Online First Article Effect of 25(OH)D 3 Supplementation in Sows’ Diets on Heart Development in Neonatal Piglets Qingyue Han 1 , Ying Li 1 , Jichang Deng 1 , Kunxuan Huang 1 , Yanyang Yang 1 , Quanwei Li 1 , Zhuowei Zhang 1 , Na Qiao 1 , Yanju Ji 2 , Khalid Mehmood 3 , Sarfaraz Ali Fazlani 4 , Hui Zhang 1 and Zhaoxin Tang 1 * 1 College of Veterinary Medicine, South China Agricultural University, Guangzhou 510642, China. 2 Huizhou Engineering Vocational College, Huizhou, China. 3 Faculty of Veterinary and Animal Sciences, Islamia University of Bahawalpur, Bahawalpur 4 Lasbela University of Agriculture Water and Marine Sciences, Uthal, Balochistan Article Information Received 28 May 2020 Revised 30 July 2020 Accepted 10 November 2020 Available online 20 May 2022 (early access) Authors’ Contribution QH, YL, HZ and ZT conceived and designed the experiments. JD, KH, YY and QL performed the experiments. MK, ZZ, NQ, YJ and SAF contributed reagents, materials, and analysis tools. HZ and QH wrote the manuscript. Key words 25(OH)D 3 , Ca 2+ , IGF pathway, Myocardial cells, Piglets The 25-hydroxyvitamin D [25(OH)D] level in serum is currently considered the best indicator of vitamin D supply to the body from cutaneous synthesis and nutritional intake. Few reports are available regarding the effects of vitamin D and its metabolites on heart development in swine. The effect of 25(OH)D 3 and Ca 2+ supplementation in diets on heart development in neonatal piglets during pregnancy were examined in this study. Total 40 sows of 7 gestational age with good health and nutritional condition were divided into four groups (n=10): the control group, low calcium, 25(OH)D 3 group and low calcium with 25(OH) D 3 group. Each groups consist of 5 piglets, randomly selected and euthanized within 2 h after birth. After euthanasia, heart was collected for histopathological examination and IGF, IGF1, IGF2, IGFBP3, PCNA and ki67 expression were analyzed. The results showed that low calcium supplementation decreased the cardiac index and development of myocardial muscle fber, while vitamins D 3 can improve the decrease of cardiac index and development of myocardial fber due to low calcium supplementation. The expression profle of IGF1, IGF2, IGFBP3, PCNA and ki67 genes were down regulated in LCa group as compared to control group; while the vitamin D 3 supplementation signifcantly up regulated the above genes expression. In conclusion, our fndings suggested that 25(OH)D 3 and Ca 2+ supplementation in sows’ diets has an important role in the development of heart and differentiation of myocardial fbers in neonatal piglets by changing the expression of the IGF pathway and myocardial cells proliferation. C alcium is a major component of mineral in pigs, which makes up the bones and teeth and plays vital role in maintaining the normal functioning of nerves and muscle tissue (Gonzalo et al., 2018; Berchtold et al., 2000). The demand of calcium in pigs is necessary, and there is a harmonious relationship between calcium and phosphorus. Inadequate or inappropriate levels of calcium directly affect the normal growth, development and production of pigs (Gonzalo et al., 2018; Berchtold et al., 2000). Calcium defciency in sows lead to birth paralysis, including prenatal and postnatal paralysis, characterized by muscle relaxation in the limbs, and low blood calcium during the prenatal and postnatal period (Tan et al., 2016). The low blood calcium in * Corresponding author: tangzx@scau.edu.cn 0030-9923/2022/0001-0001 $ 9.00/0 Copyright 2022 by the authors. Licensee Zoological Society of Pakistan. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/). sows related to the various factors; a large amount of blood calcium enters colostrum before and after birth, resulting in a sharp decline in blood calcium; Stress of birth and decrease of intestinal absorption of calcium; lack of feed calcium phosphorus proportion, vitamin D defciency, low magnesium diet may accelerate the occurrence of low blood calcium level (Braun, 1986; Tan et al., 2016; Yao et al., 2019). Vitamin D 3 improve the absorption of calcium and phosphorus, saturate the plasma calcium and plasma phosphorus levels, promote growth and bone calcifcation (Yao et al., 2019; Braun, 1986). Vitamin D 3 is an essential nutrient for animals and has an important role in promoting the absorption of calcium and phosphorus from intestine (Braun, 1986; Yao et al., 2019). Moreover, 25(OH)D3 is more effciently absorbed and has higher biological activity than vitamin D 3 (Amundson et al., 2017; Zhang et al., 2018, 2019). Previous study has shown that the circulating 25(OH)D 3 is the major indicator of vitamin D status in blood, and the concentration of 25(OH)D 3 in cord blood is about 80% of that in maternal blood at birth (Zhang et al., 2019). However, only a small amount of 25(OH)D 3 from maternal blood could be supplied to piglets through breast ABSTRACT Pakistan J. Zool., pp 1-4, 2022. DOI: https://dx.doi.org/10.17582/journal.pjz/20200528020558 Short Communication