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Background: Feed accounts for up to 75% of costs in beef production systems,thus any improvement in feed efficiency(FE) will benefit the profitability of this enterprise.Residual feed intake(RFI) is a measure of FE that is independent of level of production.Adipose tissue(AT) is a major endocrine organ and the primary metabolic energy reservoir.It modulates a variety of processes related to FE such as lipid metabolism and glucose homeostasis and thus measures of inter-animal variation in adiposity are frequently included in the calculation of the RFI index.The aim of this study was to determine the effect of phenotypic RFI status and gender on the expression of key candidate genes related to processes involved in energy metabolism within AT.Dry matter intake(DMI) and average daily gain(ADG) were measured over a period of 70 d for 52 purebred Simmental heifers(n = 24) and bulls(n = 28) with an initial BW±SD of 372±39.6 kg and 387±50.6 kg,respectively.Residual feed intake was calculated and animals were ranked within gender by RFI into high(inefficient; n = 9 heifers and n = 8 bulls)and low(efficient; n = 9 heifers and n = 8 bulls) groups.Results: Average daily gain ±SD and daily DMI ±SD for heifers and bul s were 1.2±0.4 kg and 9.1±0.5 kg,and 1.8±0.3 kg and 9.5±1 kg respectively.High RFI heifers and bulls consumed 10% and 15% more(P 0.05) than their low RFI counterparts,respectively.Heifers had a higher expression of all genes measured than bulls(P 0.05).A gender × RFI interaction was detected for HMGCS2(P 0.05) in which high RFI bulls tended to have lower expression of HMGCS2 than low RFI bulls(P 0.1),whereas high RFI heifers had higher expression than low RFI heifers(P 0.05) and high RFI bulls(P 0.05).SLC2 A4 expression was consistently higher in subcutaneous AT of low RFI animals across gender.Conclusion: The findings of this study indicate that low RFI cattle exhibit upregulation of the molecular mechanisms governing glucose metabolism in adipose tissue,in particular,glucose clearance.The decreased expression of SLC2 A4 in the inefficient cattle may result in less efficient glucose metabolism in these animals.We conclude that SLC2 A4 may be a potential biomarker for RFI in cattle.  相似文献   

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Background: Consuming moderate amounts of lean red meat as part of a balanced diet valuably contributes to intakes of essential nutrients, in this study, we merged phenotypic and genotypic information to characterize the variation in lipid profile and sensory parameters and to represent the diversity among 15 cattle populations. Correlations between fat content, organoleptic characteristics and lipid profiles were also investigated. Methods: A sample of 436 largely unrelated purebred bulls belonging to 15 breeds and reared under comparable management conditions was analyzed. Phenotypic data -including fatness score, fat percentage, individual fatty acids (FA) profiles and sensory panel tests- and genotypic information from 11 polymorphisms was used. Results: The correlation coefficients between muscle total lipid measurements and absolute vs. relative amounts of polyunsaturated FA (PUFA) were in opposite directions. Increasing carcass fat leads to an increasing amount of FAs in triglycerides, but at the same time the relative amount of PUFAs is decreasing, which is in concordance with the negative correlation obtained here between the percentage of PUFA and fat measurements, as well as the weaker correlation between total phospholipids and total lipid muscle content compared with neutral lipids. Concerning organoleptic characteristics, a negative correlation between fiavour scores and the percentage of total PUFA, particularly to n-6 fraction, was found. The correlation between juiciness and texture is higher than with flavour scores. The distribution of SNPs plotted by principal components analysis (PCA) mainly reflects their known trait associations, although influenced by their specific breed allele frequencies. Conclusions: The results presented here help to understand the phenotypic and genotypic background underlying variations in FA composition and sensory parameters between breeds. The wide range of traits and breeds studied, along with the genotypic information on polymorphisms previo  相似文献   

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Background:The expression of genes encoding proteins involved in triacyglyceride and fatty acid synthesis and storage in cattle muscle are correlated with intramuscular fat(IMF)%.Are the same genes also correlated with IMF%in sheep muscle,and can the same set of genes be used to estimate IMF%in both species?Results:The correlation between gene expression(microarray) and IMF%in the longissimus muscle(LM) of twenty sheep was calculated.An integrated analysis of this dataset with an equivalent cattle correlation dataset and a cattle differential expression dataset was undertaken.A total of 30 genes were identified to be strongly correlated with IMF%in both cattle and sheep.The overlap of genes was highly significant,8 of the 13 genes in the TAG gene set and 8 of the 13 genes in the FA gene set were in the top 100 and 500 genes respertively most correlated with IMF%in sheep,P-value = 0.Of the 30 genes,CIDEA,THRSP,ACSM1,DGAT2 and FABP4 had the highest average rank in both species.Using the data from two small groups of Brahman cattle(control and Hormone growth promotant-treated[known to decrease IMF%in muscle]) and 22 animals in total,the utility of a direct measure and different estimators of IMF%(ultrasound and gene expression) to differentiate between the two groups were examined.Directly measured IMF%and IMF%estimated from ultrasound scanning could not discriminate between the two groups.However,using gene expression to estimate IMF%discriminated between the two groups.Increasing the number of genes used to estimate IMF%from one to five significantly increased the discrimination power;but increasing the number of genes to 15 resulted in little further improvement.Conclusion:We have demonstrated the utility of a comparative approach to identify robust estimators of IMF%in the LM in cattle and sheep.We have also demonstrated a number of approaches(potentially applicable to much smaller groups of animals than conventional methods) to using gene expression to rank animals for IMF%within  相似文献   

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Background: Semen evaluation is used to estimate the testicular function. In bulls, the spermatozoa present in the ejaculate are the result of a process that begun more than 2 mo earlier, bequeathing a delayed depiction of the actual function of the testis. Since testis vascularization might be critical for the gonad function, selected pulse wave Doppler ultrasound parameters were assessed in this study, for instance the peak systolic velocity, the end diastolic velocity and the resistive index of the testicular artery along the spermatic cord, the marginal portion of the testicular artery and the intratesticular branches of the testicular artery both in healthy adult and young bulls.Correlations between these parameters and characteristics of semen that was collected numerous times, before and after the Doppler ultrasound examination.Results: The peak systolic velocity and the end diastolic velocity measured in the testicular artery along the spermatic cord(supratesticular artery – SA) were variable among the bulls and within individual bulls, likely due to the convoluted course of the vessel. The resistive index was found highly repeatable in the same bull. A reduction in the resistive index was found between the supratesticular artery and the marginal portion of the testicular artery(P 0.01), and between the marginal portion of the testicular artery and the intratesticular branches of the testicular artery(P 0.05). No differences were recorded for the pulse wave Doppler ultrasound parameters in young bulls compared with adults. A significant correlation was found between the resistive index of the marginal portion of the testicular artery and total sperm in the ejaculate(r = 0.516, P 0.05), the immature sperm(r = 0.462, P 0.05), the teratoid sperm(r = 0.375, P 0.05), and the "Dag defect" sperm(r = 0.389, P 0.05). Similarly, the resistive index of the intratesticular branches of the testicular artery were found correlated with the total sperm number in the ejaculate(r = 0.568, P 0.05), the immature sperm(r = 0.523, P 0.05), the teratoid sperm(r = 0.418, P 0.05), and the "Dag defect" sperm(r = 0.341, P 0.05).Conclusions: The data presented in this study suggest that the resistive index, measured at the marginal portion of the testicular artery, could be an easy-to-perform parameter to evaluate the spermatogenesis quality in young bulls and normal adults.  相似文献   

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Background The mechanism by which Meishan(MS) sows are superior to white crossbred sows in ovarian follicle development remains unclear. Given gut microbiota could regulate female ovarian function and reproductive capacity, this study aimed to determine the role of gut microbiota-ovary axis on follicular development in sows.Methods We compared the ovarian follicular development, gut microbiota, plasma metabolome, and follicular fluid metabolome between MS and Landrace × Yorkshire(L × Y) sows. A ...  相似文献   

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Missing genotypes are a common feature of high density SNP datasets obtained using SNP chip technology and this is likely to decrease the accuracy of genomic selection. This problem can be circumvented by imputing the missing genotypes with estimated genotypes. When implementing imputation, the criteria used for SNP data quality control and whether to perform imputation before or after data quality control need to consider. In this paper, we compared six strategies of imputation and quality control using different imputation methods, different quality control criteria and by changing the order of imputation and quality control, against a real dataset of milk production traits in Chinese Holstein cattle. The results demonstrated that, no matter what imputation method and quality control criteria were used, strategies with imputation before quality control performed better than strategies with imputation after quality control in terms of accuracy of genomic selection. The different imputation methods and quality control criteria did not significantly influence the accuracy of genomic selection. We concluded that performing imputation before quality control could increase the accuracy of genomic selection, especially when the rate of missing genotypes is high and the reference population is small.  相似文献   

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Background: Different production systems and climates could lead to genotype-by-environment(G × E) interactions between populations, and the inclusion of G × E interactions is becoming essential in breeding decisions. The objective of this study was to investigate the performance of multi-trait models in genomic prediction in a limited number of environments with G × E interactions.Results: In total, 2,688 and 1,384 individuals with growth and reproduction phenotypes, respectively, from two Yorkshire pig populations with similar genetic backgrounds were genotyped with the PorcineSNP80 panel.Single-and multi-trait models with genomic best linear unbiased prediction(GBLUP) and BayesC π were implemented to investigate their genomic prediction abilities with 20 replicates of five-fold cross-validation.Our results regarding between-environment genetic correlations of growth and reproductive traits(ranging from 0.618 to 0.723) indicated the existence of G × E interactions between these two Yorkshire pig populations. For single-trait models, genomic prediction with GBLUP was only 1.1% more accurate on average in the combined population than in single populations, and no significant improvements were obtained by BayesC π for most traits. In addition, single-trait models with either GBLUP or BayesC π produced greater bias for the combined population than for single populations. However, multi-trait models with GBLUP and BayesC π better accommodated G × E interactions,yielding 2.2% – 3.8% and 1.0% – 2.5% higher prediction accuracies for growth and reproductive traits, respectively,compared to those for single-trait models of single populations and the combined population. The multi-trait models also yielded lower bias and larger gains in the case of a small reference population. The smaller improvement in prediction accuracy and larger bias obtained by the single-trait models in the combined population was mainly due to the low consistency of linkage disequilibrium between the two populations, which also caused the BayesC π method to always produce the largest standard error in marker effect estimation for the combined population.Conclusions: In conclusion, our findings confirmed that directly combining populations to enlarge the reference population is not efficient in improving the accuracy of genomic prediction in the presence of G × E interactions, while multi-trait models perform better in a limited number of environments with G × E interactions.  相似文献   

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This study was aimed to compare the growth performance, nutrient digestion, rumen fermentation and blood physiological indexes between yaks (Bos grunniens) and cattle (Bos taurus) under low-concentrate barn fattening, which provide data reference and technical support for breed and feeding technology selection of fattening beef cattle in the Qinghai-Tibetan Plateau. In this experiment, six healthy yaks [(211 ±6) kg] and six healthy Qaidam cattle [(210±7) kg], all castrated and 4 years of age, were selected and raised in individual metabolic cages. The experimental diets consisted of concentrate (2.0 kg / d per head) and forage (ad libitum) . The pre-experiment lasted for 10 days, and the trial lasted for 95 days. The results showed as follows: 1) total dry matter intake were significantly lower in yaks than cattle (P<0.05), whereas average daily gain was not different between yaks and cattle (P>0.05), therefore, feed / gain was significantly lower in yaks than cattle (P<0.05) . 2) There was no difference between yaks and cattle in apparent digestibilities of nutrients (P>0.05) . 3) Ruminal pH tended to be higher (P = 0.083), and the concentrations of iso-volatile fatty acids (VFAs) were significantly greater in yaks than cattle (P<0.05), whereas the concentrations of total volatile fatty acids (TVFA), acetate, propionate and butyrate were not significantly different between yaks and cattle (P>0.05) . 4) Concentrations of ammonia nitrogen, free amino acid nitrogen and soluble protein nitrogen in rumen were significantly greater in yaks than cattle (P<0.05) . 5) The red blood cells (RBC) amount, hemoglobin (HGB) content, hematocrit (HCT) and red blood cell volume distribution width (RDW-CV) were significantly lower (P < 0. 05), whereas mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) content and platelets (PLT) amount were significantly higher in yaks than cattle (P<0.05) . In conclusion, yaks have lower feed intake, but have a greater feed conversion efficiency than cattle, therefore, yaks can produce a greater economic benefits than cattle under low-concentrate barn fattening system. © 2023 Authors. All rights reserved.  相似文献   

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Background: The high mortality of pre-weanling piglets is a dominant challenge which severely restricts the development of pig industry. A number of factors including nutrients imbalance and temperature variation during postnatal period of piglets have been reported to closely associated with the high mortality of postnatal piglets.This study aims to find out the relationship between fat deposition and survival of newborn piglets.Results: There were no differences in organ coefficient and bone density between the surviving and dead piglets(P 0.05). The body weight and the fat deposition in the dead piglets were lower than the live individuals(P 0.05).Consistently, the average sizes of white adipocytes in back and abdominal adipose tissues of dead piglets were smaller than the survivals(P 0.05). The protein expression levels of adipocyte differentiation markers PPARγ and C/EBPα in the back and abdominal adipose tissues were lower in dead piglets compared to live piglets. The mRNA expressions of thermogenic markers PGC1α and PRDM16 in adipose tissues were decreased in the dead piglets(P 0.05). The microarray of back fat samples from the surviving and dead piglets were conducted; two down-regulated genes namely AAMDC and CASTOR1 were identified from the dead piglets. According to quantitative real-time PCR(RT-PCR) analysis, the mRNA expression of AAMDC decreased, whereas CASTOR1 expression elevated in the dead piglets compared to the surviving piglets(P 0.05).Conclusions: The fat deposition and adipocyte differentiation in the dead piglets are insufficient compared to the surviving piglets, which may attenuate the thermogenic ability of white adipose tissue(WAT). Our data indicate that fat deposition in newborn piglets is vital to their survival.  相似文献   

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Background: Betaine affects fat metabolism in animals, but the specific mechanism is still not clear. The purpose of this study was to investigate possible mechanisms of betaine in altering lipid metabolism in muscle tissue in finishing pigs.Methods: A total of 120 crossbred gilts(Landrace × Yorkshire × Duroc) with an average initial body weight of 70.1 kg were randomly allotted to three dietary treatments. The treatments included a corn–soybean meal basal diet supplemented with 0, 1250 or 2500 mg/kg betaine. The feeding experiment lasted 42 d.Results: Betaine addition to the diet significantly increased the concentration of free fatty acids(FFA) in muscle(P 0.05). Furthermore, the levels of serum cholesterol and high-density lipoprotein cholesterol were decreased(P 0.05) and total cholesterol content was increased in muscle(P 0.05) of betaine fed pigs. Experiments on genes involved in fatty acid transport showed that betaine increased expression of lipoprotein lipase(LPL), fatty acid translocase/cluster of differentiation(FAT/CD36), fatty acid binding protein(FABP3) and fatty acid transport protein(FATP1)(P 0.05). The abundance of fatty acid transport protein and fatty acid binding protein were also increased by betaine(P 0.05). As for the key factors involved in fatty acid oxidation, although betaine supplementation didn't affect the level of carnitine and malonyl-CoA, betaine increased mR NA and protein abundance of carnitine palmitransferase-1(CPT1)and phosphorylated-AMPK(P 0.05).Conclusions: The results suggested that betaine may promoted muscle fatty acid uptake via up-regulating the genes related to fatty acid transporter including FAT/CD36, FATP1 and FABP3. On the other hand, betaine activated AMPK and up-regulated genes related to fatty acid oxidation including PPARα and CPT1. The underlying mechanism regulating fatty acid metabolism in pigs supplemented with betaine is associated with the up-regulation of genes involved in fatty acid transport and fatty acid oxidation.  相似文献   

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Background: This study was conducted to determine protein molecular structure profiles and quantify the relationship between protein structural features and protein metabolism and bioavailability of blend pel eted products(BPP) based on co-products(canola or carinata) from processing with different proportions of pulse pea screenings and lignosulfonate chemical compound.Method: The protein molecular structures were determined using the non-invasive advanced vibrational molecular spectroscopy(ATR-FT/IR) in terms of chemical structure and biofunctional groups of amides(Ⅰ and Ⅱ), α-helix and β-sheet.Results: The results showed that increasing the level of the co-products in BPP significantly increased the spectral intensity of the amide area and amide height. The products exhibited similar protein secondary α-helix to β-sheet ratio.The protein molecular structure profiles(amides Ⅰ and Ⅱ, α-helix to β-sheet) were highly associated with protein degradation kinetics and intestinal digestion. In conclusion, the non-invasive vibrational molecular spectroscopy(ATR-FT/IR) could be used to detect inherent structural make-up characteristics in BPP.Conclusion: The molecular structural features related to protein biopolymer were highly associated with protein utilization and metabolism.  相似文献   

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Background: The aim of this study was to estimate variance components and to identify genomic regions and pathways associated with resistance to gastrointestinal parasites, particularly Haemonchus contortus, in a breed of sheep adapted to tropical climate. Phenotypes evaluations were performed to verify resistance to gastrointestinal parasites, and were divided into two categories: i) farm phenotypes, assessing body condition score(BCS), degree of anemia assessed by the famacha chart(FAM), fur score(FS) and feces consistency(FC); and ii) lab phenotypes,comprising blood analyses for hematocrit(HCT), white blood cell count(WBC), red blood cell count(RBC),hemoglobin(HGB), platelets(PLT) and transformed(log10) egg per gram of feces(EPG_(log)). A total of 576 animals were genotyped with the Ovine SNP12k Bead Chip(Illumina, Inc.), that contains 12,785 bialleleic SNP markers. The variance components were estimated using a single trait model by single step genomic BLUP procedure.Results: The overall linkage disequilibrium(LD) mean between pairs of markers measured by r2 was 0.23. The overall LD mean between markers considering windows up to 10 Mb was 0.07. The mean LD between adjacent SNPs across autosomes ranged from 0.02 to 0.10. Heritability estimates were low for EPG_(log)(0.11), moderate for RBC(0.18), PLT(0.17) HCT(0.20), HGB(0.16) and WBC(0.22), and high for FAM(0.35). A total of 22, 21, 23, 20, 26, 25 and 23 windows for EPG_(log)for FAM, WBC, RBC, PLT, HCT and HGB traits were identified, respectively. Among the associated windows, 10 were shown to be common to HCT and HGB traits on OAR1, OAR2, OAR3, OAR5, OAR8 and OAR15.Conclusion: The traits indicating gastrointestinal parasites resistance presented an adequate genetic variability to respond to selection in Santa Inês breed, and it is expected a higher genetic gain for FAM trait when compared to the others. The level of LD estimated for markers separated by less than 1 Mb indicated that the Ovine SNP12k Bead Chip might be a suitable tool for identifying genomic regions associated with traits related to gastrointestinal parasite resistance. Several candidate genes related to immune system development and activation, inflammatory response,regulation of lymphocytes and leukocytes proliferation were found. These genes may help in the selection of animals with higher resistance to parasites.  相似文献   

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Live yeast(Saccharomyces cerevisiae) constitutes an effective additive for animal production;its probiotic effect may be related to the concentrate-to-forage ratio(CTFR).The objective of this study was to assess the effects of S.cerevisiae(SC) on fiber degradation and rumen microbial populations in steers fed diets with different levels of dietary concentrate.Ten Simmental × Local crossbred steers(450 ± 50 kg BW) were assigned to a control group or an SC group.Both groups were fed the same basal diet but the SC group received SC supplementation(8 × 10^9 cfu/h/d through the ruminal fistula)following a two-period crossover design.Each period consisted of four phases,each of which lasted 17 d:10 d for dietary adaptation,6 d for degradation study,and 1 d for rumen sample collection.From the 1~(st) to the 4~(th) phase,steers were fed in a stepwise fashion with increasing CTFRs,i.e.,30:70,50:50,70:30,and 90:10.The kinetics of dry matter and fiber degradation of alfalfa pellets were evaluated;the rumen microbial populations were detected using real-time PCR.The results revealed no significant(P〉 0.05) interactions between dietary CTFR and SC for most parameters.Dietary CTFR had a significant effect(P〈 0.01) on degradation characteristics of alfalfa pellets and the copies of rumen microorganism;the increasing concentrate level resulted in linear,quadratic or cubic variation trend for these parameters.SC supplementation significantly(P〈 0.05) affected dry matter(DM) and neutral detergent fiber(NDF)degradation rates(c_(DM),c_(NDF)) and NDF effective degradability(ED_(NDF)).Compared with the control group,there was an increasing trend of rumen fungi and protozoa in SC group(P 〈 0.1);copies of total bacteria in SC group were significantly higher(P〈 0.05).Additionally,percentage of Ruminobacter amylophilus was significantly lower(P〈 0.05)but percentage of Selenomonas ruminantium was significantly higher(P〈 0.05) in t  相似文献   

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