Abstract

The genetic diversity of the casein locus in cattle was studied on the basis of haplotype analysis. Consideration of recently described genetic variants of the casein genes which to date have not been the subject of diversity studies, allowed the identification of new haplotypes. Genotyping of 30 cattle breeds from four continents revealed a geographically associated distribution of haplotypes, mainly defined by frequencies of alleles at CSN1S1 and CSN3. The genetic diversity within taurine breeds in Europe was found to decrease significantly from the south to the north and from the east to the west. Such geographic patterns of cattle genetic variation at the casein locus may be a result of the domestication process of modern cattle as well as geographically differentiated natural or artificial selection. The comparison of African Bos taurus and Bos indicus breeds allowed the identification of several Bos indicus specific haplotypes (CSN1S1*C-CSN2*A²-CSN3*A_I/CSN3*H) that are not found in pure taurine breeds. The occurrence of such haplotypes in southern European breeds also suggests that an introgression of indicine genes into taurine breeds could have contributed to the distribution of the genetic variation observed.

-The genetic diversity of the casein locus in cattle was studied on the basis of haplotype analysis. Consideration of recently described genetic variants of the casein genes which to date have not been the subject of diversity studies, allowed the identification of new haplotypes. Genotyping of 30 cattle breeds from four continents revealed a geographically associated distribution of haplotypes, mainly defined by frequencies of alleles at CSN1S1 and CSN3. The genetic diversity within taurine breeds in Europe was found to decrease significantly from the south to the north and from the east to the west. Such geographic patterns of cattle genetic variation at the casein locus may be a result of the domestication process of modern cattle as well as geographically differentiated natural or artificial selection. The comparison of African Bos taurus and Bos indicus breeds allowed the identification of several Bos indicus specific haplotypes (CSN1S1*C-CSN2*A 2 -CSN3*A I / CSN3*H) that are not found in pure taurine breeds. The occurrence of such haplotypes in southern European breeds also suggests that an introgression of indicine genes into taurine breeds could have contributed to the distribution of the genetic variation observed.casein / haplotype / Bos taurus / Bos indicus / phylogeny

This study aimed to survey milk yield, lactation stages and milk quality traits of Damascus goats reared under different feeding systems. Goats were divided according to feeding systems as pasture based and concentrate based. Feeding systems were found to have significant effect on lactation milk yield but not on lactation duration. Although differences between feeding systems were not found significant on pH, milk composition factors (fat, lactose, dry matter), somatic cell count and malondialdehyde (except for early lactation stage) for each lactation stage, significant effects were detected on same parameters among lactation stages. Calcium levels at early lactation stage in milk differed either between feeding systems or among lactation stages. Also, other minerals were found to decrease with lactation. While most of the fatty acids were affected in any of the lactation stages by the feeding system, all of them were significantly altered by lactation stages. Pastured goats had a lower percentage of total saturated fatty acids, atherogenic index, thrombogenic index and odour index ratios. In accordance with milk fatty acid composition, compared to the milk obtained from goats fed with concentrate, the milk obtained from the goats that pastured was healthier and early lactation stage was found to produce healthier milk than late lactation stage.

No abstract

SummaryA new alternative genotyping method based on PCR-SSCP was developed for direct differentiation of the CSN1S1 alleles B and C in the coding region. In addition a PCR-RFLP test based on a MaeIII restriction site in the promoter region of CSN1S1, reported in the literature as an alternative test for the differentiation of CSN1S1*B and C was used and the alleles named b and c. Genotyping of 649 animals belonging to 17 European and Turkish cattle breeds showed differences in occurrence and frequency of the alleles.

Background: Factor XI (FXI) is a plasma protein that participates in the formation of blood clots. Factor XI deficiency is autosomal recessive hereditary disorder that may be associated with excess bleeding in Holstein cattle.

A screening of casein gene variability was carried out by Polymerase Chain Reaction – Single Strand Conformation Polymorphism in 8 goat breeds from Sudan (Nubian goat), Turkey (Angora Goat Lalahan Tiftic, Angora Goat Yerkoy, Hair goat) and India (Jammu, Maharashtra, Rajasthan, South Goat). A total of 16 different alleles or groups of alleles were found, showing conspicuous differences among breeds. The allele frequencies were submitted to cluster analysis in order to highlight differences between breeds, also including data from Red Sokoto, West African Dwarf Nigeria, West African Dwarf Cameroon, and Borno Goat. The tree obtained from the cluster analysis showed two main lineages. The West African goat clustered together, the Indian and Turkish breeds were in the other group. Nubian goat was found in an intermediate position

This study aimed to identify the expression levels of some candidate genes for mastitis resistance (LTF and BRCA1), milk yield (POU1F1 and IGF-1), and milk quality (PPARγ and CSN2) in different feeding systems (pen-and pasture-based) used for Damascus goats. Milk samples were taken from all goats in both pen and pasture groups at 4 times, at the 1st, 3rd, 5th, and 7th months of the study. It was found that, compared to the pen group, the LTF and CSN2 genes in the pasture group had significant levels of upregulation in the 7th month of lactation (3.538-and 5.436-fold, respectively), the PPARγ gene had downregulation at the beginning of lactation (0.399-fold), and the IGF-1 gene had upregulation in the 3rd month of lactation (2.313-fold) but had significant levels of downregulation (2.332-fold) in the 5th month of lactation. It was determined that LTF gene expression levels in goats might be used as a criterion in identifying mastitis resistance, IGF-1 for lactation milk yield, and PPARγ for milk fat yield. This study is the first report that presents LTF, BRCA1, IGF-1, and PPARγ gene expression levels in goat milk and udder epithelial cells and the effect of BRCA1, POU1F1, and PPARγ genes on milk protein yield.