Genetic Diversity Analysis of Guangxi Donglan Black-bone Chicken

[Objective] This study aimed to understand the genetic diversity and breed conservation effect, and to provide reference for future germplasm resources protection and breeding researches of Guangxi Donglan black-bone chicken. [Method] The wing venous blood of Donglan Black-bone chicken（silky feather and contour feather） was collected, and the total DNA was extracted. The 18 microsatellite loci were amplified by PCR technology, and the obtained gene fragments were scanned. The number of alleles（Na）, number of effective alleles（Ne）, heterozygosity（H） and polymorphism information content（PIC） were determined using Pop Gen 32 biological software to do cluster analysis of Guangxi indigenous chicken breeds. [Result] The18 microsatellite loci of Donglan black-bone chicken were found to be highly polymorphic. A total of 98 alleles were detected out from 80 Donglan black-bone chicken samples. The averages of Na, Ne, PIC and H per locus were 5.44, 2.78, 0.5382 and 0.596 3, respectively. A total of 93 and 98 alleles were detected out from silky- and contour-feather Donglan black-bone chickens, respectively. The averages of Ne per locus were 2.62 and 2.76, of PIC per locus were 0.508 8 and 0.539 8,of H per locus were 0.624 7 and 0.599 1, respectively. The results of cluster analysis showed that there was greater genetic distance between Donglan black-bone chicken and any of other Guangxi indigenous chicken breeds, including three yellow chicken, Xiayan chicken and Nandan Yao chicken, which was consistent with the breed evolution, geographical distribution and breeding history of Donglan black-bone chicken. [Conclusion] There are greater genetic variation and abundant genetic diversity in the conserved population of Donglan black-bone chicken, suggesting abundant genetic diversity and great breeding potential of Donglan black-bone chicken.

Effects of NPY Gene on Total Number of Eggs at 300 Days of Age in Donglan Black-bone Chicken

In this study, PCR-RFLP technique was employed to detect the genetic polymorphism of NPY gene and analyze the effects of various genotypes on the total number of eggs at 300 days of age in 135 Donglan black-bone chicken. According to the results, there were three genotypes （AA, AB and BB） of NPYgene in Donglan black-bone chicken group. Different genotypes exhibited significant effects （P 〈 0. 05 ） on the total number of eggs at 300 days of age. The total number of eggs at 300 days of age of AA genotype was significantly higher than that of BB genotype （P 〈 0. 05）. Therefore, the polymorphic site of NPY gene could be used as a candidate molecular marker that affects egg laying in Donglan black-bone chicken.

Effects of Chinese Herbal Medicine Feed Additives on Growth Performance and Dietary Nutrient Metabolism of Black-bone Chickens

[Objectives]To study the effects of Chinese herbal medicine feed additives on the growth performance and dietary nutrient metabolic rate of black-one chickens.[Methods]480 pieces of 1-day-old Donglan Black-bone Chickens were selected and divided into 4 groups,with 6 replicates in each group,with 20 pieces in each replicate.Among them,group A was the control group and was fed the basal diet;the groups B,C,and D were the experimental groups,which were separately supplemented with 0.25%,0.50%and 1.00%of Chinese herbal medicine additives in the basal diet,and the experimental period was 70 d.At the end of the feeding experiment,24 experimental chickens with similar body weight were selected from each group,and the same design of the feeding experiment was used to continue to feed the original diet for the metabolic experiment to determine the nutrient metabolic rate.[Results]Except the 50-70 d stage,the average daily gain(ADG)of group B in other stages was increased by 5.00%-9.15%(P<0.05),and the average body weight of group B at 70 d was also increased by 4.86%(P<0.05);the ADG of group C at 36-49,1-49 and 1-70 d and the average individual weight at 70 d were also higher than that of group A by 5.90%,2.66%,2.68%and 2.57%,respectively(P>0.05);at 36-49 d,the average daily feed intake(ADFI)of group A was higher than that of group B by 6.04%(P<0.01),and was also higher than that of groups C and D by 5.12%and 4.13%(P<0.05),respectively;at 1-49 d,the ADFI of group A was higher than that of group C by 2.86%(P<0.05),and there was no significant difference between the four groups of experimental chickens at each stage(P>0.05);at 22-35 and 1-70 d,the feed to gain ratio(F/G)of group B was 6.32%and 3.41%lower than that of group A(P<0.05),and at 36-49 and 1-49 d,the F/G of group B was even lower;at 36-49 d,the F/G of group C was 10.15%lower than that of group A(P<0.05),and at 1-49 d,it was also lower than that of group A by 5.29%(P<0.01);there was no significant difference between the two groups at other stages.In terms of nutrient metabolism:the three different amounts of this additive have increased the metabolic rate of DM,CP,CF,NFE,CA,Ca,P,TE and other nutrients in the diet to varying degrees,especially the addition of 0.25%and 0.50%had the significant increase.[Conclusions]The addition of 0.25%Chinese herbal medicine additives in the diet can significantly improve the growth performance and main nutrient metabolic rate of Donglan Black-bone Chickens.

Protein glycation:a wolf in sweet sheep’s clothing behind neurodegeneration

At the beginning of the 16th century,Paracelsus coined the maxim:“the dose makes the poison”.This principle can be applied to all living organisms,including organs and cells.The brain and its glial and neuronal cells are no exception.Even small compounds that are essential for the life of brain cells can become truly toxic when overdosed.

Supplementation of Lycium barbarum residue increases the growth rate of Tan sheep by enhancing their feed intake and regulating their rumen microbiome and metabolome

Lycium barbarum residue(LBR),a by-product of L.barbarum processing,is packed with bioactive components and can be potentially utilized as a feed additive in animal husbandry.However,the fundamental understanding of its effectiveness on livestock animals is still lacking,particularly in ruminants.To explore the effects of LBR on the growth performance,rumen fermentation parameters,ruminal microbes and metabolites of Tan sheep,sixteen fattening rams(aged 4 mon)were fed a basal diet(CON,n=8)or a basal diet supplemented with 5%LBR(LBR,n=8).The experiment lasted for 70 d,with 10 d adaptation period and 60 d treatment period.The results showed that the LBR enhanced the average daily feed intake,average daily gain(P<0.05),and ruminal total volatile fatty acids(P<0.01)while decreasing ammonia-nitrogen concentration and rumen pH value(P<0.05).Additionally,the LBR improved the relative abundances of Prevotella,Succiniclasticum,Ruminococcus,Coprococcus,Selenomonas,and Butyrivibrio(P<0.05)and reduced the relative abundances of Oscillospira and Succinivibrio(P<0.05).The LBR altered the ruminal metabolome(P<0.01)by increasing the abundances of ruminal metabolites involved in amino acids(e.g.,L-proline,L-phenylalanine,L-lysine,and L-tyrosine),pyrimidine metabolism(e.g.,uridine,uracil,and thymidine),and microbial protein synthesis(e.g.,xanthine and hypoxanthine).In conclusion,LBR had positive effects on the growth rate of Tan sheep as well as on rumen fermentation parameters,rumen microbiome and rumen metabolome.

Etiological Agent, Pathogenesis, Diagnosis, Treatment, Measures for Prevention and Control of Caseous Lymphadenitis Disease in the Small Ruminants with Special Reference to Sheep

Caseous lymphadenitis (CL) is a chronic infectious disease caused by Corynebacterium pseudotuberculosis (C. pseudotuberculosis) that is transmitted mainly by contact with contaminated exudate wounds. Caseous lymphadenitis affects different species of animals and is considered an occupational zoonotic disease. CL is responsible for important economic losses in the small ruminant industry, which include decreased production, damaged quality of milk and wool, reproductive disorders, total or partial confiscation of carcasses, and depreciation of the skin. Caseous lymphadenitis disease can present in two clinical pictures: a skin or superficial picture and a visceral or deep picture. The presumptive diagnosis of CL in the skin is based on the exploration of superficial lymph nodes. These have little value in diagnosing visceral CL, where the main sign is emaciation. The prevention and control of CL involve identifying the skin condition and debriding the abscesses. In addition to the treatment of superficial lesions, the animal facilities must be repaired and adapted. To avoid exposure of negative herds to CL, new animals must be subjected to observation to identify any of the clinical manifestations. Another form of control is vaccination, though only some countries have commercial vaccines. General information on the etiological agent and its characteristics can be used to improve the understanding of this disease.

LncRNA GTL2 regulates myoblast proliferation and differentiation via the PKA-CREB pathway in Duolang sheep

Long non-coding RNAs(lncRNAs),which are RNA molecules longer than 200 nucleotides that do not encode proteins,are implicated in a variety of biological processes,including growth and development.Despite research into the role of lnc RNAs in skeletal muscle development,the regulatory mechanisms governing ovine skeletal muscle development remain unclear.In this study,we analyzed the expression profiles of lnc RNAs in skeletal muscle from 90-day-old embryos(F90),1-month-old lambs(L30),and 3-year-old adult sheep(A3Y) using RNA sequencing.In total,4738 lnc RNAs were identified,including 997 that were differentially expressed.Short-time series expression miner analysis identified eight significant expression profiles and a subset of lnc RNAs potentially involved in muscle development.Kyoto Encyclopedia of Genes and Genomes enrichment analysis revealed that the predicted target genes of these lnc RNAs were primarily enriched in pathways associated with muscle development,such as the c AMP and Wnt signaling pathways.Notably,the expression of lnc RNA GTL2 was found to decrease during muscle development.Moreover,GTL2 was highly expressed during the differentiation of skeletal muscle satellite cells(SCs) and was shown to modulate ovine myogenesis by affecting the phosphorylation levels of PKA and CREB.Additionally,GTL2 was found to regulate both the proliferation and differentiation of SCs via the PKACREB signaling pathway.Overall,this study provides a valuable resource and offers novel insights into the functional roles and regulatory mechanisms of lnc RNAs in ovine skeletal muscle growth and development.

Cysticercus Tenuicollis in Visceral Organs of Goats and Sheep in Uganda: A Case Study in Lira Municipal Abattoir

Cysticercus tenuicollis is a metacestode stage of Taenia hydatigena residing in the visceral organs of small ruminants and its effects cause economic losses due to condemnation of visceral organs in slaughterhouses. This study reports on the prevalence of Cysticercus tenuicollis in small ruminants slaughtered in Lira Municipal Abattoir. A total of 70 sheep and 70 goats were sampled and examined after slaughter for the presence of Cysticercus tenuicollis in the visceral organs using standard meat inspection procedures. An abattoir data collection sheet was used to record data, which was then analysed in SPSS version 20. The study revealed 51.4% of goats and 68.6% of sheep to be infested with Cysticercus tenuicollis. Following the district of origin for the small ruminants, Otuke district had the highest prevalence of the parasite (82.6%), followed by Kole (72.4%), Alebtong (66.7%), Apac (59.4%) and Lira (31.4%). Cysticercus tenuicollis was more frequently seen in the intestines (57.8%) of sheep and goats than in any other visceral organs. The liver had a prevalence of 20.7%, the lungs 17.8%, the kidneys 3.5% and the fetal sac;(15.7%) in goats and (12.9%) in sheep. Cysticercus tenuicollis was detected in 68.8% of females and 58.8% of male small ruminants. It is recommended to routinely deworm goats and sheep by farmers most especially in districts with the highest prevalence of Cysticercus tenuicollis infestation. The sale of the condemned parts of sheep and goats and the feeding of dogs on these contaminated materials should be stopped forthwith. It is also being suggested that a national study be carried out to determine the prevalence and economic impact of Cysticercus tenuicollis in small ruminants.

Genomic signatures of selection,local adaptation and production type characterisation of East Adriatic sheep breeds

Background The importance of sheep breeding in the Mediterranean part of the eastern Adriatic has a long tradition since its arrival during the Neolithic migrations.Sheep production system is extensive and generally carried out in traditional systems without intensive systematic breeding programmes for high uniform trait production(carcass,wool and milk yield).Therefore,eight indigenous Croatian sheep breeds from eastern Adriatic treated here as metapopulation(EAS),are generally considered as multipurpose breeds(milk,meat and wool),not specialised for a particular type of production,but known for their robustness and resistance to certain environmental conditions.Our objective was to identify genomic regions and genes that exhibit patterns of positive selection signatures,decipher their biological and productive functionality,and provide a"genomic"characterization of EAS adaptation and determine its production type.Results We identified positive selection signatures in EAS using several methods based on reduced local variation,linkage disequilibrium and site frequency spectrum(eROHi,iHS,nSL and CLR).Our analyses identified numerous genomic regions and genes(e.g.,desmosomal cadherin and desmoglein gene families)associated with environmental adaptation and economically important traits.Most candidate genes were related to meat/production and health/immune response traits,while some of the candidate genes discovered were important for domestication and evolutionary processes(e.g.,HOXa gene family and FSIP2).These results were also confirmed by GO and QTL enrichment analysis.Conclusions Our results contribute to a better understanding of the unique adaptive genetic architecture of EAS and define its productive type,ultimately providing a new opportunity for future breeding programmes.At the same time,the numerous genes identified will improve our understanding of ruminant(sheep)robustness and resistance in the harsh and specific Mediterranean environment.

Research and Application of Compressed Fermented Chestnut Leaf Feed in Fattening Mutton Sheep

Chestnut leaves and bran were evenly mixed according to different mass ratios,and the mixtures were sprayed and inoculated with a certain amount of prepared EM microbial liquid,and then compressed into 70 cm×40 cm×30 cm blocks by a fully automatic yellow-storage block compression and packaging machine.The obtained blocks were packaged and sealed with plastic film,and placed in a freely ventilated place for more than 15 d of anaerobic fermentation,so as to obtain compressed fermented chestnut leaf block feed.[Results]Through the detection and analysis of nutritional components in the compressed fermented chestnut leaf block feed in the laboratory,the protein content was equal to or greater than 10.2%,which was 44.68%higher than that of unfermented chestnut leaf feed;the tannin content was equal to or greater than 638 mg/kg,which was 18.41%lower than that of the original feed;and the crude fiber content was equal to or greater than 19.5%,which was 14.09%lower than that of the original feed.[Conclusions]This study improves the palatability of chestnut leaf feed,increases the use efficiency of feed and reduces feeding cost.It is worth popularizing.

Developmental Changes of the FAS and HSL mRNA Expression and Their Effects on the Content of Intramuscular Fat in Kazak and Xinjiang Sheep

Twenty-four male Kazak sheep and 30 Xinjiang fine wool sheep at different ages were selected to investigate the development-dependent expression levels of fatty acid synthase （FAS） gene and hormone-sensitive lipase （HSL） gene in muscle and their effects on the contents of intramuscular fat （IMF）. Longissimus dorsal muscle was sampled to measure IMF and total RNA was extracted to determine FAS and HSL mRNA expression levels by real-time PCR. The results showed that： l） The IMF content increased continuously with growth and showed significant differences （P 〈 0.05） between different age groups in male Kazak sheep, but in Xinjiang fine wool sheep there was no such difference observed. Furthermore, the IMF contents in Kazak were much higher （P 〈 0.01） than that of the other breed from day 30 to 90. 2） FAS mRNA expression level was the highest （P 〈 0.05） on day 0 in Kazak sheep and then declined with growth, in the other breed the gene showed a d‘ecline-rise-decline-rise＇ expression manner as the animals grew. HSL mRNA expression level had a similar model in two breeds, in Kazak sheep it was the highest on day 0 （P 〈 0.05） and in Xinjiang fine wool sheep on day 30 （P 〈 0.01）, then both decreased after this term. 3） In male Kazak sheep, FAS and HSL mRNA expression level were both negatively related to IMF content （r= -0.485 （P = 0.02）, r= -0.423 （P = 0.05））, and the ratio of FAS/HSL expression exhibited significantly negatively related IMF contents. In male Xinjiang sheep, there were no obvious relationship between FAS and HSL expression and IMF content （P 〉 0.05）.

Effects of in Vitro Maturation Time of Oocytes on Sheep Nuclear Transfer Efficiency

[Objective] The study aimed to provide references for the time of oocyte maturation in vitro and enucleation in the course of sheep nuclear transfer(NT).[Method] Compared the effects of different maturation time of oocytes on enucleation efficiency and reconstructed embryo development by means of blind enucleation and fluorescence microscopy.[Result] Treatment of IVM(in vitro maturation)19-21 h was significantly higher than IVM 16-18 h treatment in oocyte maturation rate(P<0.05)and was significantly higher than IVM 22-24 h treatment in enucleation rate(P<0.05).Three treatments had no significant difference in cleavage rate and blastocyst rate(P>0.05),but IVM 19-21 h treatment was significantly higher than the other 2 treatments in average cell number of blastocysts(P<0.05).[Conclusion] The appropriate in vitro maturation time of oocytes was 19-21 h for sheep nuclear transfer,which could significantly improve the quality of blastocysts according to the cell number per blastocyst(P<0.05).

Comparison of Growth and Development Traits among Crossbreds of Dorset and Local Sheep Varieties in Gansu Province

In order to improve the meat production performance of local sheep varieties in Gansu Province, Dorset was introduced to crossbreed with the local sheep varieties, including Tan sheep, Small Tail Han sheep and Mongolia sheep. The offspring of different crossbreeding combinations were sampled randomly at different growth stages, and their growth and development traits were measured so as to screen out the best crossbreeding mode. The results showed that under the same crossbreeding mode, the growth rate of F3 was higher than that of F2, and of F2 was higher than that of F1. Among the F3 population, the growth rates of Dorset ×Han and Dorset × Mongolia hybrids were higher. Compared with those of Dorset ×Tan F3 hybrids, the body weights of male and female Dorset × Han and Dorset ×Mongolia F3 hybrids were increased by 5.59%, 4.40%, 5.93% and 3.76%, respectively. Among the F2 population, the growth rates of Dorset × Han and Dorset ×Mongolia hybrids were also higher. The body weights of male and female Dorset ×Han and Dorset × Mongolia F2 hybrids were higher than those of Dorset × Tan ×Han F2 hybrids by 5.99%, 3.67%, 9.80% and 5.00%, respectively. In the F1 population, the growth rates of Dorset × Han and Dorset × Mongolia hybrids were higher.Compared with those of Tan × Han F1 hybrids, the body weights of male and female Dorset × Han and Dorset × Mongolia F1 hybrids were increased by 11.32%,5.22%, 7.60% and 7.20%, respectively. Therefore, in the feeding area of Small Tai Han sheep, Mongolia sheep and Tan sheep, Dorset was the best sire for producing hybrid lambs. The economic benefit of crossbred offspring was obvious.

Effects of Lysine on the Expression of GHR mRNA in Sheep

[Objective] This study was to investgate the effects of lysine on the growth of sheep and its mechanism. [Method] Fifteen sheep about one-year old as experimental material were divided into three groups （group A, group B end group C）, into whose basal feed 0, 4 and 10 g h/sine were respectively added. After 28 d of feeding, the experimental sheep were all slaughtered for sampling; then total RNAs were extrac- ted from the samples and used to clone GHR and GAPDH genes via retrotrenscription for analyzing the expression abundance of GHR mRNA in Iongissimus dorsi muscle from different treatments. [Result] The expression of GHR mRNA in treatment B was significantly higher than that in treatment A（ P 〈0.01 ）, and significantly higher then that in treatment C （ P 〈0.05） ; while that in treatment C and treatment A was insignificantly different（ P 〉 0.05）. [ Conclusion] Addition of lysine into basal feed of sheep could dose-independently improve the expression of GHR gene in Iongissimus dorsi muscle.

Genetic Polymorphism in GDF8 Region of HU Sheep Based on Microsatellite DNA

[ Objective ] This study was to analyze the genetic polymorphism in GDF8 Region of HU sheep. [Method] Four microsatellite loci including BMS1591, TEXAN-2, FCB128 and BM81124 mapped on GDF8 region of chromosome No. 2 of sheep that may be correlated with growth performance were chosen to detect the molecular genetics foundation of growth performance of Hu sheep. [ Result] Four microsatellite loci detected were high in heterozygosity, more in effective alleles number and rich in polymorphic information, all the three indices passed through the high polymorphic level （PIC 〉0.5）. [ Conclusion ] The four microsatellite loci detected could be used to estimate the genetic polymorphism of growth performance of Hu sheep.

Effect of RPlys on Digestive Metabolism of Nitrogen in Sheep

[Objective] The aim was to study the effect of RPlys on digestive metabolism of nitrogen in sheep.[Method] The contribution of RPlys for nitrogen residual in sheep was researched by digestive metabolism test.[Result] The results showed that adding RPlys decreased excretion of urine nitrogen （P0.05） and had no significant effect on excretion of fecal nitrogen （P0.05）,and precipitation coefficient of nitrogen was increased （P0.05）.[Conclusion] RPlys is propitious to the aggradations of nitrogen in sheep.

HISTOCHEMICAL TECHNIQUES IDENTIFYING MAST CELLS IN PIG,CATTLE AND SHEEP

Carnoy′s fluid and neutral buffered formalin(NBF)have been proved to be good fixatives for preservation of mast cells in pig,cattle and sheep except NBF blocked staining of most porcine mast cells,especially those located in intestinal mucosa(MMC)and in thymus medulla(TMMC). Both toluidine blue and Alcian blue were the excellent stains generally,but Alcian blue stained more porcine mast cells than did toluidine blue( P <0 01). Staining with toluidine blue of a wide pH range(from 0 1 to 7 0)showed that porcine mast cells were not very pH dependent,but the dye at pH 0 5 seemed to have the strongest affinity for all mast cells in pigs and it was also suitable for bovine and ovine mast cell staining. In the three species,unlike in rodents,the Alcian blue method did not distinguish between mast cells in the intestinal mucosa(MMC)and those in the connective tissue of the intestinal submucosa,tongue and skin(CTMC). Porcine CTMC,but not MMC,fluoresced strongly when stained with berberine sulphate or with a mixture of berberine sulphate and acridine orange. It suggested that porcine CTMC contained heparin proteoglycan.

Seasonal Variation of Physiological and Biochemical Indexes of White-tibetan Sheep

In this study, to understand the variation regulation of physiological and biochemical indexs of White-Tibetan sheep with seasons, the physiological and bio- chemical indexs of White-Tibetan sheep in Hongyuan Areas of Sichuan Province in four seasons were measured. The results showed that the respiratory change range of white-Tibetan sheep in four seasons was from （32.74±21.33） to （49.96±17.62） times/min, and the variation ranges of body temperature and heart rate were from （39.27±1.05） to （39.73±0.31） ℃ and from （88.75±8.32） to （104.63±10.39） times/min, respectively. The indexes of WBC, MCV, MCH and MCHC in autumn and winter were extremely significantly lower than those in spring and summer, while RBC,HCT and RDW-CV in autumn and winter were extremely significantly higher than those in spring and summer, HGB and PLT changed in different seasons with no signifi- cance. The indexes of AST,TP, ALB, GLO and LDH in summer and autumn were relatively higher than those in winter and spring, while the indexes of PCHE, GLU, CHOL and CA in summer and autumn were relatively lower than those in winter and spring, however, the indexes of ALT and ALP were relatively higher in spring and autumn.

Quantitative Study on Expression of MSTN Gene in Different Tissues of Tibetan Sheep at Different Ages

[Objective] The aim was to investigate the difference in MSTN gene expression in different tissues of Tibetan sheep at different ages.[Method] According to the sequence（NM_001009428.1）published in GenBank,a pair of specific primers was designed to amplify part of cDNA sequence of MSTN by using QRT-PCR technique.The relative expression level of MSTN gene in rennet stomach,rumen,leg muscle and cardiac muscle of Tibetan sheep at different ages were analyzed.[Result] After normalization with β-actin gene,the relative expression level of MSTN gene in the 6-month-old Tibetan sheep was the highest and it was 2.52 times than that in 12-month-old Tibetan sheep（P0.05）,the relative expression level of MSTN gene in leg muscle was the highest among all tissues and it was 3 984.78 times than that in rumen（P0.01）.[Conclusion] The results established theoretical foundation for the correct use of MSTN antibody.

Developmental Changes of IGF-Ⅰ mRNA Expression Level in Sheep Muscle

[ Objective] To detect the mRNA of muscle insulin-like growth factorl （IGF-I） in the early development of Kazak sheep and Xinjiang fine-wool sheep, so as to provide information for the research about the early growth and development of sheep. [ Method] With real-time quan- titative PCR, the muscle IGF-I mRNA level was separately detected in two varieties of sheep at 2, 30, 60, 90 and 120 days old. Then the data was analyzed with SPSS software. [ Result] The IGF-I mRNA in sheep muscle first increased and then decreased with ages, peaking at 30 days old in Kazak sheep and at 60 days old in Xinjiang fine-wool sheep. The IGF-I expression level of Kazak sheep had no significant difference with Xinjiang fine-wool sheep at 2 or 90 days old （ P 〉0.05）, but was lower than that of the latter with extremely significant difference （ P 〈0.01 ） from 30 to 60 days old. [ Conclusion] The male Kazak sheep and Xinjiang fine-wool sheep have similar model of developmental changes of muscular IGF-I mRNA, but the expression level is different between these two species.