The yield of adipose tissue and by-products in the course of the slaughter of inbred and outbred bulls of the Ukrainian beef breed

Abstract

The research focuses on analysing and generalising the distribution of internal adipose tissue and organs that are not part of the carcasses of inbred and outbred bulls of the Ukrainian beef breed. Animal stock inbreeding was determined based on five breeding records according to Wright’s method modified by Kyslovskyi. Two experimental groups of 5 bulls were formed. The average inbreeding coefficient for inbred bulls was 3.43%. Animals were bred up to 18 months of age. Following slaughter, the mass and the yield of the head, liver, lungs, heart, kidneys, and brain were determined, and 4 types of fat were separated and weighed: perirenal, from the stomach, intestines, and pericardial. Inbred animals are more prone to the accretion of internal adipose tissue. Inbred bulls have 1.8 points more of it. Fat is more intensely accumulated around inbred bulls' multichambered stomachs and kidneys. Intensive fat accumulation was observed around the hearts and intestines of outbred bulls. Adipose tissue around the heart and intestines is more variable in inbred and outbred animals – from the forestomach and kidneys. The weight of inbred bulls’ liver is less by 22.4%, kidneys – by 62.5%, heart – by 11.1%, and head – by 23.8% compared to outbred ones. The weight of their lungs is more by 10.5%. At the same time, inbred bulls tend to have brain weight gain of 12.5% and testicles – by 8.3%. Thus, inbreeding application in Ukrainian beef breeds with a small population size affects the growth of internal organs and the intensity of accumulation and distribution of interior fat. Due to more intensive accumulation of internal adipose tissue, inbred bulls have increased expenditure of forage energy for its formation. They are characterized by an increased yield of low-value raw fat, making them less efficient than outbred bulls for beef production.