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1.
随着分子遗传学的发展,已经鉴定出了影响剩余采食量(RFI)的大量数量性状位点和候选基因。有丝分裂原活化蛋白3激酶5(MAP3K5),也称凋亡信号调节激酶1(ASK1),属于MAPK超家族基因之一。目前,已有细胞外信号调节蛋白激酶(ERK)、c-Jun N-末端激酶(JNK)和p38丝裂原激活蛋白激酶(p38-MAPK)这3个MAPK家族成员在哺乳动物细胞中被克隆和鉴定,其主要作用机制是介导3条MAPKs信号通路,从而影响家畜的生长、体型及产奶性状等。课题组在前期对RFI的研究中筛选出与牛剩余采食量相关的MAP3K5基因,但其功能作用尚不明确,笔者在此基础上回顾了该基因的结构、生物学功能,概述了该基因在主要畜禽采食量变异及人类肥胖表型中的功能及作用,并从遗传学的角度重点分析了MAP3K5基因在畜禽RFI表型调控中的可能机制。通过对MAP3K5基因在畜禽RFI表型调控中的研究进展进行综述,期望为后期深入开展MAP3K5基因在畜禽采食量性状调控中的分子机制研究提供思路;对于其他可能通过MAP3K5基因影响畜禽表型的因素(如肠道菌群)有待进一步探讨。  相似文献   

2.
为了分析高、低剩余采食量(residual feed intake, RFI)相关肉牛下丘脑组织中的基因表达图谱,探讨差异表达基因与牛RFI表型变异间的关系,试验选择高剩余采食量(HRFI)、低剩余采食量(LRFI)秦川牛各3头,分为HRFI组和LRFI组,采集下丘脑组织样本,从中提取总RNA进行转录组测序,筛选出RFI相关差异表达基因,对这些基因进行GO功能注释和KEGG通路富集分析,并利用STRING数据库构建差异表达基因的蛋白质相互作用网络图,最后随机选取6个差异表达基因进行实时荧光定量PCR验证。结果表明:HRFI组和LRFI组中均存在1 538个差异表达基因,包括AGRP、PMCH等与采食相关的基因,GH1、MTNR1A和RYR2等与代谢相关的基因,此外差异基因主要富集于钙信号通路、cAMP信号通路和昼夜节律等通路中。通过蛋白质相互作用网络筛选出3个核心子网络和7个核心基因。实时荧光定量PCR验证结果与转录组测序结果一致。说明下丘脑组织中AGRP、PMCH、GH1、MTNR1A和RYR2等差异表达基因及钙信号通路、cAMP信号通路和昼夜节律等多条通路可能参与调控肉牛RFI。  相似文献   

3.
本研究旨在探讨北京油鸡剩余采食量(RFI)与屠宰性能和肉质性状的关系。试验测定了400只北京油鸡70~98日龄的RFI及98日龄屠宰性能和肉品质,并对RFI与屠宰性能和肉品质的相关性进行了分析。结果显示,试验公鸡的平均日采食量(ADFI)、平均日增重(ADG)极显著高于母鸡(P<0.01),饲料转化率(FI/GW,FCR)极显著低于母鸡(P<0.01)。公鸡半净膛率、腿肌率和胸肌红度(a*)极显著高于母鸡((P<0.01)。公鸡的RFI与FCR、ADFI极显著正相关(P<0.01),与腹脂率显著正相关(P<0.05),与胸肌率和腿肌率极显著负相关(P<0.01);母鸡RFI与FCR和ADFI极显著正相关(P<0.01),与ADG显著正相关(P<0.05),而与腿肌率极显著负相关(P<0.01)。公鸡RFI与胸肌亮度(L*)极显著正相关(P<0.01),与色度(C*)显著正相关(P<0.05);母鸡RFI与胸肌a*和C*极显著正相关(P<0.01),与色调(H*)和pH极显著负相关(P<0.01),与L*和黄度(b*)显著正相关(P<0.05)。由以上结果可见,北京油鸡公鸡的饲料利用效率优于母鸡,且部分屠宰性状和肉质性状与RFI存在显著相关性。  相似文献   

4.
对384头扬翔华系杜洛克公猪生长育肥阶段背膘厚度(BF)、日增重(ADG)、日采食量(ADFI)、饲料转化率(FCR)和剩余采食量(RFI)5个性状用DMU程序进行遗传参数估计探究杜洛克公猪的遗传参数。结果表明, ADFI和RFI的遗传方差占表型方差的比例分别为87.73%和84.91%;BF和ADG的遗传方差占表型方差的比例分别是58.77%和58.91%;RFI与BF、ADG的表型相关系数均为零,而遗传相关系数分别为-0.22和0.15;RFI与ADFI的表型、遗传相关系数分别为0.98和0.99,RFI与FCR的表型、遗传相关系数分别为0.44和0.81。多性状模型与单性状模型的估计遗传力基本趋于一致,ADG和FCR遗传力分别是0.27和0.19,属于低遗传力性状;而BF、ADFI和RFI的估计遗传力在0.31~0.46范围,属于中等遗传力性状。  相似文献   

5.
提高猪饲料效率的测定与选择   总被引:1,自引:0,他引:1  
为提高猪饲料效率的选择,本试验测定一些与猪饲料效率相关的生产性状并进行遗传评估。方法:测定60头军牧1号白猪后备公猪的采食量、体增重、背膘厚等生产性状,用猪剩余采食量(RFI)和饲料转化率(FCR)作为评价饲料效率的两个指标,并对其遗传参数进行评估。结果:测定期内军牧1号公猪群体FCR均值为2.61,RFI的标准差为77.52。RFI与FCR的遗传力分别是0.35、0.33,RFI与ADFI(日采食量)、ADG(日增重)、BF(背膘厚)的遗传相关分别是0.89、0.12、-0.05,FCR与ADFI、ADG、BF的遗传相关分别是0.55、-0.65、-0.11。结论:军牧1号白猪品种内饲料效率存在较大的遗传差异,由于RFI与ADG遗传相关很低,因此用RFI作为选择性状可有效提高猪的饲料效率。  相似文献   

6.
试验旨在研究MAP3K5基因多态性与杜洛克猪生长、饲料利用性状的关联性。利用Illumina SNP60芯片测序结果比较发现了MAP3K5基因的4个SNPs位点(Ssc1:30769583 A>C;Ssc1:30781169 A>G;Ssc1:30940839 A>G;Ssc1:30962276 G>A)。统计获得MAP3K5基因的4个SNPs位点的基因型频率及等位基因频率,发现4个SNPs为低度-中度的多态突变位点。对MAP3K5基因多态性与生长、饲料利用性状的关联性进行分析,结果表明,杜洛克猪Ssc1:30769583 A>C位点CC基因型个体与AA基因型个体相比剩余采食量(RFI)性状降低了133.08 g/d(P<0.05);Ssc1:30781169 A>G位点的GG基因型个体与AG基因型个体相比RFI性状降低了116.18 g/d(P<0.05),ADFI性状降低了0.23 kg/d(P<0.05);Ssc1:30940839 A>G位点的GG基因型个体与AG基因型个体相比饲料转化率(FCR)性状降低了0.10%(P<0.05);Ssc1:30962276 G>A位点的AA基因型个体与GG基因型个体相比ADG性状降低了0.04 kg/d(P<0.05)。试验初步认为MAP3K5基因4个SNPs位点的多态性对杜洛克猪的RFI、ADFI、FCR和ADG具有一定影响。  相似文献   

7.
《中国兽医学报》2016,(5):875-879
猪剩余采食量(Residual Feed Intake,RFI)是一个有效评价生猪饲料效率的新性状,用剩余采食量来提高生猪饲料效率是当前养猪界的重要研究方向。本试验测定了2个世代198头军牧1号公猪的周采食量、日增重(ADG)和背膘(BF)等性状,和母猪453头母猪日增重(ADG)和背膘(BF)等性状,然后建立了饲料效率育种值估计模型,以剩余采食量(RFI)为主选性状,ADG和BF为辅助约束性状,通过遗传评估按育种值高低分为高RFI和低RFI 2个群体。在这2个分化群体内进行同质选配2个世代后计算其遗传进展。结果显示,RFI、ADG、BF的遗传力分别为0.15、0.22、0.28。G0代选择群体高、低RFI之间,RFI、ADG、BF性状的育种值差异分别是1.48、0.40、0.56个标准差;G1代高、低RFI测定群体之间3个性状的育种值差异分别是1.52、0.56、0.18个标准差。原始群体与G1代测定群体相比,高RFI群体的RFI、ADG、BF的遗传进展分别是0.732、-0.274、0.101个标准差,低RFI群体的RFI、ADG、BF的遗传进展是-0.788、0.283、-0.079个标准差。此外,肉质检测结果显示2群体间无显著差异。结果表明,用RFI作为主选性状可有效改变猪的饲料效率,建立饲料效率分化品系,遗传进展良好。  相似文献   

8.
剩余采食量(RFI)是肉牛实际采食量与预期采食量之间的差值,是评定肉牛饲料效率的有效指标。肉牛的能量代谢差异在很大程度上可以解释其RFI差异,而肉牛瘤胃中复杂的微生物菌群结构在瘤胃发酵及其能量代谢方面起着重要作用。因此本文主要对最近几年国外采用PCR-变性梯度凝胶电泳(DGGE)、文库克隆测序、实时定量PCR和高通量测序技术研究肉牛RFI表型与瘤胃中的细菌菌群和甲烷菌菌群结构之间的关系所取得的进展进行总结,并介绍RFI的主要预测模型。  相似文献   

9.
剩余采食量在反刍动物生产中的研究进展   总被引:1,自引:0,他引:1  
剩余采食量(RFI)是一种评价饲料利用效率的有效指标,与料重比和增重饲料比这2种评价饲料利用效率的指标相比,可以避免不同体形和不同生长时期动物之间饲料利用效率的固有差异,可以使饲料利用效率的评价更加科学。随着科学技术发展,压力传感器系统、图像信息系统能够更加快捷有效地帮助收集采食量的相关数据。研究发现,低RFI的反刍动物对粗饲料的消化能力更强,同时不同RFI的反刍动物瘤胃细菌组成也存在差异,而且在瘤胃中挥发性脂肪酸运输的关键基因与RFI具有相关性。虽然不同RFI的家畜屠宰性能和胴体性状的差异在不同种家畜的研究中还没得到一致的结果,但是在繁殖育种中选育低RFI的家畜可以提高生产效率,节约饲料成本。因此,RFI在规模化养殖中的应用可以为提高牧场生产管理水平、增加经济效益提供帮助。  相似文献   

10.
本研究旨在比较不同剩余采食量(RFI)绵羊的屠宰性能和肉品质,以探究RFI对绵羊胴体特征和肉品质的影响。选用202只萨福克羊(?)×湖羊(♀)的杂交F1代青年绵羊作为试验候选群体,进行单栏饲喂试验75 d,其中,预试期15 d,正试期60 d。筛选出RFI最小(RFI=-0.39±0.04)、平均体重为31.35 kg的8只试验羊作为低剩余采食量组(L-RFI组),RFI值最高(RFI=0.30±0.03)、平均体重为31.15 kg的8只试验羊作为高剩余采食量组(H-RFI组)。测定2组屠宰性能,并且采集背最长肌、牡蛎肌、霖肉、米龙肌、腹腩肌,测定营养成分含量、肉色指标和持水能力等指标。结果表明:1)L-RFI组的GR值显著低于H-RFI组(P<0.05),2组之间宰前活重、胴体重、屠宰率、净肉率、眼肌面积没有显著差异(P>0.05)。2) L-RFI组的背最长肌脂肪含量,牡蛎肌脂肪、灰分含量以及霖肉蛋白质含量显著低于H-RFI组(P<0.05),2组之间米龙肌、腹腩肌水分、脂肪、蛋白质、灰分含量没有显著差异(P>0.05)。3)L-RFI组的背最长肌、牡蛎肌...  相似文献   

11.
12.
剩余采食量(RFI)是实际采食量与预测采食量的差值,是衡量肉牛饲料效率的新指标。文章简要介绍了RFI的概念、测定方法、应用RFI的益处,以及影响肉牛RFI的一些生理因素,包括采食量、消化率、体组织代谢、活动量、体温调节等。最后,文章讨论了RFI在肉牛生产实践中的应用。  相似文献   

13.
Increasing feed costs and the desire to improve environmental stewardship have stimulated renewed interest in improving feed efficiency of livestock, including that of US dairy herds. For instance, USDA cost projections for corn and soybean meal suggest a 20% increase over 2010 pricing for a 16% protein mixed dairy cow ration in 2011, which may lead to a reduction in cow numbers to maintain profitability of dairy production. Furthermore, an October 2010 study by The Innovation Center for US Dairy to assess the carbon footprint of fluid milk found that the efficiency of feed conversion is the single greatest factor contributing to variation in the carbon footprint because of its effects on methane release during enteric fermentation and from manure. Thus, we are conducting research in contemporary US Holsteins to identify cows most efficient at converting feed to milk in temperate climates using residual feed intake (RFI), a measure used successfully to identify the beef cattle most efficient at converting feed to gain. Residual feed intake is calculated as the difference between predicted and actual feed intake to support maintenance and production (e.g., growth in beef cattle, or milk in dairy cattle). Heritability estimates for RFI in dairy cattle reported in the literature range from 0.01 to 0.38. Selection for a decreased RFI phenotype can reduce feed intake, methane production, nutrient losses in manure, and visceral organ weights substantially in beef cattle. We have estimated RFI during early lactation (i.e., to 90 d in milk) in the Beltsville Agricultural Research Center Holstein herd and observed a mean difference of 3.7 kg/d (P < 0.0001) in actual DMI between the efficient and inefficient groups (±0.5 SD from the mean RFI of 0), with no evidence of differences (P > 0.20) in mean BW, ADG, or energy-corrected milk exhibited between the 2 groups. These results indicate promise for using RFI in dairy cattle to improve feed conversion to milk. Previous and current research on the use of RFI in lactating dairy cattle are discussed, as well as opportunities to improve production efficiency of dairy cattle using RFI for milk production.  相似文献   

14.
Improvement in the utilization of feed in livestock is an important target of breeding and nutritional programs. Recent evidence indicates a potential association between feed efficiency and fecal cortisol metabolites, which could eventually be used as an indirect assessment of this trait. This evidence is more comprehensively evaluated in here with samples for plasma cortisol (PC; ng/ml) and fecal cortisol metabolites (FCM; ng/ml) collected more often during the entire finishing phase in beef steers. Individual daily feed intake of 112 steers fed a high-moisture corn-based and haylage diet was measured over 168 d. Body weight, blood and fecal samples were collected every 14 d and ultrasound measures of backfat thickness and longissimus muscle area were taken every 28 d. Four productive performance traits were calculated: daily dry matter intake (DMI), average daily gain (ADG), feed to gain ratio (F:G) and residual feed intake (RFI). At the end of the feedlot phase, steers were ranked according to RFI and samples were analyzed for PC and FCM from the 32 steers with greatest and 32 steers with lowest feed efficiency. In addition, a sub-group of 12 steers from each of these two groups with divergent feed efficiency were subjected to hourly blood sampling for 24 h. Less efficient steers had greater DMI, F:G and consumed 1.5 kg/d more DMI (P<0.05) than steers with improved feed efficiency. No differences (P>0.10) in PC over the 12 biweekly sampling periods between steers with divergent feed efficiency were observed. However, a trend toward significance between 19:00 and 02:00 h over the hourly sampling evaluation was noticed, with the sub-group of more feed efficient steers presenting higher levels of PC in this period of the day (P=0.08). On the other hand, FCM levels displayed a distinct pattern between RFI groups over the biweekly sampling period, with more efficient cattle presenting greater levels of these metabolites (P<0.05). This study reinforces the positive association between improved feed efficiency and FCM levels over the finishing phase; and the lack of association between feed efficiency and PC when single samples are collected every two weeks through a single jugular venipuncture performed after handling the cattle for sampling. Further studies to develop sampling protocols for assessing FCM as an indicator trait for feed efficiency are warranted, as well as, studies to understand the role of endogenous glucocorticoids in the performance of the bovine.  相似文献   

15.
本实验旨在探讨绍兴鸭剩余采食量(RFI)与生产性能及蛋品质之间的关系。测定300只绍兴鸭410~470日龄的采食量、体重、平均蛋重、蛋品质,计算出剩余采食量与料蛋比,并分析剩余采食量与生产性能及蛋品质的相关性。结果显示:绍兴鸭平均采食量、平均蛋重、体重、体增重、料蛋比、剩余采食量分别为198.8 g/d、73.0 g、1500.9 g、2.5 g/d、2.7、3.5 g/d;低剩余采食量组的剩余采食量、采食量以及料蛋比极显著低于高剩余采食量组;相关性分析表明,剩余采食量与采食量和料蛋比呈极显著正相关(P<0.01);采食量与平均蛋重、体重呈极显著正相关(P<0.01),与料蛋比呈极显著负相关(P<0.01),与体增重呈显著正相关性(P<0.05);蛋品质分析结果表明,高剩余采食量组仅蛋黄色泽水平显著高于低剩余采食量组;相关性分析表明,剩余采食量与蛋品质各指标间均无显著相关性。本试验结果表明,以剩余采食量为蛋鸭选育指标是可行的,且选育低剩余采食量的鸭子能显著降低采食量,提高饲料效率,且不改变产蛋重及蛋品质。  相似文献   

16.

Background

Methane (CH4) emissions in cattle are an undesirable end product of rumen methanogenic fermentative activity as they are associated not only with negative environmental impacts but also with reduced host feed efficiency. The aim of this study was to quantify total and specific rumen microbial methanogenic populations in beef cattle divergently selected for residual feed intake (RFI) while offered (i) a low energy high forage (HF) diet followed by (ii) a high energy low forage (LF) diet. Ruminal fluid was collected from 14 high (H) and 14 low (L) RFI animals across both dietary periods. Quantitative real time PCR (qRT-PCR) analysis was conducted to quantify the abundance of total and specific rumen methanogenic microbes. Spearman correlation analysis was used to investigate the association between the relative abundance of methanogens and animal performance, rumen fermentation variables and diet digestibility.

Results

Abundance of methanogens, did not differ between RFI phenotypes. However, relative abundance of total and specific methanogen species was affected (P < 0.05) by diet type, with greater abundance observed while animals were offered the LF compared to the HF diet.

Conclusions

These findings suggest that differences in abundance of specific rumen methanogen species may not contribute to variation in CH4 emissions between efficient and inefficient animals, however dietary manipulation can influence the abundance of total and specific methanogen species.  相似文献   

17.
Rates of gain and feed efficiency are important traits in most breeding programs for growing farm animals. The rate of gain (GAIN) is usually expressed over a certain age period and feed efficiency is often expressed as residual feed intake (RFI), defined as observed feed intake (FI) minus expected feed intake based on live weight (WGT) and GAIN. However, the basic traits recorded are always WGT and FI and other traits are derived from these basic records. The aim of this study was to develop a procedure for simultaneous analysis of the basic records and then derive linear traits related to feed efficiency without retorting to any approximation. A bivariate longitudinal random regression model was employed on 13,791 individual longitudinal records of WGT and FI from 2,827 bulls of six different beef breeds tested for their own performance in the period from 7 to 13 mo of age. Genetic and permanent environmental covariance functions for curves of WGT and FI were estimated using Gibbs sampling. Genetic and permanent covariance functions for curves of GAIN were estimated from the first derivative of the function for WGT and finally the covariance functions were extended to curves for RFI, based on the conditional distribution of FI given WGT and GAIN. Furthermore, the covariance functions were extended to include GAIN and RFI defined over different periods of the performance test. These periods included the whole test period as normally used when predicting breeding values for GAIN and RFI for beef bulls. Based on the presented method, breeding values and genetic parameters for derived traits such as GAIN and RFI defined longitudinally or integrated over (parts of) of the test period can be obtained from a joint analysis of the basic records. The resulting covariance functions for WGT, FI, GAIN, and RFI are usually singular but the method presented here does not suffer from the estimation problems associated with defining these traits individually before the genetic analysis. All the results are thus estimated simultaneously, and the set of parameters is consistent.  相似文献   

18.
Data on 380 Duroc boars from seven generations, and 1026 Landrace pigs (341 boars and 685 gilts) from six generations were used to estimate genetic parameters for daily gain (DG), backfat thickness (BF), metabolic weight (MWT), daily feed intake (FI), feed conversion ratio (FCR) and residual feed intake (RFI). Two measures of RFI were estimated as the difference between actual feed intake and that predicted from models that included initial test age and weight and DG (RFI1); and initial test age and weight, DG and BF (RFI2). Heritability estimates for DG, MWT and FI were moderate for both breeds. BF estimates were high for both the breeds. The measures of feed efficiency (FCR and RFI) were moderately heritable. Genetic correlations of BF with measures of RFI were stronger when BF was not included in the estimation of RFI (0.40 and 0.46 for Duroc and Landrace, respectively (for RFI1), compared with 0.05 and 0.06 for Duroc and Landrace, respectively (for RFI2)). Genetic correlations of MWT with measures of RFI were all negative and low. Genetic and phenotypic correlations between DG and measures of RFI were close to zero, which indicated that selection for reduced RFI could be made without adversely affecting DG. BF should also decrease, and MWT should increase under selection for reduced RFI. The reduction in BF would depend on the measure of RFI used.  相似文献   

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