【作者】 赵玉民；

【导师】 秦贵信；

【作者基本信息】 吉林农业大学 ， 动物营养与饲料科学， 2007， 博士

【摘要】 通过饲养试验、消化代谢试验、比较屠宰试验、血液生化试验和分子生物学试验，采用多因子试验设计，利用40头草原红牛及杂交牛，系统研究了遗传基础和营养水平对饲料利用效率、肉用性能、血液指标、基因表达的影响及遗传与营养的互作效应。研究结果验证了动物营养代谢的基本规律；发现了可用于肉用性状标记辅助选择的遗传标记和饲料利用效率相关的血液生化指标；探讨了营养代谢差异性的分子生物学机制；建立了遗传与营养互作模型，初步揭示了遗传基础与营养、基因型(主要候选基因)与营养互作的基本规律及其对具体性状指标的互作效应；深化并丰富了比较动物营养学的内涵；填补了草原红牛相关研究的空白。研究结果表明，肉用性状和饲料营养利用效率受遗传和营养的双重影响，互作效应显著。杂交牛的日增重和饲料转化率随着营养水平的提高而显著提高(P＜0.05)，草原红牛的反应有所差别；高营养条件下草原红牛的能量沉积量和沉积率高于杂交牛(P＜0.01)，低营养条件下相反(P＜0.05)；草原红牛高营养组的能量沉积极显著高于低营养组(P＜0.01)，杂交牛为显著(P＜0.05)。杂交牛的粗蛋白沉积高于草原红牛(P＜0.05)，高营养组的粗蛋白沉积显著高于低营养组(P＜0.05)；草原红牛的饲料利用率、增重效率、主要屠宰性状低于杂交牛(P＜0.05)。高营养有利于增加眼肌面积和大理石评分，并降低肌肉剪切力值。血液生化指标存在遗传群体差异和营养水平的差异。杂交牛在高、低营养水平下的尿素氮浓度均比草原红牛低(P＜0.05)，同种群内的高营养组高于低营养组，遗传和营养对转氨酶有互作效应(P＜0.01)。血液IGF-Ⅰ含量群体间差异极显著(P＜0.01)，杂交牛高于草原红牛；营养水平间差异显著(P＜0.05)，营养水平提高，含量增加。血液酶活性、IGF-1和GH与肉质性状、屠宰性状间存在相关关系。在不同遗传群体和不同营养条件下，GPT、GOT、LDH、AKP、Amy、IGF-Ⅰ活性与大理石花纹、肉骨比、眼肌面积等存在不同程度相关。两个群体中8个微卫星位点均有多态性，其中IDVGA44位点多态性较丰富，是最理想的选择标记。相关分析表明，BM2113等位基因C对净肉重和净肉率有正面影响；IDVGA46等位基因C对胴体重、屠宰率、净肉重和净肉率有负面影响；TGLA44等位基因E对体重、胴体重以及净肉重有正面影响。MSTN基因第一外显子SNP位点序列分析表明，杂交牛群体中呈现多态，该片段282处发生了单碱基突变(C／A)，导致编码的苯丙氨酸突变为亮氨酸；SNP位点基因型效应的最小二乘分析表明，杂交牛9个肉用指标均差异显著或极显著。不同基因型之间分析表明，由C→A突变所产生的B等位基因对杂交牛的日增重具有显著影响。H-FABP基因5’调控区SNP位点序列在142处发生了G／A转换。方差分析表明：营养因素、遗传基础和H-PABP基因对消化代谢、屠宰和肉质性状均有影响。其中营养因素对消化代谢起主要作用；屠宰性状主要与遗传基础有关；肌纤维直径受遗传基础影响较大，大理石花纹主要受营养影响，肌肉剪切力主要受H-FABP基因影响。高营养条件下，营养因素对性状的表现起决定作用；低营养条件下，基因型对消化代谢和肉质性状的决定作用和基因效应明显。高营养条件下，基因型对剪切力影响较大；低营养条件下，基因型对大理石纹和肌纤维直径有决定作用。IGF-Ⅰ基因表达量存在遗传群体间和营养水平间的差异。草原红牛在不同营养条件下IGF-Ⅰ基因表达量差异极显著且与营养水平正相关，杂交牛有明显差异但不显著。低营养条件下草原红牛IGF-Ⅰ表达量低于杂交牛，高营养条件下相反。不同营养条件下，IGF-Ⅰ基因表达量对血液生化指标有明显影响，在不同群体间与尿素氮、血糖、IGF-Ⅰ、GH、A／G、P、AKP、Amy、CHE存在不同程度的正相关或副相关。不同营养条件下，IGF-Ⅰ表达量对消化代谢、肉质和屠宰性状有较大影响。草原红牛低营养时IGF-Ⅰ表达量与粗蛋白和能量沉积的呈现高度正相关，高营养时为中度负相关；与大理石花纹、肉色、失水率及滴水损失有相关，高营养水平时与肌纤维直径和大理石花纹有相关；与眼肌面积和日增重呈中等弱相关。杂交牛低营养时IGF-Ⅰ表达量与消化代谢指标均呈正相关，高营养时均为负相关；与日增重、眼肌面积和剪切力的相关随营养水平的提高而增强；与失水率和大理石花纹低营养条件下呈中度正相关，高营养时呈中度负相关。不同遗传基础条件下，IGF-Ⅰ表达量对消化代谢、肉质和屠宰性状也有较大影响。低营养条件下，草原红牛IGF-Ⅰ表达量与粗蛋白和能量沉积呈高度正相关，而杂交牛这两个性状正相关降低但与干物质、粗纤维和能量消化量的正相关大幅度提高；与两个群体眼肌面积的相关性完全相反；与草原红牛大理石纹、失水率、滴水损失、肉色呈正相关，与杂交大理石花纹和失水率呈正相关、滴水损失和肉色呈负相关。高营养条件下，IGF-Ⅰ表达量仅与草原红牛粗脂肪消化量为正相关，与两个群体中其它消化代谢指标均为不同程度的负相关，与杂交牛眼肌面积和日增重的相关性远远大于草原红牛。营养与基因型、营养与遗传基础对部分消化代谢、屠宰性状、肉质性状、IGF-Ⅰ基因的表达量和血液含量存在互作效应。两种方式均对干物质消化有显著影响，对滴水损失几乎都没有互作效应；营养与遗传基础互作对能量消化影响显著，对蛋白质消化量、眼肌面积、失水率的互作效应明显大于营养与基因型的互作，对IGF-Ⅰ基因的表达量的互作效应显著。营养与基因型互作对大理石花纹有显著影响，脂肪消化量主要受营养与基因型互作的影响，对剪切力值的互作效应显著且远远大于营养与遗传基础的互作。更多还原

【Abstract】 A series of experiments were conducted to study the influences of genetic background and nutrition on feed efficiency, performance, blood index, gene expression as well as the interaction effect of genetic background and nutrition. Forty heads of china red cattle and its crossed herds were introduced, and multi-factor design was employed. Results of the study identified the basic regulation of nutritional metabolism in animals. Genetic markers could be used for marker assisted selection (MAS) and blood index related to beef traits and feed efficiency were found. Mechanisms of molecular biology for the differences of nutrient metabolism were discussed. Models of interaction between genetics and nutrition were established. Basic regulars of interaction between genetics and nutrition, genotype and nutrition, as well as the interaction effect on certain traits were revealed primarily. Concept of comparative animal nutrition (CAN) was deepened and flourished. Gaps of relevant studies in red cattle were filled.From the results of this study, performance and feed efficiency were influenced by genetic and nutritional factors at the same time. Daily gain (DG) and feed efficiency decreased with the increase of nutritional level of diets in red cattle while crossed herds were on the contrary. Energy retention and the efficiency in red cattle were higher than that in crossed herds under higher nutrition level (P＜0.01), while it was on the contrary under lower nutrition level (P＜0.05). Energy retention in red cattle under higher level of nutrition was higher than that of lower nutrition (P＜0.01). Protein retention in crossed herds was higher than red cattle (P＜0.05), and increased with nutrition level. Higher nutrition level contributed to eye muscle area, marbling score and lower shear force.Blood index varied among genetic and nutritional treatments. Urine nitrogen in crossed herds were higher than red cattle under two nutrition groups (P＜0.05). It was higher in higher level groups than that of lower level groups within genetic herds. Interaction existed between genetics and nutrition on nitrogen transfer enzyme (P＜0.01). There were differences of IGF-I among genetic herds (P＜0.01). It was higher in crossed herds than that of red cattle. There were significant differences among groups of nutrition (P＜0.05) and it increased with nutrition level. Correlation existed among GH, IGF-Ⅰ, and enzyme to slaughter traits and beef quality traits. There were correlations among GPT, GOT, LDH, AKP, Amy and IGF-Ⅰto marbling, eye muscle area and ratio of meat and bone in different degrees.Genetic variance and beef quality performance in red cattle and crossed herds were analyzed with microsatellite makers. All the 8 microsatellite loci were highly polymorphic in two herds and IDVGA44 was the best selection marker. Correlation analysis indicated that C allele of BM2113 locus has positive effect on lean meat weight and lean meat percentage. C allele of IDVGA46 locus has negative effect on carcass weight, slaughter rate, lean meat weight and lean meat percentage. E allele of TGLA44 locus has positive effect on some slaughter traits such as body weight, carcass weight and lean meat weight. Results of sequence analysis on SNP site of MSTN exon-1 showed that a single nucleotide transition (C/A) occurred at site 282 in crossed herds which caused a change of amino acid change from Phe to Leu and there was no mutation in red cattle. The effect of genotype for MSTN gene was analyzed with least-square method and the result showed that all the 9 beef traits but kidney fat was significantly related to genotypes of SNP site in crossed herds. The effect of different genotype analysis indicated that B allele has positive relation with daily gain significantly, and has no relation with other traits.There was a G/A transition at site 142 of H-FABP gene’s 5’ flanking region identified by sequence analysis. Variance analysis indicated that nutrition level, genetic background and H-FABP gene had influences on traits of digestive metabolism, slaughter and beef quality, of which nutrition played dominant effect on digestive metabolism and genetic background mainly on slaughter traits. But it was much more complex for beef quality traits, muscle fiber diameter was mainly influenced by genetic background, marbling score by nutrition level, and shear force mainly by H-FABP gene as well. Under higher nutrition level, the nutrient elements had a greater effect on performances, but the genotype effect would be more dominant for decision of digestive metabolism and beef quality. Different genotypes had greater effect on shear force under higher nutrition level, and on marbling and muscle fiber diameter under lower nutrition level, but little effects on slaughter traits.There were differences for IGF-Ⅰexpression volume The results of analysis for IGF-Ⅰexpression volume under different nutrition level showed that IGF-Ⅰexpression volume was significantly different in red cattle and was different but not significantly in crossed herds. It was lower for IGF-Ⅰexpression volume in red cattle than in crossed herds under low nutrition level and was significantly higher under high nutrition level. Expression volume of IGF-Ⅰin liver increased with nutrition level in both herds. IGF-Ⅰexpression had great effect on blood index under different nutrition level. Under low nutrition level, IGF-Ⅰexpression volume had low-negative correlation in red cattle and high-negative in crossed herds to urine nitrogen, and low-negative in red cattle and medium-positive in crossed herds with blood sugar, and also negative correlation in red cattle and positive correlation in crossed herds with A/G, G, ChE, AKP and IGF-Ⅰconcentration. Under high nutrition level, IGF-Ⅰexpression volume had negative correlation (-0.32) in red cattle and positive correlation in crossed herds with GH (0.39), and related coefficient with ChE and Amy concentration decreased from 0.45 and 0.82 in red cattle to 0.17 and 0.31 in crossed herds, respectively.IGF-Ⅰexpression has a great effect on traits within the same genetic groups under different nutrition level. In red cattle, its expression volume had high-positive correlation with crude protein and energy deposition under low nutrition level and medium-negative correlation under high nutrition level. For beef quality traits, its correlations were positive with marbling, beef color, dehydration ratio, water loss under low nutrition level and with muscle fiber diameter, marbling under high nutrition level. Its expression volume had low-positive correlation with loin muscle area, daily gain and little correlation with other slaughter traits. In crossed herds, IGF-Ⅰexpression volume had positive correlation under low nutrition level and negative correlation under high nutrition level with all digestive and metabolic traits. Its related coefficient with daily gain and loin muscle area under high nutrition level much more increased than that under low nutrition level. For beef quality traits, its correlations with marbling and dehydration ratio were medium-positive under low nutrition level and negative under high nutrition level, but its related coefficient with shear force was greatly increased under high nutrition level.IGF-Ⅰexpression had also great effect on traits in different population under the same nutrition level. Under low nutrition level, its expression volume had high-positive correlation with crude protein and energy deposition in red cattle, but in crossed herds, its correlations with both traits were lower and much higher with other digestive and metabolic traits as dry material, crude fiber and energy. Its correlation with loin muscle area was reversed in red cattle and crossed herds. For beef quality traits, its correlations were positive with marbling, meat color, dehydration ratio, water loss in red cattle and positive with marbling, dehydration ratio, but negative with water loss, meat color in crossed herds. Under high nutrition level, all the correlations were negative with digestive and metabolic traits in both population except with crude fat which was positive in red cattle, and the coefficient was higher in crossed herds than that in red cattle. Its related coefficients with loin muscle area and daily gain were much higher in crossed herds than that in red cattle. Under high nutrition level, its correlations with most beef traits were reversed in red cattle and crossed herds, such as pH (-0.46: 0.29), marbling (0.29: -0.22), shear force(-0.14: 0.57), water loss (0.13: -0.41), and so on, which showed that genetic background played important role on beef quality under high nutrition level.There were interaction effects of nutrition and H-FABP genotype or nutrition and genetic backgrounds on digestive metabolism, slaughter and meat traits. Interaction between nutrition and genetic backgrounds was significant on digestive and metabolic traits like dry material, crude protein, energy, and interactions between genotype and nutrition on crude fat and dry material was also significant. The marbling and shear force were greatly influenced by the interaction between nutrition and H-FAPB genotype, and the interaction effect on dehydration ratio was greatly influenced by nutrition and genetic backgrounds. There were no significant interactions on slaughter traits. Both kinds of interactions had similar interaction effects on IGF-Ⅰexpression and concentration in serum but had not significant difference.更多还原