N-carbamylglutamate (NCG), a structural analog of N-acetylglutamate, improves nitrogen utilization in dairy cows. However, the effects of NCG on bulls are unknown. The purpose of the current research was to investigate the effects of adding different amounts of NCG on growth performance, nutrient digestibility, nitrogen metabolism and plasma metabolites of fattening Holstein bulls. Twenty-four Holstein bulls with similar body weights (BW, 408 ± 21.9 kg) and ages (450 ± 6.1 d; all mean ± SD) were selected for the feeding trial. After 2 weeks of adaptation, bulls were blocked by BW and age and subsequently randomly assigned to 1 of 4 groups: (1) CON group (control diet), (2) L group (supplementation with 20 mg/kg BW NCG), (3) M group (supplementation with 40 mg/kg BW NCG), or (4) H group (supplementation with 80 mg/kg BW NCG). The addition of NCG linearly and quadratically increased the average daily gain (CON vs. L vs. M vs. H = 1.03 vs. 1.19 vs. 1.40 vs. 1.26 kg/d) (p < 0.05), feed conversion ratio (CON vs. L vs. M vs. H = 11.92 vs. 9.22 vs. 7.76 vs. 8.62) (p < 0.05), crude protein digestibility (CON vs. L vs. M vs. H = 64.3 vs. 63.8 vs. 67.7 vs. 65.8%) (0.05 < p < 0.10), N retention (p < 0.05) and N utilization (p < 0.05) of bulls, whereas the contents of fecal N (0.05 < p < 0.10) and urinary N (0.05 < p < 0.10) in NCG-fed bulls linearly decreased compared with those in CON bulls. Bulls fed NCG showed a quadratic increased plasma nitric oxide (p < 0.05) concentration. Furthermore, Arg (p < 0.05), Ile (p < 0.05), Val (p < 0.05), Ala (p < 0.05), Glu (p < 0.05), Ser (p < 0.05), total essential amino acid (p < 0.05) and total nonessential amino acid (p < 0.05) concentrations linearly and quadratically increased with increasing doses of NCG. In contrast, plasma urea (p < 0.05) and ammonia (p < 0.05) concentration linearly and quadratically decreased with increasing doses of NCG. Overall, the addition of NCG increased plasma Arg, Ile, Val, TEAA and TNEAA concentration, which in turn resulted in a higher N utilization and, therefore, higher average daily gain in NCG-fed bulls, providing baseline data for the widespread application of NCG in beef cattle production.
The main obstacles existing in the biodegradation of primary sludge are particle de-amalgamation and the degradation-resisting structure of large-size particulate. Microwave irradiation solubilizes primary sludge by interaction of the electromagnetic field with polar particles in the sludge, which leads to a temperature increase in the irradiated sample. The influence of microwave irradiation on the characteristics and biochemical methane potential of microwave-pretreated primary sludge was studied in terms of microwave intensity (40 and 80% of total microwave power), sludge solid concentration (1 to 4% total solids, w/v) and pretreatment temperature achieved (35 to 90 degrees C). Microwave irradiation was found to increase the concentration of soluble chemical oxygen demand in the sludge. The ratio of soluble to total chemical oxygen demand increased from 2.5 to between 6 and 7% for primary sludge with 4% total solids concentration at a pretreatment temperature of 90 degrees C. In biochemical methane potential tests, biogas production rate increased with both pretreatment temperature and sludge total solids concentrations. For primary sludge with 4% total solids concentration pretreated to 90 degrees C, biogas production rate increased by 37% or resulted in a 28% reduction in required digestion time to achieve 85% of the ultimate biogas production. A first-order reaction model showed a constant increase in the biogas production rate coefficient with the increase in microwave pretreatment temperature. Microwave intensity in the range of pretreatment temperatures studied (35 to 90 degrees C) presented no obvious impact on primary sludge solubilization or anaerobic digestion in terms of ultimate biodegradation efficiency.
Biomass and quality index of Chinese cabbage were investigated under the following treatment, control (CK), 25% biogas slurry + 75% fertilizer (Z-25%), 50% biogas slurry + 50% fertilizer (Z-50%), 75% biogas slurry + 25% fertilizer (Z-75%), and 100% biogas slurry (Z-100%). The results indicated that Z-25% significantly increased shoot height and fresh weight. But shoot height and fresh weight significantly decreased in a time-dependent manner when the concentration of the biogas slurry was greater than 50%. Vitamin C, soluble sugar, protein, and nitrite were measured to evaluate the effect of biogas slurry on the quality of Chinese cabbage. Z-25% treatment could remarkably increased the content of dehydroascorbate (DHA) and total Vc, whereas did not significantly affect reduced ascorbate (AsA) content compared to the CK for 60 d. The content soluble sugar and protein were significantly enhanced under Z-25% treatment. In addition, Z-25% effectively reduced nitrite content in Chinese cabbage. Biogas slurry with concentration more than 50% could not promote quality index of Chinese cabbage. To sum up, biogas slurry of water hyacinth could improve the growth and quality of Chinese cabbage under the optimal applied concentration.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.