In order to contribute to a better understanding of the biodiversity of local chicken populations, this study focused on the description of the essential qualitative parameters in the phenotypic characterization of lo...In order to contribute to a better understanding of the biodiversity of local chicken populations, this study focused on the description of the essential qualitative parameters in the phenotypic characterization of local species. Conducted in 6 localities in the Far North Region of Cameroon (Doukoula, Yagoua, Guidiguis, Dziguilao, Maroua 3rd and Méri), a population of 240 local chickens, including 172 hens and 68 cocks were characterized in family farms. The choice of localities was made on the basis of their strong potential local chicken flocks in the region. To this end, each animal was the subject of a qualitative description based on the identification of the sex of the animal, the description of the colorations of the plumage and extremities, and the description of the types of format, plumage and crests. All observations were made with the naked eye and in daylight and then photographed. The main results show that the plumage colors are multiple and dominated by the White-Pied-Black (21.7%) and the Mille-fleur (20.8%);the wattles are dominated by the red (60%) and the pink (35.4%);the tarsi are dominated by the white (43.8%) and the black (32.08%);the white skin (92.5%) dominates over the pink skin (7.5%);the “Smooth-uniform” feather is dominant (97.08%), followed by the smooth-crested type (2.08%) and the fries type (0.82%);the medium size of the chickens is dominant (86.66%), followed by the dwarf size (9.58%) and the large size (3.75%). The results of this study demonstrate that there is a strong phenotypic diversity within the local chicken population. This diversity can serve as a basis for the development of selection, conservation and genetic potential improvement programs based on rational exploitation of the local chicken.展开更多
[ Objective] The paper presents the effects of Chinese herbal extract on the performance of local chickens for its application in animal production. [Method] The herbal extract Ⅰ and Ⅱ were added to the basal diet o...[ Objective] The paper presents the effects of Chinese herbal extract on the performance of local chickens for its application in animal production. [Method] The herbal extract Ⅰ and Ⅱ were added to the basal diet of 10 day-old chickens at the ratio of 0.6%, respectively. Then the chickens was fasted and respectively weighed at 0, 17, 24 and 31 days old. And the feed consumption and mortality of each group were recorded to determine average weight, average daily gain, and feed conversion ratio. Economic benefit was also analyzed. [ Result] There was no significant difference in average daily gain between the test groups and the control group as well as between the two test groups （P〉0.05） ; there was signifi- cant difference in feed conversion ratio between the test groups and the control group （ P 〈0.05）, but no significant difference between the two test groups （ P 〉 0.05） ; the survival rate and the economic benefits of the test groups were significantly higher than that of control （ P 〈 0.05）. [ Conclusion ] Chinese herbal extract Ⅰ and Ⅱ should improve chicken average daily gain, feed conversion ratio and survival rate, promote growth, and signifi- cantly improve economic benefit.展开更多
Developing ecological scale breeding of local chickens with natural conditions, such as forest lands, grass lands, orchards and mulberry fields, not only can improve the quality of poultry products and the production ...Developing ecological scale breeding of local chickens with natural conditions, such as forest lands, grass lands, orchards and mulberry fields, not only can improve the quality of poultry products and the production benefits of chicken breeding, but also can develop and use local chicken germplasm effectively and promote their breed protection and industrialization. From integration and application of breed selection, breeding management, nutrient regulation, grass planting and grazing, a new ecological scale breeding technique of local chickens is proposed.展开更多
In this article, we reviewed the achievements of our team in genetic resource conservation and innovative use of Shandong local chicken breeds from the conservation, assessment on germplasm characteristics and breedin...In this article, we reviewed the achievements of our team in genetic resource conservation and innovative use of Shandong local chicken breeds from the conservation, assessment on germplasm characteristics and breeding of Shandong local chickens, so as to provide a reference for further research and development of local chicken breeds.展开更多
The exploitation of industrial strains of chickens in the Sahelian climate of Niger is characterized by a decline in performance and significant costs associated with their maintenance. In contrast, local chickens are...The exploitation of industrial strains of chickens in the Sahelian climate of Niger is characterized by a decline in performance and significant costs associated with their maintenance. In contrast, local chickens are well adapted to these environmental conditions but with poor production performance. Genetic selection of these local chickens could improve their productivity. The first step is to determine if the genetic parameters of their growth are high enough to ensure a successful selection strategy. To do so, weekly weights of 69 parents and 119 offspring were followed for 20 weeks. The heritability and genetic correlations of these weights were estimated through the Bayesian approach using the MCMCglmm package on R software. At hatching, weights ranged from 23 to 25 g. At 20 weeks, these weights ranged from 1031 to 1052 g for females and 1308 to 1445 g for males. Heritabilities for hatch weights at 4, 8, 12, 16, and 20 weeks of age were estimated to be 0.56, 0.31, 0.52, 0.53, 0.52 and 0.48 respectively and all genetic correlations were positive. In particular, weight at 8 weeks of age showed both good heritability (h<sup>2</sup> = 0.52) and strong, positive genetic correlations with weights at older ages. These results indicate that genetic selection to improve weight at 8 weeks of age would be a good strategy to improve the overall growth performance of these chickens.展开更多
This work aimed to evaluate the effects of supplementation of Parkia biglobosa fruit pulp flour in the CPAVI chicken ration on the growth performance and carcass characteristics of local chickens. This study involved ...This work aimed to evaluate the effects of supplementation of Parkia biglobosa fruit pulp flour in the CPAVI chicken ration on the growth performance and carcass characteristics of local chickens. This study involved 50 local chicks of eight weeks of age. Chickens were divided into 5 groups of 10 chicks corresponding to five experimental rations containing 0%, 1%, 2%, 3% and 4% pulp from fruits of P. biglobosa. The nutritional composition of P. biglobosa fruit pulps were analyzed, then growth parameters and carcass characteristics were measured. The results showed that the fruit pulps of P. biglobosa were rich in metabolizable energy (4015.02 ± 0.21 Kcal/kg), crude fiber (16.88% ADF and 19.81% NDF) and potassium (2.45% ± 0.01%). Thus, the group of local chickens fed the diet containing 1% supplementation had a significantly higher live weight (1200.85 g) and carcass yield (91.99 g) (P supplementation. Additionally, individual feed consumption and average daily gain of the group at 1% supplementation were higher. In short, the flour from the pulp of the fruit of Parkia biglobosa can be supplemented up to 1% in the CPAVI pullet type feed for local chickens.展开更多
This study investigated the effect of Israel grass in feed formulation on growth performance of local chicken.The study was conducted from October 2023 until January 2024 in Kampong Chheutel Institute of Technology.Th...This study investigated the effect of Israel grass in feed formulation on growth performance of local chicken.The study was conducted from October 2023 until January 2024 in Kampong Chheutel Institute of Technology.The CRD(Completely Randomized Design)was used with 4 treatments and 4 replications.The local chicks were purchased from local famer at 1 day old and kept in whole pen by feeding commercial feed.At 21 days old the total 320 chicks were allocated into experimental treatments.The 4 feed formulas based on the level of Israel grass added such as 0,5%,7%and 9%,were called T1(control),T2,T3 and T4 respectively.The result showed that body weight gain,feed intake,ADG(Average Daily Gain)and FCR(Feed Conversion Ratio)in all treatments were not significantly different(p>0.05).However,there was strong correlation between living weight with carcass of al treatments,but no difference among carcass percentage of local chicken for all different diet in this study.In conclusion,the Israel grass did not affect growth performance of local chickens and can be used to replace some expensive feed ingredient,such as rice bran.展开更多
This study was designed to examine the effects of dietary energy levels on some growth and reproductive parameters of local barred chickens in Cameroon. For this purpose, One hundred and forty four day-old barred male...This study was designed to examine the effects of dietary energy levels on some growth and reproductive parameters of local barred chickens in Cameroon. For this purpose, One hundred and forty four day-old barred male chicks, weighing 28.33 g in average were randomly divided into 12 groups of 12 chicks each. Three feeding programs (FP) comprising each a starter diet from day old to 12 weeks (S0: 2800 Kcal/Kg;S1: 2900 Kcal/Kg;S2: 3000 Kcal/Kg) and grower diet from 13 to 20 weeks (G0: 2900 Kcal/Kg;G1: 3000 Kcal/ Kg;G2: 3100 Kcal/Kg) were used and designated FP1, FP2 and FP3 respectively. Each of the FP was randomly allotted of 4 groups of 12 birds in a completely randomized design. Throughout experiment (1 day old to 20 weeks), body weight was recovered every 2 weeks. At 20 weeks of age, roosters were sacrificed;semen characteristic was analyzed and testes were characterized. Between 2 to 10 weeks old, body weight of cocks fed with FP3 was significantly higher (P < 0.05) as compared to others FP. Inversely, from 12 to 20 weeks, body weight of cocks receiving FP1 was significantly higher (P < 0.05) than that of cocks receiving feeding programs 2 and 3. At 20 weeks, 100% of cocks fed on FP3 produced semen versus 66.66% and 16.66% respectively for those on FP1 and FP2. Semen volume and mass motility of cocks fed on FP3 or FP1 were significantly (P < 0.05) higher than FP2. It was concluded that FP1 had more suitable dietary energy levels for growth and reproduction of local barred cocks.展开更多
[ Objective ] The study was to explore whether glutaredoxin （GRX2） and thioredoxin （TRX2） genes vary between Puerpiao chicken and Tengchongxue chicken in Yunnan Province. [ Methods ] Using Sanhuang chicken as the ...[ Objective ] The study was to explore whether glutaredoxin （GRX2） and thioredoxin （TRX2） genes vary between Puerpiao chicken and Tengchongxue chicken in Yunnan Province. [ Methods ] Using Sanhuang chicken as the control, the GRX2 and TRX2 genes were cloned from skirt tissues of Puerp/ao chicken and Tengchongxue chicken and then subjected to bioinformatics analysis. [ Results ] The sequencing results of both the GRX2 and TRX2 genes were completely consistent among Puerp/ao chicken, Tengchongxue chicken and Sanhuang chicken. And the sequences of GRX2 and TRX2 genes share a 100% homology with the results accessed in GenBank, and no any mutation was observed. [ Conclusion] The result provides scientific basis for investigating the antioxidant capacity of different chickens and utilizing elite local chicken resources.展开更多
[Objective] To observe differences in egg quality between Shandong local hens and Hyline brown hens. [Method] Hyline brown hens and three Shandong local chicken breeds including Jining Bairi chicken, Wenshang Luhua ch...[Objective] To observe differences in egg quality between Shandong local hens and Hyline brown hens. [Method] Hyline brown hens and three Shandong local chicken breeds including Jining Bairi chicken, Wenshang Luhua chicken and Laiwu black chicken were selected for egg quality comparison. [ Result] The pementage of yolk, egg-shape index and shell strength were significantly higher in the Shandong local hens than in Hyline brown hens ( P 〈 0.05), but the opposite results were found for average egg size and Haugh unit ( P 〈 0.05). The contents of essential amino acids and linoleic acid were significantly higher in the Shandong local hens than in Hyline brown hens (P 〈 0.05), but no significant differ- ence in VA content, VE content, total amino acid content and fatty acid content was found between the Shandong local hens than in Hyline brown hens. [ Conclustion] The study investigated the effects of chicken breeds on egg quality, which provides a reference for improvement of chicken breeds in future.展开更多
This study was conducted to assess production performance of chicken under farmers’ management and their roles in the household economy of local and exotic chickens reared at Yirgalem and Hawassa towns of Southern Et...This study was conducted to assess production performance of chicken under farmers’ management and their roles in the household economy of local and exotic chickens reared at Yirgalem and Hawassa towns of Southern Ethiopia. Purposive sampling method was used for selecting the respondents. Totally, 180 respondents were selected based on their experience in chicken production. The study indicates that the average number of eggs set for incubation was 10.05 ±0.81 of which the hatchability was 8.42 ±1.19 eggs. The age at first egg laying for the native chickens raised at Hawassa and Yirgalem towns was 6.31 ±0.53 and 6.10 ±0.30 months respectively with differences recorded both within and between the locations. The age at first egg laying of the Sasso hens was 5.24 ±0.43 months while the age at first egg lay for Bovans was 5.37 ±0.49 months. The difference was observed (P 【0.05) across the studied locations. The values were lower when compared to those of the native chickens. It was also observed that the contributions of the exotic chickens to the livelihood and food security of the rearers were insignificant. It was concluded from this study that the exotic chickens in the study areas performed fairly well and could do so further if they are provided with better health care, scientific nutrition and management.展开更多
通过细菌分离纯化、生化试验、血清型鉴定、16S r RNA扩增等方法,从广西三黄鸡胚胎中分离到1株肠炎沙门氏菌。药敏试验显示分离菌株对阿米卡星、环丙沙星、氧氟沙星、头孢噻呋钠等药物敏感,对庆大霉素、洛美沙星、阿莫西林等耐受;接种4...通过细菌分离纯化、生化试验、血清型鉴定、16S r RNA扩增等方法,从广西三黄鸡胚胎中分离到1株肠炎沙门氏菌。药敏试验显示分离菌株对阿米卡星、环丙沙星、氧氟沙星、头孢噻呋钠等药物敏感,对庆大霉素、洛美沙星、阿莫西林等耐受;接种4周龄昆明小鼠,致死率为100%,说明该菌株是一株致病性强的多重耐药菌。临床中可以使用阿米卡星、头孢噻呋钠等药物进行防控。本研究可为提升地方品种鸡孵化率提供科学参考。展开更多
文摘In order to contribute to a better understanding of the biodiversity of local chicken populations, this study focused on the description of the essential qualitative parameters in the phenotypic characterization of local species. Conducted in 6 localities in the Far North Region of Cameroon (Doukoula, Yagoua, Guidiguis, Dziguilao, Maroua 3rd and Méri), a population of 240 local chickens, including 172 hens and 68 cocks were characterized in family farms. The choice of localities was made on the basis of their strong potential local chicken flocks in the region. To this end, each animal was the subject of a qualitative description based on the identification of the sex of the animal, the description of the colorations of the plumage and extremities, and the description of the types of format, plumage and crests. All observations were made with the naked eye and in daylight and then photographed. The main results show that the plumage colors are multiple and dominated by the White-Pied-Black (21.7%) and the Mille-fleur (20.8%);the wattles are dominated by the red (60%) and the pink (35.4%);the tarsi are dominated by the white (43.8%) and the black (32.08%);the white skin (92.5%) dominates over the pink skin (7.5%);the “Smooth-uniform” feather is dominant (97.08%), followed by the smooth-crested type (2.08%) and the fries type (0.82%);the medium size of the chickens is dominant (86.66%), followed by the dwarf size (9.58%) and the large size (3.75%). The results of this study demonstrate that there is a strong phenotypic diversity within the local chicken population. This diversity can serve as a basis for the development of selection, conservation and genetic potential improvement programs based on rational exploitation of the local chicken.
文摘[ Objective] The paper presents the effects of Chinese herbal extract on the performance of local chickens for its application in animal production. [Method] The herbal extract Ⅰ and Ⅱ were added to the basal diet of 10 day-old chickens at the ratio of 0.6%, respectively. Then the chickens was fasted and respectively weighed at 0, 17, 24 and 31 days old. And the feed consumption and mortality of each group were recorded to determine average weight, average daily gain, and feed conversion ratio. Economic benefit was also analyzed. [ Result] There was no significant difference in average daily gain between the test groups and the control group as well as between the two test groups （P〉0.05） ; there was signifi- cant difference in feed conversion ratio between the test groups and the control group （ P 〈0.05）, but no significant difference between the two test groups （ P 〉 0.05） ; the survival rate and the economic benefits of the test groups were significantly higher than that of control （ P 〈 0.05）. [ Conclusion ] Chinese herbal extract Ⅰ and Ⅱ should improve chicken average daily gain, feed conversion ratio and survival rate, promote growth, and signifi- cantly improve economic benefit.
基金Supported by Three New Agricultural Project in Jiangsu Province(SXGC[2013]234)
文摘Developing ecological scale breeding of local chickens with natural conditions, such as forest lands, grass lands, orchards and mulberry fields, not only can improve the quality of poultry products and the production benefits of chicken breeding, but also can develop and use local chicken germplasm effectively and promote their breed protection and industrialization. From integration and application of breed selection, breeding management, nutrient regulation, grass planting and grazing, a new ecological scale breeding technique of local chickens is proposed.
基金funded by the National High Technology Research and Development Program of China (2008AA101001)Major Agricultural Stock Breeding Project of Shandong Province(2007lz014)Earmarked Fund for Modern Agro-Industry Technology Research System
文摘In this article, we reviewed the achievements of our team in genetic resource conservation and innovative use of Shandong local chicken breeds from the conservation, assessment on germplasm characteristics and breeding of Shandong local chickens, so as to provide a reference for further research and development of local chicken breeds.
文摘The exploitation of industrial strains of chickens in the Sahelian climate of Niger is characterized by a decline in performance and significant costs associated with their maintenance. In contrast, local chickens are well adapted to these environmental conditions but with poor production performance. Genetic selection of these local chickens could improve their productivity. The first step is to determine if the genetic parameters of their growth are high enough to ensure a successful selection strategy. To do so, weekly weights of 69 parents and 119 offspring were followed for 20 weeks. The heritability and genetic correlations of these weights were estimated through the Bayesian approach using the MCMCglmm package on R software. At hatching, weights ranged from 23 to 25 g. At 20 weeks, these weights ranged from 1031 to 1052 g for females and 1308 to 1445 g for males. Heritabilities for hatch weights at 4, 8, 12, 16, and 20 weeks of age were estimated to be 0.56, 0.31, 0.52, 0.53, 0.52 and 0.48 respectively and all genetic correlations were positive. In particular, weight at 8 weeks of age showed both good heritability (h<sup>2</sup> = 0.52) and strong, positive genetic correlations with weights at older ages. These results indicate that genetic selection to improve weight at 8 weeks of age would be a good strategy to improve the overall growth performance of these chickens.
文摘This work aimed to evaluate the effects of supplementation of Parkia biglobosa fruit pulp flour in the CPAVI chicken ration on the growth performance and carcass characteristics of local chickens. This study involved 50 local chicks of eight weeks of age. Chickens were divided into 5 groups of 10 chicks corresponding to five experimental rations containing 0%, 1%, 2%, 3% and 4% pulp from fruits of P. biglobosa. The nutritional composition of P. biglobosa fruit pulps were analyzed, then growth parameters and carcass characteristics were measured. The results showed that the fruit pulps of P. biglobosa were rich in metabolizable energy (4015.02 ± 0.21 Kcal/kg), crude fiber (16.88% ADF and 19.81% NDF) and potassium (2.45% ± 0.01%). Thus, the group of local chickens fed the diet containing 1% supplementation had a significantly higher live weight (1200.85 g) and carcass yield (91.99 g) (P supplementation. Additionally, individual feed consumption and average daily gain of the group at 1% supplementation were higher. In short, the flour from the pulp of the fruit of Parkia biglobosa can be supplemented up to 1% in the CPAVI pullet type feed for local chickens.
文摘This study investigated the effect of Israel grass in feed formulation on growth performance of local chicken.The study was conducted from October 2023 until January 2024 in Kampong Chheutel Institute of Technology.The CRD(Completely Randomized Design)was used with 4 treatments and 4 replications.The local chicks were purchased from local famer at 1 day old and kept in whole pen by feeding commercial feed.At 21 days old the total 320 chicks were allocated into experimental treatments.The 4 feed formulas based on the level of Israel grass added such as 0,5%,7%and 9%,were called T1(control),T2,T3 and T4 respectively.The result showed that body weight gain,feed intake,ADG(Average Daily Gain)and FCR(Feed Conversion Ratio)in all treatments were not significantly different(p>0.05).However,there was strong correlation between living weight with carcass of al treatments,but no difference among carcass percentage of local chicken for all different diet in this study.In conclusion,the Israel grass did not affect growth performance of local chickens and can be used to replace some expensive feed ingredient,such as rice bran.
文摘This study was designed to examine the effects of dietary energy levels on some growth and reproductive parameters of local barred chickens in Cameroon. For this purpose, One hundred and forty four day-old barred male chicks, weighing 28.33 g in average were randomly divided into 12 groups of 12 chicks each. Three feeding programs (FP) comprising each a starter diet from day old to 12 weeks (S0: 2800 Kcal/Kg;S1: 2900 Kcal/Kg;S2: 3000 Kcal/Kg) and grower diet from 13 to 20 weeks (G0: 2900 Kcal/Kg;G1: 3000 Kcal/ Kg;G2: 3100 Kcal/Kg) were used and designated FP1, FP2 and FP3 respectively. Each of the FP was randomly allotted of 4 groups of 12 birds in a completely randomized design. Throughout experiment (1 day old to 20 weeks), body weight was recovered every 2 weeks. At 20 weeks of age, roosters were sacrificed;semen characteristic was analyzed and testes were characterized. Between 2 to 10 weeks old, body weight of cocks fed with FP3 was significantly higher (P < 0.05) as compared to others FP. Inversely, from 12 to 20 weeks, body weight of cocks receiving FP1 was significantly higher (P < 0.05) than that of cocks receiving feeding programs 2 and 3. At 20 weeks, 100% of cocks fed on FP3 produced semen versus 66.66% and 16.66% respectively for those on FP1 and FP2. Semen volume and mass motility of cocks fed on FP3 or FP1 were significantly (P < 0.05) higher than FP2. It was concluded that FP1 had more suitable dietary energy levels for growth and reproduction of local barred cocks.
基金Supported by Major Innovation Program for Extraction of Plant-derived NaturalDisease-resistant Components and Industrialization(KX140564)
文摘[ Objective ] The study was to explore whether glutaredoxin （GRX2） and thioredoxin （TRX2） genes vary between Puerpiao chicken and Tengchongxue chicken in Yunnan Province. [ Methods ] Using Sanhuang chicken as the control, the GRX2 and TRX2 genes were cloned from skirt tissues of Puerp/ao chicken and Tengchongxue chicken and then subjected to bioinformatics analysis. [ Results ] The sequencing results of both the GRX2 and TRX2 genes were completely consistent among Puerp/ao chicken, Tengchongxue chicken and Sanhuang chicken. And the sequences of GRX2 and TRX2 genes share a 100% homology with the results accessed in GenBank, and no any mutation was observed. [ Conclusion] The result provides scientific basis for investigating the antioxidant capacity of different chickens and utilizing elite local chicken resources.
基金funded by the Agricultural Stock Breeding Project of Shandong Province (2008LZ015)
文摘[Objective] To observe differences in egg quality between Shandong local hens and Hyline brown hens. [Method] Hyline brown hens and three Shandong local chicken breeds including Jining Bairi chicken, Wenshang Luhua chicken and Laiwu black chicken were selected for egg quality comparison. [ Result] The pementage of yolk, egg-shape index and shell strength were significantly higher in the Shandong local hens than in Hyline brown hens ( P 〈 0.05), but the opposite results were found for average egg size and Haugh unit ( P 〈 0.05). The contents of essential amino acids and linoleic acid were significantly higher in the Shandong local hens than in Hyline brown hens (P 〈 0.05), but no significant differ- ence in VA content, VE content, total amino acid content and fatty acid content was found between the Shandong local hens than in Hyline brown hens. [ Conclustion] The study investigated the effects of chicken breeds on egg quality, which provides a reference for improvement of chicken breeds in future.
文摘This study was conducted to assess production performance of chicken under farmers’ management and their roles in the household economy of local and exotic chickens reared at Yirgalem and Hawassa towns of Southern Ethiopia. Purposive sampling method was used for selecting the respondents. Totally, 180 respondents were selected based on their experience in chicken production. The study indicates that the average number of eggs set for incubation was 10.05 ±0.81 of which the hatchability was 8.42 ±1.19 eggs. The age at first egg laying for the native chickens raised at Hawassa and Yirgalem towns was 6.31 ±0.53 and 6.10 ±0.30 months respectively with differences recorded both within and between the locations. The age at first egg laying of the Sasso hens was 5.24 ±0.43 months while the age at first egg lay for Bovans was 5.37 ±0.49 months. The difference was observed (P 【0.05) across the studied locations. The values were lower when compared to those of the native chickens. It was also observed that the contributions of the exotic chickens to the livelihood and food security of the rearers were insignificant. It was concluded from this study that the exotic chickens in the study areas performed fairly well and could do so further if they are provided with better health care, scientific nutrition and management.
文摘通过细菌分离纯化、生化试验、血清型鉴定、16S r RNA扩增等方法,从广西三黄鸡胚胎中分离到1株肠炎沙门氏菌。药敏试验显示分离菌株对阿米卡星、环丙沙星、氧氟沙星、头孢噻呋钠等药物敏感,对庆大霉素、洛美沙星、阿莫西林等耐受;接种4周龄昆明小鼠,致死率为100%,说明该菌株是一株致病性强的多重耐药菌。临床中可以使用阿米卡星、头孢噻呋钠等药物进行防控。本研究可为提升地方品种鸡孵化率提供科学参考。
