Effects of arginase inhibition via jugular infusion of Nω-hydroxy-nor-l-arginine on metabolic and immune indices in lactating dairy cows

Abstract

Transformation of Arg to nitric oxide and ornithine (Arg-Orn) constitutes the main route of Arg metabolism in mammals. The primary objective of this work was to determine the effects of inhibiting the Arg-Orn pathway via N ω-hydroxy-nor-l-arginine (nor-NOHA) on health of lactating cows. Furthermore, we also explored the effect of Arg-Orn inhibition on the efficiency of nitrogen utilization to find support for previous research that showed the inhibition of Arg-Orn inhibited milk protein synthesis. Six healthy Chinese Holstein cows of similar body weight (550.0 ± 20 kg), parity (4.0 ± 0), body condition score (3.0 ± 0), milk yield (21.0 ± 1.0 kg), and days in milk (80 ± 2 d) were selected and randomly assigned to 3 treatments in a replicated 3 × 3 Latin square design with 22 d for each period (7 d for infusion and 15 d for washout). The treatments were (1) saline infusion (control); (2) infusion of 125 mg/L of nor-NOHA; and (3) infusion of 125 mg/L of nor-NOHA with 9.42 g/L of Arg. Dry matter intake, apparent digestibility of nutrients, urinary N, N in milk, and blood indices of metabolism and immune function were determined. Compared with the control, the infusion of nor-NOHA had no effect on the concentrations of cholesterol, high-density lipoproteins, IgA, IL-1β, tumor necrosis factor-α, and alanine transaminase. In addition, the dry matter intake, apparent digestibility of N, and the concentration of milk protein N in the Nor-NOHA did not differ from the control; however, the infusion of nor-NOHA and Arg resulted in greater concentrations of high-density lipoprotein, IgA, IL-1β, and tumor necrosis factor-α, and lower concentrations of cholesterol in serum compared with the control. Moreover, the addition of Arg to cows infused with nor-NOHA increased the concentration of nitrate (the indicator of nitric oxide) in serum and was associated with greater milk protein N production due to greater milk yield compared with those infused with nor-NOHA. Overall, the results indicated important roles of Arg in immunity and mammary N utilization, whereas a minor role of the Arg-Orn pathway in these physiologic processes was found.

Effects of prepartum zinc-methionine supplementation on feed digestibility, rumen fermentation patterns, immunity status, and passive transfer of immunity in dairy cows

“…Colostrum composition, including lactose, fat, protein, total solids, and nonfat solids, was determined using a MilkoScan FT 120 (Foss Electric, Hillerød, Denmark). Commercial ELISA kits [MBS702497 (detection range: 1.56-100 μg/mL), MBS282896 (detection range: 0.16-10.00 μg/mL), and MBS285353 (detection range: 31.25-2,000 μg/mL), respectively; MyBioSource Inc., San Diego, CA] were used to determine IgA, IgM, and IgG concentrations of colostrum and calf serum IgA, IgM, and IgG, respectively, as described by Ding et al (2019). The interassay coefficients of variation were lower than 10%, and the intraassay coefficients of variation were lower than 12%.…”

Immunobiological aspects of cow lactation

“…The organism of animal is a complex biological selfreplicating self-regulatory system that has adapted during evolution to exist in relatively unstable environmental conditions. In the course of long phylogeny in mammals, clear mechanisms of interaction between microorganisms and the organism of animals and humans were formed, and the immune protection system was evolved, and immunity was formed (Ceniti et al, 2017;Ding et al, 2019). In the modern sense of immunity means the ability of the body to protect itself from genetically extraneous (as well as other pathogenic factors), aimed at maintaining biological homeostasis (Kurjogi & Kaliwal, 2014;Günther et al, 2017;.…”

Supplementation with N-carbamoylglutamate during the transition period improves the function of neutrophils and reduces inflammation and oxidative stress in dairy cows

“…Therefore, nutritional strategies are effective ways to improve the functions of PMN. Arginine is another essential and functional AA for dairy cows (NRC, 2001) and plays an important role in immune function (Wu and Meininger, 2002;Ding et al, 2019). Savoini et al (1984) found that defensins in bovine PMN are rich in cysteine and Arg (38-42 residues) and display bactericidal activity against many gram-positive, gram-negative, and anaerobic bacteria as well as fungi and viruses.…”