1Jiangsu Province Key Laboratory of Gastrointestinal Nutrition and Animal Health,College of Animal Science and Technology,Nanjing Agricultural University,Nanjing 210095,P.R. China.
2Jiangsu Lihua Animal Husbandry Stock Co., Ltd,Changzhou 213100,P.R. China.
Animal. 2018 Aug;12(8):1611-1620. doi: 10.1017/S1751731117003147. Epub 2017 Dec 4.
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.
精氨酸是精子发生所必需的营养氨基酸，在动物健康中具有多种作用，可作为提高高温环境下公猪繁殖性能的潜在手段。本研究旨在确定日粮精氨酸是否可以缓解公猪热应激引起的不育。共选择 20 头公猪（ PIC 1040；体重 248.59±3.84kg，年龄 407.65±6.40 天），并将其随机分配到四个组（组 0.0%，基础日粮；组 0.6%、0.8%或 1.0%，分别在基础日粮中添加 0.6%、0.8%或 1.0%精氨酸（wt：wt）。通过添加适量的 l-丙氨酸使四种日粮达到等氮水平。公猪在预饲期内预饲相应的实验日粮 42 天。然后，在炎热的夏季（25.5°至 33.0°C）期间，评估精液特性和性欲 6 周。结果表明，日粮精氨酸可显著提高精子活力、正常性、总精子数和有效总精子数。此外，日粮精氨酸可改善精液抗氧化能力，如精子中丙二醛和 8-羟基-2'-脱氧鸟苷含量的降低（P<0.05）、谷胱甘肽和氧化型谷胱甘肽、总抗氧化能力、谷胱甘肽过氧化物酶和过氧化氢酶活性的增加在精液中（P<0.05）。补充精氨酸组的大多数线粒体都含有完整的超微结构，并且与 0.0%组相比，ATP 含量也更高。添加精氨酸 0.8%的公猪表现出更高水平的雌二醇-17β和睾酮，并表现出比 0.0%组更高的性欲表现。添加日粮精氨酸可线性增加（P=0.002）一氧化氮含量（随着精氨酸的增加）。与 0.0%组相比，0.6%、0.8%和 1.0%组的阴囊表面温度分别降低了 0.9°C、0.9°C 和 0.4°C。精氨酸水平对公猪精液质量和抗氧化能力有线性影响，对性欲性能有二次影响。在炎热的夏季，最佳精液质量和抗氧化能力的最佳精氨酸水平预测为 0.8%至 1.0%，最佳性欲表现为 0.8%。可以得出结论，精氨酸可用作缓解公猪热应激引起的不育的有效手段，0.8%至 1.0%可视为最佳剂量。
