Population structure and inbreeding of Holstein cattle in southern Brazil

Abstract

Breeding and genetics Full-length research article Population structure and inbreeding of Holstein cattle in southern Brazil ABSTRACT-The present investigation aimed to evaluate the population structure and inbreeding of Holstein herds in southern Brazil. To carry out the analysis, the Associação Paranaense de Criadores de Bovinos da Raça Holandesa (APCBRH) in Brazil provided the data, which consisted of a pedigree file of 206,796 animals born between 1970 and 2014. Results regarding the following parameters were determined: pedigree integrity, effective number of founders, effective number of ancestors, generation interval, inbreeding coefficient, realized effective population size, and average relatedness coefficient. POPREP and ENDOG v.4.5 software packages were employed to estimate these parameters. Based on the data set, the mean generation interval was found to be 6.3 years, and the average inbreeding coefficient, related to inbred animals, was 4.99%. Furthermore, the realized effective population size varied throughout the time period, ranging from 22 to 114, whereas the rate of inbreeding in this same period showed a decreasing trend towards the later years in the period until 2014. Upon evaluation, average relatedness coefficient was estimated to be 0.71%. Moreover, the effective number of founders and ancestors were estimated as 418 and 400 animals, respectively. According to the level of inbreeding observed, it could be noticed that genetic diversity remains elevated, which will be important to the genetic progress in the Holstein breeding program in Southern Brazil.

Genetic Variation and Population Differentiation in the Bovine Lymphocyte Antigen DRB3.2 Locus of South African Nguni Crossbred Cattle

“…They were comparable to genetic differentiation (F ST = 0.009) identified in Holstein cattle [59], albeit the Holstein study covered samples from four different South American countries. This, therefore, depicts the retention of important alleles in cattle, or the high degree of inbreeding in the Holstein breed [60,61]. The population differentiation estimates in the current study were, however, lower than those reported for Mexican creole breeds [4].…”

Allele Frequency of APAF1 Mutation in Holstein Cattle in Brazil

“…Although the genetic basis of the Holstein Brazilian herd has been formed by animals, semen, and embryos imported from Europe and North America (13) and previous studies in other countries have indicated the importance and impact of this mutation in the breed (3)(4)(5)(8)(9)(10)(11)(12), the APAF1 mutation has not been described in Brazil yet. In the present study, the first report that evaluated allele frequency of this mutation in Brazil, all animals assessed were homozygous for the wild-type allele, that is, no animal carried the mutant APAF1 allele.…”

“…Seventy percent (23/33) of the bulls were descendants from Walkway Chief Mark and 30% (10/33) from S-W-D Valiant, important sires in the history of the Holstein breed and used for the study and validation of APAF 1 mutation by Adams and collaborators ( 3 ). Considering that inbreeding is a widespread practice in bovine reproduction and production ( 3 , 13 ), there are differences between the frequency of occurrence of APAF 1 in some Holstein populations due to knowledge about HH1 and implementation of reproduction methods to eliminate the mutation of the breed ( 3 ).…”

Análisis de la consanguinidad sobre parámetros reproductivos en un rebaño lechero en costa central

“…Las poblaciones actuales de ganado Holstein, están mostrando un incremento de la consanguinidad, así un estudio realizado en el ganado Holstein en el sur de Brazil, Sieklicki et al (2020) determinaron la estructura genética determinando un intervalo de generación de 6,3 años y la media de consanguinidad de la población de 4,99%, observándose que la diversidad genética se mantiene elevada, el cual es importante para lograr un progreso genético en los programas de mejora en el ganado Holstein. Doekes et al (2019) evaluando la depresión endogámica en el ganado Holstein Alemán, reportaron un incremento en el intervalo entre partos de 0,48 días (ES=0,15) por cada 1% de incremento en la consanguinidad genómica (FROH).…”