Identification of SNPs in Bovine SLC27A1 Gene and Its Effects on Milk Production Traits in Chinese Holstein Cattle

[Objective] This study discussed the SNPs of SLC27A1 gene and its relationship with milk production traits in Chinese Holstein Cattle in order to find the SNP site which had significant effect on milk production traits in Chinese Holstein Cattle.[Method] DNA was extracted from the bleed of 48 Chinese Holstein Cattle selected according to phenotypic character and mixed into DNA pool for SNPs detection by polymerase chain reaction-single strand conformation polymorphism（PCR-SSCP）and cloning sequencing.Then different genotypes were detected in other 231 Chinese Holstein Cattle by PCR-RFLP.The association between genotype and production traits was assessed by GLM procedure,SAS version 8.02.[Result] There were T112C in exon3 and G64A loci in 3＇UTR,among them the T112C in exon3 was synonymous mutation.There were 3 genotypes TT,TC and CC in T112C locus and 3 genotypes GG,GA and AA in G64A locus.The population was at Hardy-Weinberg equilibration.Cows with genotype CC had significantly highest milk yield than those with genotype TC（P0.01）,and there were no significant differences among the 3 genotypes on milk protein percent and milk fat percent（P0.05）,but the tendency of CC TC TT on milk protein percent and the tendency of TT TC CC on milk fat percent were showed.There was no significant difference among the 3 genotypes of G64A loci on milk yield,milk protein percent and milk fat percent（P0.05）,but the tendency of GA GG AA on milk yield and the tendency of AA GG GA both on milk protein percent and milk fat percent were showed.[Conclusion] There was certain relation between the T112C locus and milk yield traits;It may improve milk yield to raise the frequency of genotype CC;SLC27A1 gene could be a useful candidate gene in selection program on milk yield traits in Chinese Holstein Cattle,which provided a theoretical basis for the marker-assisted breeding and further study of SLC27A1 gene.

Genetic Polymorphism of Milk Protein and Their Relationships with Milking Performances in Chinese Yak

The milk protein polymorphisms were typed by polyacrylamide gel electrophoresis (PAGE)from 109 Maiwa and 100 Jiulong yaks, and the relationships among milk protein polymorphisms,milking traits and milk protein compositions were studied. The results showed thatβ-CN,κ-CN andα-La were monomorphic,αs1-CN andβ-Lg were polymorphic, the dominantgenes were αs1-CN D and β-Lg E,respectively. The frequencies of αs1-CN D were 0.8073and 0.6000 and β-Lg E were 0.9770 and 0.9700 in two populations respectively.The meanheterozygosities were 0.1021 and 0.1867 in two populations. No significant effects onmilking traits and milk protein compositions were observed except for αs1-CN locus onfat percentage in Jiulong yak.

Fine Mapping QTLs Affecting Milk Production Traits on BTA6 in Chinese Holstein with SNP Markers

Our previous studies demonstrated that the region around markers BMS470 and BMS1242 on BTA6 showed a linkage to 305-d milk yield and composition traits in the Chinese Holstein population. We herein focused on such narrow region to fine map milk production QTLs with 15 SNPs across 25 Mb with each SNP in 1 Mb within most regions in a Chinese Holstein population with daughter design. 1 449 Holstein cows and 11 sires were genotyped for such SNPs by using TaqMan probe and RFLP assays. Multipoint linkage analysis across family revealed a QTL affecting milk yield between PPARGC1A C4075T and SLC34A2 T1713C. Meanwhile, within family analysis found three milk yield QTLs （two in CR T60984131G-CEP135 C501T and one in PDLIM5 A106C-OPN T3907, a fat yield QTLin UGDH T1670C-CR T60984131G region, and two protein yield QTLs in TBC1D1 G501C-UGDH T1670C and PPARGC1A C4075T-SLC34A2 T1713C, respectively. Associations between aforementioned significant SNP markers and milk production traits were further implemented. We found significant associations of PPARGC1A C4075T, SLC34A2 T1713C with milk yield （P0.05, P0.01, P0.01）, UGDH T1670C, and CR T60984131G with fat yield （P0.01, P0.01）, and PPARGC1A C4075T, SLC34A2 T1713C, UGDH T1670C and OPN T3907 with protein yield （P0.01, P0.01, P0.01, P0.01）. Our findings implied that QTLs affecting milk production traits on BTA6 were pleictropism or multigenic effect and PPARGC1A and OPN may be the causal mutations behind milk production QTLs on BTA6 in the Chinese Holstein population.

Comparison the Genetic Potential of Some Growth ＆ Milk Trait, s of Hybrid （Crossed） Saanen with Native Goat （Lori Black Goat） versus Native Goats in Qom Province

The performance of some growth and milk traits of selected Qomi native （Lori black） goats and hybrids of saanen with native goats during 2008-2010 was compared. Growth traits include birth weight （BW）, one-month weight （1 MW）, weaning weight （WW） and 6-month weight （6 MW）. Also the milk production traits was monthly milk production on 2, 3, 4, 5th months （quantitative traits） and some milk composition included dry matter （%DM）, fat （%F）, and protein （%P） percentage on during of production （qualitative traits）. There were no significant differences in sex, birth type and genetic group for BW. Also the effect of genetic groups on 1 MW, WW, and 6 MW was significant, while effects of sex and birth type on 1 MW, WW and 6 MW was not significant. Also MW （Mothe＇s weight） had no significant effect on BW, 1 MW, WW and 6 MW. The average of daily milk records was 0.48 kg for nativel and 1.1 kg for crossed goats. The maximum monthly milk records in two groups were in second month （native： 0.64 -4- 0.05, crossed： 1.44 ~： 0.12） and the minimum were in fifth month （native： 0.36 ＋ 0.03, crossed： 0.77 -4- 0.05）. %DM, %F and %P in 5th month were higher than other months in two groups. Effects of genetic groups on milk production and also on average of%F, %DM and %P were significant. This study showed that the crossbreeding has a significant effect on most milk production and growth traits in Iranian native goats.

Fine mapping quantitative trait loci affecting milk production traits on bovine chromosome 6 in a Chinese Holstein population

To fine map the previously detected quantitative trait loci （QTLs） affecting milk production traits on bovine chromosome 6 （BTA6）, 15 microsatellite markers situated within an interval of 14.3 cM spanning from BMS690 to BM4528 were selected and 918 daughters of 8 sires were genotyped. Two mapping approaches, haplotype sharing based LD mapping and single marker regression mapping, were used to analyze the data. Both approaches revealed a quantitative trait locus （QTL） with significant effects on milk yield, fat yield and protein yield located in the segment flanked by markers BMS483 and MNB209, which spans a genetic distance of 0.6 cM and a physical distance of 1.5 Mb. In addition, the single marker regression mapping also revealed a QTL affecting fat percentage and protein percentage at marker DIK2291. Our fine mapping work will facilitate the cloning of candidate genes underlying the QTLs for milk production traits.

A post-GWAS replication study confirming the association of C14H8orf33 gene with milk production traits in dairy cattle

Genome-wide association studies with an Illumina Bovine50K chip have detected 105 SNPs associated with one or multiple milk production traits in the Chinese Holstein population.Of these,38 significant SNPs detected with high confidence by both L1-TDT and MMRA methods were selected to further mine potential key genes affecting milk yield and milk composition.By blasting the flanking sequences of these 38 SNPs with the bovine genome sequence combined with comparative genomics analysis,26 genes were found to contain or be near to such SNPs.Among them,the C14H8orf33 gene is merely 87 bp away from the significant SNP,Hapmap30383-BTC-005848.Hence,we report herein genotype-phenotype associations to further validate the genetic effects of the C14H8orf33 gene.By pooled DNA sequencing of 14 unrelated Holstein sires,a total of 18 with seven novel SNPs were identified.Among them,nine SNPs were in the 5′regulatory region,one in exon 6 and the other in the 3′UTR and 3′regulatory region.A total of nine of these identified SNPs were successfully genotyped and analyzed by mass spectrometry for association with five milk production traits in an independent resource population.The results showed that these SNPs were statistically significant for more than two traits[P<(0.0001–0.0267)].In addition,mRNA expression analyses revealed that C14H8orf33 was ubiquitous in eight different tissues,with a relatively higher expression level in the mammary gland than in other tissues.These findings,therefore,provide strong evidence for association of C14H8orf33 variants with milk yield and milk composition traits and may be applied in Chinese Holstein breeding programs.

Involvement of Quebracho tannins in diet alters productive and reproductive efficiency of postpartum buffalo cows

This study was conducted to investigate the effects of 10 weeks supplementation of Quebracho tannins(QT; 0 [control], 100 [QT100] or 200 g/[cow$d] [QT_(200)]) to 30 multiparous postpartum buffalo cows(10 cows per group) on milk yield and composition, blood metabolites and reproductive performance.Supplementation of QT100 had no significant effect on milk yield, whereas QT_(200) decreased(P < 0.05) this trait. Compared with the control group, both QT levels decreased(P < 0.05) fat-corrected milk(FCM)yield, but no significant effects were found on percentages of milk fat and protein. Contrariwise, yields of milk fat, lactose and milk protein were decreased(P < 0.05) when QT_(200) was supplemented. The solids nonfat(SNF) percentage and yield were decreased(P < 0.05) with QT100 supplementation. Moreover, QT tended to numerically reduce total number of ovarian follicles, number of small follicles, peripheral progesterone concentration and conception rate. Supplementation of QT_(200) numerically increased number of large follicles, mean diameter of large follicle, number and diameters of corpora lutea. The inclusion of QT_(200) shortened days open(DO) and decreased number of services per conception.Contrariwise, QT did not show significant effects on serum total protein, albumin, globulin, glucose,cholesterol and triglycerides concentrations. Supplementation of QT100 caused an increase(P < 0.05) of serum urea compared with that in control and QT_(200) groups. Generally, QT decreased(P < 0.05) serum creatinine concentration. Therefore, the supplementation of a commercial QT to early lactating Egyptian buffalo cows displayed negative consequences on their productive and reproductive performances.