Effect of leptin C528T and leptin C73T polymorphisms and pregnancy on adipose tissue formation and carcass grade in Aberdeen Angus heifers and first-calf cows

Abstract

Background and Aim: The leptin (LEP) gene plays a role in the regulation of the activity required to obtain food, energy metabolism, and fat deposition and affects the body composition of animals. Lipogenesis is an ineffective process. A lot of energy from feed is expended on the synthesis of adipose tissue. This study aimed to determine the effect of LEP C528T and LEP C73T polymorphisms and pregnancy on adipose tissue formation and carcass grade in Aberdeen Angus heifers and first-calf cows. Materials and Methods: Heifers (n = 49) and first-calf cows (n = 30) were grouped according to their genotype for LEP C528T and LEP C73T polymorphisms at the age of 24 months. DNA samples were isolated from whole blood. Experimental animals were slaughtered at the age of 24 months, and a chemical analysis of samples of longissimus dorsi muscle and ground beef was performed. Results: The maximum internal fat weight, back-fat thickness, and fat content of the longissimus dorsi muscle and ground beef were determined in heifers heterozygous for both LEP C528T and LEP C73T polymorphisms. The ranking of genotypes in terms of adipose tissue formation did not change in first-calf cows compared to heifers carrying the same LEP gene variants. Pregnancy had a more significant (p < 0.05–0.001) effect on slaughter parameters and lipogenesis in animals of different genotypes than studied polymorphisms. Heterozygosity of the LEP gene was much more strongly expressed in the carcass grade of heifers. "Prime" grades were assigned to 66.7% of carcasses heterozygous for LEP C528T and "Top Choice" to 58.8% of carcasses with LEP C73T nucleotide substitutions. Conclusion: LEP C528T and LEP C73T polymorphisms were shown to affect the extent of fat formation in Aberdeen Angus heifers and first-calf cows. Animals with heterozygous genotypes exhibited the maximum development of internal fat, back-fat, and intramuscular fat. Pregnancy had a more significant effect on slaughter parameters and adipose tissue formation than studied polymorphisms. First-calf cows had a significantly lower fat content in carcasses than heifers. These results can aid in the production of efficient mature herds of Aberdeen Angus cattle.

Características De La Canal en Ganado Simmental Y Simbrah en México

“…Los productores de ganado pueden utilizar el ultrasonido como un método rápido, económico y no invasivo para obtener mediciones de los atributos de las canales de animales vivos (Schmidt et al, 2020). Para esto se deben realizar mediciones del área del músculo Longisssimus dorsi, que se relaciona con el rendimiento de la canal y la proporción de carne de cortes de mejor calidad (Magnabosco et al, 2006;Choi et al, 2015;Ladeira et al, 2021); grasa dorsal, importante porque actúa como aislante térmico durante el proceso de enfriamiento de la canal, disminuyendo la pérdida de calidad de la carne (Guedes, 2005;Dzhulamanov et al, 2022); grado de rendimiento de la canal que, entre otras características, permite estimar la cantidad de los cortes de carne de la canal; y grado de marmoleo, que es una puntuación asignada a la cantidad de grasa intramuscular y permite a los productores una bonificación económica en el mercado internacional al dotar a sus canales con valor agregado al sacrificio (BIF, 2021;Londoño et al, 2022).…”

Effect of TG5 and LEP polymorphisms on the productivity, chemical composition, and fatty acid profile of meat from Simmental bulls

“…Nevertheless, the fat content and FA composition of beef remain important characteristics for both producers and consumers [ 9 ]. Many researchers have identified polymorphisms in the leptin ( LEP ) and thyroglobulin ( TG5 ) genes as significant genetic factors that influence the intensity and characteristics of fat metabolism in the body [ 10 , 11 ]. Thus, the C422T polymorphism occurs in the 5’-promoter region of the TG5 gene [ 12 ].…”