Relationship between systemic leptin concentration and reproductive state in llamas (Lama glama) from southern Chile

Abstract

Reproductive efficiency of domestic camelids belonging to the Peruvian High Andes is affected by high rates of early embryonic mortality. Leptin is a protein hormone synthesized mainly by the adipocyte and its plasma concentration responds to the energy balance and affects implantation and embryo development. The objective of the study was to determine plasma leptin concentrations in pregnant and non-pregnant well-nourished llamas. Eighteen mature, non-lactating llamas from a breeding farm in southern Chile were classified according to their physiological status in: pregnant, in the last third of gestation (n=9) or non-pregnant (n=9). Morphometric measurement, body condition score, and blood samples for the determination of a biochemical profile including total plasma proteins concentration, NEFA, triglycerides, cholesterol, and leptin were obtained from each group. Morphological measurements, body condition score, biochemical profile and plasma leptin concentration did not differ between groups (P>0.1). BCS and the metabolic profile indicated that both groups were in a well-nourished and energy balanced state. Plasma leptin concentration of pregnant llamas showed a strong correlation (r=0.8; P=0.001) with BCS. We concluded that gestation did not affect plasma leptin concentrations in non-lactating, well nourished, energy balanced llamas during the last third of gestation and the BCS have a strong influence on their leptin levels.