| China is one of the largest sheep producing country in the world. Xinjiang Provinces is its major production base for sheep. Bashibai sheep is a best breed in found in mainly in Xinjiang its other provinces and also in few other countries. Bashibai sheep possess special biological features and characteristics. Recently, conventional breeding of Bashibai sheep was performed, with little research about biological characteristics and genetic diversity at the molecular level and no research has been carried out from morphological characteristics to the systematic study with molecular genetic markers.In this study, we have used various research methods as morphological marker, cell genetic markers, biochemical markers of molecular genetic markers, the biological characteristics and genetic diversity of Bashibai sheep was more systematic studied, sheep production in the future by the conventional and molecular breeding of systematic breeding methods, the improvement of modern animal husbandry, development of regional economy to provide some practical and theoretical basis.1. Biological characteristics studied are:(1) Bashibai sheep germplasm characteristicsBashibai sheep showed a square-round shape, the body symmetry of all parts of the structure, apparently the meat-type with genetic stability and strong body. Coarse hair, mainly coat with red hair, also black and white hair, absences/presences of horn and polygons.There was no significant difference at weaning between male and female lambs by growth parameters, growth index differences increase with age, the most significant difference for the adult sheep was (P<0.01).Dressing percentage, meat percentage and meat-bone ratio from weaning to adult was found with an average of 56%,45% and 4:1. Performance from spring to autumn fatten up to 20-25% wtih grazing conditions.Pregnancy rate, fertility rate and lamb survival rate was 97%,110% and 98% respectively.Bashibai sheep was common in the normal physiological range, physiological and biochemical indicators of blood serum cholesterol were recorded low in comparison of other indigenous sheep breeds while other components are within the normal range.Bashibai sheep was timid, easily frightened, good gregarious, difficult to separate the herd in normal circumstances, with good grazing characteristics, showed faster feeding, climbing ability, the choice of feeding process is not strong, feeding rate and feed forward faster.(2) Meat production performance of Bashibai sheepBashibai sheep in the natural grazing conditions with absence of any forage supply, the average dressing percentage of 4.5 months old weaned lambs was 56.00%,19.0kg carcass weight,45.7% meat percentage, meat-bone ratio of 4:1, aged and adult male, ewes also maintain this level. These four major meat production index ranks first in China, which is close to the middle level of 6 months old lamb in Europe.Bashibai sheep loin eye area 15.60 cm2, waist thick and big thigh muscle thick 4 cm, hip fat and total fat each accounted for 5% and 19.39% of live weight.Bashibai sheep with flesh red, tender and juicy, full nutrition, trace elements abundant, protein content 19.38%, fat content 10.1%, cholesterol content 42mg/100g, essential fatty acid content 44.25%, essential amino acids and delicious amino acids accounting for 88.27% ototal amino acid.(3) Growth pattern of Bashibai sheepBashibai sheep was typically premature sheep breeds, the highest absolute growth rate and intensity of weight gain is 0-60 days from birth, male lambs 393g-295g/d, female lambs 372g-275g/d.High relative growth intensity,80.38%-19.22% for male lambs, 78.37%-18.92% for female lambs, four-month old lamb weight 35.5kg, more than half of adult sheep weight.(4) Bashibai sheep hybrid with Ovis Argali (wild sheep) analysisHybridization of three generations (backcross generation) lean meat weight was significantly higher than pure Bashibai sheep (P<0.05), and intramuscular fat and back fat thickness was significantly lower than pure Bashibai sheep (P<0.05), hip fat weight and total fat weight, fat hip and live weight ratio, total fat and live weight ratio, waist fat thickness were measured and found significantly lower than pure Bashibai sheep (P<0.01).The rate of the dressing percentage, lean meat weight, meat percentage and meat-bone ratio of backcross generation were similar with pure Bashibai sheep, but total fat 3910g less than pure Bashibai sheep, lean meat weight increased 15.0%, lipid hip decreased 85.3%, waist and thigh muscle thick added 0.5 cm, waist and back fat layer thinning of 1.5cm and 1.0cm, total fat content decreased 53.36%. Tail fat, intramuscular fat, kidney fat and large networks membrane fat were decreased.Conventional meat nutrients, as moisture, protein, calcium, phosphorus and cholesterol level showed some differences, but not significant (P> 0.05), fat content is significant (P<0.05).Hybrid progeny and pure Bashibai sheep, no significant difference (P>0.05) was recorded between the fatty acidsPure Bashibai sheep components of meat potassium were significantly (P<0.05) higher than hybrid progeny, zinc level was significantly (P<0.01) lower, other components are not significant difference (P>0.05).Hybrid progeny and pure Bashibai sheep between each amino acid is not significantly different, but the essential amino acids and delicious amino acids combined significant difference (P<0.05).Hybrid progeny improved significantly, have retained Bashibai sheep’s own advantages, also absorb the advantages of Ovis Argali, double-efficient hybrids heterosis. 2. Polymorphism study of Bashibai sheep(1) Morphological markersBashibai sheep hair with red, black, white, is affected by three levels dominant control of multiple alleles, rating of the red> black> white, in the Hardy-Weinberg disequilibrium (P>0.05). Red-gene’s gene, genotype frequency and meat productivity advantage over others hair color of sheep, the different hair color can be used for meat production performance of morphological genetic markers.Bashibai sheep angular genetic rather special, with polygonal, polygonal in the male and female sheep, a unique species mark. The angular affected by three pairs of alleles from the genetic control and domination. The dressing percentage of horn sheep was lower than non-horn sheep, which features in the same group, same age, same sex and live weight sheep showed more prominent. The angular gene in Hardy-Weinberg genetic imbalance is (P> 0.05). This is consistent with the direction of actual breeding. Bashibai sheep white face traits controlled by a pair of genes, and certainly autosomal dominant genetic.(2) Cell genetic markers Bashibai sheep normal body cells of chromosome number 2n=54, sex chromosome constitute the male XY,female XX. Normal somatic cells (2n=54) of the total observed number of cells was 90.42%, while the 2n≠54 cell frequency of 9.58%. Some chromosome structure and number of variations may fall within the normal range.(3) Biochemical genetic markersBashibai sheep LDH isoenzyme levels LDH1> LDH3> LDH2> LDH5> LDH4; with polymorphisms among other species.LDH1 and LDH3 has a significant (P<0.01) positive correlation to the sheep’s weight. LDH2, LDH4 and LDH5 was negatively correlated with body weight, LDH2 and LDH4 significantly (P<0.01) negative correlation. LDH1 and LDH3 could be the early selection of sheep meat production traits subsidies genetic markers.Es isozymes in addition to Es5 was significantly (P<0.01) positive correlation with body weight, the rest of all was negative correlation, and Esl, Es3, Es4 was significantly (P<0.01) negative. So only Es5 can be used for Bashibai sheep meat production characteristics to the early genetic markers.Tfa and Tfp was the dominant gene of the seven alleles of Tf loci, gene frequencies were 0.3750 and 0.2292. Hb locus A, B alleles, the gene frequency of 0.5208 and 0.4792. We found that HbAB between plateau and the plain, with wide range of altitude adaptation, can be used as early selection of genetic markers. HbAB genotype of each group of the seats are in Hardy-Weinderg equilibrium (P> 0.05), more appropriate for male sheep’s early selection.(4)Microsatellite markersa. In 10 microsatellite loci, a total of 110 alleles were detected, the average number of alleles per locus 11.b. The average of Bashibai sheep red hair strain, black hair strain, white hair strain and new lean strain polymorphism information content (PIC) was 0.7926,0.7690,0.7721 and 0.8320, heterozygosity (H) were 0.8174,0.7985,0.7921 and 0.8468, genetic diversity.c. The global heterozygote deficit across all populations was-0.1782, inbreeding as-0.2112, coefficient of genetic differentiation was 0.0237, It was indicated that 2.37% of the total genetic variation could be explained by breed differences and remaining 97.63% by differences among individuals for each population. The average gene flow was 8.9167. The cluster analysis showed that the genetic relationship between red hair strain and black hair strain was nearer, and then got together with white hair strain, and at last got together with new lean sheep. The cluster analysis was generally in accordance with their breeding history.d. Microsatellite loci of BM143, OARJMP8, BL1038, OARHH35, ILSTS018, BMS648 BM143, BM4311 eight markers have different significantly correlated with body size and weight on three strains of red hair, black hair, and white hair. However, the lean strains have no significant correlation. BMS648 for all growth parameters were significantly correlated (P<0.01) on red hair strait. BL1038 has significant correlation (P<0.01) with body length, chest and tibia circumference, body height and weight were significantly correlated (P<0.05). BM143 has significant correlation (P<0.01) with chest and tibia circumference, body weight and length was significantly correlated (P<0.05). ILSTS018 has significant correlation (P<0.01) with body length, tibia circumference and body weight, chest circumference was significantly correlated (P<0.05). Others loci were not relevant. OARHH35 has significant correlation (P<0.01) with body weight on black hair strait, and body length and chest circumference were significantly correlated (P<0.05). Others loci were not relevant. BMS648 has significant correlation (P<0.01) with body height and weight on white hair strait, chest circumference and body weight were significantly correlated (P<0.05). Others loci were not relevant.Significant difference between the loci of the different genotypes of multiple comparisons showed that: the same loci on different strains of different genotypes have positive and negative effects on growth index.(5) Callipyge and Leptin geneThe double muscled gene (CLPG) and leptin gene (LEPTIN) SNPs of Bashibai sheep detected by PCR-SSCP, found CLPG and LEPTIN SNPs polymorphism.CLPG1 and CLPG2 primer amplification regions found AA, AB and BB genotypes in the four groups but did not find mutation Aâ†'G. L1, L2 regions found AA, AB genotype, L3 regions found AA, BB homozygous genotype. |
PDF Full Text Request