Rumen-protected l-carnitine supplementation during mating period altered metabolic status and reproductive performance of ewes.

Abstract

Current study hypothesized that dietary l-carnitine (LC) inclusion during the mating period ameliorates both metabolic status and reproductive performance of ewes. Seventy Baluchi ewes (52 ± 4.2 kg of bodyweight and 18 ± 6 months old of age) were enrolled in this study. Animals were randomly allocated into two dietary treatments, control (only basal diet) or basal diet plus supplementation with a rumen-protected LC (Carneon 20 Rumin-pro; 20% LC; Kaesler Nutrition GmbH) at the rate of 10 g/head/day from 21 days before until 35 days after introducing rams to the ewes (MP). Feed intake was monitored by subtracting the ort from feed offered. Blood sample collection was conducted on Days -10, +10 and +20 relative to MP. Pregnancy was confirmed on Day 30 post-MP. Feed intake of the ewes in the LC group was higher than the control (p < 0.05). LC supplementation increased the cholesterol concentration in the ewes (p < 0.05). Blood urea concentration of animals in the LC group was significantly lower than the control (p < 0.05). The mRNA expression of toll-like receptor 4 was evidently lower in animals supplemented with LC than the control (p < 0.05). Both lambing and fecundity rates in the LC group tended to be higher compared with the control. LC supplementation showed potential to alter certain metabolites in the ewes. A tendency for higher lambing rate may partly be driven by dams efficient energy partitioning to support foetal growth and maintaining pregnancy.