Nitrogen Intake and Its Partition on Urine, Dung and Products of Dairy and Beef Cattle in Chile

Nitrogen that is excreted through the urine and dung of cattle is an important source of nitrous oxide and ammonia emissions. In Chile, several studies have evaluated nitrogen (N) intake and its partitioning into urine and dung from beef and dairy cattle, however, there are no studies collating all data into one central database, which would allow an estimation of N excretion and its key variables to be developed. The aim of this study was to determine the N partition (milk or meat, urine and dung) and variables influencing the nitrogen use efficiency (NUE) and urinary N excretion of cattle based on a database generated from Chilean studies. The search of studies was carried out using a keyword list in different web-based platforms. Nitrogen excretion into urine and dung was calculated using equations reported in the literature for beef and dairy cattle. Mixed models were used to identify variables influencing the N partitioning. Nitrogen intake and its partitioning into the animal product, urine and dung were higher for dairy compared to beef cattle. For dairy cattle, NUE was influenced by milk yield, the non-fibrous carbohydrates (NFC)/crude protein ratio, acid detergent fiber intake and milk urea N (MUN), while urinary N excretion was influenced by milk yield, MUN and NFC intake. For beef cattle, N intake and its excretion were greater for grazing compared to the confined system, while NUE was greater for confined animals. This database supplies new information on N intake and its partitioning (milk, meat, urine and dung) for dairy and beef cattle, which can be used for the estimation of greenhouse gas emissions from pasture-based livestock in Chile. Additionally, our study supplies new information on nutritional variables determining NUE and urinary N excretion for dairy cattle, which can be used by farmers to reduce N excretion into the environment.

Comparison between conventional urea and slow-release urea on concentration of ammonia in the rumen: A meta-analysis

Urea is a source of Non-Protein Nitrogen (NPN). The utilization of urea in the ration is useful for increasing digestibility, dry matter intake, and increasing protein content. This study aims to compare the utilization of conventional urea and Slow Release Urea (SRU) to reduce ammonia concentration by in vivo study using meta-analysis. A total of 13 studies were obtained that consisted of 41 data points. The parameters in this study include pH, Dry Matter Intake (DMI), Volatile Fatty Acid (VFA), ammonia concentration, and nitrogen intake. The database compiled was statistically analyzed using a mixed model method. Different studies were considered as random effects, and the level of urea was treated as fixed effects. The model statistics used were the p-values and the Akaike information criterion. The significance of an effect was stated when its p-value was <0.05. The results revealed that level SRU and conventional urea had a significant linear effect on ammonia concentration, DMI, VFA, pH and nitrogen intake. However, the effect of giving SRU was better than conventional urea. It can be concluded that SRU can control ammonia concentration, DMI, VFA, pH and nitrogen intake better than urea.

The contribution of plasma urea to total osmolality during iatrogenic fluid reduction in critically ill patients

Hyperosmolality is common in critically ill patients during body fluid volume reduction. It is unknown whether this is only a result of decreased total body water, or an active osmole-producing mechanism similar to that in aestivating animals where muscle degradation increases urea levels to preserve water. We hypothesized that fluid volume reduction in critically ill patients contributes to a shift from ionic to organic osmolytes similar to mechanisms of aestivation. We performed a post-hoc analysis on data from a multicenter observational study in adult ICU patients in the post-resuscitative phase. Fluid, electrolyte, energy and nitrogen intake, fluid loss, estimated glomerular filtration rate (eGFR) and estimated plasma osmolality (eOSM) were registered. Contributions of osmolytes Na+, K+, urea and glucose to eOSM expressed as proportions of eOSM were calculated. 241 patients were included. eOSM increased (median change 7.4 mOsm/kg (IQR −1.9–18) during the study. The of sodium's and potassium's proportions of eOSM decreased (P &lt; 0.05 and P &lt; 0.01 respectively), whereas the urea's proportion increased (P &lt; 0.001). Urea's proportion of eOSM was higher in patients with negative vs. positive fluid balance. The urea's proportion of eOSM increased with eOSM (r = 0.63; adjusted for eGFR r = 0.80), but not nitrogen intake. In patients without furosemide and/or renal replacement therapy (n = 17), urea's proportion of eOSM and eOSM correlated strongly (r = 0.92). Urea's proportion of eOsm was higher in patients not surviving to 90 days. In stabilized ICU patients the contribution of urea to plasma osmolality increased during body water volume reduction, statistically independently of nitrogen administration and eGFR. The shift from ionic osmolytes to urea during body fluid volume reduction is similar to that seen in aestivating animals. ClinicalTrials.org Identifier: NCT03972475

Carbon and nitrogen budgets and respiration rates of selected foraminifera of the Gullmar Fjord in Sweden

&lt;p&gt;Benthic foraminifera are highly abundant, ubiquitous&amp;#160;marine protists, with many species feeding on microalgae or phytodetritus. Knowledge about carbon and nitrogen budgets and metabolic activities of benthic foraminifera can help to increase our understanding about their ecology and their role in aquatic biogeochemistry at the sediment-water interface. This can further increase their application as proxies for&amp;#160;environmental changes. Shifts in the benthic foraminiferal communities of the Swedish Gullmars Fjord document the shift from well oxygenated bottom waters to seasonal hypoxia at its deepest location the Alsb&amp;#228;ck Deep (125 m), during the last century.&lt;/p&gt;&lt;p&gt;So far there are only investigations available relating foraminiferal community composition with increased primary productivity and resulting hypoxia in this Fjord. In contrast, studies about&amp;#160;the species-specific feeding ecology or food derived foraminiferal carbon and nitrogen fluxes are scarce.&lt;/p&gt;&lt;p&gt;Therefore, laboratory feeding experiments and respiration rate measurements were carried out with &lt;em&gt;Bulimina marginata&lt;/em&gt;, &lt;em&gt;Cassidulina laevigata&lt;/em&gt;&amp;#160;and &lt;em&gt;Globobulima turgida&lt;/em&gt;,&amp;#160;abundant foraminifera in such environments, collected in August 2017.&lt;/p&gt;&lt;p&gt;Experiments were conducted&amp;#160;to evaluate the carbon and nitrogen intake and turnover of dual (&lt;sup&gt;13&lt;/sup&gt;C and &lt;sup&gt;15&lt;/sup&gt;N) isotope labelled &lt;em&gt;Phaeodactylum tricornutum&lt;/em&gt;&amp;#160;detritus;&amp;#160;detritus of a common diatom in the Gullmar Fjord. For the feeding experiments, foraminifera were incubated at 9.1&amp;#176;C in the dark, in sterile filtered seawater at ambient oxygen concentrations. The foraminifera were fed for a period of 24 hours and subsequently incubated without food for&amp;#160;another 24 hours. After each incubation cycle, foraminiferal respiration rates were measured. The individuals were analyzed via Elemental Analyzer-Isotope Ratio Mass Spectroscopy to evaluate &lt;sup&gt;13&lt;/sup&gt;C/&lt;sup&gt;12&lt;/sup&gt;C and &lt;sup&gt;15&lt;/sup&gt;N/&lt;sup&gt;14&lt;/sup&gt;N ratios and their bulk content of organic carbon and nitrogen.&lt;/p&gt;&lt;p&gt;Additionally, we present carbon&amp;#160;and nitrogen to volume ratios for the foraminifera &lt;em&gt;B. marginata&lt;/em&gt;, &lt;em&gt;C. laevigata&lt;/em&gt;, &lt;em&gt;G. turgida&lt;/em&gt;, &lt;em&gt;G. auriculata&lt;/em&gt;&amp;#160;and &lt;em&gt;Nonionella turgida&lt;/em&gt;,&amp;#160;as derived from elemental analysis and light microscopy imaging.&lt;/p&gt;&lt;p&gt;The results show, that &lt;em&gt;B. marginata&lt;/em&gt;, an opportunistic species associated with high fluxes of organic matter, had the highest rate of specific carbon and nitrogen intake and turnover. &lt;em&gt;Cassidulina laevigata&lt;/em&gt;,&amp;#160;a species&amp;#160;that co-occurs&amp;#160;with fresh phytodetritus&amp;#160;and&amp;#160;does not tolerate very low oxygen concentrations, showed lower carbon and nitrogen intake rates. &lt;em&gt;Globobulima turgida&lt;/em&gt;,&amp;#160;a denitrifying infaunal species that thrives under hypoxia, showed the lowest specific carbon and nitrogen intake and turnover rates. Respiration rates of all species did not depend on incubation with or without a food source.&amp;#160;The foraminifera showed similar carbon and nitrogen densities per test volume across all species.&lt;/p&gt;&lt;p&gt;Overall this study helps to improve the knowledge on the nutritional ecology of the investigated species, demonstrating the close relation between feeding/metabolic rates and their environmental niche&amp;#160;and highlighting the need to introduce foraminiferal data in future marine carbon and nitrogen flux models.&lt;/p&gt;

Dry Matter Intake and In Vivo Digestibility of Grass-Only and Grass-White Clover in Individually Housed Sheep in Spring, Summer and Autumn

Intake and digestibility are key drivers of animal production from grazed forage. The objective of this study was to compare the in vivo digestibility and voluntary dry matter (DM) intake of grass-only and grass-white clover (grass-clover) forage in individually housed sheep. This study was a Latin square design, repeated on three occasions in 2017: Spring (27 March–29 April), summer (19 June–22 July) and autumn (4 September–29 September). Grass-clover and grass-only swards were harvested daily and offered ad libitum to 6 individually housed wether sheep per treatment per period. Digestibility of DM, organic matter (OM), neutral detergent fibre (NDF) and acid detergent fibre (ADF) were determined using the total faecal collection method. Dry matter intake was not significantly different between treatments. White clover inclusion increased forage crude protein concentration in autumn (p < 0.001) and reduced NDF concentration in the offered forage (p < 0.001), increasing nitrogen intake per sheep in autumn (p < 0.001) and decreasing NDF intake per sheep in autumn (p < 0.001). Grass-clover swards had a significantly greater OM and DM digestibility compared to grass-only swards (p < 0.05). This could potentially result in increased animal production from grass-clover swards compared to grass-only swards.

Water And Feed Utilization Relationship In West African Dwarf (Forest) Goats Of Southern Nigeria

Eight bucks weighing between 12 and 15kg liveweight and age range of 9 -12 months were used in a 42-day feeding and metabolism trials to study the water intake and feed utilization relationship in the West African Dwarf (forest) goats of Southern Nigeria. There was no significant difference in the average water intake between the groups but feed intake was significantly different between the groups (P<0.05). Feed efficiency was very similar between the groups; Dry Matter (DM) intake to water intake ratios were 0.21 and 0.27 respectively while mean daily liveweight gains were significantly different. Nitrogen utilization showed significantly higher nitrogen intake and nitrogen loss between the groups but nitrogen retained as percent of nitrogen intake was however not different between the groups. Results from the study established a positive correlation between water intake and feed intake in the experimental goats with correlation (r) values of 0.47 and 0.53 for the two groups respectively.

Nutrient intake and digestibility of selected browse plants fed in combination with Panicum maximum to West African dwarf (WAD) bucks

A study was conducted to evaluate nutrient intake and digestibility of Panicum maximum fed in combination with selected browse plants to West African dwarf (WAD) bucks. Four intact West African dwarf (WAD) bucks of mean body weight 17.50kg were used to conduct digestibility study in a 4 x 4 Latin Square design experiment. Four forage combinations, diets A, B, C and D were fed to the goats. Diet A, the control, was 100% Panicum maximum, while diets B, C and D contained 60% Panicum maximum each plus 40% of Alchornea cordifolia, Manniophyton fulvum and Gmelina arborea, respectively. The study lasted 56 days in a 14-day x 4 change over periods. Data were collected on dry matter intake (DMI), nutrient intake and digestibility. Simple linear regression and correlation were used to assess the degree of relationship between some of the digestion components. The result of proximate analysis indicated that the diets (P. max + browse) B, C and D had significantly (p<0.05) higher dry matter (%DM) contents of 81.12, 81.09 and 80.68%, respectively, than the 75.71% for diet A (sole P.max). Crude protein content of 17.56, 15.62 and 17.52%, respectively were also higher (p<0.05) than the 8.38% for diet A. There was higher (p<0.05) ether extract content of 2.43, 2.38 and 2.32%, for diets B, C, and D, respectively than the 1.32% for diet A. The ash content of 10.71, 9.78 and 9.76% for diets B, C and D respectively, were also higher (p<0.05) than the 7.83% for diets A. Metabolizable energy (MJKg-1) values of 1.41, 1.42 and 1.42 for diets B, C and D were also higher (p<0.05) than the 1.31 for diet A. However, the crude fibre value of the diet A (27.26%) was significantly (p<0.05) higher than the 18.30, 19.30 and 18.58% for diets B, C and D. respectively. There were significant (p<0.05) differences in DMI among treatment means. Nitrogen intake (g/d) was significantly (p<0.05) higher for animals fed diets B(15.04), C(13.12 ) and D(14.48 ) wherein P.max was fed in combination with browse plants than in the diet A( 6.28) group fed sole P.max. Faecal nitrogen showed no significant (p>0.05) difference among treatment means. Urinary nitrogen was significantly (p<0.05) higher in diet A group (0.39) than in diets B (0.30), C (0.34) and D (0.43) groups. There was positive nitrogen balance for all in the treatment groups. Apparent nitrogen digestibility (%) was significantly (p<0.05) higher in diets B (92.37), C (90.51) and D (91.63) groups than in diet A (79.49). Nitrogen intake(g/d) could not reliably predict faecal nitrogen (g/kgDM) in diets C and D groups. Absorbed 0.75 0.75 nitrogen (g/d/WKg 0.75 ) could not predict urinary nitrogen (g/d/WKg 0.75 ) in any of the diets. Biological value (BV) of the diets were A (55), B (45), C (81) and D (97). The result of this study shows that the animals fed P. max + browse recorded higher DMI, nutrient intake and digestibility than the sole P.max diet. These evaluation indices were, however, mostly better in the diet B group (60% P. maximum + 40% Alchornea cordifolia). The combination of 60% P. maximum + 40% Alchornea cordifolia is therefore recommended for West African dwarf (WAD) goats reared in the humid tropics of Nigeria for optimum intake and improved nutrient utilization.

Effect Of Parity On Intake And Utilization Of A High Forage Low Concentrate Ration By Bunaji Cows In Early Lactation

During the early lactation of three groups of four Bunaji cows each in the first, fourth and seventh parities, a 3:1 hay mixture of Cyonodon nlemfuensis variety robustus and Gliricidia sepium leaves fed ad libitum was supplemented for ten weeks with concentrate that supplied 16% of the daily total dry matter intake (DMI). On metabolic size basis, the intake of actual and digestible dry matter, crude protein (CP) and energy declined with increasing parity, the values for the seventh parity being significantly lower (P<0.05) than those for earlier parities. Animals in the 4th parity produced maximum fat-corrected milk (FCM), solids-corrected milk (SCM) and actual milk that contained the least total solids (TS), fat, and caloric value but highest solids-not-fat (SNF) and lactose (P<0.05). They also most efficiently converted DM, digestible CP (DCP) and digestible energy (DE) consumed into actual milk, FCM and SCM and the nitrogen intake or absorbed into milk nitrogen. Differences in these parameters during the earlier and later parities were similar (P>0.05). On the average, animals in the 4th parity apparently lost or gained no weight. Primiparous animals gained one and half times as much weight as the oldest animals and more efficiently utilized the DM, DCP and DE consumed for weight gain while the ratio of their live weight gain to milk yield was higher (P<0.05). Multiparous animals required 110% of the recommended CP but all animals required 70 - 85% of the recommended DE for maintenance and productive purposes.

Performance of grower rabbits fed Gmelina arborea leaf meal

Forty five weaner rabbits, aged four weeks of mixed sexes were used to investigate the performance of rabbits fed Gmelina arborea leaf meal (GALM) at 0,10,20,30 and 40% inclusion level. Increasing the level of GALM had no significant effect (P>0.05) on feed intake, weight gain and feed to gain ratio. There was also no treatment effect on nitrogen intake (P>0.05). Furthermore, increasing the dietary level of GALM in the diet also had no significant effect (P>0.05) on faecal nitrogen, nitrogen retained and nitrogen digestibility. However, the cost of feed declined with the corresponding increase in the GALM dietary level. The result shows that Gmelina arborea leaf meal could be fed to grower rabbits up to 40% inclusion level without any adverse effect.

Nitrogen utilization by male WAD sheep fed graded levels of boiled CST and SMD based diets

The study was carried out to investigate the nitrogen utilization by male West African Dwarf (WAD) sheep fed boiled Cocoa Seed Testa (CST) and Sorghum Malt Dust (SMD)-based diets. Twenty-eight male animals were divided into seven groups with similar average initial live weight in a completely randomized design. Each group contained four animals. The trial consisted of seven dietary treatments which comprised CST at 10, 20 and 30% levels, SMD at 10, 20 and 30% levels and a control. The trial lasted for 90 days. Data generated were subjected to a one-way analysis of variance. Apparent nitrogen intake (19.41g/d) and retention (9.67g/d) were significantly (P<0.05) higher in the treatment with 20% SMD. Generally, dietary inclusion of CST and SMD improved the nitrogen intake by male WAD sheep with the best result from sheep fed 20% sorghum malt dust based diets.