Urea Supplementation Research Articles

Effect of Replacing Barley Grain by Urea in the Diet of Iraqi Lambs

This study conducted to seeks the effects of partially changing barley grain (BG) with different levels amount of urea on growth performance, rumen fermentation, nutrient digestion and blood parameters in fattening lambs. Twelve Awassi male lambs were divided according to body weight (BW) into three equal groups (4 lambs per each group) and housed in individual pens and assigned to one of three dietary treatments in a randomized block design: barley grain (BG)were given to animals according to the body weight of lambs (3 % of BW) and (BG) reduced and replace with 0, 10, 20, gm urea. Compared with the control the lambs fed the reduced GB diet plus urea was higher (p < 0.01) concentrations of ruminal ammonia and increased with increasing the urea supplementation. As well as increased the crude protein (CP) intake , blood urea nitrogen (BUN), final BW, dry matter intake (DMI) and average daily gain (ADG) were observed with the increasing urea addition to the diet, results showed that 10 gm of urea could substitute of 10 gm BG per kg feed DM without any negative effect on health performance of fattening lambs when fed urea.

Synergistic Benefits of Dietary Silymarin and Selenium on Growth, Immune Functions, Antioxidants, and Gut/Liver Health of Thinlip Mullet (Liza ramada) Juveniles

Abstract This study investigates the synergistic impact of silymarin (SI) levels combined with inorganic selenium (sodium selenite: Se) on growth, feed utilization, biochemical parameters, antioxidants, innate immunity, intestinal and liver histology, and gene expression of thinlip mullet (Liza ramada) juveniles. The experimental design involved thinlip mullets initially weighing 3.5±0.13 g, distributed in a completely randomized design with 30 fish per hapa (0.5 × 0.5 × 1 m), and conducted in triplicate over 60 days. Seven experimental diets were employed, including a control (without SI and Se supplementation), a negative control (with only Se supplementation), and four treatments with varying levels of silymarin (250, 450, 650, 850 mg/kg) alongside selenium (0.5 mg/kg diet). The growth performance results highlighted significant enhancements in final body weight, weight gain, and specific growth rate, particularly in the SI 850 mg/kg + Se treatment. Survival rates, feed intake, and feed conversion ratios showed positive trends across the SI-Se supplemented groups. Biochemical profiles of serum exhibited that the control diet induced elevated concentrations of glucose, cholesterol, alanine aminotransferase, aspartate aminotransferase, and urea, while Se or SI supplementation significantly mitigated these levels, with the lowest concentrations observed in the SI-Se supplemented groups. Moreover, SI supplementation increased serum protein content. Antioxidant enzyme activities, represented by superoxide dismutase (SOD), catalase (CAT), and catalase (GPx), demonstrated notable improvements in the SI-Se fortified groups, with significantly elevated GPx activity compared to the Se-supplemented and control groups. Immune system responses, including lysozyme, bactericidal, nitro-blue tetrazolium (NBT%), and serum alternative complement pathway (ACH50) activities, were highest in the SI-Se augmented groups. SI and Se in L. ramada reduce liver pro-inflammatory gene expression (IL-1 β, hepcidin) vs. control group. Histological examinations of the intestine and liver depicted structural enhancements, especially at moderate and high levels of SI with Se supplementation. The results indicate improved intestinal villi morphology and hepatic architecture, supporting the positive influence of dietary treatments on the health of thinlip mullet juveniles. In conclusion, the combined supplementation of SI at 850 mg/kg diet and Se at 0.5 mg/kg diet positively influenced the growth, biochemical profiles, antioxidant status, immune responses, gene expression, and histological integrity of thinlip mullet juveniles, providing valuable insights for optimizing aquafeed formulations.

LGG-04. TRAMETINIB COMBINED WITH CHEMOTHERAPY FOR INFANT BRAF-FUSED CHIASMATIC GLIOMA

Abstract BACKGROUND Infant chiasmatic gliomas present a major therapeutic challenge due to large size, threat to vision and progressive nature. Infants <1 year respond poorly to Vincristine/Carboplatinum chemotherapy (SIOP-LGG2). BRAF fusion is common, so MEK inhibitors have been used second line in older children, but time to response is slow (median ~20 months). Data on the use of these drugs in infants is limited as is data on the safety and efficacy of combining chemotherapy with MEK inhibitors. METHODS We report two infants treated successfully for BRAF fused chiasmatic glioma - both presented age 5 months with nystagmus and diencephalic syndrome. Both had significant tumor progression within 6 weeks of starting Vincristine/ Carboplatin which responded rapidly to the addition of Trametinib. RESULTS Case 1 required tumor debulking at week 6 of chemotherapy due to progressive hyponatremia, hydrocephalus and brainstem compression. Surgery caused diabetes insipidus, hemianopia and hemiparesis. Tumor growth continued despite reinstating chemotherapy. Addition of trametinib caused tumor shrinkage by 75% within 12 weeks and 90% by 1 year. Minirin doses were reduced by 80% on Trametinib. After 1.3 years, chemotherapy was stopped & Trametinib continued alone. Case 2 - tumor growth and severe hyponatremia by week 6 of chemotherapy prompted addition of Trametinib without surgery. There was tumor reduction of 50% over 6 months and improvement of severe failure to thrive. Hyponatremia, requiring sodium and urea supplementation, stabilized. Bilateral vision and age-appropriate development are maintained. Hypertension developed early, but resolved completely after stopping and then gradually reintroducing Trametinib. Recurrent diarrhea required dose reduction. CONCLUSIONS We show the safety and efficacy of combined treatment with chemotherapy and MEK inhibition in infants and postulate that both the combination and the young age at initiation of therapy may have contributed to the excellent outcome. We urge for clinical trials of combination therapy in this age group.

Effect of nitrate supplementation on diurnal emission of enteric methane and nitrous oxide

The objective of this study was to investigate the effect of nitrate supplementation on diurnal enteric methane (CH4) and nitrous oxide (N2O) emissions in dairy cows. Four Danish Holstein dairy cows fitted with ruminal cannulas were used in a 2 × 2 crossover design with 2 periods of 14 d duration. Cows were fed ad libitum with 2 experimental diets based on either urea or nitrate (8.6 g NO3−/kgofDM) supplementation. Samples of ruminal fluid, blood, and rumen headspace gas samples were collected. Gas exchange was measured in respiration chambers during a 96-h period. N2O emission was calculated from the ratio between CH4 and N2O in the rumen head space and the measured CH4 emission. Nitrate supplementation resulted in a lower daily CH4 production (g/d), CH4 yield (g/kg of DMI), a lower CH4 per kg of FPCM, a tendency of lower CH4 intensity (g/kg ECM), and higher daily hydrogen (H2) production, H2 yield, and daily N2O production compared with urea supplementation. The only difference in ruminal volatile fatty acid composition was a higher valerate proportion in cows receiving nitrate compared with urea supplementation. In conclusion, nitrate compared with urea supplementation reduced CH4 production, mainly just after feeding, but also increased N2O production.

Effects of dietary urea supplementation on performance of selected insect species.

Feeding costs of farmed insects may be reduced by applying alternative nitrogen sources such as urea that can partly substitute true proteins. The aim of this study was to examine the effects of different nitrogen sources on body weight (BW) and survival rate (SR) of the Jamaican field cricket (JFC, Gryllus assimilis), the house cricket (HC, Acheta domesticus), yellow mealworm larvae (YM, Tenebrio molitor) and superworm larvae (SW, Zophobas morio). Crickets were either housed individually or in groups, and larvae were group-housed. Six isonitrogenous feeds composed of 3.52% nitrogen were designed forall four insect species using four independent replicates with micellar casein: urea proportions of 100-0%, 75-25%, 50-50%, 25-75%, 0-100% and 100% extracted soybean meal. All selected insect species were able to utilise urea. However, urea as the only nitrogen source resulted in low final BW. Inthe HC, the JFC, and the YM on nitrogen basis urea can replace 25% of micellar casein without having any negative effects on BW and SR in comparison to the 100% micellar casein group. In the SW, a 25% urea level did not have a significant effect on final BW, but SR decreased significantly.

Comparative Studies on the Strength and Swell Characteristics of Cohesive Soils Using Lime and Modified Enzyme-Induced Calcite Precipitation Technique

Enzyme-induced calcite precipitation (EICP) emerges as a highly effective and well-established technique within bio-cementation approaches, offering notable advantages over traditional methods. Conversely, lime, known for its accessibility, cost-effectiveness, and efficacy, serves as a valuable material in enhancing the engineering properties of problematic soils. This study explores the application of EICP and lime treatments separately on two distinct soils (low-plastic and high-plastic soil) exhibiting different mineralogical and plasticity characteristics to assess their impact on strength and swell characteristics. Various combinations of treatments, including jack bean (JICP), soya bean (SICP), and bio-enhancer (BICP), were employed for EICP treatment. Bio-enhancer, rich in natural urea and urease enzyme, was particularly remarkable due to its compatibility with urea supplementation. Similarly, jack bean and soya bean exhibited high efficacy in natural urease enzyme content. The study has revealed that the unconfined compression strength (UCS) of red soil increased significantly by six times at the end of 21 days of the curing period with JICP treatment, while lime treatment was more effective for the black soil. Specifically, the UCS of black cotton soil increased by 11 and 17 times when treated with Enzyme-Induced Calcite Precipitation (EICP) and lime, respectively. Moreover, EICP with J2 solution (jack bean solution with 1M urea and 4 g/L non-fat milk powder) reduced swell pressure by 60% and 67.5% in low-plastic and high-plastic soil, respectively. Lime treatment, on the other hand, led to a swell pressure reduction of 47% and 70% in low-plastic and high-plastic soil, respectively. As a result, EICP proved efficient in mitigating swell pressure for red soil, whereas lime treatment performed exceptionally well for black soil, highlighting the soil-specific effectiveness of each method. Furthermore, a life cycle assessment revealed substantial carbon footprint emission savings with EICP treatment strategy. In brief, this paper contributes to understanding the phenomena and significance of these two treatment techniques on distinct mineralogical soils.

Combined effect of LED light color and nitrogen source on growth, pigments composition and oxidative stress in Arthrospira platensis

Artificial lighting with light-emitting diodes (LED) is proposed as a suitable solution to reach stable yearly production of high value molecules from microalgae under unfavorable climates. However, available studies are inconsistent regarding the effect of LED color on cultures performance. This study examined the response of Arthrospira platensis to three different LED lighting conditions (white, red, and red-blue 70:30) when is grown in three media with different nitrogen composition. Growth, phycobiliproteins and lipophilic pigments content were determined. In addition, antioxidant enzymes (GST, lipid peroxidation) and morphology were analyzed to enlighten new perspectives on the health status of microalgae production.The highest biomass production (2.13 g/L) was achieved under red LED when Zarrouk medium was supplemented with urea. Regarding pigment production (phycobilins, chlorophyll a and β- carotene), the most desirable combination was red: blue together with urea supplementation. In addition, this combination showed a high biomass production (2.03 g/L) and low expression of antioxidant enzymatic activity. This research shows a novel combination of LED technology and nutrients to enhance microalgae biomass production and high value metabolites with a lower economic cost.

Urea supplementation improves mRNA in vitro transcription by decreasing both shorter and longer RNA byproducts

ABSTRACT The current letter to the editor describes the presence of RNA byproducts in small-scale in vitro transcription (IVT) reactions as evaluated by capillary gel electrophoresis, asymmetric flow field flow fractionation, immunoblotting, cell-free translation assays, and in IFN reporter cells. We compare standard T7 RNA polymerase (RNAP) based IVT reactions to two recently described protocols employing either urea supplementation or using the VSW3 RNAP. Our results indicate that urea supplementation yields considerably less RNA byproducts and positively affects the overall number of full-length transcripts. In contrast, VSW3 IVT reactions demonstrated a low yield and generated a higher fraction of truncated transcripts. Lastly, both urea mRNA and VSW3 mRNA elicited considerably less IFN responses after transfection in mouse macrophages.

Use of irradiated chitosan as a matrix for slow-release urea and in vitro fermentation characteristics of slow-release urea supplementation in ruminant rations

Background and Aim: Irradiated chitosan can be used as a matrix for slow-release urea (SRU) production. This study aimed to (1) determine the optimal formulation of irradiated chitosan matrix for controlling nitrogen release and (2) evaluate the characteristics of SRU in vitro fermentation based on irradiated chitosan as a feed supplement. Materials and Methods: In the first phase of the investigation, four chitosan-based SRU formulations with varying amounts of acrylamide (3 and 5 g) and gamma irradiation (5 and 10 kGy) were evaluated. Scanning electron microscopy, Fourier transform mid-infrared spectroscopy, and ammonia release characteristics were used to observe morphological, functional group, and ammonia release characteristics. In the second phase of research, the most effective SRU formulation was utilized as a supplement to ruminant rations based on rice straw, sorghum straw, and alfalfa. Gas production, rumen fermentation characteristics, and methane gas production were observed in vitro. Results: On the basis of surface image analysis, the four SRU formulas generate a similar appearance. Compared with untreated urea, the SRU3 formula reduced the percentage of ammonia emission by 12.85%–27.64% after 24 h of incubation (p = 0.05), as determined by the first phase study. SRU3 became the basis for the second testing phase. The addition of SRU3 did not affect the optimal gas production in vitro. SRU3 treatment produced less gas than Optigen® treatment (p = 0.05). With regard to rumen fermentation and digestibility, Optigen® yielded better results than SRU3 (p = 0.05). However, the treatment with SRU3 resulted in reduced methane production compared to that in the control (p = 0.05). Conclusion: Irradiated chitosan as an SRU matrix may control the release of ammonia in the rumen medium. The SRU3 formulation is the most effective. The addition of SRU to rice straw-based rations reduces methane production without affecting in vitro digestibility. Keywords: fermentation characteristics, irradiated chitosan, ruminant, slow-release urea.

Supplementation of crossbred boer goats with cottonseed meal and/or urea enhances estimated metabolizable protein intake, crude protein digestibility and nitrogen retention

This study aimed to determine feed intake, apparent digestibility, and nitrogen retention of crossbred Boer bucks supplemented with urea or cottonseed meal (CSM)when fed tropical Rhodes (Chloris gayana) grass hay (RGH) as a basal diet. Twelve eight-month-old bucks (23.9±1.1 kg live weight) were allocated to one of the four dietary treatments in a randomised block design. The treatments were 1) maize supplement (Control); or maize plus 2) urea supplement (M+U), 3) urea and CSM (M+UCSM); and (4) CSM (M+CSM). All bucks were held in individual metabolism crates for 21 days (11 days of adaptation and 10 days collection period) with ad libitum access to RGH and fresh drinking water in addition to the supplements. A one-way ANOVA and Duncan’s multiple range tests were used to test for differences between means at a significance level of P < 0.05. Results indicated higher feed intake, apparent digestibility of crude protein and digestible nutrient intake in goats supplemented with M+CSM and M+UCSM, but not M+U alone. Supplementation with M+CSM increased nitrogen retention by 300%. Supplementation with M+UCSM and M+CSM increased the total feed intake of Boer goats on tropical grass hay by 13 and 20%, respectively. Supplementation with M+U, M+UCSM, and M+CSM improved the apparent digestibility of crude protein by 9.7, 15.7 and 15.1%, respectively. It can be concluded that total feed intake and nutrient digestibility was increased on growing Boer goats fed RGH as a basal diet supplemented with true protein from CSM or a mixture of true protein and rumen degradable protein from urea.

Evaluation of Nutrient Levels, Optical Sensors and Decision Support Tools for Nitrogen Optimization in Rice during Dry Season

Background: Improving the efficiency of nitrogen utilization in rice is vital for achieving significant crop yields with minimum harm to the environment. To tackle this challenge, various portable optical sensors and decision-support tools have been emerging in recent times. However, there is currently a lack of comprehensive assessment and comparison of these tools with different levels of fertilizer recommendation with and without additional supplementation of nano urea. Methods: The current study was carried out during the dry season of 2021 and 2022 at the P.G. Experimental Farm of Centurion University of Technology and Management. The investigated treatments encompassed the following: T1: Absolute control, T2: 90-45-45 (N-P2O5-K2O kg/ha), T3: 120-60-60 (RDF), T4: 150-75-75, T5: T2+NU @ 2 ml/L at panicle initiation, T6: T3+NU @ 2 ml/L at panicle initiation, T7: N application at LCC d™ 3, T8: N application at LCC d™4, T9: N application at SI less than 90%, T10: Nutrient Expert (TY: 5.5 t/ha), T11: Rice crop manager (TY: 5.5t/ha) which were allocated in randomized block design with three replications. Result: The findings showed that implementing nitrogen (N) application when the sufficiency index (SI) is below 90% led to a significant 16.85% boost to grain yield of rice compared to the application of 120-60-60 at fixed intervals as per the standard recommendation. In the former approach, 150 kg N/ha was applied in four splits. However, N application at a leaf color chart (LCC) value of 4 or less was considered efficient, with maximum agronomic efficiency (18.22 and 19.22 kg grain/kg N applied) and recovery efficiency (43.27% and 50.25%) observed in 2021 and 2022, respectively since, this approach resulted in a comparable yield increase and nitrogen absorption with a reduced nitrogen input.

Growth and economic value of goat rations supplemented with ground corn gelatinization product with urea

The aim of this study was to evaluate the growth of goats and the economic value of rations by using ground corn gelatinization products with urea as slow-release urea in ration supplements. The experiment was conducted on twelve male local goats, aged 1-1.5 years with a body weight of 12.839 ± 0.496kg. The ration was prepared with a 60:40 ratio of forage to concentrate. The basal feed was made of Gamal leaves, while the concentrate consisted of soybean meal, ground corn, rice bran, coconut meal, and ground corn gelatinization product with urea. The experimental method used in this study was a 4x3 completely randomized design (CRD) with four treatments. The treatments applied were T0 (control), T1, T2, and T3. T0 was the basal feed + concentrate without ground corn gelatinization product with urea, while T1, T2, and T3 were the basal feed + concentrate with 1.5%, 2.5%, and 3.75% ground corn gelatinization product with urea, respectively. The data collected were statistically analyzed using analysis of variance and Duncan's multiple range test. The results showed that the treatment had a significant effect (P <0.05) on total dry matter consumption, ration utilization efficiency, and economic value of rations. In conclusion, the study found that the use of ground corn gelatinization products with urea is a viable option for enhancing the quality of goat rations.

Nitrogen Utilization in Goats Consuming Buffelgrass Hay and Molasses-Based Blocks with Incremental Urea Levels.

The use of goats for meat production faces challenges from environmental and nutritional factors. Urea is an affordable non-protein nitrogen source commonly utilized in ruminant nutrition. The objective of this study was to investigate nitrogen utilization in goats fed low-quality hay supplemented with molasses blocks containing urea. Twenty Anglo-Nubian doelings were individually housed in metabolic cages and provided with chopped Buffelgrass (Cenchrus ciliaris) hay ad libitum. Goats were randomly assigned to four urea levels (0, 2, 4, and 6%; n = 5 per treatment) in molasses blocks for a duration of 30 days. A negative nitrogen balance (-2.458 g/day) was observed in doelings consuming blocks without urea, compared with a positive balance (0.895 g/d) for those consuming the 6% urea blocks. Block nitrogen intake significantly increased with urea level, but urea supplementation did not affect dry matter (DM) or neutral detergent fiber (NDFom) intake or digestibility. A minimum crude protein (CP) requirement of 8% for maintenance in doelings consuming low-quality forage with a urea-based supplement was determined through regression analysis between CP intake (% of DM) and N balance (r2 = 0.479; p < 0.002). The value of 8% of CP obtained in this study is similar to several previous studies reported in the literature, but in this case, the increments in CP came exclusively from urea. In this study, increasing the urea content of molasses blocks up to 6% significantly increased nitrogen intake, retention, and balance in goats. These results contribute to a better understanding of nitrogen utilization in goats fed low-quality hay with urea supplementation.

PSVI-3 Effects of Different Concentrate Inclusion Levels in Diets Containing Agri002E Sorghum Silage on Intake and Digestibility in Growing Nellore Bulls

Abstract The sorghum hybrid, AGRI002E, sorghum was developed for high dry matter (DM) production per area. However, there are no reports in the literature evaluating the use of this silage with different inclusion levels of concentration on the ingestive and digestive variables of beef cattle. Therefore, this study aimed to access the effects of different concentrate levels in diets containing AGRI002E sorghum silage (SS) on feed intake, ruminal and apparent total tract digestibilities of organic matter (OM), neutral detergent fiber corrected for contaminant ash and protein (apNDF), and starch. Nellore rumen-cannulated bulls (n = 5; BW = 242 ± 5 kg) were used in a 5×5 Latin square design. The experimental treatments consisted of five concentrate levels (0, 200, 400, 600, and 800 g of concentrate/kg of diet DM) in SS-based diets. The concentrates used in the experimental diets were based on corn, soybean meal, sulfated urea, virginiamycin, and mineral supplement. The diets were formulated to provide approximately 120 g of crude protein per kg dietary DM. In the 0% concentrate diet, the protein level was adjusted with sulfated urea. All diets contained the same amount of virginiamycin and mineral supplement. Each experimental period lasted 24 d, with 17 d adaptation, 4 d of total feces collection, and 3 d collection to obtain omasal flow using a double marker technique (indigestible NDF and Co-EDTA). Data were analyzed using MIXED-SAS. Starch and OM intake linearly increased (P &amp;lt; 0.001) with increasing concentrate inclusion. Intake of apNDF decreased linearly (P = 0.018) and tended to be quadratically influenced (P = 0.022) with increasing concentrate inclusion (Table 1). Ruminal digestibility of OM increased linearly (P &amp;lt; 0.001) with increasing concentrate inclusion. Starch ruminal digestibility decreased linearly (P = 0.003) and tended to be influenced quadratically (P = 0.0015) with increasing concentrate inclusion. Ruminal digestibility of apNDF tended to decrease linearly (P = 0.057) with increasing concentrate inclusion. Total apparent digestibility of OM increased linearly (P &amp;lt; 0.001) and apNDF and starch total apparent digestibility decreased linearly (P ≤ 0.002) with increasing concentrate inclusion. Increasing inclusion of concentrate in AGRI002E sorghum silage-based diets increased OM and starch intake, and ruminal and total apparent OM digestibility and decreased apNDF intake and ruminal and apNDF and starch total apparent digestibility.

Can the post-ruminal urea release impact liver metabolism, and nutritional status of beef cows at late gestation?

We aimed to evaluate the effects of post-ruminal supply of urea (PRU) on nutritional status, and liver metabolism of pregnant beef cows during late gestation. Twenty-four Brahman dams, pregnant from a single sire, and weighing 545 kg ± 23 kg were confined into individual pens at 174 ± 23 d of gestation, and randomly assigned into one of two dietary treatments up to 270 d of gestation: Control (CON, n = 12), consisting of a basal diet supplemented with conventional urea, where the cows were fed with diets containing 13.5 g conventional urea per kg dry matter; and PRU (PRU, n = 12), consisting of a basal diet supplemented with a urea coated to extensively prevent ruminal degradation while being intestinally digestible, where the cows were fed with diets containing 14,8 g urea protected from ruminal degradation per kg dry matter. Post-ruminal supply of urea reduced the urine levels of 3-methylhistidine (P = 0.02). There were no differences between treatments for dry matter intake (DMI; P = 0.76), total digestible nutrient (TDN) intake (P = 0.30), and in the body composition variables, such as, subcutaneous fat thickness (SFT; P = 0.72), and rib eye area (REA; P = 0.85). In addition, there were no differences between treatments for serum levels of glucose (P = 0.87), and serum levels of glucogenic (P = 0.28), ketogenic (P = 0.72), glucogenic, and ketogenic (P = 0.45) amino acids, neither for urea in urine (P = 0.51) as well as urea serum (P = 0.30). One the other hand, enriched pathways were differentiated related to carbohydrate digestion, and absorption, glycolysis, pyruvate metabolism, oxidative phosphorylation, pentose phosphate pathway, and biosynthesis of amino acids of the exclusively expressed proteins in PRU cows. Shifting urea supply from the rumen to post-ruminal compartments decreases muscle catabolism in cows during late gestation. Our findings indicate that post-ruminal urea supplementation for beef cows at late gestation may improve the energy metabolism to support maternal demands. In addition, the post-ruminal urea release seems to be able to trigger pathways to counterbalance the oxidative stress associated to the increase liver metabolic rate.

FRI385 Influence Of Maternal Dietary Protein Precursor On Reproductive Endocrinology Of Neonatal Bovine Offspring

Abstract Disclosure: J.F. Thorson: None. L.D. Prezotto: None. Bovine oogenesis and follicular maturation are initiated during in utero development, a process that is stringently orchestrated by the endocrine milieu. Of paramount importance are the three major biologically active estrogens: estron, estradiol, and estriol that are involved in the development and maintenance of germ cells. Previous work using the current model have revealed that maternal urea (protein precursor) supplementation reduces the ovarian follicular reserve without compromising the number of secondary and tertiary follicles. Therefore, we did not anticipate an influence of dietary treatment on biologically active estrogens. However, as the ovarian reserve is positively associated with circulating concentrations of anti-Mullerian hormone (AMH) we hypothesized that offspring from dams supplemented urea would have reduced circulating concentrations of AMH at birth. To characterize the effects of maternal urea supplementation, multiparous cows pregnant with female calves were individually-fed isocaloric dietary treatments consisting of chopped forage top-dressed with a control (0 g urea/animal/d) or urea (80 g urea/animal/d) pelleted supplement. Diets met or exceeded dietary requirements throughout gestation. Blood samples were collected from offspring at birth for the collection of plasma. Plasma was analyzed for concentration of estradiol, estrone, unconjugated estriol, and AMH using commercially available ELISA kits. The effect of maternal dietary treatment on concentration of hormones in offspring were evaluated by ANOVA. As expected, maternal dietary treatment did not influence circulating concentrations of estradiol (P = 0.41), estrone (P = 0.35), or unconjugated estriol (P = 0.31). However, it was not anticipated that maternal dietary treatment would have no effect on circulating concentrations of AMH (P = 0.97) as offspring of urea-supplemented dams had fewer primordial and primary follicles than offspring from control dams. From these results we infer that maternal urea supplementation induces precocious follicular activation and/or increases the number of follicles recruited during maturation through an AMH-independent mechanism. Moreover, these data illustrate that while offspring of dams offered urea throughout pregnancy have a reduction in primordial and primary follicles, the steroidogenic competence of secondary and tertiary follicles is no different than dams offered the control diet. Presentation: Friday, June 16, 2023

Efficiency of Amino Acid Utilization in Nellore Cattle Grazing Low-Quality Forage Supplemented with Different Sources of Nitrogen.

This study aimed to evaluate the effects of supplementation with non-protein nitrogen (NPN) or ruminal undegradable protein (RUP) on intake, digestibility, and amino acid (AA) use efficiency of Nellore cattle grazing during the dry season. Eight Nellore steers (12 ± 2 months old) were used in quadruplicate Latin squares (2 × 2). The animals were placed on Urochloa brizantha cv. Xaraés under continuous grazing. The treatments included the following: (1) urea supplementation (NPN) and (2) supplementation of corn gluten meal 60 (CGM, RUP). Animals supplemented with CGM showed higher intakes of dry matter (DM) supplement, total AA, essential AA, and individual AA. The supplementation did not affect the total AA digestibility, total AA flux, and the AA fluxes of microbial origin and RUP from the diet (p > 0.05). The ruminal microorganism origin flux of total AA to the duodenum was 44.5% and 52.7% for animals supplemented with NPN and CGM, respectively. Animals supplemented with CGM showed an increase in blood concentrations of isoleucine (+19.09 μmol/L), cystine (+27.29 μmol/L), and albumin (+0.11 g/dL) (p < 0.05), but this increase was not accompanied by an improvement in N use efficiency of steers (p > 0.05). RUP supplementation via CGM can be an efficient nutritional strategy to enhance the intake and absorption of AA by Nellore cattle grazing low-quality forage during the dry season.

Bioacetoin Production by Bacillus subtilis subsp. subtilis Using Enzymatic Hydrolysate of Lignocellulosic Biomass

Acetoin is an important bio-product useful in the chemical, food and pharmaceutical industries. Microbial fermentation is the major process for the production of bioacetoin, as the petroleum resources used in chemical methods are depleting day by day. Bioacetoin production using wild microorganisms is an easy, eco-friendly and economical method for the production of bioacetoin. In the present study, culture conditions and nutritional requirements were optimized for bioacetoin production by a wild and non-pathogenic strain of B. subtilis subsp. subtilis JJBS250. The bacterial culture produced maximum bioacetoin (259 mg L−1) using peptone (3%) and sucrose (2%) at 30 °C, 150 rpm and pH 7.0 after 24 h. Further supplementation of combinatorial nitrogen sources, i.e., peptone (1%) and urea (0.5%), resulted in enhanced titre of bioacetoin (1017 mg L−1) by the bacterial culture. An approximately 46.22–fold improvement in bioacetoin production was achieved after the optimization process. The analysis of samples using thin layer chromatography confirmed the presence of bioacetoin in the culture filtrate. The enzymatic hydrolysate was obtained by saccharification of pretreated rice straw and sugarcane bagasse using cellulase from Myceliophthora thermophila. Fermentation of the enzymatic hydrolysate (3%) of pretreated rice straw and sugarcane bagasse by the bacterial culture resulted in 210 and 473.17 mgL−1 bioacetoin, respectively. Enzymatic hydrolysates supplemented with peptone as a nitrogen source showed a two to four-fold improvement in the production of bioacetoin. Results have demonstrated the utility of wild type B. subtilis subsp. subtilis JJBS250 as a potential source for economical bioacetoin production by making use of renewable and cost-effective lignocellulosic substrate. Therefore, this study will help in the sustainable management of agricultural waste for the industrial production of bioacetoin, and in combating environmental pollution.

Effect of nitrate supplementation, dietary protein supply, and genetic yield index on performance, methane emission, and nitrogen efficiency in dairy cows

The objective was to investigate the effect of nonprotein nitrogen source, dietary protein supply, and genetic yield index on methane emission, N metabolism, and ruminal fermentation in dairy cows. Forty-eight Danish Holstein dairy cows (24 primiparous cows and 24 multiparous cows) were used in a 6 × 4 incomplete Latin square design with 4 periods of 21-d duration. Cows were fed ad libitum with the following 6 experimental diets: diets with low, medium, or high rumen degradable protein (RDP):rumen undegradable protein (RUP) ratio (manipulated by changing the proportion of corn meal, corn gluten meal, and corn gluten feed) combined with either urea or nitrate (10 g NO3-/kg of dry matter) as nonprotein nitrogen source. Samples of ruminal fluid and feces were collected from multiparous cows, and total-tract nutrient digestibility was estimated using TiO2 as flow marker. Milk samples were collected from all 48 cows. Gas emission (CH4, CO2, and H2) was measured by 4 GreenFeed units. We observed no significant interaction between dietary RDP:RUP ratio and nitrate supplementation, and between nitrate supplementation and genetic yield index on CH4 emission (production, yield, intensity). As dietary RDP:RUP ratio increased, intake of crude protein, RDP, and neutral detergent fiber and total-tract digestibility of crude protein linearly increased, and RUP intake linearly decreased. Yield of milk, energy-corrected milk, and milk protein and lactose linearly decreased, whereas milk fat and milk urea nitrogen concentrations linearly increased as dietary RDP:RUP ratio increased. The increase in dietary RDP:RUP ratio resulted in a linear increase in the excretion of total purine derivatives and N in urine, but a linear decrease in N efficiency (milk N in % of N intake). Nitrate supplementation reduced dry matter intake (DMI) and increased total-tract organic matter digestibility compared with urea supplementation. Nitrate supplementation resulted in a greater reduction in DMI and daily CH4 production and a greater increase in daily H2 production in multiparous cows compared with primiparous cows. Nitrate supplementation also showed a greater reduction in milk protein and lactose yield in multiparous cows than in primiparous cows. Milk protein and lactose concentrations were lower for cows receiving nitrate diets compared with cows receiving urea diets. Nitrate supplementation reduced urinary purine derivatives excretion from the rumen, whereas N efficiency tended to increase. Nitrate supplementation reduced proportion of acetate and propionate in ruminal volatile fatty acids. In conclusion, no interaction was observed between dietary RDP:RUP ratio and nitrate supplementation, and no interaction between nitrate supplementation and genetic yield index on CH4 emission (production, yield, intensity) was noted. Nitrate supplementation resulted in a greater reduction in DMI and CH4 production, and a greater increase in H2 production in multiparous cows than in primiparous cows. As the dietary RDP:RUP ratio increased, CH4 emission was unaffected and RDP intake increased, but RUP intake and milk yield decreased. Genetic yield index did not affect CH4 production, yield, or intensity.

The Effect of Microbial Inoculum and Urea Supplements on Nutritive Value, Amino Acids Profile, Aerobic Stability and Digestibility of Wheat and Corn Silages.

Wheat and corn silages are widely used as ruminant feed in Israel due to their availability and cost-effectiveness. To ensure long-term preservation without compromising nutritional quality, effective methods must be employed. The inclusion of additives during harvest and ensiling can enhance efficiency and address preservation challenges. In the current study, the effects of microbial inoculum (MI) and urea on the chemical composition, amino acid profiles, aerobic stability, and in vitro digestibility of wheat and corn silages were investigated. Samples of wheat and corn were subjected to four treatments: control, MI, urea and a combination of MI + urea. The treatments were ensiled in anaerobic conditions and opened after 1, 7, 14 or 28 days. The results showed that additives improved the quality parameters of wheat and corn silages. The inclusion of MI produced the most aerobically stable silages. The inclusion of urea in silages decreased aerobic stability. Additives improved in vitro cell wall carbohydrates' digestibility in both silages and was the best when MI was combined with urea. These results imply that additives could be incorporated in silages to enhance their nutritional value, aerobic stability and digestibility. Nonetheless, increased CP content with additives was not accompanied with a parallel increase in amino acids' content in corn silage.