Chromium propionate or calcium salts of palm oil in the diets of ewes in late pregnancy and lactation and the effects on the offspring

ABSTRACT Ruminants in late gestation and lactation have high energy requirements, which can be effectively met with diets that include chromium and protected fat. This study aimed to compare the effects of chromium propionate and rumen-protected fat supplementation in the diet of ewes in late gestation and lactation and to evaluate their impact on the performance, metabolism, carcass, and meat quality of the offspring. The study population consisted of 25 mixed-breed ewes, aged 3 ± 1 years, with a body weight (BW) of 57 ± 10 kg, and a single gestation. All ewes in the study gave birth to males. The experimental design was a randomized block design with three dietary treatments: a control diet (CTL; n = 8) consisting of corn as the primary energy source; a chromium propionate treatment (CRPR; n = 9) consisting of the CTL diet plus 0.5 mg of chromium propionate per kg of dry matter (DM); and a calcium-salts from palm oil treatment (FAT; n = 8) - CTL diet plus calcium salts from palm oil. The ewes were fed the diets for 50 days of gestation and 70 days of lactation. Following weaning, the lambs were confined for of 60 days and subsequently slaughtered. The means were compared using Tukey’s test with a statistical probability of 5 %. The maternal diets of CRPR and FAT resulted in lambs with higher BW at weaning and slaughter, greater chest and leg width, and higher aspartate aminotransferase (AST) and insulin values, as well as lower cholesterol and low-density lipoprotein (LDL) levels. The FAT treatment reduced cooking losses and alterations in lambs’ sarcomere length (SL) and muscle fiber area. It can be concluded that the inclusion of CRPR and FAT in the diet of pregnant and lactating ewes has beneficial effects on the offspring.