Comparison of pre- and postpartum serum leptin, ghrelin, and lipid levels in sheep

Abstract

IntroductionAwassi sheep are primarily found in southeastern Turkey as well as the Middle East. Awassi sheep are a breed of dairy sheep bred for multiple lambing and high milk yield in Turkey (1). Pregnancy is the most important metabolic burden in ewes, which have multiple offspring (2,3). In this period, energy and protein intake usually do not cover the energy and protein requirements in many sheep herds (3,4).Leptin, a product of the ob gene, is a protein mainly secreted by white adipose tissue (5). This hormone is responsible for the long-term regulation of energy balance and depressing appetite (6). Leptin plays an important role in energy metabolism during pregnancy and lactation (7,8). Many studies showed that plasma leptin level increased during pregnancy and declined during the transition to lactation (9-12). Carcangiu et al. (13) reported that body condition scores were positively correlated with serum leptin concentration but were negatively correlated with milk yield after delivery in ewes with production levels. Additionally, leptin was negatively correlated with growth hormone (GH) and nonesterified fatty acid (NEFA) in the lactation periods (13).Otherwise, ghrelin mainly arises from the abomasum in ruminants. Ghrelin induces GH release and stimulates appetite in the brain (14-16). Ghrelin concentration increases prior to meals, but it is suppressed after feeding. Ghrelin also decreases fat oxidation and increases insulin concentration (17)(18)(19).The objective of the present study was to evaluate fluctuations and possible interactions of the leptin, ghrelin, and lipid profile of ewes in the pre-and postparturient periods and control sheep. Materials and methods Animals and nutritionThe present study was carried out in the town of Nilüfer in Bursa Province, Turkey. Pregnant Awassi ewes (last week before lambing) that were (n = 15) or were not pregnant (control group) (n = 15), weighing 68.4 ± 10.4 kg (53.4-80.6 kg), and aged 2 years were used in the study. All ewes were selected from among those that were to have twin lambs. During this study period, all sheep were fed a controlled diet and water was provided ad libitum. All animals were housed under the same conditions. The herd consisted of a Abstract: Serum leptin and ghrelin play important roles in energy metabolism and inducing appetite during pregnancy and lactation. We investigated the serum levels of leptin and ghrelin and their relationship with the duration of lactation and serum biochemical responses during the prepartum (last week before lambing) and postpartum periods in sheep. They were also evaluated between pregnant and nonpregnant (control ewes) ewes. For these purposes, pregnant (n = 15) and control Awassi ewes (n = 15) that were 2 years of age were used in this study. Blood samples were collected 1 week before the expected date of lambing (baseline) and for 12 weeks after parturitions. Serum leptin, ghrelin, cholesterol, triglyceride, VLDL, LDL, HDL, NEFA, and phospholipid levels were assayed. Leptin and ghrelin levels of the pr...

Lamb weight gain and reproductive performance of post-partum ewes supplemented with palm kernel cake and sexual stimulated by a ram

“…Similarly, a higher incidence of degenerated embryos was observed in postpartum cows suffering greater weight loss compared to those with less severe weight loss (Carvalho et al, 2014). Postpartum weight loss indicates the presence of a negative energy balance in the animal, mainly because nutrients from feed intake are redirected to sustain milk production after parturition, which causes a hormonal imbalance in the animal, such as the observed reduction of leptin blood concentrations in sheep and cattle (Temizel et al, 2018;Młynek, Strączek, & Głowińska, 2022).…”