The quality traits of fresh marketable chicken eggs collected during winter, autumn and summer periods from different local markets in Lebanon were evaluated in order to understand the reproductive fitness of the chic...The quality traits of fresh marketable chicken eggs collected during winter, autumn and summer periods from different local markets in Lebanon were evaluated in order to understand the reproductive fitness of the chicken and the correlation between collection dates. A total of 2000 brown and white eggs were analyzed and compared for their external quality parameters such as egg weight, length, width, size, shell thickness, specific gravity and for their internal quality traits such as Haugh unit, yolk diameter, yolk color, and yolk height. Results show that egg weight and size varied markedly and tended to be smaller during summer period. A significant difference was found between white and brown eggs in some quality traits such as egg weight, shell thickness, egg length, and yolk diameter parameters. Egg quality parameters were significantly reduced during summer season where eggs are exposed to high temperature conditions. For grading analysis, 80% of the total eggs were classified as A with a significant difference (p < 0.05) between white and brown egg and during collection dates. Overall, brown eggs graded better than white eggs in external quality cleanliness and shape. Based on our analysis, the results of this study show that Lebanese eggs are of good quality and suggest that proper egg handling and storage conditions should be applied especially at warm environmental conditions to improve egg quality during summer season.展开更多
[ Objective] To observe biological characteristics of brown-egg dwarf layers. [ Method ] Physiological and biochemical indicators of brown-egg dwarf layers were determined at the age of 20, 40 and 60 weeks, respective...[ Objective] To observe biological characteristics of brown-egg dwarf layers. [ Method ] Physiological and biochemical indicators of brown-egg dwarf layers were determined at the age of 20, 40 and 60 weeks, respectively. Fifty-four chickens were detected, nine roosters and nine hens at each age. [Result] As analyzed by ttest and multiple comparisons, during 20 -60 weeks old, the RBC, HGB, MPV, PDW, LYMPH%, TP and CHO showed an increasing trend. However, during this period, the HCT, MCV, RDW, WBC and LYMPH first decreased and then de- clined, while the MCH, MCHC, PLT, PCT, MID, MID%, GRAN, GRAN%, AST, ALB, TG, ALT and GLU changed contrarily. The chickens at different ages had significantly different physiological and biochemical indicators （P 〈 0.05）. The RBC, HCT, HGB, WBC, LYMPH and AST were significantly different between the roosters and hens during 20 -60 weeks old. [ Conclusion] In the brown-egg dwarf layers, the physiological and bi- ochemical indicators vary with aging, and their difference levels also change with aging.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
The mutant efficiency and hatching ratio are two key factors that significantly affect the construction of genome-modified mutant insects.In the construction of CRISPR/Cas9-mediated dsLmRNase2^(–/–)mutant locusts,we...The mutant efficiency and hatching ratio are two key factors that significantly affect the construction of genome-modified mutant insects.In the construction of CRISPR/Cas9-mediated dsLmRNase2^(–/–)mutant locusts,we found that the tanned eggs which experienced a 20-min contact with the oocyst exhibited a higher success rate compared to fresh newly-laid eggs that were less tanned.However,the heritable efficiency of the dsLmRNase2 deletion to the next generation G_(1 )progeny was similar between adults derived from the tanned or less tanned engineered eggs.Further,the similar effective mutant ratios in the normally developed eggs and G_(0) adults of tanned and less tanned eggs also indicated that tanning did not reduce the absolute mutation efficiency induced by CRISPR/Cas9.Moreover,we found that the syncytial division period,which was longer than the time for tanning,conferred a window period for microinjection treatment with efficient mutation in both tanned and less tanned eggs.We further found that tanned eggs exhibited a higher hatching rate due to a reduced infection rate following microinjection.Both the anti-pressure and ultrastructure analyses indicated that the tanned eggs contained compressed eggshells to withstand increased external pressure.In summary,tanned eggs possess stronger defense responses and higher efficiency of genome editing,providing an improved model for developing Cas9-mediated gene editing procedures in locusts.展开更多
Background: Nest sanitation behavior is one of the most important means to ensure high reproductive efficiency. In avian brood parasitism, nest sanitation behavior may be a pre-adaptation of host birds that allows the...Background: Nest sanitation behavior is one of the most important means to ensure high reproductive efficiency. In avian brood parasitism, nest sanitation behavior may be a pre-adaptation of host birds that allows them to identify the parasitic eggs, so that egg discrimination behavior may have evolved from nest sanitation behavior. However, whether nest sanitation behavior could improve egg rejection in cuckoo hosts was inconclusive.Methods: In this study, we investigated the relationship between nest sanitation and egg discrimination behavior in a potential cuckoo host, the Brown-breasted Bulbul(Pycnonotus xanthorrhous) with two experimental groups. In the first group, we added a blue, non-mimetic egg to the nest of the host, while in the second group we added a blue, non-mimetic egg and a peanut half-shell.Results: The results showed that in the first group, the probability of rejecting the non-mimetic eggs was 53.8%(n = 26 nests). In comparison, all of the Brown-breasted Bulbuls in the second group were able to rapidly remove the peanut shells from the nest, but only 52.6%(n = 19 nests) rejected the non-mimetic eggs. The rejection rates of the non-mimetic eggs in both experimental groups were not significantly different.Conclusions: Our study indicated that nest sanitation behavior of Brown-breasted Bulbuls did not influence their egg recognition and that egg discrimination ability of Brown-breasted Bulbuls was not directly related to nest sanitation behavior.展开更多
Background:Red-winged Blackbirds(Agelaius phoeniceus),hereafter red-wings,are much less frequently parasitized by Brown-headed Cowbirds(Molothrus ater)in eastern North America than in central North America and had not...Background:Red-winged Blackbirds(Agelaius phoeniceus),hereafter red-wings,are much less frequently parasitized by Brown-headed Cowbirds(Molothrus ater)in eastern North America than in central North America and had not been recorded as hosts in our study area in southeastern Pennsylvania.Although hosts of Old World cuckoos(Cuculidae)often show geographic variation in egg rejection behavior,cowbird hosts typically exhibit uniform responses of all acceptance or all rejection of cowbird eggs.Thus,geographic variation in cowbird parasitism frequencies might reflect a different behavioral response to parasitism by hosts where only some populations reject parasitism.In this study,we tested whether egg rejection behavior may explain the lack of parasitism observed in our eastern red-wing population,which may provide insight into low parasitism levels across eastern North America.Methods:We parasitized red-wing nests with model cowbird eggs to determine their response to parasitism.Nests were tested across three nest stages and compared to control nests with no manipulations.Because rejection differed significantly by stage,we compared responses separately for each nest stage.We also monitored other songbird nests to identify parasitism frequencies on all potential hosts.Results:Red-wings showed significantly more rejections during the building stage,but not for the laying and incubation stages.Rejections during nest building involved mostly egg burials,which likely represent a continuation of the nest building process rather than true rejection of the cowbird egg.Excluding these responses,red-wings rejected 15%of cowbird eggs,which is similar to rejection levels from other studies and populations.The overall parasitism frequency on 11 species surveyed in our study area was only 7.4%.Conclusions:Egg rejection behavior does not explain the lack of parasitism on red-wings in our eastern population.Alternatively,we suggest that cowbird preference for other hosts and the low abundance of cowbirds in the east might explain the lack of parasitism.Future research should also explore cowbird and host density and the makeup of the host community to explain the low levels of parasitism on red-wings across eastern North America because egg rejection alone is unlikely to explain this broad geographic trend.展开更多
文摘The quality traits of fresh marketable chicken eggs collected during winter, autumn and summer periods from different local markets in Lebanon were evaluated in order to understand the reproductive fitness of the chicken and the correlation between collection dates. A total of 2000 brown and white eggs were analyzed and compared for their external quality parameters such as egg weight, length, width, size, shell thickness, specific gravity and for their internal quality traits such as Haugh unit, yolk diameter, yolk color, and yolk height. Results show that egg weight and size varied markedly and tended to be smaller during summer period. A significant difference was found between white and brown eggs in some quality traits such as egg weight, shell thickness, egg length, and yolk diameter parameters. Egg quality parameters were significantly reduced during summer season where eggs are exposed to high temperature conditions. For grading analysis, 80% of the total eggs were classified as A with a significant difference (p < 0.05) between white and brown egg and during collection dates. Overall, brown eggs graded better than white eggs in external quality cleanliness and shape. Based on our analysis, the results of this study show that Lebanese eggs are of good quality and suggest that proper egg handling and storage conditions should be applied especially at warm environmental conditions to improve egg quality during summer season.
基金supported by the grants from the Earmarked Fund for Modern Agro-industry (Layer Industry) Technology Research System (nycytx-41-g19)the National Key Technology R&D Program (2008BAD2B06)
文摘[ Objective] To observe biological characteristics of brown-egg dwarf layers. [ Method ] Physiological and biochemical indicators of brown-egg dwarf layers were determined at the age of 20, 40 and 60 weeks, respectively. Fifty-four chickens were detected, nine roosters and nine hens at each age. [Result] As analyzed by ttest and multiple comparisons, during 20 -60 weeks old, the RBC, HGB, MPV, PDW, LYMPH%, TP and CHO showed an increasing trend. However, during this period, the HCT, MCV, RDW, WBC and LYMPH first decreased and then de- clined, while the MCH, MCHC, PLT, PCT, MID, MID%, GRAN, GRAN%, AST, ALB, TG, ALT and GLU changed contrarily. The chickens at different ages had significantly different physiological and biochemical indicators （P 〈 0.05）. The RBC, HCT, HGB, WBC, LYMPH and AST were significantly different between the roosters and hens during 20 -60 weeks old. [ Conclusion] In the brown-egg dwarf layers, the physiological and bi- ochemical indicators vary with aging, and their difference levels also change with aging.
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.
基金This work was supported by the National Natural Science Foundation of China(32070502,31730074,32072419 and 31501905).
文摘The mutant efficiency and hatching ratio are two key factors that significantly affect the construction of genome-modified mutant insects.In the construction of CRISPR/Cas9-mediated dsLmRNase2^(–/–)mutant locusts,we found that the tanned eggs which experienced a 20-min contact with the oocyst exhibited a higher success rate compared to fresh newly-laid eggs that were less tanned.However,the heritable efficiency of the dsLmRNase2 deletion to the next generation G_(1 )progeny was similar between adults derived from the tanned or less tanned engineered eggs.Further,the similar effective mutant ratios in the normally developed eggs and G_(0) adults of tanned and less tanned eggs also indicated that tanning did not reduce the absolute mutation efficiency induced by CRISPR/Cas9.Moreover,we found that the syncytial division period,which was longer than the time for tanning,conferred a window period for microinjection treatment with efficient mutation in both tanned and less tanned eggs.We further found that tanned eggs exhibited a higher hatching rate due to a reduced infection rate following microinjection.Both the anti-pressure and ultrastructure analyses indicated that the tanned eggs contained compressed eggshells to withstand increased external pressure.In summary,tanned eggs possess stronger defense responses and higher efficiency of genome editing,providing an improved model for developing Cas9-mediated gene editing procedures in locusts.
基金supported by the National Natural Science Foundation of China(Nos.31672303 to CY,31472013 and 31772453 to WL)
文摘Background: Nest sanitation behavior is one of the most important means to ensure high reproductive efficiency. In avian brood parasitism, nest sanitation behavior may be a pre-adaptation of host birds that allows them to identify the parasitic eggs, so that egg discrimination behavior may have evolved from nest sanitation behavior. However, whether nest sanitation behavior could improve egg rejection in cuckoo hosts was inconclusive.Methods: In this study, we investigated the relationship between nest sanitation and egg discrimination behavior in a potential cuckoo host, the Brown-breasted Bulbul(Pycnonotus xanthorrhous) with two experimental groups. In the first group, we added a blue, non-mimetic egg to the nest of the host, while in the second group we added a blue, non-mimetic egg and a peanut half-shell.Results: The results showed that in the first group, the probability of rejecting the non-mimetic eggs was 53.8%(n = 26 nests). In comparison, all of the Brown-breasted Bulbuls in the second group were able to rapidly remove the peanut shells from the nest, but only 52.6%(n = 19 nests) rejected the non-mimetic eggs. The rejection rates of the non-mimetic eggs in both experimental groups were not significantly different.Conclusions: Our study indicated that nest sanitation behavior of Brown-breasted Bulbuls did not influence their egg recognition and that egg discrimination ability of Brown-breasted Bulbuls was not directly related to nest sanitation behavior.
基金provided by a BEARS Grant and a Neag Undergraduate Research Grant from Kutztown University
文摘Background:Red-winged Blackbirds(Agelaius phoeniceus),hereafter red-wings,are much less frequently parasitized by Brown-headed Cowbirds(Molothrus ater)in eastern North America than in central North America and had not been recorded as hosts in our study area in southeastern Pennsylvania.Although hosts of Old World cuckoos(Cuculidae)often show geographic variation in egg rejection behavior,cowbird hosts typically exhibit uniform responses of all acceptance or all rejection of cowbird eggs.Thus,geographic variation in cowbird parasitism frequencies might reflect a different behavioral response to parasitism by hosts where only some populations reject parasitism.In this study,we tested whether egg rejection behavior may explain the lack of parasitism observed in our eastern red-wing population,which may provide insight into low parasitism levels across eastern North America.Methods:We parasitized red-wing nests with model cowbird eggs to determine their response to parasitism.Nests were tested across three nest stages and compared to control nests with no manipulations.Because rejection differed significantly by stage,we compared responses separately for each nest stage.We also monitored other songbird nests to identify parasitism frequencies on all potential hosts.Results:Red-wings showed significantly more rejections during the building stage,but not for the laying and incubation stages.Rejections during nest building involved mostly egg burials,which likely represent a continuation of the nest building process rather than true rejection of the cowbird egg.Excluding these responses,red-wings rejected 15%of cowbird eggs,which is similar to rejection levels from other studies and populations.The overall parasitism frequency on 11 species surveyed in our study area was only 7.4%.Conclusions:Egg rejection behavior does not explain the lack of parasitism on red-wings in our eastern population.Alternatively,we suggest that cowbird preference for other hosts and the low abundance of cowbirds in the east might explain the lack of parasitism.Future research should also explore cowbird and host density and the makeup of the host community to explain the low levels of parasitism on red-wings across eastern North America because egg rejection alone is unlikely to explain this broad geographic trend.
