Effects of restricted nutrition and flushing on reproductive performance and metabolic profiles in sheep

• Published in: Livestock science 2022-04, Vol.258, p.104870, Article 104870
• Main Authors: Yıldırır, Mesut, Çakır, Dilek Ülker, Yurtman, İsmail Yaman
• Format: Article
• Language: English
• Subjects: Flushing; Lambing performance; Metabolic profile; Ovulation rate; Restricted nutrition; Sheep
• ISSN: 1871-1413; 1878-0490
• DOI: 10.1016/j.livsci.2022.104870

•Restricted nutrition during lactation may have some negative long-term effects on reproductive performance of the ewes which is not overcome by flushing.•BCS is a more useful tool in judging the nutritional status of ewes compared to LW.•Estrus was significantly earlier after the flushing treatment in restricted group of animals. The aim of this study was to assess the impact of dietary restriction during the lactation period on flushing performance and metabolic profiles in sheep. The treatments were performed in a 2 × 2 factorial arrangement with (i) adequate and restricted feeding treatment during lactation and (ii) flushing and control feeding treatment during mating season. Eighty-four Karacabey Merino ewes were divided into two groups for adequate energy (100%) and restricted (70%) at energy requirements for three months of lactation. Each group was also divided into two sub-groups based on flushing diet (AL-F, RL-F; 150%) or control diet (AL-C, RL-C; 100%) during the mating season. Live weight (LW), body condition score (BCS), serum metabolites and hormone concentrations, ovulation rate, estrus performance and lambing performance of ewes were observed. Data from this study showed that average difference (P < 0.001) of LW and BCS between groups were 5.45 kg and 0.54 respectively at the end of lactation. No significant effects of nutritional treatments (P > 0.05) were observed; the average fecundity, litter size and ovulation rates of ewes were 1.30±0.07, 1.44±0.06 and 1.53±0.07 respectively. The onset of estrus was earlier (P = 0.021) in RL-F ewes (7.0 d) than for AL-F, AL-C and RL-C ewes (11.0, 12.2 and 10.9 d respectively). Mean PRG concentration of ewes was lower (P = 0.011) in RL-C group than ewes in AL-C group (1.859±0.266 and 3.143±0.272 ng/ml respectively) at the ram introduction day. Serum biochemical variables blood urea nitrogen (BUN), glucose (GLUC), triglycerides (TGL) and very low density lipoprotein cholesterol (VLDL-CHOL) concentrations- decreased (P < 0.05), while non-esterified fatty acid (NEFA), cholesterol (CHOL), high density lipoprotein cholesterol (HDL-CHOL) and low density lipoprotein cholesterol (LDL-CHOL) concentrations increased (P < 0.05) in the restricted ewes compared with adequate ewes in the different months. In conclusion, in addition to BCS, blood total protein, BUN, GLUC, NEFA and CHOL can be recommended for testing flock metabolic profiles as specific blood metabolites. Flushing did not cause significant difference