Journal Article

Dietary l-arginine supplementation improves semen quality and libido of boars under high ambient temperature

Chen, J. Q., Li, Y. S., Lu, H. X., Li, C. M., Li, Z. J., Zhu, P. Q.

2018

Overview

l-Arginine is a nutritionally essential amino acid for spermatogenesis and plays versatile roles in animal health and can be utilized as a potential agent to improve reproductive performance of boars under high ambient temperature. The present study aimed to determine whether dietary l-arginine could alleviate heat stress-induced infertility in boars. In all, 20 boars (PIC 1040; 248.59±3.84 kg BW and 407.65±6.40 days of age) were selected and randomly assigned to four groups (group 0.0%, basal diet; group 0.6%, 0.8% or 1.0%, basal diet added with 0.6%, 0.8% or 1.0% l-arginine (wt:wt), respectively.) The four diets were made isonitrogenous by addition of appropriate amounts of l-alanine. Boars were pre-fed the corresponding experimental diet for 42 days. Then, the semen characteristics and libido were accessed for 6 weeks during the hot summer period (25.5° to 33.0°C). Results show that dietary l-arginine remarkably improved sperm motility, normality, total sperm number and effective total sperm number. Also, dietary l-arginine improved semen antioxidant capacity, such as decrease of malondialdehyde and 8-Hydroxy-2'-deoxyguanosine content in sperm (P<0.05), increase of the ratio of glutathione and oxidized glutathione, total antioxidant capacity, glutathione peroxidase and catalase activities in seminal plasma (P<0.05). Most of mitochondria contained intact ultrastructure in l-arginine-supplemented group which also accompany with higher ATP content than the 0.0% group. The boars fed 0.8% l-arginine show increased levels of estradiol-17β and testosterone and exhibit improved libido performance than boars in the 0.0% group. Adding dietary l-arginine linearly increased (P=0.002) nitric oxide content (as l-arginine increased). The scrotal surface temperature in the 0.6%, 0.8% and 1.0% group were decreased by 0.9°C, 0.9°C and 0.4°C, respectively, compared with the 0.0% group. l-Arginine levels caused linear effect on semen quality and antioxidant capacity, also caused quadratic effect on libido performance. During the hot summer months, the predicted optimal l-arginine levels for best semen quality and antioxidant capacity was 0.8% to 1.0% and for best libido performance was 0.8%. It can be concluded that l-arginine can be used as an effective agent to alleviate heat stress-induced infertility of boar, and that 0.8% to 1.0% can be considered as the optimum dosage.

• Publisher: Cambridge University Press,Elsevier Limited,Elsevier
• Subject: 17β-Estradiol / adenosine triphosphate / Alanine / Ambient temperature / Amino acids / Animal Feed / Animal health / Animals / antioxidant activity / Antioxidants / Arginine / Arginine - pharmacology / boar / boars / Catalase / Deoxyguanosine / Diet / Dietary supplements / enzyme activity / essential amino acids / experimental diets / Experiments / Glutathione / Glutathione peroxidase / Heat / Heat stress / Heat tolerance / High temperature / Hogs / Infertility / L-Alanine / l-arginine / Libido / Male / Malondialdehyde / Mitochondria / Motility / Nitric oxide / Normality / Optimization / oxidation / Peroxidase / Physiology / Physiology and functional biology / Quality / R&D / Reproduction / reproductive performance / Research & development / Research Article / Semen / Semen Analysis / semen quality / seminal plasma / Sex hormones / Soybeans / Sperm / Sperm Motility / Spermatogenesis / Spermatozoa / summer / Surface temperature / Swine - physiology / Temperature / Temperature effects / Testosterone / Ultrastructure