• Korean Journal of Agricultural Science
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• v.48 no.1
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• pp.171-178
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• 2021

A comparative study was conducted to examine the effects of mixed and separate gender feeding on growth performance of Korean native chickens (KNC) against a white semi-broiler (WSB) and a commercial broiler (CB) over five weeks. 576 chicks were used with eight birds per cage in a randomized complete block design with 18 replicates per breed. For the KNC lines, three groups of male (M), female (F) and mixed-gender (FM) were used. Fresh water and feed were supplied on an ad-libitum basis. Birds were fed a standard starter (d 1 - 22) and grower diet (d 23 - 35). Body weight (BW), feed intake, and shank length (SL) were measured weekly. From the BW and feed consumed data, the average daily feed intake (ADFI), average daily gain (ADG), and feed conversion ratio (FCR) were calculated. The commercial broiler showed higher performance (p < 0.05) for all the indices measured for the entire period. The CB group consumed more feed and were more feed-efficient thus grew faster. This group was followed by the white semi-broiler and the KNC, in order. An intra-breed comparison for KNCs revealed that the males showed better growth performance with longer SL (p < 0.05) compared to the female and mixed-gender groups. The results showed that other than the breed type, mixed and separate gender feeding impacted on the growth performance of the two lines of Korean native chickens. Males for both lines of KNC generally performed better for the parameters measured, as determined by a greater BW and reduced FCR.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.7
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• pp.987-997
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• 2016

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 $pH^{15}$ values in breast meat, and for crude ash, crude protein, and $pH^{15}$ 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.

• Animal Bioscience
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• v.34 no.11
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• pp.1829-1838
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• 2021

Objective: The effects of maternal dietary energy levels on breast muscle fibre development in offspring of broiler breeders were investigated. Methods: A total of 480 20-week-old Arbor Acres (AA) healthy female broiler breeders, with an average body weight of 2.33±0.01 kg, were randomly divided into 4 treatment groups with 6 replicates and 20 broiler breeders for each replicate and fed a corn and soybean meal diet with 100%, 80%, 70%, and 50% energy levels, respectively. Approximately 300 eggs per treatment were collected for incubation for 6 days. Then, 120 0-day-old female broilers at each energy level were randomly selected and divided into 6 replicates with 20 broilers for each replicate, with this experimental phase with the offspring lasting for 49 days. Results: Compared with the 100% energy group, the breast muscle fibre diameter at embryonic day 21 in the 80% energy group was significantly reduced (p<0.05). In the 80% energy group, the muscle fibre density of the breast increased significantly (p<0.05) at embryonic days 15 and 21. The breast muscle fibre diameter of the offspring in each group was significantly decreased (p<0.05) on the 1st day. The breast muscle sarcomere length of the embryos in the 80% energy group was significantly higher (p<0.05) than those in the 70% and 50% energy groups. Compared with the 100% energy group, the expression of the myostatin gene in the offspring was significantly decreased (p<0.05). Conclusion: In conclusion, the effects of a maternal dietary energy level of 80% in this study were found to be optimal for breast muscle fibre development in offspring, which indicated that the metabolic energy level of AA broilers of 9.36 MJ/kg for the mid-term diet for laying eggs has a more practical significance.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.1
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• pp.118-125
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• 2019

Objective: This study investigated the effects of soapnut (Sapindus mukorossi) shell powder (SSP) on serum hormone level, egg quality, semen characteristics and reproductive performance of broiler breeders fed with a maize-soybean meal based diet. Methods: Ninety six female and twenty four male CARIBRO-VISHAL broiler breeders, 38-week old, were individually caged and randomly allocated to four treatment groups (24 female breeders/treatment and 6 male breeders/treatment): an un-supplemented control (T1) and three groups with 0.0176% SSP (group T2), 0.026% SSP (group T3) and 0.0528% SSP (group T4), to have supplementary saponin at 0, 50, 75, and 150 ppm, respectively, for 42 days. Results: The results indicated that serum (p<0.001) and seminal plasma (p<0.05) testosterone level, semen volume (p<0.001), mass motility (p<0.001), and live spermatozoa count (p<0.001) was increased in groups T3 and T4 compared to T2 and control groups. Compared with control group, total sperm count was increased (p<0.001) and dead spermatozoa count was decreased (p<0.001) in SSP supplemented groups. Supplementation of SSP did not affected the quality of egg lay. Compared with control group, fertility (p<0.01) and hatchability (total eggs set and fertile eggs set) (p<0.001) were significantly improved in SSP supplemented groups with the highest improvement in T3 treatment group. Embryonic death was decreased (p<0.001) in SSP supplemented groups compared to control; lowest embryonic death was recorded in T3 treatment group. Conclusion: Thus, it was concluded that dietary supplementation of 0.026% SSP (saponin equivalent 75 ppm) improved the reproductive performance of broiler breeders.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.9
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• pp.1376-1382
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• 2008

The carcass characteristics and composition of both male and female commercial broiler chickens (CB) and the red jungle fowl (RJF) were compared at a common body weight of $800{\pm}25.6g$. The RJF and CB were 133 and 17 d of age, respectively, when they reached 800 g. The yields of breast and thigh portions and their muscle to bone ratios were higher for RJF as compared to CB. On the other hand, the latter had significantly greater hearts, livers and gizzards. The weights of the whole thigh and drumstick, and their muscles were lower in females than males. The CB had more abdominal fat than RJF. While sex had no significant effect on the absolute weights of abdominal fats in CB, the female RJF were fatter than their male counterparts. The fat and cholesterol contents of the breast and leg muscles of CB were significantly higher than those of RJF. The opposite was noted for protein content of both muscles. The effect of sex on fat and cholesterol contents varied according to muscle type. Comparison of CB and RJF at a common body weight suggested that the rate of development of body components have changed concomitantly with selection for rapid growth in the former.

• Korean Journal of Poultry Science
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• v.12 no.2
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• pp.53-57
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• 1985

This study was carried out to estimate genetic correlations among broiler body weights for the selection of broiler breeders at early age, and to investigate the difference of growth rates between male and female in mixed-sex population of broiler from 2wks to 8 wks of age. A total of 1109 records were used in this study. the heritability estimates from combined variance components for 2-,4-, 6- and 8- weeks body weights were 0.32, 0.31, 0.35 and 0.29 respectively. Genetic correlations were 0.91 between 4wks and 8wks body weights, 0.94 between 6wks and 8wks body weights. Records obtained on 4wks and 8wks might be useful in a selection program to improve traits in 8wks broiler weight. Growth rates of male and female from nonlinear equations from 2wks to 8wks were shown differently in both linear and quadratic terms, Even though both sexes showed closely equal body weights at 2wks of age, they manifested great difference about 300g at 8wks of age. At all. ages roles were havier, grew at a faster than female. From this result it might be profitable either to select the combination of lines which has little sex effect or to rear male and female broiler separately up to the marketing body weights.

• Korean Journal of Poultry Science
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• v.29 no.3
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• pp.185-194
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• 2002

This study was conducted to compare the biochemical properties on chicken meat among Korean Ogol Chicken(KOC), the Cross-bred Ogol chicken(CBO), and broiler(BRO). The results were as follows: the total protein content of the CBO was significantly(P<0.05) higher by 0.83% in male and by 1.37% in female than that of KOC. In the total protein content, CBO also had significantly(P<0.05) higher percentages than that of BRO(21.73%). In the total fat content of CBO, there was a significant (P<0.05)difference between male(0.69%) and female(0.91%). However, on the regarding both sexes the total fat content percentage of CBO was a greatly lower than that of BRO(1.92%). The CBO showed a significantly (P<0.05) higher calcium ion content, with 103.67 ppm and 118.00 ppm in male and female, respectively, than traditional broiler breed(73.80 ppm). But KOC and CBO contained similar calcium ion content in each other. The CBO contained significantly(P<0.05) higher essential amino acids(cystine, serine, lucine, phenylalanine, arginine, proline) than the BRO. In fatty acid composition, the CBO contained higher unsaturated fatty acids, with 34.22 and 26.23% for male and female, respectively, than the KOC containing 29.76 and 24.59% fur male and female, respectively. These were substantially higher levels compared to 19.59% in BRO. Higher trend in Docosa hexaenoic acid(DHA) level was observed in the CBO(5.47% and 2.89% for male and female, respectively) compared to the KOC(2.92% and 1.00%). While DHA in the broiler meat was not detectable. In the ratio between n-6 and n-3, the CBO(3.87∼6.14) appeared to have a better profile than BRO(25.71). The brightness of Commision Internationale do L＇Eclairage for CBO were 56.97 and 58.06 for male and female, respectively. Whereas broiler meat showed 62.88. Collectively, these color properties were higher than KOC.

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

• Korean Journal of Poultry Science
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• v.30 no.2
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• pp.91-94
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• 2003

Artificial insemination of cryopreserved semen is not practiced in broiler breeder industry although its benefit has been recognized for years. Thus, the present study explored the possibility of artificial insemination with cryopreserved semen in Ross broiler breeders. Sixty Ross female broiler breeders were artificially inseminated either with fresh or with cryopreserved semen pooled from five male Ross broiler breeders. On.e hundred eighty eggs were collected from each semen treatment and hatched. Fertility and hatchability of fertilized eggs collected from hens artificially inseminated with cryopreserved semen were 68.0 and 47.1％, respectively, compared to 88.3 and 87.2％ with fresh semen. Both unfertilized eggs and dead embryos during hatch were significantly (P<0.05) higher in the cryopreserved semen­treated group by approximately 2.7­ and 3.2­fold than the fresh semen­treated counterparts. the moderately low fertility and markedly low hatchability of fertilized eggs obtained from cryopreserved semen observed in this study may be of practical interests in broiler breeder industry and deserves further study.

• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.167-181
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• 1991

In order to study the effects of dietary yeast (Saccharomyces cerevisiae) products on the performance of broiler chickens, tow feeding trial using Arbor Acres strain were conducted. In experiment 1, 200 hatched male broiler chickens were divided into groups of 10 birds each and four groups were given each of the five dietary treatments : control, 0.25% yeast culture supplemented (YC-0.25%), 2.5% yeast culture supplemented(YC-2.5%), 0.05% live yeast supplemented(LY-0.05%) and 0.1% live yeast supplemented(LY-0.1%) . In experiment 2, 240 hatched broiler chickens(120 birds in each sex) were assigned to 2$\times$3(sex$\times$feed) factorial design Dietary treatments were control, 0.1% live yeast supplementation in finisher diet(LY-Finisher) , and 0.1% live yeast supplementation in whole period (LY-Whole). Results of experiment 1 showed that weight gain, feed intake and mortality were not significantly different among treatments. However, weight .gain of YC-0.25% and LY-0.1% tended to be greater than other treatments after 3wks of age Feed efficiency of LY-0.05% was poorer than those of control, YC-0.25% and LY-0.1% . Although nutrients availabilities were not significantly different among treatments, availiabilities of Ca and P were greater in yeast products supplemented groups than in control group. The number of Lactobacillus spp., Streptococcus spp . and yeast in small intestine tended to be greater in supplemented groups while that of Coliforms bacteria tended to be greafter in control group. In experiment 2, there were significant effects of factors (feed and sex) and interaction on growth rate. LY-Whole groups showed best weight gain in male while LY-Finisher groups did best in female broiler chickens. Feed intake and mortality were significantly higher in male broiler chickens. Feed$\times$sex interaction had a significant effect on feed efficiency. LY-Whole groups showed best feed efficiency in male while LY-Finisher did best in female broiler chickens. Availabilities of dry matter, Ca and P were higher in male than in female broiler chickens. Availabilities of Ca and P were higher in live yeast supplemented groups than in control groups. Live yeast supplemented groups tended to have greater number of Lactobacillus spp . and yeast in the small intestine and Stre))tococcu spp. in the small intestine and cecum, and lesser number of Coliforms bacteria in the small intestine The pH of small intestinal contents tended to be higher in live yeast supplemented groups.