Estimates of genomic inbreeding and identification of candidate regions that differ between Chinese indigenous sheep breeds

Background:A run of homozygosity(ROH)is a consecutive tract of homozygous genotypes in an individual that indicates it has inherited the same ancestral haplotype from both parents.Genomic inbreeding can be quantified based on ROH.Genomic regions enriched with ROH may be indicative of selection sweeps and are known as ROH islands.We carried out ROH analyses in five Chinese indigenous sheep breeds;Altay sheep(n=50 individuals),Large-tailed Han sheep(n=50),Hulun Buir sheep(n=150),Short-tailed grassland sheep(n=150),and Tibetan sheep(n=50),using genotypes from an Ovine Infinium HD SNP BeadChip.Results:A total of 18,288 ROH were identified.The average number of ROH per individual across the five sheep breeds ranged from 39(Hulun Buir sheep)to 78(Large-tailed Han sheep)and the average length of ROH ranged from 0.929 Mb(Hulun Buir sheep)to 2.544 Mb(Large-tailed Han sheep).The effective population size(Ne)of Altay sheep,Large-tailed Han sheep,Hulun Buir sheep,Short-tailed grassland sheep and Tibetan sheep were estimated to be 81,78,253,238 and 70 five generations ago.The highest ROH-based inbreeding estimate(FROH)was 0.0808 in Large-tailed Han sheep,whereas the lowest F_ROHwas 0.0148 in Hulun Buir sheep.Furthermore,the highest proportion of long ROH fragments(>5 Mb)was observed in the Large-tailed Han sheep breed which indicated recent inbreeding.In total,49 ROH islands(the top 0.1% of the SNPs most commonly observed in ROH)were identified in the five sheep breeds.Three ROH islands were common to all the five sheep breeds,and were located on OAR2:12.2-12.3 Mb,OAR12:78.4-79.1 Mb and OAR13:53.0-53.6 Mb.Three breed-specific ROH islands were observed in Altay sheep(OAR15:3.4-3.8 Mb),Large-tailed Han sheep(ORA17:53.5-53.8 Mb)and Tibetan sheep(ORA5:19.8-20.2 Mb).Collectively,the ROH islands harbored 78 unique genes,including 19 genes that have been documented as having associations with tail types,adaptation,growth,body size,reproduction or immune response.Conclusion:Different ROH patterns were observed in five Chinese indigenous sheep breeds,which reflected their different population histories.Large-tailed Han sheep had the highest genomic inbreeding coefficients and the highest proportion of long ROH fragments indicating recent inbreeding.Candidate genes in ROH islands could be used to illustrate the genetic characteristics of these five sheep breeds.Our findings contribute to the understanding of genetic diversity and population demography,and help design and implement breeding and conservation strategies for Chinese sheep.     

Molecular cloning and characterization of the endothelin 3 gene in black bone sheep

Background: Black bone sheep was first discovered in Yunnan province of China in 1970, with unique black pigmentation on the body and internal organs. Endothelin 3(EDN3) has been known as a key gene causing hyperpigmentation in black bone chicken, the Silky fowl.Methods: In this study, EDN3 was employed as a candidate gene for regulating black color pigmentation. First,EDN3 was cloned from sheep to obtain the full-length cDNA by using the rapid amplification of cDNA ends(RACE).Genomic EDN3 was screened and a total of thirty predicted single nucleotide polymorphisms(SNPs) were genotyped for allele and genotype frequency analysis in a case-control study involving two black bone sheep populations. Genomic copy number analysis of EDN3 in sheep was conducted to measure the variation in copy number. EDN3 expression levels were observed among the groups in adult liver, lymph node, and kidney tissues, as well as embryo kidney samples. Also, among the tissues of black bone and non-black bone sheep.Results: The size of the full-length cDNA was 1,578 bp, which included 426 bp of 5′-untranslated region(5′-UTR),an open reading frame(ORF) of 639 bp encoding a protein of 212 amino acids, and a 3′-UTR of 513 bp. Genotype and allele frequencies of all the discovered SNPs were found insignificantly different in black bone and non-black bone sheep(P 0.05). Genomic copy number analysis of EDN3 in sheep revealed no significant difference between the two sheep groups. No significant variations were found in the adult liver and kidney embryo samples. However,the expression in lymph node and kidney tissue was significantly higher in black bone sheep than that in non-black bone sheep(P 0.05). Significant variations in the EDN3 expression levels were observed among the tissues of nonblack bone sheep.Conclusions: The findings of the present study indicate that unlike in Silky chickens, EDN3 is not responsible for hyperpigmentation but may play a key functional role in immune and excretory systems of black bone sheep.     

Dynamic changes of genomic methylation profiles at different growth stages in Chinese Tan sheepOA

Background: Tan sheep, an important local sheep breed in China, is famous for their fur quality. One-month-old Tan sheep have white, curly hair with beautiful flower spikes, commonly known as "nine bends", which has high economic value. However, the "nine bends" characteristic gradually disappears with age; consequently, the economic value of the Tan sheep decreases. Age-related changes in DNA methylation have been reported and may be responsible for age-induced changes in gene expression. Until...     

Dual-energy X-ray absorptiometry scans accurately predict differing body fat content in live sheep

Background: There is considerable interest in implementing mobile scanning technology for on-farm body composition analysis on live animals.These experiments evaluated the use of dual energy X-ray absorptiometry(DXA) as an accurate method of total body fat measurement in live sheep.Results: In Exp.1,visceral and whole body fat analysis was undertaken in sheep with body condition scores(BCS)in the range 2 to 3.25(scale 1: thin to 5: fat).The relationship of BCS was moderately correlated with visceral fat depot mass(r = 0.59,P 0.01,n = 24) and whole body fat(r = 0.70,P 0.001,n = 24).In Exp.2,sheep with BCS in the range 2.25 to 3.75 were blood sampled to analyse circulating leptin concentrations,and were DXA scanned immediately post mortem for total body fat.Plasma leptin concentrations had low correlations with BCS(r = 0.50,P 0.05,n = 17) and DXA body fat(r = 0.42,P 0.05,n = 17),and no correlation with chemical body fat(r = 0.17,P 0.05,n = 9).There was a moderate correlation between DXA body fat and BCS(r = 0.70,P 0.01,n = 17),and DXA body fat was highly correlated with chemical body fat(r = 0.81,P 0.001,n = 9).In Exp.3,a series of five DXA scans,at 8-week intervals,was performed on growing sheep over a 32-week period.The average BCS ranged from 2.39 ± 0.07(S.E.M.) to 3.05 ± 0.11 and the DXA body fat(%) ranged from 16.8 ± 0.8 to 24.2 ± 1.2.There was a moderate correlation between DXA body fat and BCS over the 32 weeks(r = 0.61,P 0.001,n = 24).Conclusions: Overall,these experiments indicated that there was good agreement between BCS,DXA and chemical analysis for measuring total body fat in sheep,and that DXA scanning is a valid method for longitudinal measurement of total body fat in live sheep.     

Effects of Compound Plant Nutrients on Rumen Fermentation Parameters,Rumen Microbiota and Fatty Acid Composition of Longissimus dorsi Muscle in Finishing Small Tail Han Sheep北大核心CSCD

This study was conducted to investigate the effects of compound p1ant nutrients (CPN) on rumen fermentation parameters, rumen microbiota and fatty acid composition of longissimus dorsi musc1e in finishing sma11 tai1 Han sheep. Sixteen 4-month-o1d finishing sma11 tai1 Han sheep with an initia1 body weight (BW) of (24.18±0.31) kg were random1y divided into two groups, name1y, with 8 rep1icates per group and 1 sheep per rep1icate. The sheep in the contro1 group were fed a basa1 diet, whereas the sheep of the contro1 group (CPN group) was fed the basa1 diet supp1ementation with 3‰ CPN. The experiment 1asted for 97 days after 7 days adaption. The resu1ts showed as fo11ows: compared with the contro1 group, 1) adding CPN decreased the concentration of ammonia nitrogen (NH3-N) (P<0.05); 2) CPN supp1ementation affected beta diversity of rumen microbiota; 3) the re1ative abundance of Acidobacteriota, Erysipe1otrichaceae_UCG-002, Lactobacillus, and Megasphaera were enhanced by adding CPN (P<0.05), whereas, the re1ative abundance of Bacteroidetes and Prevotella was 1ower (P<0.05); 4) the supp1ementation of CPN had no significant effect on fatty acid composition of longissimus dorsi musc1e of fattening sma11-tai1ed Han sheep (P>0.05); 5) the contents of tota1 MUFA, C18:1n9c, C14:1, C16:1, C18:2n6c, C18:3n3 and n-3PUFA in the longissimus dorsi musc1e were corre1ated with the re1ative abundance of Megasphaera, Erysipe1otrichaceae_UCG-002, Succiniclasticum and Ruminococcus (P<0.05). In conc1usion, CPN can regu1ate the rumen microbiota structure and reduce the rumen NH3-N concentration of fattening sma11-tai1ed Han sheep. In production practice, CPN can be used as a rumen eco1ogica1 regu1ator. © 2023 Authors. All rights reserved.     

The Analysis for the Single Nucleotide Polymorphism of TGF-β1 and Its Association with Reproduction in Different Sheep Breeds

A single nucleotide polymorphism(SNP)of 805 bp region in the intron 6 of transforming growth factor β1(TGF-β1)gene was identified by polymerase chain reaction-single-strand composition polymorphism(PCR-SSCP)in 196 sheep among Small-tailed Han sheep,Tong sheep,Tan sheep and Oula sheep.Comparative sequence analysis of cloned products revealed an AGAC deletion at 294 bases upstream of exon 7 of the TGF-β1 gene(site 14201 in gi76871756).Statistical results of the genotype and allele frequencies in different breeds showed that genotype AB was dominant in the Small-tailed Han sheep.Genotype BB,however,was in majority in low-fecundity sheep.The results of a Chi-square test indicated that all the populations were in Hardy-Weinberg equilibrium.     

Effects of Chinese herbal medicine on plasma glucose,protein and energy metabolism in sheep

Background： The use of antibiotics in animal diets is facing negative feedback due to the hidden danger of drug residues to human health. Traditional Chinese herbal medicine has been used to replace antibiotics in the past two decades and played an increasingly important role in livestock production. The present study was carried out to assess the feeding effects of a traditional nourishing Chinese herbal medicine mixture on kinetics of plasma glucose, protein and energy metabolism in sheep. Ruminal fermentation characteristics were also determined. Methods： Four sheep were fed on either mixed hay （MH-diet） or MH-diet supplemented with 2% of Chinese herbal medicine （mixture of Astragalus root, Angelica root and Atractylodes rhizome; CHM-diet） over two 3S-day periods using a crossover design. The turnover rate of plasma glucose was measured with an isotope dilution method using [U-^13C]glucose. The rates of plasma leucine turnover and leucine oxidation, whole body protein synthesis （WBPS） and metabolic heat production were measured using the [1-^13C]leucine dilution and open circuit calorimetry. Results： Body weight gain of sheep was higher （P = 0.03） for CHM-diet than for MH-diet. Rumen pH was lower （P = 0.02）, concentration of rumen total volatile fatty acid tended to be higher （P = 0.05） and acetate was higher （P = 0.04） for CHM-diet than for MH-diet. Turnover rates of plasma glucose and leucine did not differ between diets. Oxidation rate of leucine tended to be higher （P = 0.06） for CHM-diet than for MH-diet, but the WBPS did not differ between diets. Metabolic heat production tended to be greater （P = 0.05） for CHM-diet than for MH-diet. Conclusions： The sheep fed on CHM-diet had a higher body weight gain and showed positive impacts on rumen fermentation and energy metabolism without resulting in any adverse response. Therefore, these results suggested that the Chinese herbal medicine mixture should be considered as a potential feed additive for sheep.     

Morphological and microsatellite DNA diversity of Nigerian indigenous sheep

Background: Sheep is important in the socio-economic lives of people around the world. It is estimated that more than half of our once common livestock breeds are now endangered. Since genetic characterization of Nigerian sheep is still lacking, we analyzed ten morphological traits on 402 animals and 15 microsatellite DNA markers in 384 animals of the 4 Nigerian sheep breeds to better understand genetic diversity for breeding management and germplasm conservation. Results: Morphological traits of Uda and Balami were significantly (P < 0.05) higher than Yankasa, which were both higher than West African Dwarf (WAD) sheep. Stepwise discriminant analysis showed tail length, rump height, chest girth, ear length and chest depth as the most discriminating variables for classification. Mahalanobis distances show the least differentiation between Uda and Balami and the largest between WAD and Balami sheep. While 93.3% of WAD sheep were correctly assigned to their source genetic group, 63.9% of Yankasa, 61.2% of Balami and 45.2% of Uda were classified correctly by nearest neighbour discriminant analysis. The overall high Polymorphism Information Content (PIC) of all microsatellite markers ranged from 0.751 to 0.927 supporting their use in genetic characterization. Expected heterozygosity was high for all loci (0.783 to 0.93). Mean heterozygote deficiency across all populations (0.171 to 0.534) possibly indicate significant inbreeding (P < 0.05). Mean values for FST , FIT and FIS statistics across all loci were 0.088, 0.394 and 0.336 respectively. Yankasa and Balami are the most closely related breeds (DA = 0.184) while WAD and Balami are the farthest apart breeds (DA = 0.665), which is coincident with distance based on morphological analysis and population structure assessed by STRUCTURE. Conclusions: These results suggest that within-breed genetic variation in Nigerian sheep is higher than between-breeds and may be a valuable tool for genetic improvement and conservation. The higher genetic variability in Yankasa suggests the presence of unique ancestral alleles reflecting the presence of certain functional genes which may result in better adaptability in more agro-ecological zones of Nigeria. These genetic characteristics are potentially useful in planning improvement and conservation strategies in Nigerian indigenous sheep.     

Strategies to improve genomic predictions for 35 duck carcass traits in an F2 populationOA

Background Carcass traits are crucial for broiler ducks,but carcass traits can only be measured postmortem.Genomic selection(GS) is an effective approach in animal breeding to improve selection and reduce costs. However,the performance of genomic prediction in duck carcass traits remains largely unknown.Results In this study,we estimated the genetic parameters,performed GS using different models and marker densities,and compared the estimation performance between GS and conventional BLUP on 35 c...     

Oxytocin in pig seminal plasma is positively related with in vivo fertility of inseminated sowsOA

Background: Identification of relevant in vivo biomarkers for fertility remains a challenge for the livestock industry.Concentrations of the small peptide hormone oxytocin(OXT), involved in male reproductive function and present in the seminal plasma(SP) of several species could be a robust one. This study characterized concentrations of SPOXT in ejaculates from boars used in artificial insemination(AI) programs aiming to evaluate its relationship with sperm quality variables and in vivo fertili...     

Protein profiles of enzymatically isolated rumen epithelium in sheep fed a fibrous diet

Background: The rumen wall plays a major role in efficient transfer of digested nutrients in the rumen to peripheral tissues through the portal venous system. Some of these substrates are metabolised in the epithelium during this process. To identify the specific proteins involved in these processes, we used proteomic technologies. Protein extracts were prepared from ventral rumen tissue of six sheep fed a fibrous diet at 1.5× maintenance energy requirements.Using a newly developed method, we were able to enzymatically isolate the epithelial cells from underlying tissue layers, thus allowing cytosol and membrane fractions to be independently analysed using liquid chromatography tandem mass spectrometry(LC MS/MS).Results: Using our procedure we identified 570 epithelial proteins in the Ovis aries sequence database. Subcellular locations were largely cytosolic(n = 221) and extracellular(n = 85). However, a quarter of the proteins identified were assigned to the plasma membrane or organelle membranes, some of which transport nutrients and metabolites. Of these 91 were transmembrane proteins(TMHMM), 27 had an N-terminal signal peptide(signalP) and TMHMM motif,13 had a glycosylphosphatidylinositol(GPI) anchor and signalP sequence, 67 had beta(β) strands or 17 β strands and a transit peptide sequence, indicating the identified proteins were integral or peripheral membrane proteins. Subunits of the 5 protein complexes involved in mitochondrial cellular energy production were well represented. Structural proteins(15%), proteins involved in the metabolism of lipids and proteins(26%) and those with steroid or cytokine action were a feature of the proteome.Conclusion: Our research has developed a procedure to isolate rumen epithelium proteins from the underlying tissue layers so that they may be profiled using proteomic technologies. The approach improves the number of proteins that can be profiled that are specific to the epithelium of the rumen wall. It provides new insights into the proteins of structural and nutritional importance in the rumen epithelium, that carry out nutrient transport and metabolism, cell growth and signalling.     

Associations of genome-wide structural variations with phenotypic differences in cross-bred Eurasian pigsOA

Background During approximately 10,000 years of domestication and selection, a large number of structural variations(SVs) have emerged in the genome of pig breeds, profoundly influencing their phenotypes and the ability to adapt to the local environment. SVs(≥ 50 bp) are widely distributed in the genome, mainly in the form of insertion(INS), mobile element insertion(MEI), deletion(DEL), duplication(DUP), inversion(INV), and translocation(TRA). While studies have investigated the SVs in pig genom...     

The age at first consumption of forage in calves and its effect on growth and rumination in the short-and long-termOA

Background Previous investigations into the effect of dietary forage on calf performance have been inconsistent, and there is a paucity of information exploring the effect of age on the growth performance and rumination of calves. Eighty-four female Holstein calves(41.5 ± 4.2 kg) were enrolled at birth, a subset of the calves were fed calf starter only(CON, n = 21)while the rest(n = 63) were classified into three treatment groups: the early(EHAY, n = 26, 5.1 ± 0.8 d), the middle(MHAY, n = 21,7.9...     

A gene expression estimator of intramuscular fat percentage for use in both cattle and sheep

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     

Preslaughter diet management in sheep and goats:effects on physiological responses and microbial loads on skin and carcass

Sixteen crossbred buck goats(Kiko x Spanish;BW = 32.8 kg) and wether sheep(Dorset x Suffolk;BW = 39.9 kg) were used to determine the effect of preslaughter diet and feed deprivation time(FDT) on physiological responses and microbial loads on skin and carcasses.Experimental animals were fed either a concentrate(CD) or a hay diet(HD)for 4 d and then deprived of feed for either 12-h or 24-h before slaughter.Blood samples were collected for plasma Cortisol and blood metabolite analyses.Longisimus muscle(LM) pH was measured.Skin and carcass swabs were obtained to assess microbial loads.Plasma creatine kinase activity(863.9 and 571.7 ± 95.21 IU) and non-esterified fatty acid concentrations(1,056.1 and 589.8 + 105.01 mEq/L) were different(P 0.05) between sheep and goats.Species and diet treatments had significant effects on the ultimate pH of LM.Pre-holding total coliform(TCC) and aerobic plate counts(APC) of skin were significantly different between species.Goats had lower(P 0.05) TCC(2.1 vs.3.0 log_(10) CFU/cm~2) and APC(8.2 vs.8.5 log_(10) CFU/cm~2) counts in the skin compared to sheep.Preslaughter skin E.coli counts and TCC were different(P 0.05) between species.Goats had lower(P 0.05) counts of E.coli(2.2 vs.2.9 log_(10) CFU/cm~2) and TCC(2.3 vs.3.0 log_(10) CFU/cm~2) in the skin compared with those in sheep.Diet,species,and FDT had no effect(P 0.05) on E.coli and TCC in carcass swab samples.The APC of carcass swab samples were only affected(P 0.05) by the FDT.The results indicated that preslaughter dietary management had no significant changes on hormone and blood metabolite concentrations and sheep might be more prone for fecal contamination than goats in the holding pens at abattoir.     

The optimal dietary arginine level of laying hens fed with low-protein dietsOA

Background: Arginine(Arg) is an essential amino acid(EAA) in poultry, an important substrate for protein synthesis and a precursor of several molecules. Supplementation of EAAs with low protein(LP) diet increases the utilization efficiency of dietary crude protein(CP). However, if the EAA requirement is changed in hens fed a LP diet remains to be elucidated. The aim of the present study was to evaluate the optimal level of dietary Arg in the LP diet of hens. A total of 1350 Hy-Line Brown laying ...     

Detection of the FecX~R Mutation of BMP15 Gene in Sheep and Goats

<正>PCR-SSCP was used to detect mutations of bone morphogenetic protein 15(BMP15) gene in both high prolificacy(Small Tail Han sheep,Hu sheep,Jining Grey goat and Boer goat) and low prolificacy breeds(Dorset sheep,Texel sheep,Inner Mongolia Cashmere goat and Angora goat).Both the nucleotide sequences and the amino acid sequences were compared in amplification fragments of both Small Tail Han sheep and Jining Grey goat.The results indicated that none of the four sheep and the four goat breeds carried the same FecX~R mutation of the BMP15 gene as do Rasa Aragonesa sheep.The nucleotide sequence of Small Tail Han sheep was completely identical with that of the sheep BMP15 sequence(GenBank AF236079,NM_001114767).Three base substitutions(T529G,C530G and T576C) and two amino acid changes(V155G and S171P) were found in Jining Grey goat compared with Small Tail Han sheep.The FecX~R mutation of the BMP15 gene had no significant effect on high prolificacy of Small Tail Han sheep, Hu sheep,Jining Grey goat and Boer goat.     

Isolation and Identification of Sheep Pseudorabies Virus

In a sheep farm with mixed culture of pig and sheep in Shandong Province,sheep were attacked by a disease featured by foaming at the mouth,neurological symptoms and partial hair slip of legs,and the mortality of the disease was as high as 100%.In order to determine the pathogen,dead sheep were analyzed through pathogen isolation,PCR assay and direct immunofluorescence identification,and the pathogen was confirmed as pseudorabies virus(PRV).Sequencing results showed that the g E gene of the isolated strain shared the homology of 97%-99% with the nucleotide sequence of known PRV genome in the NCBI databases,suggesting the isolate was PRV.The virus had obvious cytopathic effect through BHK cell line passage till the seventh generation,and the amount of half virus tissue cell infection(TCID50) was 1×107.5/m L following ReedMuench method.Two healthy sheep with the body weight of 20 kg were injected with the viral fluid of the isolate,and typical symptoms of pseu-dorabies(PR) were observed after 4 d.According to clinical symptoms and PCR diagnosis results,the epidemic situation of sheep farm was effec-tively controlled through comprehensive measures such as eliminating swinery in the farm,strengthening disinfection of pigsty,injecting sick sheep with pseudorabies serum,supplementing healthy sheep herb with antivirus traditional medicine Qiqing Baidu granule.     

Evaluation of fatty acid metabolism and innate immunity interactions between commercial broiler,F1 layer × broiler cross and commercial layer strains selected for different growth potentials

Background: The broiler industry has undergone intense genetic selection over the past 50 yr. resulting in improvements for growth and feed efficiency, however, significant variation remains for performance and growth traits. Production improvements have been coupled with unfavourable metabolic consequences, including immunological trade-offs for growth, and excess fat deposition. To determine whether interactions between fatty acid(FA) metabolism and innate immunity may be associated with performance variations commonly seen within commercial broiler flocks, total carcass lipid %, carcass and blood FA composition, as wel as genes involved with FA metabolism, immunity and cel ular stress were investigated in male birds of a broiler strain, layer strain and F1 layer × broiler cross at d 14 post hatch. Heterophil:lymphocyte ratios, relative organ weights and bodyweight data were also compared.Results: Broiler bodyweight(n = 12) was four times that of layers(n = 12) by d 14 and had significantly higher carcass fat percentage compared to the cross(n = 6; P = 0.002) and layers(P = 0.017) which were not significantly different from each other(P = 0.523). The carcass and whole blood FA analysis revealed differences in the FA composition between the three groups indicating altered FA metabolism, despite al being raised on the same diet. Genes associated with FA synthesis andβ-oxidation were upregulated in the broilers compared to the layers indicating a net overal increase in FA metabolism,which may be driven by the larger relative liver size as a percentage of bodyweight in the broilers. Genes involved in innate immunity such as TLR2 and TLR4, as wel as organel e stress indicators ERN1 and XBP1 were found to be nonsignificant, with the exception of high expression levels of XBP1 in layers compared to the cross and broilers. Additional y there was no difference in heterophil: lymphocytes between any of the birds.Conclusions: The results provide evidence that genetic selection may be associated with altered metabolic processes between broilers, layers and their F1 cross. Whilst there is no evidence of interactions between FA metabolism, innate immunity or cel ular stress, further investigations at later time points as growth and fat deposition increase would provide useful information as to the effects of divergent selection on key metabolic and immunological processes.