groups were assigned based on stocking density as low stocking density (9 birds/m2; LSD) or high stocking density (19 birds/m2; HSD), and CC supplementation as without (0 g/kg feed; −CC) or with (1 g/kg feed; +CC) supplementation. Data were collected from week three to week five of age. Production performance was monitored and meat quality was assessed. Blood samples were collected to measure stress markers, humoral immune response, inflammatory cytokines, and antioxidant activity levels. The results indicated that HSD induced production performance reduction, immunosuppression, and imbalance redox status, along with elevation in inflammation and stress markers levels. Breast meat weight and yield were reduced in the HSD groups by 9 and 1%, respectively, compared to LSD groups. However, CC supplementation to HSD birds was able to slightly improve daily weight gain, body weight gain, and breast weight, showing no significant difference compared to the LSD-CC group, and significantly increased breast yield. Furthermore, CC supplementation significantly reduced inflammatory cytokines and stress markers levels. Under HSD, both cell-mediated and humeral immune responses were elevated with CC supplementation compared with the non-supplemented group. It can be concluded that HSD is a detrimental factor in the commercial poultry industry, which generates oxidative and inflammatory responses and, subsequently, immunosuppression and impaired performance. Nevertheless, dietary CC supplementation can be used as a natural antioxidant source to mitigate the negative impacts of HSD on broilers’ production performance, as well as physiological competency.

Individual and Combined Effects of a Direct-Fed Microbial and Calcium Butyrate on Growth Performance, Intestinal Histology and Gut Microbiota of Broiler Chickens

This study evaluated the effects of a Bacillus direct-fed microbial and microencapsulated calcium butyrate fed individually and in combination, as compared to an antibiotic growth promoter, on growth performance, processing characteristics, intestinal morphology, and intestinal microbiota of Ross 708 broilers reared from 0 to 47 d post-hatch. Dietary treatments included: (1) a negative control with no antimicrobial (NC), (2) a positive control diet containing bacitracin methylene disalicylate (PC), (3) a diet containing a Bacillus direct-fed microbial (CS), (4) a diet containing microencapsulated calcium butyrate (BP), and (5) a diet containing both CS and BP. Treatments were replicated with 10 pens of 20 birds each. From 0 to 15 d post-hatch, the FCR of broilers fed the PC, CS, BP, and CS + BP diets were lower (p < 0.05) than those fed the NC diet, but treatment effects (p > 0.05) were not observed on subsequent performance. BP supplementation improved (p < 0.05) total breast meat weight and yield at processing. Intestinal histology was not influenced (p > 0.05) by the treatment. Analysis of the jejunal microbiota collected at 15 d post-hatch revealed that the genus SMB53 was significantly lower for the CS group, and Sporanaerobacter was lower in the CS and CS + BP groups compared with the NC (p < 0.05). The jejunal microbiota from broilers in the CS + BP group had higher (p < 0.05) alpha and beta diversities compared with broilers fed the NC and CS diets. The results reflected synergistic effects between CS and BP in modulating the jejunal microbiota at 15 d that may have been related to enhanced feed efficiency (i.e., lower FCR) observed during this period.

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.

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.

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.

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<0.05) in control and closely followed by birds on GT, CM, BP and RS. The lowest blood (p<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<0.05) live weight (2.05kg) and highest acceptability (p<0.05) for organoleptic properties. The breast meat weight was also highest (p<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.

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.

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.

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.

Internal organ and skeletal muscle development in commercial broilers with woody breast myopathy

Increasing growth rate, body weight, and breast muscle yield have been linked to broiler muscle problems such as woody breast (WB). The aim of this study was to investigate the internal organ and skeletal muscle development of broilers with WB myopathy under dietary and Eimeria challenge treatments. A 3 diet (control, antibiotic, or probiotic) × 2 challenge (control or Eimeria) × 2 sex factorial arrangement of treatments was used in a randomized complete block design. Ross × Ross 708 chicks were randomly assigned to 96 floor pens with 12 treatment combinations (8 replicates per treatment). Internal organs were sampled on d 13 and 41. Skeletal muscles were sampled on d 41. Internal organ and skeletal muscle weights were analyzed using a 3-way analysis of variance (ANOVA). Relationships between WB and internal organ and skeletal muscle weights were analyzed using one-way ANOVA as all treatments were pooled together and regrouped according to WB scores. On d 41, absolute and relative heart weights were greater in males when they were averaged over diet and challenge treatments (P < 0.001 and P = 0.026, respectively). The birds with WB score 3 had greater absolute heart (P = 0.0002) and spleen weights (P = 0.016), but there was no difference in relative spleen weight (P > 0.05). When averaged over diet and challenge treatments, males have greater absolute duodenum, jejunum, and ileum weights (for all P < 0.0001). Compared with birds with normal breasts, the birds with WB scores 1, 2, and 3 had a greater live weight (for all P < 0.0001) and absolute and relative breast weights (for all P < 0.0001). The birds with WB score 1, 2, and 3 had greater (P < 0.0001) absolute but lower (P < 0.0001) relative drumstick, thigh, and wing weights. Results indicated that broilers with WB had lower relative proventriculus and gizzard weights and greater relative breast meat weight with lower relative drumstick, thigh, and wing muscle weights.

Potential Probiotic Acceptability of a Novel Strain of Paenibacillus konkukensis SK 3146 and Its Dietary Effects on Growth Performance, Intestinal Microbiota, and Meat Quality in Broilers.

Simple SummaryThis study investigated the probiotic characteristics of Paenibacillus konkukensis and its dietary effects on growth performance, intestinal characteristics, intestinal microbiota, and meat quality in broilers. Through this study, P. konkukensis showed non-hemolytic activity, variable antibiotic susceptibility, and moderate acid and bile tolerance. Supplementary feeding of P. konkukensis as bacterial culture did not affect the growth performance parameters and meat quality, with positive effects on meat yield and intestinal microflora. Overall, dietary P. konkukensis may not have any adverse effects and might be considered as a probiotic feed additive in poultry.This study evaluates the in vitro probiotic characteristics of P. konkukensis sp. nov. SK-3146, which was isolated from animal feed, and its dietary effects on growth performance, intestinal characteristics, intestinal microbiota, and meat quality in broilers. In vitro experiments revealed that P. konkukensis was non-hemolytic with variable antibiotic susceptibility, and acid as well as bile tolerance. To assess the effect of P. konkukensis on broilers, a total of four hundred eighty 1-day-old Ross 308 broiler chicks were allocated to 3 treatment groups with 4 replicates of 40 birds each; the negative control group was fed a basal diet without any feed additives (NC), the positive control group was fed a basal diet containing 0.01% enramycin (PC), and the experimental group was fed a basal diet containing P. konkukensis bacterial culture (PK) at 104 CFU/g of the diet based on bacterial count. The experiment lasted for 35 days. Results indicated that there were no significant differences in any growth performance parameters among the dietary treatments (p > 0.05). In addition, the inclusion of P. konkukensis in the broilers’ diet did not affect meat cooking loss, color, and pH but increased the relative weight of breast meat (p < 0.05). The PK group showed heavier intestinal weight and shorter intestinal length than the NC group (p < 0.05). The ratio of the intestinal weight to length of jejunum was the highest in the PK group (p < 0.05). The PK group showed increased counts of Streptococcus thermophilus (p < 0.05) with no adverse effects of P. konkukensis on other intestinal microbiota in the jejunum. This study implies that P. konkukensis might have the potential to be applied as a probiotic feed additive in poultry.

The effects of stocking density on slaughter performance and some meat quality parameters of Pekin ducks.

The effects of stocking density on slaughter performance and meat quality were primarily investigated in this research. A total of 240 Pekin ducks were used, and they were reared until slaughter age (42 d) in three different stocking density groups (three, five and seven ducklings m). To compare the slaughter performance of the ducklings' live weight, carcass weight, carcass yield, thigh and breast meat weight and yield, and edible giblet weight (heart, liver and gizzard) were investigated. The meat quality was compared between the treatment groups based on dry matter ratio, cooking loss, water-holding capacity, pH values, and colour parameters (, , , , and values). Carcass weight, carcass yield, thigh and breast meat weight were found to decrease in parallel to the increasing stocking density, resulting in a reduction in thigh and breast meat weights and ratios (). Increasing the stocking density decreased the heart weight and positively improved the liver and gizzard ratio (). However, it did not affect the meat quality parameters investigated in this research (). The breast meat of the ducks reared under higher stocking density had higher , and values, lower value (), and similar and values (). Evaluating the overall research findings, it was concluded that increased stocking density when rearing ducks negatively affects the slaughter performance, affecting only breast meat colour and weight of thigh meat with skin in investigated meat quality parameters.

Effect of β-Mannanase Supplementation on Growth Performance, Ileal Digestibility, Carcass Traits, Intestinal Morphology, and Meat Quality in Broilers Fed Low-ME Diets.

Simple Summaryβ-mannans, an example of non-starch polysaccharides, is one of the important anti-nutritional factors found in many leguminous feedstuffs used as raw material in poultry feed formulation. β-mannans bind to nutrients, reduce their bioavailability, and also increase the viscosity of intestinal digesta, which prevents the proper mixing of enzymes with digesta and affects the digestibility of nutrients. All these conditions ultimately reduce the growth performance of poultry birds. So, the objective of present study was to lower the effect of β-mannans by using β-mannanase in broiler diets. Results suggested that β-mannanase supplementation improved the intestinal morphology, which helped to increase the dry matter and crude fiber digestibility in broilers fed low energy diets. In addition, growth performance of broilers was not affected by reducing dietary energy levels with added β-mannanase than the Control group. Similarly, carcass traits were not affected by decreasing dietary energy levels with supplementation of β-mannanase. In conclusion, it could be stated that a low caloric diet with added β-mannanase had no negative effect on growth performance and carcass characteristics; however, it improved the dry matter and crude fiber digestibility.Experiment was designed to analyze the effect of low caloric diets, supplemented with β-mannanase on growth performance, carcass characteristics, nutrient digestibility, and other parameters in broilers. In this study, 400 broiler chicks were randomly divided into four treatments (Cont: without β-mannanase; LM-30, MM-60, and HM-90: supplemented with 200, 400, and 600 mg/kg β-mannanase, respectively). Dietary metabolizable energy (ME) in Cont was standard (starter diet 3100 kcal/kg; finisher diet 3200 kcal/kg) and reduced by 30, 60, and 90 kcal/kg, correspondingly in β-mannanase-supplemented treatments. The results exhibited that growth performance was not affected by reducing dietary energy levels with supplementation of β-mannanase. Ileal digestibility of DM and CF was improved (p < 0.01) by supplementation of β-mannanase at low dietary ME levels. Concerning carcass traits, the relative weight of breast meat, drumstick, and abdominal fat increased (p < 0.05) with β-mannanase supplementation in low-ME diets. Treatment HM-90 showed significantly (p < 0.05) better results regarding villus height and VH:CD. It could be concluded from the present results that supplementation of β-mannanase could improve the nutrient digestibility so that it is possible to reduce the dietary energy level without compromising production performance, carcass trails, and meat quality in broilers.

Role of steroid growth promoter on growth performance and meat quality traits in broiler

Growth promoters are added with broiler feed to boost the overall feed efficiency and growth rate. The current study investigated the effect of dexamethasone (DEX)—a commonly used growth promoter—on the broiler growth rate, meat quality, and muscle biology. Four homogenous groups (20 chicks/group) of broiler one-day-old chicks were fed commercial broiler feed where the treatment groups received 3, 5, and 7 mg/kg of DEX with their diet for 28 d. Feed consumption and body weight were monitored on a daily basis. Muscle samples were collected on 7, 14, 21, and 28 d of the experiment to investigate meat quality and muscular biology. The residue of DEX in meat was detected using thin-layer chromatography. We observed that DEX had substantially decreased (P < 0.05) feed intake, feed efficiency, and overall weight gain in the broiler. While the weight of breast and thigh meat was decreased, the relative meat weight (meat/body weight) was increased significantly in chicks fed DEX. Simultaneously, body fat decreased while the percentage of fat increased significantly (P < 0.05) in the DEX groups. Contrariwise, DEX improved the investigated meat quality parameters with the potential threat of accumulation of DEX residue in the meat at a high dose (7 mg/kg). We also observed that DEX significantly increased the number of myofibers and decreased the cross-sectional area of myofibers. Based on these findings, we conclude that DEX reduces feed intake, feed efficiency, and growth rate, but might improve meat quality with a potential risk of residual DEX accumulation if fed at a high dose.

사료 내 단백질 함량 및 합성아미노산 첨가에 따른 육계의 사양성적 및 가슴육 성상에 미치는 영향

The present study was conducted to determine the effect of reduced dietary crude protein (CP) with a synthetic indispensable amino acids (AA) supplement on the growth performance, economics, and breast meat quality. A total of 450 male broilers (Ross 308) were used from the age of 7 to 28 days. On d 7, the birds were individually weighed and randomly assigned to three treatment diets with six replicate pens for each treatment in a randomized complete block design. The experimental diets were: (1) a control diet, (2) a diet with a reduction of 1% of the dietary CP with synthetic AA supplements to meet the indispensable AA requirement (OAA) of broiler chickens, and (3) a diet with a reduction of 1% of the dietary CP with synthetic Lys, Met, and Thr supplementation to exceed 5% of the indispensable AA requirement (HAA). There were no differences among the treatments on the final body weight, weight gain, and feed intake. However, the HAA diet impaired the feed conversion ratio at d 21 and during the overall feeding periods (<i>P</i>&lt;0.05). The predicted total feed intake and feed price required to reached 1.5 kg BW was higher than for the birds fed the HAA diet (<i>P</i>&lt;0.05). The breast meat muscle fiber cross sectional area and fiber density varied between the treatments (<i>P</i>&lt;0.05). However, there were no differences in breast meat weight. In conclusion, reducing 1% of dietary CP had no adverse effects on the growth performance or breast meat yields.