ESTIMATE OF GENETIC COMPONENTS OF BIRTH WEIGHT USING MULTI-BREED MODELS WITH DIFFERENT PEDIGREE STRUCTURES IN MESTIZO SHEEP

The objectives of this paper were to verify the influence of the multi-breed model and pedigree structure in the estimates of the genetic components to birth weight in a mestizo herd. Using 1234 birth weight records in two ways, one dataset with complete pedigree information (n = 1028) and another with incomplete pedigree information (n = 1234). The pedigree was composed for 10 sires, 366 and 448 dams for complete and incomplete pedigree, respectively. Used for analysis the maximum restricted likelihood method about the animal model, considering the birth weight trait, for a dataset with or not complete pedigree, used the WOMBAT program. The direct heritability coefficients in both datasets did not present large difference, 0.06 and 0.09 to best models in the complete and incomplete pedigree, respectively. However, in the incomplete pedigree, the maternal heritability was 0.29. The residual variance, which on the best model of the dataset with complete pedigree presented 0.51 and 0.35 for the best model of the dataset with incomplete pedigree. Concluding, we find the influence of de multi-breed model only in the dataset with complete pedigree, that considered the direct and breed effects. In the dataset with incomplete pedigree, the better model was that considered the direct and maternal additive effects.

Pedigree Analysis of Warmblood Horses Participating in Competitions for Young Horses

The aim of the study was to characterize the population structure and assess the genetic diversity of warmblood horses used in the show jumping discipline. Pedigree data of 1,048 horses participating in the Polish Championships for Young Horses were analyzed. The pedigree of these animals included 12 863 individuals. The study consisted in analysis of the pedigree structure of the horses and characterization of the homozygosity and genetic diversity in the population. It was found that pedigree completeness and depth were sufficient for reliable assessment of the genetic diversity in the analyzed population. Although the average inbreeding coefficient exhibited at an acceptable level (approx. 1.01%), the increasing percentage of inbred animals seems disturbing. The results have shown that modern sport horses are derived from a small number of high-quality sires whose offspring were intensively used for breeding—bottleneck effect. In consequence, a greater part of the genetic variation reduction was observed in the non-founder generations. Given the changes in the studied population, the level of inbreeding in modern sport horses should be monitored, and pedigree data should be effectively used in selection for mating.

Genomic Prediction in Family Bulks Using Different Traits and Cross-Validations in Pine

Genomic prediction (GP) integrates statistical, genomic and computational tools to improve the estimation of breeding values and increase genetic gain. Due to the broad diversity in biology, breeding scheme, propagation method, and unit of selection, no universal GP approach can be applied in all crops. In a genome-wide family prediction (GWFP) approach, the family bulk is the basic unit of selection. We tested GWFP in two loblolly pine (Pinus taeda L.) datasets: a breeding population composed of 63 full-sib families (5-20 individuals per family), and a simulated population with the same pedigree structure. In both populations, phenotypic and genomic data was pooled at the family level in silico. Marker effects were estimated to compute genomic estimated breeding values at the individual (GEBV) and family (GWFP) levels. Less than six individuals per family produced inaccurate estimates of family phenotypic performance and allele frequency. Tested across different scenarios, GWFP predictive ability was higher than those for GEBV in both populations. Validation sets composed of families with similar phenotypic mean and variance as the training population yielded predictions consistently higher and more accurate than other validation sets. Results revealed potential for applying GWFP in breeding programs whose selection unit are family bulks, and for systems where family can serve as training sets. The GWFP approach is well suited for crops that are routinely genotyped and phenotyped at the plot-level, but it can be extended to other breeding programs. Higher predictive ability obtained with GWFP would motivate the application of GP in these situations.

Circulating miRNAs associated with bone mineral density in healthy adult baboons

MicroRNAs (miRNAs) regulate gene expression post-transcriptionally and circulate in the blood, making them attractive biomarkers of disease state for tissues like bone that are challenging to interrogate directly. Here we report on five miRNAs – miR-197-3p, miR-320a, miR-320b, miR-331-5p, and miR-423-5p – that are associated with bone mineral density (BMD) in 147 healthy adult baboons. These baboons range in age from 15 to 25 years (45 to 75 human equivalent years) and were 65% female with a broad range of BMDs including a minority of osteopenic individuals. miRNAs were generated via RNA sequencing from buffy coats collected at necropsy and areal BMD evaluated via DXA of the lumbar vertebrae post-mortem. Differential expression analysis controlled for the underlying pedigree structure of these animals to account for genetic variation which may be driving miRNA abundance and BMD values. While many of these miRNAs have been associated with risk of human osteoporosis, this finding is of interest because the cohort represent a model of normal aging and bone metabolism rather than a disease cohort. The replication of miRNA associations with osteoporosis or other bone metabolic disorders in animals with healthy BMD suggests an overlap in normal variation and disease states. We suggest that these miRNAs are involved in the regulation of cellular proliferation, apoptosis, and protein composition in the extracellular matrix throughout life. However, age-related dysregulation of these systems may lead to disease causing associations of the miRNAs among individuals with clinically defined disease.

Identification of Genomic Regions for Carcass Quality Traits within the American Simmental Association Carcass Merit Program

USDA quality and yield grade are primary driving forces for carcass value in the United States. Carcass improvements can be achieved by making selection decisions based on the results of genetic evaluations in the form of expected progeny differences (EPD), real-time ultrasound imaging, and physical evaluation of candidate breeding animals. In an effort to advance their ability to accurately predict the breeding value of potential sires for carcass traits, the American Simmental Association launched the Carcass Merit Program as a means to collect progeny sire group carcass information. All records were extracted from the American Simmental Association database. Progeny data were organized by sire family and progeny performance phenotypes were constructed. Sire genotypes were filtered, and a multi-locus mixed linear model was used to perform an association analysis on the genotype data, while correcting for cryptic relatedness and pedigree structure. Three chromosomes were found to have genome-wide significance and this conservative approach identified putative QTL in those regions. Three hundred ninety-three novel regions were identified across all traits, as well as 290 novel positional candidate genes. Correlations between carcass characteristics and maternal traits were less unfavorable than those previously reported.

Pedigree analysis of a red fox (Vulpes vulpes) population

Fur animal breeding has a long history. In many countries several fur animal species (including the red fox) have been recognized as livestock. The aim of this study was to estimate the pedigree parameters in the population of red fox on a Polish breeding farm. The data set consisted of information on 39 434 individuals, including 18 697 females and 20 004 males (733 animals were of unknown sex), from the years 1956–2016. The following pedigree parameters were estimated: average number of discrete generation equivalents, individual inbreeding coefficient, total and effective number of founders, effective population size, average relationship, founder genome equivalent, effective number of non-founders, and genetic diversity coefficient. The population size changed in successive years. The average inbreeding level was 5.34% for the population as a whole, and 6.04% for the inbred population. The estimated effective number of founders of the population was 84.18. The founder genome equivalent, which indicates the anticipated loss of genetic diversity caused by genetic drift, reached 9.59 in 2016 from an initial value of 34.22 in 1956. The loss of genetic diversity caused by the unequal contribution of the founder alleles did not change significantly over the years. Generally, the results indicate the good pedigree structure (including pedigree completeness) of the population studied. This implies reliable estimation of the inbreeding level, as one of the most important parameters in the genetic improvement programme.

Evaluation of qualitative and quantitative ratio of lineages in broodstock of Novoaltaiskaya breed of horses in the Altai Republic as of 2018

One of the most important and promising areas of domestic productive horse breeding today is herd meat. It is most sustainable and has a positive trend of development, due to the low-cost technology of keeping, breeding and growing, compared with other sectors of grazing. An analysis of the pedigree structure of herds in the Altai Republic showed that the main role in the herd horse breeding of the region is given to horses of the Novoaltaiskaya breed of meat direction of productivity, the basis of which, like any other factory breed, are brood mares. It is well known and repeatedly confirmed by studies that the hereditary and phenotypic properties of the mother have a great impact on the quality of the offspring of any lineage. The aim of the study was to determine the severity of the uterine composition of Novoaltaiskaya breed of horses of economically useful traits and to identify the most promising and valuable breed lineages in the Altai Republic. Methods. The lineage ratios in the broodstock of horses of Novoaltaiskaya breed in the farms of the region as of 2018 are analyzed. The characteristics of the uterus of various lineages by age and quantity are given. A linear analysis of the indicators of the main economically useful features is carried out. The results of the study showed the superiority of the uterus of the Rekrut and Mech lineages in the main breeding traits – live weight, basic measurements and assessment of conformation. Based on the results of the study, the further direction of breeding work to improve the horses of Novoaltaiskaya breed in the Altai Republic was determined. The scientific novelty of the study is a comparative analysis of the current state of the lineages of the Novoaltaiskaya breed of horses in the context of the broodstock of the Altai Republic.

Features of structure of radical darkconiferous forest stands of Vishera Nature Reserve

On the basis of the standard techniques the pedigree structure of forest stands and distribution of trees on diameter of climax darkconiferous stands of the Vishera national Nature Reserve located in the northeast of Perm District (Northern Urals) is studied and analysed. It is established that the wood layer of the explored climax darkconiferous forests of Northern Urals has multispecies structure. At domination of a spruce fir and the fir (up to 5 units) and, substantially a birch and, also participates, the cedar. In type of the wood Firspruce fernytallgrass as the as a part of a forest stand there is a rowan. Both lowproductive, and highly productive forest stands are formed. In a structure of forest stands of the darkconiferos woods of Vishera Nature Reserve the considerable variation of trees on diameter caused both by forest vegetation conditions of plantings, and influence of negative natural factors the periodic local fires and a windfall is revealed. Distribution of trees on diameter in forest stands, except for postwindfall, is well approximated by the equations of the 2nd order. Distribution of trees on diameter in postwindfall darkconiferous community is best of all described by the equation of the 4th order. The considerable righthand asymmetry of distribution of trees on diameter for all studied forest stands, and, in particular, the affected local fires or a windfall is noted. Such distribution of trees on diameter classes of a trunk reflects processes of natural renewal and development of forest stands, long on time. The revealed features of distribution of trees on pedigree structure and of diameter classes in the studied radical forest stands demonstrate that even in the conditions of influence of negative natural factors processes of natural renewal in general, provide maintenance of multispecies structure of radical plantings. However, impact of the periodic local fires negatively affects renewal of a cedar.

ОЦЕНКА ПРОДУКТИВНЫХ КАЧЕСТВ МОЛОЧНЫХ ПОРОД КРУПНОГО РОГАТОГО СКОТА БЕЛГОРОДСКОЙ ОБЛАСТИ

В статье изложены материалы о сравнительной оценке скота красно-пестрой, симментальской, черно-пестрой и голштинской пород, разводимых в племенных хозяйствах Белгородской области. Установлено, что в период с 2010 по2017 год численность молочного скота во всех категориях хозяйств снизилась на 42,9 тыс. голов, в том числе коров — на 27,4 тыс. голов. Численность племенного скота к общему поголовью в области в 2017 году составляла 19,5%. За последние 8 лет резко изменилась породная структура. На долю племенного скота голштинской породы в 2017 году приходилось 46,2%, в том числе 48,9% коров, что объясняется импортом маточного поголовья за указанный период в количестве более 30 тыс. голов. В породной структуре племенных стад на долю коров голштинской породы приходилось 48,9% от их общей численности племенного скота, красно-пестрой — 25, черно-пестрой — 15,9 и симментальской —2,7%.Одним из лимитирующих факторов роста молочной продуктивности является относительно низкая живая масса полновозрастных коров, которая составляла в 2017 году 559—603кг, что ниже оптимальной на 35—50 кг. Максимальная молочная продуктивность коров за 305 дней лактации в племенных хозяйствах отмечена у животных черно-пестрой породы — 8365 кг, голштинской — 8863, симментальской — 7159 и красно-пестрой — 6494кг. У последних низкая молочная продуктивность обусловлена издержками в кормлении и технологии содержания животных. В лучших хозяйствах этот показатель составлял более 7000 кг молока за 305 дней лактации. В молочных стадах наблюдается снижение показателей среднего возраста коров и возраста их выбытия из стад.The article presents the materials on the comparative evaluation of cattle red-and-white, simmental, black-and-white and holstein breeds bred in breeding farms of the Belgorod region. It is established that in the period from 2010 to 2017 the number of dairy cattle in all categories of farms dreamed of 42.9 thousand, including cows on 27.4 thousand. The number of breeding cattle to its total population in the region in 2017 was 19.5%. Over the past eight years, the breed structure has changed dramatically, the share of breeding cattle of holstein cattle in 2017 accounted for 46.2%, including 48.9% of cows, which explained by the import of breeding stock of this breed for the specified period in the amount of more than 30 about thousand. In the pedigree structure of breeding herds the share of holstein cows accounted for 48.9% of their total number of breeding cattle, red-and-white — 25, black-and-white — 15.9 and Simmental — 2.7%. One of the limiting factors of growth of milk productivity of cows is relatively low live weight of mature cows, the value of which was in 2017 559—603 kg, which is below the optimal 35—50 kg. Maximum milk productivity of cows over 305 days of lactation in breeding farms marked by black-and-white breed — 8365 kg, Holstein — 8863, Simmental — 7159 and red-and-white — 6494 kg. The last low milk productivity is due to costs in the feeding and care of animals. It is no accident that in the best farms this figure was more than 7.0 thousand kg of milk for 305 days of lactation. In dairy herds, there is a decrease in the average age of cows and their disposal from the herds.

Pedigree structure of American bison (Bison bison) population

An effective realization of breeding programs in zoos is strongly determined by completeness of animal pedigree information. The knowledge of pedigree structure allows to maintain optimal genetic variability of a given population. The aim of this study was to estimate the parameters describing the pedigree structure of American bison housed in zoos in the context of further management of the population. Finally, 4269 American bison were analysed (1883 males, 2217 females, and 169 with unknown sex). The registered animals were born between years 1874 and 2013. The following pedigree parameters were estimated: number of fully traced generations, number of complete generations equivalent, index of pedigree completeness, individual inbreeding coefficients, increase of inbreeding for each individual, effective population size, and genetic diversity. The maximum number of fully traced generations was 3 (the mean value is 0.693). The mean inbreeding coefficient for the population studied was 3.26%, whereas individual increase in inbreeding ranged from 0 to 25.12%. Although the pedigree parameters (including the inbreeding level) in the American bison obtained in the present study seem to be acceptable (from the perspective of other wild animal populations), they can be over/underestimated due to incomplete pedigree.