Evaluation of the Factors Contributing to Broiler Meat and Functional Quality a Systemic Review

In ovoL-leucine administration stimulates lipid metabolisms in heat-exposed male, but not female, chicks to afford thermotolerance

1. An experiment was conducted to evaluate the effect of dietary zinc proteinate (ZP) supplementation on growth performance and on skin and meat quality of male and female broiler chicks. 2. A total of 240 1-d-old male and 240 1-d-old female broiler chicks were randomly distributed into 24 floor pens (12 replicate pens/sex; 20 birds/pen) and were given either 0 (Control diet) or 40 mg/kg ZP (ZP 40), resulting in a 2 × 2 factorial arrangement of treatments. 3. The growth performance of male and female broiler chicks was not affected by the ZP supplementation, but the males showed significantly higher growth performance than did females. 4. ZP supplementation increased the total thickness of skin in both sexes, and males had thicker skin than females. It also increased the collagen content of skin, but not that of meat. Males had higher skin collagen contents than did females, but no sex difference was found in the meat collagen contents. 5. ZP supplementation did not affect the shear force values of skin and meat; however, males had higher shear force values of back skin than females. ZP supplementation increased the zinc contents of thigh meat and plasma in both sexes. Males had higher zinc contents in back skin than females. 6. It is concluded that dietary ZP supplementation could increase the skin quality of broiler chicks in both sexes, particularly in female broilers, without any effect on growth performance. Male broilers have better growth performance and skin quality than females.

The objective of the study was to compare the carcass characteristics, meat quality, and blood parameters of slow and fast grown female broiler chickens fed in organic or conventional production system. The two genotypes tested were medium slow-growing chickens (SG, Hubbard Red JA) and commercial fast-growing chickens (FG, Ross 308). Both genotypes (each represented by 400 chickens) were divided into two sub-groups fed either organic (O) or conventional (C) systems. Chickens of each genotype and system were raised in a semi environmentally controlled poultry house until 21 d of age and were assigned to 5 pens of 40 chickens each. Then, O system chickens were transferred into an open-side poultry house with an outdoor run. At 81 d of age, 10 female chickens from each genotype and from each production system (n = 40) were randomly chosen to provide material for analysis, and were weighed and brought to the slaughterhouse to assess carcass characteristics and meat quality. The blood parameters were determined by using 5 female chickens from each genotype and from each production system (n = 20). FG had the higher live weight, along with carcass, breast, and thigh-drumstick weights compared to SG (p<0.05). FG had the higher breast yield, whereas SG had the higher thigh-drumstick yield (p<0.05). The O system resulted in a higher amount of abdominal fat (p<0.05). In addition, the O system values were higher for dry matter, crude ash, crude protein, and pH15 values in breast meat, and for crude ash, crude protein, and pH15 values in drumstick meat (p<0.05). In addition, total saturated fatty acids, total mono-unsaturated fatty acids, and total omega 3 were significantly higher in the O system than in the C system. Thus, the O system showed a positive advantage compared to the C system regarding female chicken meat quality, primarily within the ash, protein, and total omega 3 fatty acid profiles. In conclusion, the present study indicated that the main factor affecting the carcass characteristics of female chickens was genotype, whereas the organic system contributed to enhanced meat quality. These findings provide a better understanding of the relative roles of genotype and production systems in female broiler characteristics, and might aid producers in designing their facilities to optimize yield and quality while maintaining acceptable animal welfare standards.

The present study aimed to evaluate how dietary supplementation with a microencapsulated sodium butyrate (500 mg/kg; 30% Na-butyrate) in 768 male and female broiler chickens affected growth performance, jejunum gut morphology and caecal microbiome at different ages (11, 24, and 35 d), slaughter results, meat quality, and myopathy (white striping, wooden breast, and spaghetti meat) occurrence. No health problem was recorded (mortality < 1%) and Na-butyrate supplementation did not affect performance throughout the trial, nor did it affect gut morphology or microbiota composition and abundance at different ages. Additionally, dietary treatment did not affect slaughter results, meat quality, or myopathy rate, whereas the rate of females affected by spaghetti meat tended to be higher in those fed the control compared with the Na-butyrate diet (33.3% versus 16.7%; p = .06). Moreover, males showed a higher wooden breast (21.9% versus 7.3%; p ≤ .01) and a lower spaghetti meat (3.1% versus 25.0%; p ≤ .001) rate compared with females. Finally, the richness index (i.e. the number of different species represented in an ecological community, landscape, or region) in the caecum increased (p ≤ .001) with increasing chicken age, and the community composition was also affected (adonis p ≤ .001). In conclusions, under the good health condition of the present trial, the tested Na-butyrate had no effect on performance and gut response at different ages of broiler chickens. Moreover, the occurrence of spaghetti meat and wooden breast differed between males and females. Highlights Under optimal health conditions, Na-butyrate supplementation did not affect performance or gut response at different ages of broiler chickens. Males showed a significantly higher occurrence of wooden breasts, whereas females had higher rates of spaghetti meat. In females, the Na-butyrate supplementation tended to reduce the occurrence of spaghetti meat.

1. Two experiments were carried out to determine the response of broiler chicks to threonine-supplemented diets between 10 and 28 d and 7 and 21 d of age, respectively. 2. In the first experiment female broiler chicks were fed on 11 experimental diets. Two iso-energetic basal diets (diets 1 and 2) were prepared with 200 and 160 g CP/kg and 7.6 and 6.0 g threonine/kg respectively. Both diets contained 11.5 g lysine and 8.7 g sulphur-containing amino acids/kg. Diet 3 was composed of diet 2, supplemented with all essential and non-essential amino acids (EAA and NEAA, respectively) except threonine, to the concentrations of the amino acids in diet 1. The NEAA were added as a combination of glutamic acid and glycine. Diets 4 to 11 had the same compositions as diet 3, but contained increasing amounts of threonine. 3. For birds fed on diet 2, gain was significantly lower and food/gain ratio was significantly higher than for birds fed on diet 1. Supplementation with EAA, NEAA and threonine to the same concentrations in diet 1 resulted in a performance similar to that found on diet 1. 4. In experiment 2, male and female broiler chicks both received 10 experimental diets. Diet 1 contained 220 g CP/kg and 8.5 g threonine/kg, diet 2 contained 160 g CP/kg from natural raw materials and 6 g threonine/kg. Both diets contained 12.4 g lysine and 9.3 g sulphur-containing amino acids/kg. Basal diet 2 was supplemented with all EAA and NEAA to the concentrations of basal diet 1, except for threonine. Diets 3 to 10 had the same compositions as the supplemented diet 2, but contained increasing amounts of threonine. 5. For male and female chicks on diet 2, gain was significantly lower and food/gain ratio significantly higher than those on diet 1. Diet 10 (160 g CP/kg plus all EAA, including threonine, and NEAA supplemented to the concentrations of diet 1) resulted in the same performance as diet 1. 6. The results indicate that, when low protein maize-soyabean meal diets supplemented with EAA and NEAA with 13.31 MJ ME/kg were fed to male and female broiler chicks until 21 d of age, improvements in gain and food/gain ratio were obtained when the dietary threonine content was increased to 7.25 g/kg. When female chicks were fed threonine-supplemented diets to 28 d of age, improvement in gain and food/gain ratio was obtained when the threonine concentrations were increased to 6.32 g/kg diet.(ABSTRACT TRUNCATED AT 400 WORDS)

Electrical waterbath stunning: Influence of different waveform and voltage settings on the induction of unconsciousness and death in male and female broiler chickens

The population of commercial broiler chickens in Indonesia is increasing along with the high level of consumption of Indonesian poultry meat. The difference in the weight of broiler chicken harvest due to sex differences allows for differences in the percentage of carcass, non carcass and physical quality of broiler chicken meat. The aim of study was to analysis the sex differences in broiler chickens against the carcass and non carcass characteristics produced. 10 broiler chickens, each of male and female aged 30 days randomized from 14 000 broiler chickens that maintained in closed house were analyzed. The variables observed were carcass characteristics (carcass percentage, cut up of carcass, edible and non edible carcass components, and physical quality of breast meat) and non carcass characteristics (non carcass components). The data obtained were analyzed using the t-test. The average body weight of male and female chickens were 1 834.10 g and 1 659.40 g. The carcases percentage of male and female broilers were 69.38% and 70.78%. The bone percentage of male and female broilers were 17.27% and 15.56%. The cooking shrinkage value of male and female broilers breast meat were 36.32% and 42.50%. As a conclusion, male broilers with greater body weight produced a smaller significant of carcas percentage, and a significantly greater of bone percentage, but had better in physical quality than female broiler chickens.

Male and female broiler chickens differ in performance and this will cause unwanted experimental errors in research. For this reason, single-sex or mixed-sex broilers are used in most studies. This study aimed to assess the performance differences between groups of chickens with varying male/female ratios to determine how sex ratio can affect performance criteria. Birds (N = 550) were separated by sex and placed in 11 groups (pens) according to the male/female ratios, including group 1 (10 males + 0 female), group 2 (9 males + 1 female), group 3 (8 males + 2 females), group 4 (7 males + 3 females), group 5 (6 males + 4 females), group 6 (5 males + 5 females), group 7 (4 males + 6 females), group 8 (3 males + 7 females), group 9 (2 males + 8 females), group 10 (1 male + 9 females), and group 11 (0 male + 10 females). The results showed that male broiler chickens had higher feed intake and body weight gain than female broiler chickens, but the feed conversion ratio was not affected by gender. The digestibility of phosphorus, bone strength, bone density, bone calcium and phosphorus, pH, and redness and water holding capacity of meat were higher in male broilers. The dripping loss was higher in female broilers. This study showed that male and female broiler chickens differed in most of the parameters examined in the research, and the use of separate breeding affected the research results.

Selected parameters characterizing the chemical composition of bones were determined in 60 male and 60 female hybrid Ross 308 chickens aged 40 days at the end of the fattening period. The chickens received a complete feed mixture intended for pre-feeding (starter) in a period from the start of the experiment until Day 10, followed by the feed mixture intended for fattening until Day 30 (grower), and the feed mixture for the third phase of fattening, i.e. until Day 40 (finisher). The feed mixtures and drinking water were provided &lt;I&gt;ad libitum&lt;/I&gt;. At the end of the experiment, chickens were slaughtered and the femur and the tibiotarsus from the right pelvic limb were collected and the following parameters were determined in wet tissue: dry matter (DM), crude protein (CP) (N × 6.25), fat, ash, calcium (Ca), phosphorus (P) and magnesium (Mg); the content of organic matter was calculated. The resultant values were recalculated to 100% of DM. Differences between males and females in the chemical composition of retrieved bones were investigated. The content of CP in wet tissue from both bones ranged from 354.0 ± 11.8 to 365.1 ± 14.3 g/kg being significantly lower (&lt;I&gt;P&lt;/I&gt; &lt; 0.01) in the tibiotarsus. Differences between sexes were very small. The content of fat in the bones ranged from 16.12 ± 8.71 to 16.17 ± 8.85 g/kg, with higher levels of fat being detected in female chickens (17.16 ± 8.53 to 17.24 ± 8.28 g/kg) as compared to male chickens (15.01 ± 9.05 to 15.19 ± 9.12 g/kg). No statistically significant differences between the femur and the tibiotarsus were detected. The levels of ash ranged from 472.2 ± 13.1 to 480.1 ± 10.83 g/kg, being statistically higher in the tibiotarsus in both male and female chickens (&lt;I&gt;P&lt;/I&gt; &lt; 0.01; &lt;I&gt;P&lt;/I&gt; &lt; 0.001). The levels of Ca ranged from 180.4 ± 8.57 to 181.6 ± 12.32 g/kg, showing higher values in both bones from female chickens (181.7 ± 9.17 to 183.8 ± 14.71 g/kg), as compared to male chickens (179.2 ± 7.8 to 179.3 ± 8.91 g/kg). No statistically significant changes were found. The levels of P ranged from 83.17 ± 9.82 to 83.29 ± 7.42 g/kg, with higher levels being observed in female chickens (84.1 ± 9.21 to 89.8 ± 7.47 g/kg), as compared to male chickens (76.5 ± 6.93 to 82.5 ± 5.00 g/kg). The levels of P were significantly higher in the femur (&lt;I&gt;P&lt;/I&gt; &lt; 0.001) in female chickens and in the tibiotarsus (&lt;I&gt;P&lt;/I&gt; &lt; 0.001) in male chickens. The Ca:P ratios for both analysed bones was greater in males (femur 2.20, tibiotarsus 2.21), as compared to females (femur 1.98, tibiotarsus 2.09). The mean weight of male and female broiler chickens on Day 40 was 2 694 ± 32.6 g and 2 345 ± 23.9 g, respectively. In comparison with the expected performance parameters of ROSS 308 hybrid chickens, the weight increased in both male and female chickens by 8.2% and 10.6%, respectively. Although the chickens grew very quickly, no clinical signs indicating pathological changes in the bone system were found.

The study was conducted to determine the effect of dietary energy level and tanniniferous Acacia karroo leaf meal level of supplementation at finisher stage on performance and carcass characteristics of male and female Ross 308 broiler chickens. Three hundred and sixty, 21 days old male and female broiler chickens were assigned to twelve treatments with three replications of ten birds in a 2 (sex) x 3 (dietary energy level) x 3 (tanniniferous Acacia karroo leaf meal level) factorial, complete randomized design. Supplementation with Acacia karroo leaf meal had no effect on diet intake, digestibility and live weight of broiler chickens. However, supplementation with 9 and 12 g of Acacia karroo leaf meal per kg DM feed reduced fat pad weights in male broiler chickens by 26 and 29% points, respectively. Similarly, supplementation with 9 and 12 g of Acacia karroo leaf meal per kg DM feed reduced fat pad weights in female chickens by 26% points. These reductions were achieved without any significant reduction in feed intake and digestibility. However, the physiological explanation for this effect is not clear and it, thus, merits further investigation.

A research was conducted to determine the influence of the conventional and the free-range broiler housing systems using female broiler chicks had low hatching weight on growth performance, breast meat characteristics and some blood plasma parameters. In the conventional (totally confined) housing system sixty one-day-old female Ross broiler chicks were placed in indoor floor pens with three replicates of 20 chicks. In the free-range (partly-confined) housing system, sixty one-day-old Ross broiler chicks were placed in indoor floor pens and also accessed to a grass paddock during 44 day experimental period after 7 days old. Birds of both systems were fed the same commercial broiler diet. The free-range housing system significantly decreased the total feed intake and body weight of broilers (p<0.05). The redness (a* color) and yellowness (b* color) in breast meat were affected by the housing systems (p<0.05). The housing systems had no affect on fatty acids composition of breast meat (p>0.05). The plasma triglyceride and VLDL levels of the conventional reared birds were significantly higher than those reared the free-range (p<0.05). In conclusion, longer growth period was necessary to the free-range reared broilers.

Reevaluation of digestible amino acid requirements of male and female broilers based on different ideal amino acids ratios in starter period

An experiment was conducted to investigate the effect of dietary mercury concentrations on growth performance and relative organ weight in female broiler chickens. A total of 400 2-d-old Ross 308 female broiler chicks were housed in 40 battery cages for a 5-wk feeding trial. Birds were randomly allotted to 1 of 5 dietary treatments with 8 replicated cages. Each replicate had 10 birds per replicate. Dietary mercury concentrations were set to 0, 50, 100, 250, or 500 mg/kg by adding mercury chloride (≥ 73.9%) at the expense of the celite. At the conclusion of the experiment, 1 bird per replicate with a body weight (BW) close to the replicate mean BW (i.e., 8 birds per treatment) were euthanized by CO2 asphyxiation, then immediately dissected. The breast, liver, heart, kidney, spleen, lung, bursa of Fabricius, and small intestine were collected and weighed individually. Relative organ weight was expressed as a percentage of live BW. Results indicated that increasing mercury concentrations in diets decreased BW gain (linear and quadratic, P < 0.05) and feed intake (linear, P < 0.01) of female broiler chickens. Birds fed diets containing 500 mg/kg mercury showed less (P < 0.05) body weight gain and feed intake than those fed the control diets. However, there were no differences in feed efficiency and mortality among dietary treatments. The relative weight of the liver was increased (linear, P < 0.05) with increasing mercury concentrations in diets. There was a quadratic relationship (P < 0.01) between the relative weight of the small intestine and increasing mercury concentrations in diets. In conclusion, the concentrations of 500 mg/kg mercury in diets are toxic to female broiler chickens. The liver is likely the most sensitive organ to the toxic concentrations of mercury in diets for female broiler chickens.

Effect of dietary melamine concentrations on growth performance, excreta characteristics, plasma measurements, and melamine residue in the tissue of male and female broiler chickens

The influence of supplementing diets with various levels of organic zinc (OZ) on the performance, meat quality attributes,and sensory properties of broiler chickens was investigated. A total of 3,200 1-d-old female broiler chicks were randomlyallotted to 16 floor pens (replicates) with 200 birds per pen. A corn-wheat-soybean meal basal diet (control) was formulatedand 20 ppm OZ (20 OZ), 40 ppm OZ (40 OZ), or 80 ppm OZ (80 OZ) was added to the basal diet to form four dietarytreatments with four replicates per treatment. Live performance of broiler chickens, meat quality, and sensory propertieswere evaluated. The results showed no significant difference among the treatments for live performance of broiler chickens.Significant increases ( p<0.05) in thigh skin epidermis and dermis thickness were shown in the OZ supplementation groups;however, no effect of OZ on the thickness of back skin epidermis or dermis was found. Dietary OZ levels did not affect thepH of breast and thigh meat or the water holding capacity (WHC) of thigh meat, but the WHC of breast meat increasedsignificantly (p<0.05) when birds were fed 40 OZ and 80 OZ. Results of a sensory analysis showed no differences amongthe dietary treatments. In conclusion, dietary OZ did not affect live performance or sensory properties of broiler chickensbut did increase the WHC of breast meat and thickness of skin layers; thus, improving carcass quality in broiler chickens. Key words: organic zinc, live performance, meat quality attributes, sensory properties, broilers