Genetic parameters and genetic trend of some yield traits of Holstein Friesian cattle population in Tropical Region (Teke).

This study was conducted to determine the milk yield and reproduction characteristics, genetic trend, and breeding values of Holstein cattle reared in Teke region (Antalya, Burdur, Denizli, and Isparta provinces) of Turkey. In this study, 9844 lactation and reproductive records of Holstein Friesian dairy cattle for the period of 2010 to 2017 were used. For this purpose, variance components and the heritability were calculated based on calving interval (CI) and number of inseminations per conception (NIC) from fertility characteristics and lactation length (LL), 305-day milk yield (305 DMY), and dry period (DP). It was determined that CI, NIC, LL, 305 DMY, and DP were 0.11, 0.10, 0.11, 0.33, and 0.01, respectively. The genetic trend of 305 DMY was 111.5 kg/year. The average breeding value was negative between 2005 and 2009 and positive between 2010 and 2015. In conclusion, the fact that especially 305 DMY heritability was generally higher in this study than the values reported by other studies conducted in Turkey and the genetic trend for 305 DMY was positive and high indicates that breeding value of Holstein cattle in the Teke region is high. Therefore, it can be recommended to continue the pedigree breeding of Holstein cattle in this region, keep pedigree and yield records meticulously, estimate breeding values for selecting animals with superior yield characteristics and using them in future generations, and include current biotechnological methods in breeding program to increase the efficiency in selection.

Phylogenetic Relationships of Turkish Indigenous Donkey Populations Determined by Mitochondrial DNA D-loop Region.

In this study, to analyze the mtDNA D-loop region and the origin of the maternal lineages of 16 different donkey populations, and to assess the domestication of Turkish indigenous donkeys in seven geographical regions, we investigated the DNA sequences of the D-loop region of 315 indigenous donkeys from Turkey. A total of 54 haplotypes, resulting from 35 polymorphic regions (27 parsimoniously informative and 6 singleton sites), were defined. Twenty-eight of these haplotypes are unique (51.85%), and 26 are shared among different Turkish indigenous donkey populations. The most frequent haplotype was Hap 1 (45.71%), followed by two haplotypes (Hap 4, 15.55% and Hap 7, 5.39%). The breed genetic diversity, evaluated by the haplotype diversity (HD) and nucleotide diversity (πD), for the Turkish donkey populations ranged from 0.533 ± 0.180 (Tekirdag-Malkara, MAL) to 0.933 ± 0.122 (Aydin, AYD), and from 0.01196 ± 0.0026 (Antalya, ANT) to 0.02101 ± 0.0041 (Aydin, AYD), respectively. We observed moderate-to-high levels of haplotype diversity and moderate nucleotide diversity, indicating plentiful genetic diversity in all of the Turkish indigenous donkey populations. Phylogenetic analysis (NJT) and median-joining network analysis established that all haplotypes were distinctly grouped into two major haplogroups. The results of AMOVA analyses, based on geographic structuring of Turkish native donkey populations, highlighted that the majority of the observed variance is due to differences among samples within populations. The observed differences between groups were found to be statistically significant. Comparison among Turkish indigenous donkey mtDNA D-loop regions and haplotypes, and different countries' donkey breeds and wild asses, identified two clades and which is named Somali (Clade IV) and Nubian (Clade V) lineages. The results can be used to understand the origin of Turkish donkey populations clearly, and to resolve the phylogenetic relationship among all of the different regions.

Genetic Characterization of Native Donkey (Equus asinus) Populations of Turkey Using Microsatellite Markers.

This study presents the first insights to the genetic diversity and structure of the Turkish donkey populations. The primary objectives were to detect the main structural features of Turkish donkeys by microsatellite markers. A panel of 17 microsatellite markers was applied for genotyping 314 donkeys from 16 locations of Turkey. One hundred and forty-two alleles were identified and the number of alleles per locus ranged from 4 to 12. The highest number of alleles was observed in AHT05 (12) and the lowest in ASB02 and HTG06 (4), while ASB17 was monomorphic. The mean HO in the Turkish donkey was estimated to be 0.677, while mean HE was 0.675. The polymorphic information content (PIC) was calculated for each locus and ranged from 0.36 (locus ASB02) to 0.98 (locus AHT05), which has the highest number of alleles per locus in the present study. The average PIC in our populations was 0.696. The average coefficient of gene differentiation (GST) over the 17 loci was 0.020 ± 0.037 (p < 0.01). The GST values for single loci ranged from -0.004 for LEX54 to 0.162 for COR082. Nei's gene diversity index (Ht) for loci ranged from 0.445 (ASB02) to 0.890 (AHT05), with an average of 0.696. A Bayesian clustering method, the Structure software, was used for clustering algorithms of multi-locus genotypes to identify the population structure and the pattern of admixture within the populations. When the number of ancestral populations varied from K = 1 to 20, the largest change in the log of the likelihood function (K) was when K = 2. The results for K = 2 indicate a clear separation between Clade I (KIR, CAT, KAR, MAR, SAN) and Clade II (MAL, MER, TOK, KAS, KUT, KON, ISP, ANT, MUG, AYD and KAH) populations.