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The experiment was conducted to investigate the effect of dietary hydroxy-methionine (MHA) chelate supplementation on the production performance, antioxidation performance, immune and reproductive hormone indexes of Xuefeng black bone breeding chickens. A total of 324 healthy 32-week-old Xuefeng black bone chickens with similar body weight were randomly divided into three groups, with six replicates per group and 18 chickens per replicate. The prefeeding period lasted for two weeks and the trial period lasted for eight weeks. The chickens in the control group were fed a basal diet. The experimental groups added 30 mg/kg MHA-Zn (MZ group, calculated by zinc), 25 mg/kg MHA-Mn (MM group, calculated by manganese) and 30 mg/kg MHA-Zn + 25 mg/kg MHA-Mn (MZM group) in the basal diet, respectively. The results showed that compared with the control group, the laying rate and healthy chick rate of the experimental groups were significantly increased (P<0.05). The hatching rate of the MZM group was significantly higher than that of the control group and MM group (P<0.05). The death rate of embryos in the MZ group and MZM group was significantly lower than that in the control group and MM group (P<0.05). The serum content of progesterone, folliclestimulating hormone, estradiol and parathyroid hormone in the MZM group was significantly higher than those in the other groups ( P<0.05). The activity of total superoxide dismutase and catalase in the serum of MZM group was significantly higher than those of the control group and MZ group (P<0.05). The serum activity of manganese superoxide dismutase and glutathione peroxidase in the MZM group was significantly higher than those in the control group and MM group (P<0.05). The serum malondialdehyde content in the MM group and MZM group was significantly lower than that in the control group (P<0.05). Compared with the control group, the content of immunoglobulin A, immunoglobulin M and interleukin-2 in the serum of the MZM group was significantly increased ( P<0.05). The study indicates that adding of MHA chelate in the diet can improve the production performance of Xuefeng black bone chickens by increasing antioxidation performance, immune and reproductive hormone levels. [ABSTRACT FROM AUTHOR]

The experiment was to comparative analysis of muscle fatty acid composition in 12 local chicken breeds. Based on the results of previous studies, the nutritional composition and muscle fatty acid content of 12 chicken breeds (White-eared chicken, Langshan chicken, Xiaoshan chicken, Beijing-You chicken, Silky chicken, Yugan black chicken, Chongren Ma chicken, Sanhuang chicken, Kangle chicken, Tibetan chicken, Wuding chicken and Dawei Mountain chicken) were analyzed. The results showed that the system hydraulic force, shear force and pH value of Sanhuang chickens were better than Xiaoshan chickens, White-eared chickens and Beijing-You chickens. The crude fat content of Tibetan chicken was significantly higher than that of the other 11 chicken breeds. The amino acid nutritional value of Sanhuang chicken, White-eared chicken and Tibetan chicken was higher. Silky chicken had the highest relative content of saturated fatty acids (44.96%) and Tibetan chicken had the lowest saturated fatty acid content (31.67%). Tibetan chicken had the highest unsaturated fatty acid (68.22%) and unsaturated fatty acids of Langshan chicken and Silky chicken were the lowest (54.34% and 54.43%). The first six principal components obtained by principal component analysis could explain 69.153% of total variance, of which the first, second and third principal components explained 27.352%, 25.371% and 16.431% of total variance, respectively. The phylogenetic clustering diagram based on principal component values classified 12 local chicken breeds in China into four categories, Yugan black chicken, Sanhuang chicken, Kangle chicken and Chongren Ma chicken were in one category. Beijing-You chicken, Tibetan chicken and Wuding chicken were in one category. Xiaoshan chickens, Dawei Mountain chickens, Langshan chickens and Silky chickens were in one category. White-eared chickens formed independent branches. The study indicates that unsaturated fatty acids of Tibetan chicken, Yugan black chicken and Sanhuang chicken are significantly higher than saturated fatty acids and their composition was more in line with standard of human diet. [ABSTRACT FROM AUTHOR]

【Objective】 The study was carried out to evaluate genetic diversity level of Qilin chicken inferred from complete mitochondrial DNA (mtDNA) D-loop sequences in order to clarify the bread formation of Qilin chicken. 【Method】 Three populations (yellow, white and black-feathered Qilin chickens) and eight indigenous chicken breeds were used for direct sequencing with PCR products of complete mtDNA D-loop region, and these sequences were then used to calculate the genetic variation and neutral test, to construct median networks of haplotypes and to investigate the breeding history of Qilin chickens. 【Result】 The length of mtDNA D-loop complete sequence ranged from 1 231 to 1 232 bp. The content of C+G (39.8%) was lower than that of T+A (60.2%). The total nucleotide diversity of Qilin chickens was 0.00630±0.00054, which was significantly higher than that of each of the eight indigenous chicken breeds. The haptype diversity and nucleotide diversity in yellow, white and black-feathered Qilin chickens were 0.777±0.076, 0.816±0.060, 0.710±0.057 and 0.00699±0.00115, 0.00662±0.00090, 0.00546±0.00062, respectively. The level of genetic diversity was positively correlated with population size. The K2P genetic distance and net genetic distance between Qilin chickens and eight indigenous chicken breeds ranged from 0.008 to 0.009 and 0.003 to 0.005, respectively, which were greater than those between the eight indigenous chicken breeds. A total of 45 mutation sites were detected in 90 samples of Qilin chickens. Seventeen haplotypes were defined in Qilin chickens, with eight exclusive haplotypes and haplotype diversity of 0.773±0.039. The numbers of haptypes of yellow, white and black-feathered Qilin chickens were 12, 7 and 5, respectively. Nineteen haplotypes were defined in eight adjacent indigenous chicken breeds, and no haplotype was shared with Qilin chickens. The number of haptypes of Hetian chicken (8) was greater than that of other chickens, and Ningdu yellow chicken only had three haptypes. The neutral test indicated that all chickens used in this study did not show obvious population expansion at the breed level, with the exception of black-feathered Qilin chickens. The haplotypes of Qilin chickens were distributed in clades A, B, C and E, and the dominated haplogroups were B (30.0%) and E (64.4%). The haplotypes of the eight indigenous chicken breeds were mainly distributed in clades A and B. 【Conclusion】 Unique haptypes indicated that Qilin chickens had an independent breed formation history, and the relatively higher level of genetic diversity of this breed will facilitate its protection and utilization. [ABSTRACT FROM AUTHOR]

Probiotics can improve the intestinal flora structure of host, improve the digestion and absorption of nutrients, enhance the body immunity and promote the healthy growth of animals and improve performance. The paper reviews the biological functions of probiotics and their application in chicken production, to provide reference for the for the application of probiotics in chicken breeding. [ABSTRACT FROM AUTHOR]