Article

Intramuscular fat formation in fetuses and the effect of increased protein intake during pregnancy in Hanwoo cattle

Jun Sang Ahn1, Gi Hwal Son2, Eung Gi Kwon2, Ki Yong Chung3, Sun Sik Jang1, Ui Hyung Kim1, Jae Yong Song4, Hyun Jeong Lee1, Byung Ki Park2,*
Author Information & Copyright
1Hanwoo Research Institute, National Institute of Animal Science, RDA, Pyeongchang 25340, Korea.
2Department of Animal Science, Kangwon National University, Chunchoen 24341, Korea.
3Department of Beef Science, Korea National College of Agriculture and Fisheries, Jeonju 54874, Korea.
4Nonghyup Feed Co., LTD, Seoul 05398, Korea.
*Corresponding Author: Byung Ki Park, Department of Animal Science, Kangwon National University, Chunchoen 24341, Korea, Republic of. E-mail: animalpark@kangwon.ac.kr.

© Copyright 2023 Korean Society of Animal Science and Technology. This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Understanding adipocyte development in fetus during bovine pregnancy is important for strengthening fattening technology. Additionally, nutritional level of dams during pregnancy has the potential to improve offspring growth and fat development. The purpose of this study is to evaluate the intramuscular adipocyte development and expression level of related genes in bovine fetus, and the effect of increased crude protein (CP) intake during pregnancy on the growth performance and carcass characteristics of male offspring. Eighty six pregnant Hanwoo cows (average body weight, 551.5 ± 51.3 kg, age 5.29 ± 0.61 y) were used. Fetuses were collected at 90, 180 and 270 d of gestation from 18 pregnant Hanwoo cows. The remaining 68 pregnant cows were randomly assigned to 2 feeding groups. The control (CON) group was provided the standard protein diet (n = 34), and treatment (TRT) group was provided a diet with a 5% increase in CP intake (n = 34). Male offspring were divided into two groups according to protein treatment of the pregnant cows: CON male offspring (CON-O) and TRT male offspring (TRT-O). Intramuscular adipocytes were found in the fetal skeletal muscle after 180 days of gestation. Male calf’s birth weight increased in the TRT group compared to that in the CON group (<italic>p </italic>&lt; 0.002). The final body weight (<italic>p</italic> &lt; 0.003) and average daily gain (<italic>p </italic>&lt; 0.019) of male offspring were significantly higher in TRT-O than in CON-O. The feed conversion ratio was also improved by 10.5% in TRT-O compared to that in CON-O (<italic>p </italic>&lt; 0.026). Carcass weight was significantly higher in the TRT-O group than that in the CON-O group (<italic>p </italic>&lt; 0.003), and back fat was thicker in the TRT-O group (<italic>p</italic> = 0.07). The gross receipts and net income were higher in TRT-O than in CON-O (<italic>p</italic> &lt; 0.04). Thus, fetal intramuscular fat can be formed from the mid-gestation period, and increased CP intake during pregnancy can increase net income by improving the growth and carcass weight of male offspring rather than intramuscular fat.

Keywords: Fetal; Intramuscular adipocyte; Hanwoo; crude protein intake; Net income