Effect of Late Gestational Betaine Supplementation on Intermediate Metabolites, Homocysteine and Lipid Peroxidation in Pregnant Ewes and Their Offspring

Abstract

Betaine (trimethylglycine) is a methyl group donor involved in important physiological processes including homocysteine synthesis, alleviating the oxidative stress, and reducing the lipid peroxidation. In the present study, the effect of dietary betaine supplementation on blood concentrations of beta-hydroxybutyrate (BHB), homocysteine, glutathione peroxidase (GPx), catalase (CAT), and malondialdehyde (MDA) and serum concentrations of glucose, urea, total protein in pregnant ewes were evaluated. Furthermore, the influence of prepartum supplementation of ewes with betaine on serum concentrations of glucose, urea, and insulin in their lambs was investigated. During the last month of gestation, 20 multiparous pregnant Sanjabi ewes were fed either a basal diet (control: 71.2±3.6 kg BW) or a basal diet supplemented with 5 g betaine hydrochloride per day per head (betaine: 71.6±3.8 kg BW). Blood samples were taken from ewes at parturition, and from lambs at birth, 14 and 28 days of age. Betaine supplemented ewes had lower BHB (0.55±0.18 <em>vs.</em> 1.88±0.37 mmol/L) and MDA (8.1±0.51 <em>vs</em>. 9.1±0.61 µmol/L) than the control ewes, while blood concentrations of homocysteine, antioxidant enzymes, glucose, urea, and total protein remained unchanged. Lambs of betaine ewes tended to be heavier at birth compared to those born from control ewes (4.41±0.18 <em>vs</em>. 3.95±0.18 kg; P=0.06). However, all lambs had similar growth performance until day 60 of age. Late gestational betaine supplementation did not affect circulating glucose, insulin, and urea in lambs. In conclusion, betaine supplementation reduced circulating BHB most likely via suppressing lipid oxidation in pregnant ewes leading to greater birth weight of lambs.