Banca de QUALIFICAÇÃO: VINICIUS DA SILVA BOTELHO DUARTE GOMES

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : VINICIUS DA SILVA BOTELHO DUARTE GOMES
DATE: 30/06/2021
TIME: 14:00
LOCAL: Vídeo Conferência
TITLE:

POLYMORPHISMS IN CSN1S1 AND CSN3 GENES ON THE PRODUCTION AND YIELD OF MINAS FRESCAL CHEESE IN MURRAH BUFFALO

KEY WORDS:

Genomic selection, caseins, proteins, alpha-s1-casein, kappa-casein, dairy products.

PAGES: 17
BIG AREA: Ciências Agrárias
AREA: Zootecnia
SUBÁREA: Produção Animal
SPECIALTY: Manejo de Animais
SUMMARY:

We aimed to evaluate the influence of genetic polymorphisms in the CSN1S1 and CSN3 genes, responsible for encoding the protein fractions (α-S1-casein and k-casein, respectively) in milk on the production and composition of milk and the yield of Minas Frescal cheese from the milk of buffaloes (Bubalus bubalis) of the Murrah breed. 41 buffaloes of the Murrah Breed (± 30 days of lactation) were used. The determination of CSN1S1 and CSN3 alleles was performed by nucleotide sequencing. For evaluation of milk production and composition (fat, protein, lactose, total dry extract, defatted dry extract, urea nitrogen in milk, casein, somatic cell count and total bacterial count), Minas Frescal cheese yield and characterization and quantification of milk and whey protein fractions (alpha-S1 and S2-casein, beta-casein, kappa-casein, alpha-lactalbumin and beta-lactoglobulin) were collected and monthly measured for milk (eight collections). The protein fractions of milk and whey were performed using RP-HPLC after a preparative method by liquid chromatography. Three distinct genotypes for the α gene - CSN1S1 casein were identified: two homozygous (AA) and (GG) and one heterozygote (AG), with only one individual with GG pattern, not considered in this study. For the CSN3 κ-casein gene, three genotypes were also identified: two homozygous (CC) and (TT) and one heterozygote (CT), with only two individuals with the homozygous TT pattern, not considered in this study. There was an interaction between the CSN1S1 and CSN3 genes for the variables milk production and individual cheese yield per cow (kg/cow), where animals with the AACC genotype showed higher milk production (kg/day). Animals with AGTC and AACC genotypes showed higher individual cheese yield (kg/cow). Cows that were identified with the combined allele expression AATC produced the highest amount of the alpha-s2-casein protein fraction in milk, followed by those with the combined AGCC alleles. A trend of interaction between genes was observed for the concentration of kappa-casein X1. The effect of the CSN3 gene was verified for the concentration of the fraction of kappa-casein X2 with the animals with the CC alleles with higher concentrations of this fraction in milk. Polymorphism of CSN1S1 and CSN3 genes with AACC allelic combinations may be associated with higher milk production in Murrah buffaloes. On the other hand, the highest cheese yield per cow is associated with animals with AGTC allelic combinations. This genotypic information can assist in targeting crosses and premature selection of animals for milk production and individual Minas Frescal cheese yield

BANKING MEMBERS:
Presidente - 1143911 - RAYLON PEREIRA MACIEL
Interna - 1839209 - DAIANY IRIS GOMES
Interna - 1957010 - MARILIA DANYELLE NUNES RODRIGUES
Externo ao Programa - 236.511.898-48 - JULIÁN ANDRÉS CASTILLO VARGAS - UFRA
Externa à Instituição - DENISE RIBEIRO DE FREITAS - UFS