Banca de DEFESA: MICHAEL DOS SANTOS MACIEL

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MICHAEL DOS SANTOS MACIEL
DATE: 27/05/2022
TIME: 09:30
LOCAL: Plataforma Google Meet
TITLE:

ANALYSIS OF THE POPULATION STRUCTURE OF THE MANGALARGA BREED

KEY WORDS:

ANCESTORS, HORSES, INBREEDING, PEDIGREE

PAGES: 49
BIG AREA: Ciências Agrárias
AREA: Zootecnia
SUBÁREA: Genética e Melhoramento dos Animais Domésticos
SUMMARY:

The Mangalarga breed originated from the cross between locally adapted mares and Portuguese horses from the Alter Stud Farm. Due to the sportive ability and diagonal and comfortable gait of these animals, the breed soon became popular. The expansion of the Mangalarga herd and the emergence of new breeders intensified the selection, making the process more professional and leading to the creation of the Brazilian Association of Mangalarga Breed Horse Breeders (ABCCRM). Since the foundation of ABCCRM, the breed has gone through several morphological patterns. Currently, the guidelines prioritize the selection of animals that fit the saddle type. The study of the genetic structure of a population allows the identification of events that affected the genetic diversity of the breed, in addition to describing the evolution of the level of inbreeding and defining the kinship between individuals to monitor genetic diversity. The objective of this work was to study the population structure of the Mangalarga breed, through pedigree data. Genealogical information of 206,426 animals of the Mangalarga breed, registered in the period from 1919 to 2018, were used. Using the ENDOG v4.6 software, the parameters were estimated: pedigree completeness, level of ancestor identification, generation interval, number of founders ( Nf), number of ancestors, effective number of founders (fe), effective number of ancestors (fa), inbreeding coefficient (F) and average relative coefficient (AR), number of animals in the reference population, base population, population real base, number of ancestors that gave rise to the reference population, number of ancestors that explain 50%, ancestors that most contributed to the genetic variability of the breed, percentage of inbred individuals (End), average inbreeding for inbred individuals (FEnd) , effective number (Ne) of the breed, average number of maximum and complete generations. Among the results obtained, it was possible to identify ancestors in the Mangalarga breed up to the fifth generation. In addition, for the four gametic passages, the average age of the parents at the birth of their offspring was 9.43 ± 5.46 years, in relation to the generation interval, a general average of 9.07 ± 4.75 was recorded. years old. Of the total of 206,426 animals, 7.20% are part of the base population (founders and ancestors). With a number of ancestors 8,908, with only 44 being the effective number of ancestors. The effective number of founders was equal to 100.31 animals. As for the genetic variability in the breed, 50% of it is explained by contributions from only 48 animals. The inbreeding coefficient (F) and the average kinship coefficient (AR) for the entire population were 2.26% and 2.41%, respectively. Among the ancestors that most contributed to the genetic variability of the breed, nine animals are responsible for 21.58% of the variability, of which only two are females. From 1980 onwards there was an increase in F and AR and between 2010 and 2020 there was a deceleration of these two parameters in the Mangalarga herd.

BANKING MEMBERS:
Externa à Instituição - IAÇANÃ VALENTE FERREIRA GONZAGA - UFRB
Externo à Instituição - ALESSANDRO MOREIRA PROCÓPIO
Presidente - 2441476 - JORGE EDUARDO CAVALCANTE LUCENA