Circadian clocks and energy metabolism interact, and nutrient utilization is affected by the time of feed intake even when the same type of feed and the same number of calories are consumed, in addition, feeding with a high energy diet in the evening increases the risk of obesity more than feeding with a high energy diet before 12:00, and that evening or night feeding increases milk fat synthesis and energy production. If the feeding to animals coordinated with endogenous physiological rhythms, it would optimize mammalian production.

Calcium (Ca) demands are understandably greater in modern sow lines with larger litter sizes and greater milk production capabilities during late pregnancy and lactation. Researchers from the Institute of Subtropical Agriculture (ISA) of the Chinese Academy of Sciences found that the time of Ca to sows during late pregnancy and lactation affected productive performance of sows, compared to conventional feeding regimes.

 A total of 75 pregnant sows were assigned to three groups: The control (C), earlier-later (E-L), and later-earlier (L-E) groups. During late pregnancy, the C group was fed an extra 4.5 g Ca (in the form of CaCO ) at both 06:00 and 15:00, the E-L group was fed an extra 9 g Ca at 06:00, and the L-E group was fed an extra 9 g Ca at 15:00. Similar treatments with double the amount of Ca were applied during lactation. The results show that, compared with the C group, L-E feeding decreased the number of stillbirths and the duration of farrowing and placenta expulsion (FARPLA), and increased the average daily weight gain (ADG) of piglets. Similarly, E-L feeding increased the ADG of piglets (p < 0.05). Furthermore, both E-L and L-E feeding increased the Ca levels in sow serum and umbilical serum, and the Fe levels in umbilical serum, and decreased the Ca levels in the placenta and colostrum (p < 0.05). E-L feeding activated the mRNA expression of TRPV5, S100G, SLC30A7, SLC39A4, and Ferroportin1, while it inhibited the mRNA expression of ATP7A in the placenta (p < 0.05). Moreover, L-E feeding up-regulated the mRNA expression of ATP2B and IREB2, while it down-regulated the mRNA expression of ATP7B in the placenta (p < 0.05). The researchers also found that maternal Ca feeding at 15:00 h during late pregnancy and lactation decreased FARPLA and stillbirths and improved the growth performance of suckling piglets by altering the metabolism of mineral elements in the umbilical serum and milk, compared to conventional feeding regimes. In their previous studies, they also found that crude protein feeding time modulates the lipid profiles in sow milk and plasma; and Ca feeding time in laying hens or sows affected the expression of genes related to the circadian clock and Ca transporters.

The study entitled “The time of Calcium Feeding Affects the Productive Performance of Sows” was published in Animals, details can be found at https://www.mdpi.com/2076-2615/9/6/337. It was supported by the National Key Research and Development Program of China.

Contact: WU Xin

E-mail: wuxin@isa.ac.cn

Institute of Subtropical Agriculture, Chinese Academy of Sciences