• 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.15 no.2
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• pp.73-79
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• 1988

In order to study the effects of feeding time (08：00 and 14：00 hours) and frequency (once a day, twice a day and once every other day) on the performances of broiler breeder hens, two experiments were conducted with 1, 248 hens of Maniker strain during 24－2 weeks (Experiment 1) and 42－60 weeks (Experiment 2) of age. The results obtained are summarized as follows ： 1. No significant differences were observed in hen－day egg production and feed conversion rate between feeding times or among feeding frequencies through the entire experimental period. 2. Mean egg weight during the age of 24－42 weeks was significantly increased by feeding in the afternoon (p＜0.01). But it was not significantly affected by feeding time or frequency during 42－60 weeks of age. 3. Fertility and hatchability of eggs at 36 weeks and 60 weeks of age were not significantly different among treatments. 4. By feeding in the afternoon egg breaking strength at 60 weeks of age was significantly improved (p＜0.05), but not at 36 weeks of age. 5. In diurnal distribution of egg production, hens fed in the afternoon produced more eggs in the afternoon than hens fed during the morning (p＜0.01).

• Korean Journal of Poultry Science
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• v.29 no.2
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• pp.89-94
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• 2002

This study was performed to evaluate effects of different holding temperatures and storing periods during the pre-incubation period on egg hatchability of hens egg in broiler breeders. For the treatments 1(T1)~7(T7), which were stored fur 1(T1) to 7 days(T7) before egg incubation, respectively. There were three replicates per treatment and forty eggs per replicate. This study was performed twice, which were 40(Summer) and 50 weeks of age(Autumn) in broiler breeders. Storing ambient temperature of egg, egg weight, at 0 and 18 days during incubation, fertility, hatchability and embryo mortality were examined. Average hatchability was rapidly decreased only in Summer. Although it was not significantly different in Autumn. This experiment was concluded that storing periods of hatchery egg was influenced hatchability, especially in high ambient temperature conditions(Summer, above $25^{\circ}C$ ). In conclusion, we found out that optimum hatchability can be achieved with a storage temperature of 13 ~$19^{\circ}C$ for broiler breeder eggs stored for up to 7 days.

• Korean Journal of Poultry Science
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• v.30 no.2
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• pp.101-106
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• 2003

In order to study the optimum daily protein allowance for broiler breeders of 24 to 64 weeks of age on a control-fed basis, an experiment was carried out with 400 hens of Arbor Acres strain. Four levels of protein allowances were used to supply 18 to 24g of protein per day in 2g increments. As the age of hens increased, a same stepwise increase and decrease in daily energy allotment was used in all treatments. Same amount of calcium, phosphorus, methionine and lysine were supplied in all treatments and throughout laying period. Hen-day egg production was highest in hens receiving 20g protein per day(p<0.05), but there was no significant difference among those fed daily protein ranging 18 to 22g, and increasing the daily protein allotment up to 24g resulted in a significant decrease(p<0.05). Average egg weight showed a trend to increase as the daily protein allowance increase(p<0.05), but no significant difference was found among the hens fed daily protein 20 to 24g. Feed and ME conversion was superior in hens receiving 20g daily protein(p<0.05). CP conversion was increased as the daily protein allowance increase(p<0.05), but there was no significant difference between hens receiving 18 and 20g daily protein. Feed cost required per egg or per kg egg was lowest in hens fed 20g daily protein. It could be concluded that the optimum daily protein allowance was 20g in all performances.

• Korean Journal of Poultry Science
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• v.49 no.4
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• pp.247-253
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• 2022

This study was conducted to investigate the effects of γ-aminobutyric acid (GABA) and a probiotic mixture on egg quality, blood parameters, and corticosterone content in broiler breeder stock in summer in Korea. A total of 72 broiler breeders (Arbor Acres) at 49 weeks old were randomly divided into the following three groups of 24 heads each: control, GABA, and probiotics (1 × 10⁸/g Bacillus licheniformis, 1 × 10⁷/g Lactiplantibacillus plantaru, and 1 × 10⁷/g Clostridium butyricum). The hens were fed a diet containing 50 mg of GABA/kg of feed and 0.1% probiotics for 6 weeks. Egg quality, blood parameters, and stress levels (corticosterone concentration) of the broiler breeders were evaluated. No significant differences were observed in the egg weight, albumen height, Haugh units, yolk color, shell thickness, or shell strength between the groups. There were no significant between-group differences in the blood biochemical profile, including total cholesterol, triglyceride, glucose, total protein, aspartate aminotransferase, alanine aminotransferase, albumin, and inorganic phosphorus concentrations. The corticosterone concentration was significantly lower in the GABA and probiotics groups than the control group (P < 0.05) at 6 weeks of age. In conclusion, these results suggest that dietary probiotics and GABA significantly improve the stress levels of broiler breeders in summer in Korea.

• Korean Journal of Poultry Science
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• v.33 no.3
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• pp.225-231
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• 2006

To investigate the effect of feeding rare earth (RE) on the performance of breeder hens a feeding trial with sixteen thousands of 158 day old Ross broiler breeder hens was conducted for thirty weeks. A mixture of RE- chlorides containing mainly La, Ce, and Pr was mixed into corn-soy based diet at two levels, 300 and 600 mg/kg, All the hens were housed in flat layer houses and the ratio of male to female was maintained at one to ten. Dietary supplementation of the of RE at a level of 300 mg/kg made the hens reach egg production peak higher by about 6% and earlier by about two weeks. As a result, it made higher hatchable egg production by 3.5%. It also reduced dramatically the mortality of both male and female breeders(P<0.05). Egg weight was slightly increased but egg qualify was not much influenced by dietary supplementation of RE. Egg albumin hight and Haugh unit were significantly improved while egg shell thickness, egg breaking strength and yolk color were similar to those of the control. Experimental results appeared to show a good possibility that egg fertility and hatchability were improved by feeding RE. Dietary supplementation of RE at a level of 300 mg/kg should be acceptable but not the 600 mg/kg level for breeder hens. Further studies on the effect of RE on egg fertility and hatchability appears to be necessary.

• Korean Journal of Poultry Science
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• v.31 no.4
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• pp.299-306
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• 2004

The objective of this study was to investigate the influence of egg storage, broiler breeder age, and the change of egg weight during incubation on growth rate of chicks and 43-day-old dressing percentage. The trials involved hatching eggs obtained from 27-wk-old hens and stored for 6 d for the Young-EXP group, from 28-wk-old hens and stored for 0 d for the Young-CON group, from 51-wk-old hens and stored for 6 d for the Old-EXP group, and from 52-wk-old hens and stored for 0 d for the Old-CON group, The hens were two commercial broiler breeder flocks of the same strain (Cobb) but of different egg producing stages(early and middle stages of egg production). The chicks were grown on floor pens for 6 wks, The differences of setting egg weights between Old-CON and Old-EXP groups were 1 g, but those between Young-CON and Young-EXP groups were 2.9 g(P<0,05). The loss of egg weight during 18 d incubation did not greatly differ among four groups, but the loss of egg weight during 21 d incubation was significantly (P<0.05) more in the middle stage of egg production groups than in the early stage of egg production groups. The mean birth weights of the middle stage of egg production groups were significantly(P<0,05) heavier by 8,7 g than those of the early stage of egg production groups; however, the differences of 6-wk-old body weight were not significant between egg producing stages. The differences of body weights in both egg producing stages were not significantly influenced by egg storage period in overall wks of ages. Egg storage and hen age did not greatly influence to the 43 d dressing percentages, either, The correlations of the setting egg weight with 18 d egg weight during incubation, growth rate of chicks, or 43 d dressing percentage were not significant.

• Korean Journal of Poultry Science
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• v.30 no.4
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• pp.229-233
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• 2003

A study was conducted to investigate the effects of different BW control methods during rearing on laying performance of broiler breeder pullets. D-old 540 female breeder chicks (Arbor Acres) were assigned to three treatments consisted of standard BW (Control), 110% of standard BW at 12 wk of age (T1), and 90% of standard BW at 12 wk of age (T2), with three replicates of 60 birds per replicate (pen) for each treatment. At 20 wk of age, all birds from three treatments reached the BW reqired in the Arbor Acres Manual. There were no significant differences in egg production, egg weight and viability during laying period(p>0.05). However, total egg production rates were improved in T2 and T3. Average egg weight was the highest in T1 among all treatments. Fertility and hatchability were similar among treatments, but T2 tended to be higher than other treatments at 37 and 53 wk of age. No significant difference was found in hatchability among three treatments. The number of hatching egg of T2 reached 168 per year, showing higher number of eggs than did the other treatments. The number of hatched chicks in T2 was 131, which was also higher than the other treatments, but the difference was not significant. It appears that the laying performance of broiler breeder hens could be improved when their BW at 12 wk of age are kept at 90% of standard BW, and reach the standard BW at 20 week of age.

• Korean Journal of Poultry Science
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• v.30 no.3
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• pp.169-175
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• 2003

This experiment was conducted to study the optimum energy feeding regimens fur broiler breeders peaked in winter season with 400 caged hens of Ross strain. Four energy supply regimens which were different in daily energy allotment during laying period were employed for 40 weeks from 24 to 64 weeks of age. All experimental diets were formulated to contain 2,750 kcal ME/kg with adjustments made in total feed allotment to provide the desired energy levels. Total consumption of the feed would provide 20 g of protein, 4 g of calcium and 0.35 g of available phosphorus. There were no difference in hen-day egg production and average egg weight among the regimens of energy supply. Feed, ME and feed cost required per egg or per kg egg were significantly increased as the level of energy allotment increased(p<0.05). It was concluded that the energy supply regimen, which supplied 280 kcal ME per day at the age of 24 weeks and then increased the energy supply up to 400 kcal ME per day at the peak period of 30∼34 weeks of age, was superior in feed, ME and feed cost required per egg or per kg egg without any adverse effect on eg production and egg weight.

• Korean Journal of Poultry Science
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• v.30 no.2
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• pp.107-112
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• 2003

This experiment was conducted to study the optimum energy feeding system for broiler breeders peaked in summer season with 400 caged hens of Ross strain. Four of energy supply series which were different in daily energy allotment during laying period were employed for 40 weeks from 24 to 64 weeks of age. All experimental diets were formulated to contain 2,750 kcal ME/kg with adjustments made in total feed allotment to provide the desired energy levels. Total consumption of the feed would provide 20 grams of protein, 4 grams of calcium and 0.35 grams of available phosphorus. There were no significant difference in hen-day egg production and average egg weight among the series of energy supply, but egg production showed a trend to decline as the level of energy allotment increased. Feed, ME and CP conversion and feed cost required per egg or per kg egg were significantly increased as the level of energy allotment increased(p<0.05). It was concluded that the Treatment 1, which supplied 280kcal ME per day at the age of 24 weeks and then increased the energy supply up to 400kcal ME per day at the peak period of 30∼34 weeks of age, was superior in all production parameters.