[Objective] The paper was to study the effects of diet formulation with different nutrition levels on growth and slaughter performance ofblack muscovy duck at the age of 43-91 days. [Method] Totally 288 individuals of...[Objective] The paper was to study the effects of diet formulation with different nutrition levels on growth and slaughter performance ofblack muscovy duck at the age of 43-91 days. [Method] Totally 288 individuals of 43dayold black muscovy duck were randomly divided intonine treatments, four repeats each treatment and eight ducks each repeat. UsingL9 （34） orthogonal experiment design （four factors and three levels）,three metabolic energy levels （12.32, 12.72, 13.12 MJ/kg）, three crude protein levels （14%, 16%, 18%）, three calcium levels （0.6%, 0.8%, 1.0%）and three available phosphorus levels （0.30%, 0.45%, 0.6%） were designed, and a total of nine feeding groups （C1C9） were designed according todifferent nutritional levels. Through combination of feeding test （49 d） and metabolic test （pretest 4 d and formal test 3 d）, the growth performance,meat performance and apparent nutrient digestibility of ducks were determined. [Result] The ducks in experimental group C2 had the highest average daily gain, the lowest feed gain ratio, the largest body oblique length, chest width, chest depth and tibia length, which had significant or extremely significant differences with other groups （P〈0.05 or P〈0.01）. The slaughter rate, semieviscerated rate, eviscerated rate and meat quality ofducks in C2 group were higher （P〈0.05）. The apparent digestibility of crude protein and dietary metabolic energy in C2 group were 88.68% and63.07%, respectively, both were significantly or extremely significantly higher than the other groups（P〈0.05 or P〈0.01）, while the interaction effectof calcium and phosphorus level on apparent digestibility was not obvious. [Conclusion] Under the experimental conditions, the suitable metabolicenergy, crude protein, calcium, available phosphorus and total phosphorus levels of 43 -91 days old black muscovy ducks were 12.32 MJ/kg,16.10%, 0.92%, 0.45% and 0.68%, respectively.展开更多
Background: Black bone sheep was first discovered in Yunnan province of China in 1970, with unique black pigmentation on the body and internal organs. Endothelin 3(EDN3) has been known as a key gene causing hyperpigme...Background: Black bone sheep was first discovered in Yunnan province of China in 1970, with unique black pigmentation on the body and internal organs. Endothelin 3(EDN3) has been known as a key gene causing hyperpigmentation in black bone chicken, the Silky fowl.Methods: In this study, EDN3 was employed as a candidate gene for regulating black color pigmentation. First,EDN3 was cloned from sheep to obtain the full-length cDNA by using the rapid amplification of cDNA ends(RACE).Genomic EDN3 was screened and a total of thirty predicted single nucleotide polymorphisms(SNPs) were genotyped for allele and genotype frequency analysis in a case-control study involving two black bone sheep populations. Genomic copy number analysis of EDN3 in sheep was conducted to measure the variation in copy number. EDN3 expression levels were observed among the groups in adult liver, lymph node, and kidney tissues, as well as embryo kidney samples. Also, among the tissues of black bone and non-black bone sheep.Results: The size of the full-length cDNA was 1,578 bp, which included 426 bp of 5′-untranslated region(5′-UTR),an open reading frame(ORF) of 639 bp encoding a protein of 212 amino acids, and a 3′-UTR of 513 bp. Genotype and allele frequencies of all the discovered SNPs were found insignificantly different in black bone and non-black bone sheep(P > 0.05). Genomic copy number analysis of EDN3 in sheep revealed no significant difference between the two sheep groups. No significant variations were found in the adult liver and kidney embryo samples. However,the expression in lymph node and kidney tissue was significantly higher in black bone sheep than that in non-black bone sheep(P < 0.05). Significant variations in the EDN3 expression levels were observed among the tissues of nonblack bone sheep.Conclusions: The findings of the present study indicate that unlike in Silky chickens, EDN3 is not responsible for hyperpigmentation but may play a key functional role in immune and excretory systems of black bone sheep.展开更多
基金Supported by Science and Technology Support Plan(Agriculture)Project of Taizhou City(TN201503)
文摘[Objective] The paper was to study the effects of diet formulation with different nutrition levels on growth and slaughter performance ofblack muscovy duck at the age of 43-91 days. [Method] Totally 288 individuals of 43dayold black muscovy duck were randomly divided intonine treatments, four repeats each treatment and eight ducks each repeat. UsingL9 （34） orthogonal experiment design （four factors and three levels）,three metabolic energy levels （12.32, 12.72, 13.12 MJ/kg）, three crude protein levels （14%, 16%, 18%）, three calcium levels （0.6%, 0.8%, 1.0%）and three available phosphorus levels （0.30%, 0.45%, 0.6%） were designed, and a total of nine feeding groups （C1C9） were designed according todifferent nutritional levels. Through combination of feeding test （49 d） and metabolic test （pretest 4 d and formal test 3 d）, the growth performance,meat performance and apparent nutrient digestibility of ducks were determined. [Result] The ducks in experimental group C2 had the highest average daily gain, the lowest feed gain ratio, the largest body oblique length, chest width, chest depth and tibia length, which had significant or extremely significant differences with other groups （P〈0.05 or P〈0.01）. The slaughter rate, semieviscerated rate, eviscerated rate and meat quality ofducks in C2 group were higher （P〈0.05）. The apparent digestibility of crude protein and dietary metabolic energy in C2 group were 88.68% and63.07%, respectively, both were significantly or extremely significantly higher than the other groups（P〈0.05 or P〈0.01）, while the interaction effectof calcium and phosphorus level on apparent digestibility was not obvious. [Conclusion] Under the experimental conditions, the suitable metabolicenergy, crude protein, calcium, available phosphorus and total phosphorus levels of 43 -91 days old black muscovy ducks were 12.32 MJ/kg,16.10%, 0.92%, 0.45% and 0.68%, respectively.
基金supported by National Nature Science Foundation of China(U1136605)the Innovation Base Cultivation and Development Projectresearch on Precise genetic modification in sheep(Z171100002217072)Program for Changjiang Scholar and Innovation Research Team in University(IRT1191)
文摘Background: Black bone sheep was first discovered in Yunnan province of China in 1970, with unique black pigmentation on the body and internal organs. Endothelin 3(EDN3) has been known as a key gene causing hyperpigmentation in black bone chicken, the Silky fowl.Methods: In this study, EDN3 was employed as a candidate gene for regulating black color pigmentation. First,EDN3 was cloned from sheep to obtain the full-length cDNA by using the rapid amplification of cDNA ends(RACE).Genomic EDN3 was screened and a total of thirty predicted single nucleotide polymorphisms(SNPs) were genotyped for allele and genotype frequency analysis in a case-control study involving two black bone sheep populations. Genomic copy number analysis of EDN3 in sheep was conducted to measure the variation in copy number. EDN3 expression levels were observed among the groups in adult liver, lymph node, and kidney tissues, as well as embryo kidney samples. Also, among the tissues of black bone and non-black bone sheep.Results: The size of the full-length cDNA was 1,578 bp, which included 426 bp of 5′-untranslated region(5′-UTR),an open reading frame(ORF) of 639 bp encoding a protein of 212 amino acids, and a 3′-UTR of 513 bp. Genotype and allele frequencies of all the discovered SNPs were found insignificantly different in black bone and non-black bone sheep(P > 0.05). Genomic copy number analysis of EDN3 in sheep revealed no significant difference between the two sheep groups. No significant variations were found in the adult liver and kidney embryo samples. However,the expression in lymph node and kidney tissue was significantly higher in black bone sheep than that in non-black bone sheep(P < 0.05). Significant variations in the EDN3 expression levels were observed among the tissues of nonblack bone sheep.Conclusions: The findings of the present study indicate that unlike in Silky chickens, EDN3 is not responsible for hyperpigmentation but may play a key functional role in immune and excretory systems of black bone sheep.
