• Food Science of Animal Resources
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• v.33 no.1
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• pp.89-95
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• 2013

This research was conducted to compare the meat characteristics of Korean native duck and imported commercial duck. The Korean native ducks and imported commercial ducks (broiler duck: Grimaud) were raised under identical rearing and feeding conditions for 8 wk and 6 wk, respectively. At the end of the rearing period, ten ducks from each group were slaughtered, and breast and leg meat were obtained 24 h after slaughtering for analyses of meat characteristics. The results showed that the breast of Korean native ducks contained lower moisture and fat, and higher protein and water holding capacity (WHC) than those of imported commercial ducks (p<0.05). The breast of Korean native ducks also had higher CIE $a^*$ and lower CIE $L^*$ (p<0.05). After cooking, the breast meat of Korean native ducks had higher shear-force, sensory attributes of texture, taste and overall likeness (p<0.05). Also, the breast meat of Korean native ducks contained a higher percentage of palmitic acid ($C_{16:0}$) and arachidonic acid ($C_{20:4}$) (p<0.05) than those of imported commercial ducks. Furthermore, the leg meat of Korean native ducks contained higher percentages of total unsaturated fatty acid and lower percentages of total saturated fatty acid (p<0.05). It is concluded that the meat from Korean native ducks, especially breast meat, had better quality parameters and contained higher amounts of unsaturated fatty acids.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.2
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• pp.155-159
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• 2000

In the spring silkworm rearing period of year 1998, some nutritional aspects were studied in the Agricultural Research Station of the Komotini town in Greece, to investigate the feeding behaviour of some Bulgarian silkworm hybrids, suitable for spring rearing, during the fourth and fifth instal under the local climatic conditions. The silkworms were fed by locally cultivated Japanese Kinriu mulberry (Morus alba L.) variety leaves. Eight Bulgarian hybrids had been used, namely Vratza-53xVratza-52, Ukraine-20xVratza-53, Super 1xHessa 2, Merefa 2xVratza 35, as well as their reciprocal crosses. The studies showed out a remarkably higher feed intake and feed utilization by the hybrids Hessa 2xSuper-1, Merefa 2xVratza 35 and Vratza-52xVratza-53. The same hybrids showed an efficient food utilization by means of daily growths cocoon shell ratio and raw silk output. In terms of food to silk conversion efficiency Hessa 2xSuper-1 hybrid gave the best results. Larval stage duration for fourth and fifth instar was not affected by feed intake and utilization. All hybrids showed a good adaptation to the local environment and their feeding performance was equal to the international existing standards. All calculated parameters were found to be around the mean values of other up to date presented results and thus considered as acceptable for the needs of the local production.

• Fisheries and Aquatic Sciences
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• v.26 no.8
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• pp.461-469
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• 2023

The objective of this study was to evaluate how the tank colours may change the effects of extreme temperature on the survival, growth, and quality of juvenile golden trevally (Gnathanodon speciosus). The experiment was set up with fifteen treatments of five tank colours (blue, red, yellow, grey, and white) and three temperatures (30℃, 32℃, 34℃) with three replications. Fish performance was assessed for four weeks. The results showed that tank colours and elevated temperatures affected the quality of golden trevally juveniles. The survival and growth rate of fish tend to decrease gradually, but the deformation rate of fish tended to increase in the order of tank colours: red, yellow > grey, blue, and white. The growth and survival rate of fish gradually decreased when the rearing temperature increased from 30℃ to 34℃ and this effect was independent of tank colors. Importantly, the deformation rate increased under elevated temperature, particularly in blue and white tanks with potential long-term effects. It is, therefore, not recommended to use blue and white tanks for rearing the golden trevally juveniles, particularly during extremely high temperatures from heatwave events.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.4
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• pp.559-568
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• 2012

White (Lohmann LSL) and Brown (ATAK-S) laying hens, were reared under organic and conventional cage rearing systems, and the effects of the rearing system on performance parameters, egg production, egg characteristics, and immune response were investigated. For this purpose, a total of 832 laying hens of two commercial hybrids, i.e., 416 white (Lohmann LSL) and 416 Brown (ATAK-S) layers, were used. The experiment lasted between 23 and 70 wk of age. In this study, the white layers yielded more eggs as compared to the brown layers in both organic and conventional production systems. Egg weight exhibited a similar pattern to that of laying performance. However, the total hen-housed egg number for the white birds in the organic system was fewer than that of white birds in the conventional cage facility; conversely, a contradictory tendency was observed for the brown birds. Livability of the white layers in the organic system was remarkably lower (14%) than that of the brown line, whereas the white line survived better (3.42%) than their brown counterparts in conventional cages. The feed conversion ratio of the white hens was markedly inferior in the organic system as compared to that of the white hens in the conventional system, whereas relatively lower deterioration was reported in brown layers when reared in an organic system. The organic production system increased egg albumen height and the Haugh unit in eggs of the brown layers. The yolk color score of organic eggs was lower than that of conventional eggs for both brown and white hens. The egg yolk ratio of eggs from white layers was found to be higher in organic eggs as compared to those obtained in the conventional system. All organic eggs had heavier shells than those produced in the conventional system. Eggs from brown layers had more protein content than eggs from white layers. Neither housing systems nor genotype influenced egg yolk cholesterol concentration. When compared to conventional eggs, n-3 fatty acid content was lower in organic eggs, and the n-6:n-3 ratio was higher in organic eggs. In conclusion, two hen genotypes showed different responses in terms of performance and egg quality to two different rearing systems. A commercial white strain produced more eggs with higher egg quality as compared to a native brown strain. The brown strain was found to have adapted well to organic production conditions when survival and total egg number was taken into consideration.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.2
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• pp.262-269
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• 2008

The aim of this study was to determine the effects of breeder age and stocking density on performance, carcass characteristics and some stress parameters (H-L ratio, serum glucose, cholesterol and triglyceride levels, tonic immobility test (TI), antibody production, relative asymmetry (RA) and external appearances). This experiment was carried out with 705 one-day old male broiler chicks (Ross 308) obtained from three different ages of broiler breeder (32, 48 and 61 wks). Each age group was randomly divided into two stocking density groups (11.9 and 17.5 broilers per $m^2$) with 5 replications per group. The experimental period was 6 weeks. Broilers from 32 wk-old breeders had lower initial weight (p<0.001), body weight gain of the first 3 week of rearing (p<0.01), the percentage of abdominal fat (p<0.001) and serum cholesterol level (p<0.01); higher percentage of gizzard (p<0.01) and longer TI duration (p<0.001) than those from 48 and 61 wk-old breeders. Broilers reared at 17.5 b/m2 had lower final BW, body weight gain, feed consumption, feather condition and foot health (p<0.001), higher percentage of heart, H-L ratio, serum glucose and cholesterol levels (p<0.001), and longer TI durations (p<0.001). There were no significant interactions in examined parameters except for feed to gain ratio between breeder age and stocking density.

• International Journal of Industrial Entomology and Biomaterials
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• v.28 no.2
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• pp.32-38
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• 2014

Food consumption and conversion efficiency of eri silkworm Samia ricini Donovan were studied during $4^{th}$ and $5^{th}$ larval instars by feeding castor leaves fortified with 100, 200, 300, 400 and 500 ppm concentrations of aqueous extracts of cyanobacteria Anabaena variabilis. The nutritional indices viz., ingesta, digesta, approximate digestibility (%), reference ratio and efficiency parameters like ECI and ECD were recorded which were significantly high at 400 ppm concentration treated batches of $4^{th}$ instar larvae over control batches. The decline in nutritional efficiency parameters of $5^{th}$ instar treated larvae might be due to higher utilization of the digested food for metabolic activities. Significant difference of ECI to cocoon % and non-significant difference of ECD to cocoon% and shell were observed between the treatments and control. Cyanabacteria feed supplement contains antibiotic and nutritions factors which has reflective effect on the biological parameters in eri silkworm and therefore has greater application in commercial eri silkworm rearing.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.7
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• pp.1038-1047
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• 2008

This study aimed at targeting fixed increases in body weight (100 g/wk) by quantitatively regulating energy allowances (ME) in broiler breeders from 5 to 20 wks of age. Four energy regimes were tested: 1. The energy required for maintenance, activity and growth was calculated for 100 g increases in body weight/wk and a measured quantity of grower diet (160 g protein and 2,600 kcal ME/kg) was offered to the control group (ME-100) to achieve the anticipated weight gain. The energy allowances increased with age from 132 to 294 kcal/d. 2. Additionally, three energy regimes were considered, quantitatively reducing ME by 10% (ME-90) or 20% (ME-80) and increasing by10% (ME-110) over the control group. Each test group had 23 replicates5 female chicks housed in cages. The influence of energy regimes and age on growth, nutrient digestibility, carcass attributes, bone parameters and stress was evaluated at 4 wk intervals. Quantitative ME restriction by 10% (119-265 kcal/d) produced an average weight gain of 98.1 g/wk, which was closer to the targeted increase of 100 g/wk, whereas the control group attained it nine days earlier. Restriction of energy by 10 or 20% produced better conversion efficiency of feed, energy and protein and apparent digestibility of protein, Ca and P than 10% excess ME. Energy regimes did not influence eviscerated meat yield, but higher energy allowances (ME-110) significantly increased abdominal fat pad and liver weights and decreased giblet weight, percent muscle protein and tibia ash. Relatively higher stress was recorded in ME-restricted groups, as reflected by wider heterophil and lymphocyte ratios and increased bursa weight. Early age (5-12 wk) significantly influenced bone mineralization, conversion efficiency of feed, energy and protein and apparent digestibility of protein, Ca and P, while later ages (13-20 wk) increased eviscerated meat yield, abdominal fat, tibia weight and muscle protein and reduced stress. Energy regime x age interactions were significant and are discussed. In conclusion, the synthetic broiler line used in our study responded positively to controlled energy feeding during the rearing period. Breeders offered 119-265 kcal/d, a reduction of 10% energy over the control group, were more effective in regulating grower performance than the latter. In addition to energy regimes, age intervals also exhibited significant influence on specific parameters during the grower phase.

• International Journal of Industrial Entomology and Biomaterials
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• v.9 no.1
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• pp.79-87
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• 2004

The silkworm rearing and growth parameters of 63 multivoltine silkworm accessions under extended period of egg preservation at 5$^{\circ}C$ from 30 days to 45 days were studied. The results indicate that, nine accessions did not respond to extended period of egg preservation at low temperature and the remaining 54 accessions responded to the treatment and three rearings were conducted for comparision with the control; to estimate the effect of prolonged egg preservation at low temperature. The non-parametric tests statistics (Wilcoxon tests) was adopted for comparing the mean performance of treated batches (45 days) over the control (30 days). Highly significant variability was found among the accessions for all the parameters under study. The genetically controlled morphological characters were not altered in the treated batches, which were found to be on par with that of control. However, the total larval duration varied significantly over the control in 51 accessions. Similarly, the fifth age larval duration of 27 accessions showed decreasing trend compared to control. Altogether 41 accessions were found to be tolerant to long-term cold preservation upto 45 days, without showing any significant variation for morphological as well as essential quantitative traits. These accessions may be recommended for long-term egg preservation schedule up to 45 days, which will reduce the cost of conservation of these silkworm germplasm.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.6
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• pp.914-922
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• 1999

An experiment was conducted to determine the effects of dietary energy and protein on performance and carcass composition of broilers under heat stress during the growing period (3-6 weeks). A factorial arrangement of three levels of energy (3.0, 3.2 and 3.4 kcal/g), three levels of protein (18, 20 and 22%), an two rearing temperatures were used in this study. Groups of birds were kept under moderate temperature ($24{\pm}1^{\circ}C/24h$) or hot cycling temperature ($26-34^{\circ}C/6h$, $34{\pm}1^{\circ}C/12h$, and $34-26^{\circ}C/6h$). Body weight (BW), weight gain (WG), feed intake (FI), feed conversion (feed : gain) (FC), carcass weight (CW), carcass yield (YP), breast meat (BM), abdominal fat (AF), drumsticks (DS), and thighs (TH) percentages were determined at the end of the experiment. Hot cycling temperature significantly (p<0.05) decreased BW, WG, FI, CW, and BM, increased FC, YP, DS, and TH but did not affect AF. High energy significantly (p<0.05) increased BW, WG, CW, YP, AF, and TH, decreased FI and FC but did not affect BM or DS. This improvement was observed only under moderate temperature resulting in significant (p<0.05) energy by temperature interaction. High protein significantly (p<0.05) increased BW, WG, CW and BM, decreased AF but did not affect FI, FC, TP, DS, or TH. There were no significant protein by temperature interactions for any of the parameters tested except CW. It is concluded, under the conditions imposed in this experiment, that increasing dietary energy did not alleviate the depressing effect of heat stress while increasing dietary protein up to 22% improved the performance of broilers irrespective of rearing temperature.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.4
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• pp.599-603
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• 2015

The objective of the current pilot study was to evaluate the reproductive performance and health indicators in Dorper, White Dorper, and Tsigai breed ewes managed semi-intensively under European temperate conditions. A total of 544 ewe-year units were observed, with ewes (ranging from 1.5 to 8 years of age) managed under identical rearing conditions for a period of two consecutive production cycles (2012 through 2013 and 2013 through 2014). In general, significant ($p{\leq}0.001$) genotype-related disparities were found in occurrence rates for all health parameters taken into study. Clinical mastitis incidence was significantly lower ($p{\leq}0.05$) in Dorper (9.4%) and White Dorper (10.8%) breeds compared to that of Tsigai ewes (17.4%). Significant differences ($p{\leq}0.05$) for lameness were found between Dorper and Tsigai breeds, with occurrence rates of 8.0% and 2.9%, respectively. Incidence for pneumonia and abortion was not influenced (p>0.05) by the ewes' genotype. Litter size was significantly lower ($p{\leq}0.05$) in White Dorper breed than for Dorper and Tsigai ewes, of 1.21, 1.40, and 1.45, respectively. Conception rates and lambs survival were not affected (p>0.05) by genotype. Results suggest that South African Dorper and White Dorper sheep breeds have adapted well to the specific rearing conditions.