RESUMEN

The synthesis of fatty acids plays a critical role in shaping milk production characteristics in dairy cattle. Thus, identifying effective haplotypes within the fatty acid metabolism pathway will provide novel and robust insights into the genetics of dairy cattle. This study aimed to comprehensively examine the individual and combined impacts of fundamental genes within the fatty acid metabolic process pathway in Jersey cows. A comprehensive phenotypic dataset was compiled, considering milk production traits, to summarize a cow's productivity across three lactations. Genotyping was conducted through PCR-RFLP and Sanger sequencing, while the association between genotype and phenotype was quantified using linear mixed models. Moderate biodiversity and abundant variation suitable for haplotype analysis were observed across all examined markers. The individual effects of the FABP3, LTF and ANXA9 genes significantly influenced both milk yield and milk fat production. Additionally, this study reveals novel two-way interactions between genes in the fatty acid metabolism pathway that directly affect milk fat properties. Notably, we identified that the GGAAGG haplotype in FABP3×LTF×ANXA9 interaction may be a robust genetic marker concerning both milk fat yield and percentage. Consequently, the genotype combinations highlighted in this study serve as novel and efficient markers for assessing the fat content in cow's milk.

Asunto(s)

Ácidos Grasos , Lactancia , Leche , Animales , Bovinos/genética , Bovinos/fisiología , Ácidos Grasos/metabolismo , Leche/química , Leche/metabolismo , Femenino , Lactancia/genética , Haplotipos , Variación Genética , Genotipo , Fenotipo , Proteína 3 de Unión a Ácidos Grasos/genética , Proteína 3 de Unión a Ácidos Grasos/metabolismo , Anexinas/genética , Anexinas/metabolismo

RESUMEN

This research was carried out to determine the effect of a specific single nucleotide polymorphism (SNP) region in exon 10 of the growth hormone receptor (GHR) gene on milk production traits in Jersey and Holstein cows raised in Turkey. Milk samples were recorded as a test day milk yield (TDMY) and an adjusted based 305 d milk yield (305-DMY). Also, milk component traits were detected. Based on the scope of this study, a total of 748 dairy cows, including 305 Holsteins raised in the Marmara Region and 163 Holstein and 280 Jersey raised in the Black Sea Region, were genotyped for the GHR gene using the RFLP-PCR technique. Jersey cows carrying the GG genotype (5.24 %) were associated with higher fat content ( P < 0.05 ). Jersey cows with GG and AG also had a higher protein content (3.44 % and 3.38 %, respectively) ( P < 0.05 ). Similarly, the protein content was the highest in Holstein cows with the GG genotype (3.46 %) ( P < 0.01 ), whereas Holstein cows having AA genotypes displayed higher TDMY (24.64 kg/d) ( P < 0.05 ) and 305-DMY (8472.4 kg) ( P < 0.01 ). The estimated increase in milk protein and fat contents due to the G allele was 0.07 % and 0.22 % in the Jersey breed, respectively. On the other hand, allele A was highly related to an increase in protein yield and 305-DMY of 0.04 and about 675 kg in the Holstein breed, respectively. The GHR gene should be considered as a potential candidate gene in marker-assisted selection programs to improve the performance of milk and related traits in Turkey dairy cattle populations.