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

Jun Sang Ahn; Gi Hwal Son; Eung Gi Kwon; Ki Yong Chung; Sun Sik Jang; Ui Hyung Kim; Jae Yong Song; Hyun Jeong Lee; Byung Ki Park

doi:10.5187/jast.2023.e33

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

J Anim Sci Technol. 2023 Jul;65(4):818-837. doi: 10.5187/jast.2023.e33. Epub 2023 Jul 30.

Authors

Jun Sang Ahn¹, Gi Hwal Son², Eung Gi Kwon², Ki Yong Chung³, Sun Sik Jang¹, Ui Hyung Kim², Jae Yong Song⁴, Hyun Jeong Lee¹, Byung Ki Park²

Affiliations

¹ Hanwoo Research Institute, National Institute of Animal Science, RDA, Pyeongchang 25340, Korea.
² Department of Animal Science, Kangwon National University, Chunchoen 24341, Korea.
³ Department of Beef Science, Korea National College of Agriculture and Fisheries, Jeonju 54874, Korea.
⁴ Nonghyup Feed Co., LTD, Seoul 05398, Korea.

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 (p < 0.002). The final body weight (p < 0.003) and average daily gain (p < 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 (p < 0.026). Carcass weight was significantly higher in the TRT-O group than that in the CON-O group (p < 0.003), and back fat was thicker in the TRT-O group (p = 0.07). The gross receipts and net income were higher in TRT-O than in CON-O (p < 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: Crude protein intake; Fetal; Hanwoo; Intramuscular adipocyte; Net income.