Yaroslavl Breeds Research Articles

Genetic Diversity of Historical and Modern Populations of Russian Cattle Breeds Revealed by Microsatellite Analysis.

Analysis of ancient and historical DNA has great potential to trace the genetic diversity of local cattle populations during their centuries-long development. Forty-nine specimens representing five cattle breeds (Kholmogor, Yaroslavl, Great Russian, Novgorod, and Holland), dated from the end of the 19th century to the first half of the 20th century, were genotyped for nine polymorphic microsatellite loci. Using a multiple-tube approach, we determined the consensus genotypes of all samples/loci analysed. Amplification errors, including allelic drop-out (ADO) and false alleles (FA), occurred with an average frequency of 2.35% and 0.79%, respectively. A significant effect of allelic length on ADO rate (r2 = 0.620, p = 0.05) was shown. We did not observe significant differences in genetic diversity among historical samples and modern representatives of Kholmogor and Yaroslavl breeds. The unbiased expected heterozygosity values were 0.726–0.774 and 0.708–0.739; the allelic richness values were 2.716–2.893 and 2.661–2.758 for the historical and modern samples, respectively. Analyses of FST and Jost’s D genetic distances, and the results of STRUCTURE clustering, showed the maintenance of a part of historical components in the modern populations of Kholmogor and Yaroslavl cattle. Our study contributes to the conservation of biodiversity in the local Russian genetic resources of cattle.

Продуктивность и воспроизводительные качества коров ярославской породы разных генотипов

Цель исследований – изучение основных показателей молочной продуктивности и воспроизводительных качеств чистопородных и помесных коров ярославской породы в зависимости от разной доли кровности по голштинской породе. Исследования проводили на коровах стада одного из сельскохозяйственных предприятий Ярославской области. В качестве объекта исследований были отобраны чистопородные и помесные полновозрастные коровы (71 гол.), имеющие три законченные лактации. Животные были разделены на четыре группы: 1 группа – чистопородные ярославские коровы, 2 группа – с кровностью по голштинской породе 50–74,9% (средняя 66,5%), 3 группа – с кровностью 75% (3/4 по голштину) и 4 группа – 76% и более (средняя 83,0% по улучшающей породе). Проведённые исследования показали, что за три лактации различие по общему надою чистопородных коров с голштинизированными находилось на уровне 2466,1–3173,1 кг. По среднему надою за три лактации чистопородные коровы имели достоверно меньшие значения в сравнении с другими группами. По массовой доле жира в молоке чистопородные коровы превосходят другие группы на 0,17, 0,13 и 0,10% соответственно. Чистопородные коровы имеют несколько больший показатель содержания белка в молоке (3,15%), у коров с кровностью 50–74% и 75% он ниже. Как чистопородные, так и голштинизированные коровы имеют значения межотельного периода, обеспечивающие коэффициент воспроизводительной способности коров на уровне 0,96–0,98%. Уменьшение возраста их первого отёла способствует увеличению индекса плодовитости коров. The purpose of the research is to study the main indicators of milk producing ability and reproductive qualities of purebred and cross-breeding cows of the Yaroslavl breed depending on the different blood percentage in the Holstein breed. Researches were carried out on cows of a herd of one of the agricultural enterprises of the Yaroslavl region. Pure-bred and cross-breeding full-aged cows (71 animals) with three complete lactations were selected as the object of research. The animals were divided into four groups: group 1 – purebred Yaroslavl cows, group 2 – with a blood content of Holstein breed 50–74.9% (average 66.5%), group 3 – with a blood content of 75% (3/4 for Holstein) and group 4 – 76% or more (average 83.0% for improving breed). Conducted researches have shown that for three lactations the difference in total yields of purebred cows with Holstein cows was at the level of 2466.1-3173.1 kg. According to the average milk yield for three lactations purebred cows had significantly lower values in comparison with other groups. By mass fraction of fat in milk purebred cows are superior to other groups by 0.17, 0.13 and 0.10%, respectively. Purebred cows have a slightly higher indicator of protein content in milk (3.15%), in cows with a blood content of 50–74% and 75% it is lower. Both purebred and Holstein cows have calving interval values providing a cow reproduction rate of 0.96–0.98%. Decreasing the age of their first calving contributes to an increase in the fertility index of cows.

Характеристика продуктивно-хозяйственных показателей коров ярославской породы различных генотипов

Abstract. Aim. The study of the influence of crossbriding on the growth and development of heifers and subsequent productive and reproductive qualities of cows on the first lactation. Methods. Using statistical methods, correlation analysis and ANOVA for evaluated genetic indicators of economic-valuable traits of dairy cattle. In particular was studied live weight of heifers from birth to 18 months, first insemination age and first fecundation age, live weight at fecundation, frequency of insemination, first calving age, days open, live weight at first lactation, milk yield for 305 days (kg), fat (%, kg) and protein (%, kg) in milk. Results. Relationship between productive indicators and the genotype of the animal is established. When assessing the strength of the influence of the factor «blood on the Holstein breed» it was found that the greatest impact can be traced at the age of 6 and 18 months, and is respectively 12.7 % and 17.1 %.The reproductive qualities of the first-calf cows decreased with the increase percent of blood in the Holstein breed. Evaluation of the impact of crossbreeding on milk production at first lactation has revealed significant strong influence on milk yield for 305 days of first lactation, and related signs the amount of milk fat and protein. According to qualitative indicators, the low influence of the Holstein blood fraction was found, while to a greater extent on the fat content than on the protein content in milk. Evaluation of phenotypic and genotypic correlations of milk yield and quality components of milk revealed average negative phenotypic and low negative genotypic correlation in all groups. The exception was in heifers of Yaroslavl breed with percent of Holstein blood less than 50 %, in which the relationship of yield x protein was positive. The relationship between milk yield and fat and protein content in milk has the opposite moderate character and strength. Practical significance. Studies was established that breeding of animals of Holstein and Yaroslavl breeds in one herd allows to receive an optimum ratio of milk production with optimal percentage fat and protein. For this herd among animals of the improved genotypes of the Yaroslavl breed, the use of genotypes with a percent of blood in the Holstein breed from 75.1 % to 87.6 % is optimal, which should be taken into account when selecting bulls to the breeding program.

Продолжительность использования коров ярославской породы различных генотипов

Продолжительность использования коров ярославской породы различных генотипов

Влияние заболеваний вымени на воспроизводительные качества коров

The article presents the results of the analysis of the impact of udder diseases of subclinical and clinical forms of mastitis of different breeds of cows.The fertility of cows, which were ill, in comparison with healthy cows, was reduced. This fact has reflected in the increase of the length of service and the interlactation period. The subclinical and clinical forms of mastit has reflected as a great reduction of live weight of the cows of the studied breeds. Significantly, the greatest difference was obtained from crossbred cows of the Yaroslavl breed, which was 37 kg.

κ-casein gene (CSN3) allelic polymorphism in Russian cattle breeds and its information value as a genetic marker

The frequencies of the κ-casein gene (CSN3) alleles and genotypes have been determined in five Russian cattle breeds (Bestuzhev, Kalmyk, Russian Black Pied, Yaroslavl, and Yakut breeds) by means of PCR-RFLP analysis using two independent restriction nucleases (HinfI and TaqI) and by allele-specific PCR. Typing alleles A and B of CSN3 is of practical importance, because allele B is correlated with commercially valuable parameters of milk productivity (protein content and milk yield) and improves the cheese yielding capacity. The frequencies of the B allele of CSN3 in the breeds studied vary from 0.16 to 0.50; and those of the AB and BB genotypes, from 0.27 to 0.60 and from 0.02 to 0.23, respectively. The Yaroslavl breed had the highest frequencies of CSN3 allele B and genotype BB (0.50 and 0.23, respectively). The frequencies of the B allele and BB genotype in other breeds studied varied from 0.25 to 0.32 and from 0.03 to 0.09, respectively. In none of the breeds studied have the observed and expected heterozygosities been found to differ from each other significantly. However, the observed genotype distributions significantly differ from the expected one in some herds (in most such cases, an excess of heterozygotes is observed). Two herds of the Yaroslavl breed dramatically differ from each other in the heterozygosity level: a deficit (D = −0.14) and an excess (D = 0.20) of heterozygotes have been observed at the Mikhailovskoe and Gorshikha farms, respectively. In general, however, the heterozygosity of the Yaroslavl breed corresponds to the expected level (D = 0.04). Analysis of breeds for homogeneity with the use of Kulback’s test has shown that all cattle breeds studied are heterogeneous, the CSN3 diversity within breeds being higher than that among different breeds, which is confirmed by low Fst values (0.0025–0.0431). Thus, a DNA marker based on CSN3 gene polymorphism is extremely important for breeding practice as a marker of milk quality; however, it is inapplicable to marking differences between breeds or phylogenetic relationships between cattle breeds because of the high diversity with respect to this locus within breeds.

Association of DNA polymorphisms of the growth hormone and prolactin genes with milk productivity in Yaroslavl and Black-and-White cattle

Polymorphisms of the prolactin (bPRL) and growth hormone (bGH) genes were studied comparatively in the Russian and German Black-and-White and Yaroslavl cattle breeds. Two polymorphisms were studied for each gene. In the case of the bPRL gene, the polymorphism of the 5'-untranslated region was examined by microsatellite analysis and the RsaI polymorphism of exon 3, by RFLP analysis. In the case of the bGH gene, the MspI polymorphism of intron III and the AluI polymorphism of exon 5 were assessed by RFLP analysis. Differences in allele and genotype frequencies were observed both between and within breeds. The heterozygosity at the RsaI marker was low (9.4%) in the Russian Black-and-White breed; that at the microsatellite of the bPRL gene was low (3.2-24%) in all breeds examined. Homozygotes BB at the bPRL gene, which had not been reported earlier for European cattle breeds, were detected in the German Black-and-White and Yaroslavl breeds (at frequencies 0.16 and 0.13, respectively). The frequency of allele MspI(-) of the bGH gene in the Yaroslavl breed was extremely low (0.02), comparable only with that of the Holstein cattle (0.02). The heterozygosity at the AluI polymorphism was higher than at the MspI polymorphism of the bGH gene and reached 55% in the Yaroslavl breed. Genotype BB of the RsaI polymorphism of the bPRL gene tended to show a negative association with the fat content in milk. The genotypes of the AluI polymorphism of the bGH gene were associated with the fat content in milk in the Yaroslavl (F = 4.56, P = 0.013) and German Black-and-White (F = 4.1, P = 0.014) breeds: the highest fat content in milk was observed in the subsample of cows with heterozygous genotype VL.