• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.11
• /
• pp.1616-1623
• /
• 2008

This study was conducted to determine the effect of hot environment and dietary crude protein level (CP) on performance, carcass characteristics, meat visual quality, muscle chemical composition and malondialdehyde (MDA) concentration of tissues in broilers. Two hundred and sixteen 21-d old Arbor Acre broilers were used in a $4\times3$ factorial arrangement and randomly reared in 4 environmental chambers and fed on 3 diets with different CP levels for 3 weeks. The results showed: (1) when air temperature (AT) rose to $33^{\circ}C$, average daily feed intake, average daily gain, carcass weight, right breast meat weight, left thigh and drumstick meat weight decreased (p<0.05) and feed conversion rate decreased (p<0.05), but the ratio of carcass to live weight and of left thigh and drumstick meat weight to carcass weight increased (p<0.05). (2) There were significant differences in pH and shear force in breast meat, and shear force, L* and a* in thigh meat (p<0.01 or 0.05) among hot environments. Dietary CP level tended to affect breast meat pH and pH and L* of thigh meat (p<0.06 or 0.09). Compared to the normal temperature ($22^{\circ}C$), low temperature ($15^{\circ}C$) and hot humid (AT $33^{\circ}C$, relative humidity (RH) 80%) treatments significantly (p<0.05) decreased the tenderness of thigh meat. L* and a* value in thigh meat under high temperature treatments, regardless of RH, were higher (p<0.05) than those under normal temperature. (3) Protein content in breast and thigh meat of broilers fed under high temperature ($33^{\circ}C$) was lower (p<0.05) than that under $22^{\circ}C$, but fat content had an adverse change. High temperature ($33^{\circ}C$) increased the moisture of breast meat significantly (p<0.05). Protein content in breast meat increased significantly (p<0.05), in which fat content had an adverse change (p<0.05), when the dietary protein rose. (4) MDA concentration in liver and breast meat under hot humid (AT $33^{\circ}C$, RH 80%) treatment increased markedly (p<0.05). (5) High humidity could sharpen the bad effect of high temperature on performance, carcass yield and choice cuts, crude protein and moisture content in breast meat. It was concluded that a hot environment could affect the performance and meat quality of broiler chicks more significantly than CP level and that high humidity would aggravate the bad influence of high temperature on the broiler.

• Food Science of Animal Resources
• /
• v.31 no.2
• /
• pp.207-214
• /
• 2011

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 randomly allotted to 16 floor pens (replicates) with 200 birds per pen. A corn-wheat-soybean meal basal diet (control) was formulated and 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 dietary treatments with four replicates per treatment. Live performance of broiler chickens, meat quality, and sensory properties were 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 the pH of breast and thigh meat or the water holding capacity (WHC) of thigh meat, but the WHC of breast meat increased significantly (p<0.05) when birds were fed 40 OZ and 80 OZ. Results of a sensory analysis showed no differences among the dietary treatments. In conclusion, dietary OZ did not affect live performance or sensory properties of broiler chickens but did increase the WHC of breast meat and thickness of skin layers; thus, improving carcass quality in broiler chickens.

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.1
• /
• pp.108-115
• /
• 2013

The effects of dietary Coptis chinensis herb extract (CHE) on growth performance, blood characteristics, nutrient digestibility and meat quality of growing-finishing pigs were investigated in an 18-wk feeding trial. A total of 36 Landrace${\times}$Yorkshire-Duroc pigs with an initial body weight of $20{\pm}1.0$ kg were randomly assigned to 3 dietary treatments with 6 replications per treatment and 2 pigs per pen. A maize-soybean meal-based diet was formulated as a control diet and other treatment diets were supplemented with 0.5, or 1 g CHE/kg, respectively. After the feeding period, meat samples were collected from those pigs that had reached the market BW. During the experimental periods, growth performance and apparent total tract digestibility of dry matter and nitrogen were unaffected (p>0.05) by the dietary supplementation of CHE. Plasma erythrocytes counts were increased (Linearly, p<0.05) in response to application of CHE at the end of the experiment. Moreover, pigs fed the CHE diets had better (p<0.05) meat color, pH and water holding capacity (WHC) than pigs fed the control diet. In conclusion, dietary supplementation with CHE could increase blood erythrocytes counts and improve meat quality in growing-finishing pigs but not improve growth performance.

• Korean Journal of Poultry Science
• /
• v.43 no.3
• /
• pp.169-176
• /
• 2016

An experiment was conducted to evaluate the growth performance and meat quality traits of broilers fed a diet supplemented with dry-ground curry leaves (Murraya koenigii). A total of 750 one-day-old broiler chicks (Cobbs 500) were arranged in the experiment with a completely randomized design and allotted to one of five treatments, with $T_1-Control$ and $T_2-T_5$ curry leaves powder levels (i.e., 0.3%, 0.6%, 0.9% and 1.2%, respectively). The initial body weights, final body weights and daily feed intake were measured over an experimental period of 32 days. At the conclusion of the experiment, the carcass weights and meat quality parameters were measured. The birds fed diets supplemented with curry leaves powder had a higher weight gain (P<0.05; ADG), improved feed conversion ratio (P<0.05; FCR) and lower mortality (P<0.05) rates compared to the birds in the control group. Nonetheless, there was no difference (P>0.05) in feed intake among the dietary treatments. Similarly, supplementation of curry leaves powder had no effect (P>0.05) on the proportions of the carcass, leg meat and drumstick. No differences were (P>0.05) observed in cooking loss or the pH of meat from broilers fed the curry leaves supplemented diet. However, curry leaf supplementation affected (P<0.05) the meat water holding capacity. A sensory evaluation showed higher levels of taste and tenderness in meat from broilers fed with curry leaves powder. In conclusion, our results suggested that curry leaves powder improved the growth performance of broilers, with a lower incidence of mortality and improvement of some meat qualities.

• Nuclear Engineering and Technology
• /
• v.53 no.11
• /
• pp.3723-3740
• /
• 2021

The harsh conditions in the reactor affect the thermal and mechanical performance of the fuel plate heavily. Some in-pile behaviors, like fission-induced swelling, can cause a large deformation of fuel plate at very high burnup, which may even disturb the flow of coolant. In this research, the emphasis is put on the thermal expansion, fission-induced swelling, interaction layer (IL) growth, creep of the fuel meat, and plasticity of the cladding for the U₃Si₂/Al dispersion fuel plate. A detailed model of the fuel meat swelling is developed. Taking these in-pile behaviors into consideration, the three-dimensional large deformation incremental constitutive relations and stress update algorithms have been developed to study its thermal-mechanical performance under normal conditions using Abaqus. Results have shown that IL can effectively decrease the thermal conductivity of fuel meat. The high Mises stress region mainly locates at the interface between fuel meat and cladding, especially around the side edge of the interface. With irradiation time increasing, the stress in the fuel plate gets larger resulting from the growth of fuel meat swelling but then decreases under the effect of creep deformation. For the cladding, plasticity deformation does not occur within the irradiation time.

• Animal Bioscience
• /
• v.35 no.4
• /
• pp.567-576
• /
• 2022

Objective: An experiment was conducted to determine the effect of algae-based antioxidant containing Se yeast (EconomasE^®) on the growth performance, visceral organ weight, meat quality, and oxidative stability of broiler chickens. Methods: Nine hundred sixty, day-old male broiler chickens (Cobb, 43.97±0.55 g) were divided into three dietary treatments and allocated into 12 deep litter pens in a completely randomized design giving 4 replicate cages for each treatment. Three dietary treatments were: i) control (CON, basal diet with sufficient nutrient), ii) vitamin E (VitE, basal diet supplemented with 100 IU VitE), and iii) Algae-based antioxidant containing Se yeast (EcoE, basal diet supplemented with 0.2% algae-based antioxidant containing Se yeast: EconomasE^®). Maize soybean meal based basal diets were formulated to meet or exceed the nutrition requirement for broiler chickens. Chickens were fed ad-libitum experimental diets during the 42 days experiment period. On days 21 and 42, body weight and feed intake were measured to calculate the feed conversion ratio of the chickens. Intestine and visceral organs were measured together with meat quality and oxidative stability on days 14 and 42. Results: Chickens fed with EcoE showed improved (p<0.05) growth performance, meat quality, and higher (p<0.05) oxidative stability compared to the chicken fed on CON. Moreover, broiler chickens fed with EcoE showed similar (p<0.05) growth performance with better (p<0.05) meat quality and higher oxidative stability compared to the broiler chickens fed VitE (p<0.05). Conclusion: The algae-based antioxidant containing Se yeast can be supplemented into commercial broiler diets as a substitution of VitE while maintaining growth performance with enhancing meat quality and oxidative stability of the broiler chickens.

• Animal Bioscience
• /
• v.35 no.6
• /
• pp.884-891
• /
• 2022

Objective: Free-range systems have been increasingly available to the consumer due to increased demand for more sustainable meat-products. In the current study, the effect of free-range (FR) and cage system (CS) was explored on growth performance, meat quality and oxidation products in Italian White breed rabbits during the growing-fattening phase (5 to 13 weeks of age). Methods: Forty rabbits were randomly allotted to two treatment groups according to the rearing system, and each treatment group was replicated five times with four subjects in each replicate (20 rabbits per treatment-group). All rabbits fed the same diet as pelleted, and under FR system, no additional feeds were available to animals. Results: Rearing system had significant effect on rabbit growth performance, where CS group resulted in higher final body weight (p<0.045) and gain (p<0.029) and better feed efficiency (p<0.025) compared to FR rabbits. Most carcass traits were not affected by rearing system; however, a reduction of abdominal fat content (p<0.015) and meat lipids (p<0.034) was observed in FR rabbits. Rearing system had no effects on meat fatty acid profile, whereas meat from FR rabbits resulted less susceptible to lipid and protein oxidation compared to caged animals. Conclusion: In overall, FR system could be suggested as a substitute for conventional caged system because of FR system preserved rabbit meat from oxidation.

• Animal Bioscience
• /
• v.34 no.7
• /
• pp.1181-1192
• /
• 2021

Objective: The objective of the current study was to investigate the effects of dietary hatchery by-products (HBPs) as a replacement of fish meal (FM) on growth performance, relative organ weight, plasma measurements, immune organ index, meat quality, and tibia characteristics of broiler chickens. Methods: A total of 720 broiler chickens (3 d of age) were randomly allotted to 1 of 9 treatments with 8 replicates. Each replicate consisted of 5 male and 5 female birds. The basal diet was formulated to contain 5.0% commercial FM, whereas eight treatment diets were prepared by replacing 25%, 50%, 75%, or 100% of FM in the basal diet with infertile eggs (IFE) or a mixture of various HBPs (MIX); therefore, the inclusion levels of IFE or MIX in the experimental diets were 1.25%, 2.50%, 3.75%, or 5.00%. The diets and water were provided on an ad libitum basis for 32 d. Results: Increasing inclusion levels of IFE as a replacement of FM in diets had no effects on growth performance, plasma measurements, immune organ index, and tibia characteristics of broiler chickens. Increasing inclusion levels of IFE in diets increased (linear, p<0.05) meat lightness (L^*) but decreased (linear, p<0.05) meat redness (a^*). The breast meat pH at 1-h postmortem was increased (linear, p<0.05) by increasing inclusion levels of IFE in diets. Likewise, increasing inclusion levels of MIX in diets had no effects on growth performance, relative organ weight, plasma measurements, immune organ index, and tibia characteristics. However, increasing inclusion levels of MIX in diets increased (linear, p<0.05) 1-h postmortem pH but decreased (linear, p<0.05) 24-h postmortem pH of breast meat. Increasing inclusion levels of MIX in diets decreased (linear, p<0.05) thiobarbituric acid reactive substances values of breast meat. Conclusion: Both IFE and MIX are suitable alternatives to FM as protein ingredients in broiler diets.

• Animal Bioscience
• /
• v.34 no.9
• /
• pp.1544-1551
• /
• 2021

Objective: The purpose of this study was to investigate growth performance, carcass traits, meat quality and hair follicle development of growing Rex rabbits as affected by different environmental enrichment materials. Methods: A total of one hundred and twenty Rex rabbits were randomly assigned to four groups; reared in conventional cages (not enriched) and in enriched cages with either willow stick (WS), rubber duck, or a can containing beans (CB), for 44 days. Results: The average daily gain of the CB group was the highest and had a significant difference from that of the other groups (p<0.05). The spleen and cecum weight of the CB group was greater than those of the WS and control groups (p<0.05). The redness (Commission Internationale de l'Eclairage a^*) of the meat sample of the control group was lower than those of the enriched cage groups (p<0.05). Moreover, the hue value of the CB group was significantly lower than that of the other groups (p<0.05). The tenderest meat belonged to the CB group. In addition, more secondary (p<0.05) and primary follicles were found in the CB group than in the control group. Conclusion: Environmental enrichment increased the average daily gain and improved some carcass traits, meat quality, and hair follicle density. Among the three environmental enrichment materials, CB could be recommended for rabbit husbandry.

• Asian-Australasian Journal of Animal Sciences
• /
• v.26 no.1
• /
• pp.128-133
• /
• 2013

The objective of the study was to determine the effect of Acacia karroo supplementation on growth, ultimate pH, colour and cooking losses of meat from indigenous Xhosa lop-eared goats. Eighteen castrated 4-month-old kids were used in the study until slaughter. The kids were subdivided in two treatment groups A. karroo supplemented (AK) and non-supplemented (NS). The supplemented goats were given 200 g per head per d of fresh A. karroo leaves. The kids were slaughtered on d 60 and sample cuttings for meat quality assessment were taken from the Longistimus dorsi muscle. The supplemented kids had higher (p<0.05) growth rates than the non-supplemented ones. The meat from the A. karroo supplemented goats had lower (p<0.05) ultimate pH and cooking loss than the meat from the non-supplemented goats. Acacia karroo supplemented goats produced higher (p<0.05) $b^*$ (yellowness) value, but supplementation had no significant effect on $L^*$ (lightness) and $a^*$ (redness) of the meat. Therefore, A. karroo supplementation improved growth performance and the quality of meat from goats.