Non-protein nitrogen supplementation increases gluconeogenic capacity in sheep

Noro, Mirela; Bertinat, Romina; Yáñez, Alejandro J.; Slebe, Juan C.; Wittwer, F

doi:10.1016/j.livsci.2012.06.013

Cited by 10 publications

(6 citation statements)

References 32 publications

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“…In agreement with Noro et al [46], glycaemia tended to increase with the proportion of urea in the diet. It has been suggested that this effect could be due to either an underutilization of glucose by insulin-sensitive extrahepatic tissues or an improvement of gluconeogenic capacity [47].…”

Section: Discussionsupporting

confidence: 92%

Replacing Soybean Meal with Urea in Diets for Heavy Fattening Lambs: Effects on Growth, Metabolic Profile and Meat Quality

Saro

Mateo

Andrés

et al. 2019

Animals

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Simple SummaryThere is a renewed interest on the potential inclusion of urea in ruminant diets, reducing the contribution of vegetable protein supplements. This study was designed to evaluate the effect of replacing soybean meal with different proportions of urea in protein-rich diets for heavy fattening lambs (from 29 to 50 kg of live body weight). Our results suggest that 39% of soybean meal of such diets can be replaced with urea reducing the feeding costs without any adverse effects on feed efficiency, rumen fermentation, or carcass and meat quality. Nevertheless, urea supplementation even at levels of 1% of dry matter may trigger mild metabolic acidosis that can affect animal health in the long term.AbstractThirty-six Assaf male lambs (29.4 ± 3.10 kg body weight (BW)) were used to study the feasibility of including urea (at 0, 0.6 or 0.95% of dry matter for Control, Urea1, and Urea2 diets, respectively) in substitution of soybean meal in fattening diets. Animals were individually penned and feed intake was recorded daily. Blood samples were taken at days 35 and 63 of the experimental period to determine the acid-base status and the biochemical profile. At the end of the experiment (nine weeks), lambs were slaughtered, ruminal contents were collected and carcass and meat quality were evaluated. There were not differences (p > 0.05) among treatments in dry matter intake, animal performance, ruminal fermentation pattern, and carcass and meat parameters. Serum albumin concentration was higher and concentration of HCO3 and total CO2 in blood were lower in Urea2 compared to Urea1 and Control lambs. These results, together with the tendency to lower (p = 0.065) blood pH in this group might suggest a moderate metabolic acidosis. Partial replacement of soybean meal with urea did not impair growth rate in heavy fattening Assaf lambs (from 29 to 50 kg body weight), reduced feeding costs and had no adverse effects on feed efficiency, rumen fermentation and carcass and meat quality.

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Section: Discussionsupporting

confidence: 92%

Replacing Soybean Meal with Urea in Diets for Heavy Fattening Lambs: Effects on Growth, Metabolic Profile and Meat Quality

Saro

Mateo

Andrés

et al. 2019

Animals

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“…A similar result was reported by Noro et al (2012) when evaluating the effects of three levels of urea in feed (0.00, 0.55 and 1.28 g N kg of metabolic weight -1 ) on the energy metabolism of lambs. The authors attributed the higher glucose levels in lambs fed on a diet with high NPN to high phosphoenolpyruvate carboxykinase (PEPCK) enzyme activity in the liver, which plays an important role in hepatic gluconeogenesis process.…”

Section: Resultssupporting

confidence: 86%

Performance and serum chemistry profile of lambs fed on rations with increasing levels of urea

Vivian

Neto

Freitas

et al. 2017

SCA

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Feed intake and efficiency, animal performance, and protein and energy metabolism were studied in lambs that were fed on increasing levels of urea (0.0, 0.5, 1.0, and 1.5% of dry matter [DM]). A completely randomized design was used, with four treatments (urea levels) and six replicates. The lambs were fed ad libitum for 56 days until they reached an average body weight of 35 kg. The rations were composed of 34% Tifton 85 hay (Cynodon spp.) and 66% concentrate. Crude protein (CP) constituted 17% of the diet on a dry matter basis, and total digestible nutrients (TDN) accounted for 65%, on average. The dry matter intake (DMI) and crude protein intake (CPI) were not influenced by the urea levels in the diet, presenting average values of 1.175 and 0.206 kg animal -1 day -1 , respectively. The average daily gain (ADG), feed conversion ratio (FCR) and gross feed efficiency (GFE) were also not influenced by urea levels (0.225 kg day -1 , 5.33 kg DM kg gain -1 and 0.195 kg gain kg DM -1 , respectively). Except for urea and glucose concentrations, blood parameters did not change with increasing urea in the diets. The mean values for total protein, albumin, globulin and creatinine in the serum were 7.11 g dL -1 , 3.36 g dL -1 , 3.75 g dL -1 and 0.91 mg dL -1 , respectively. Serum urea decreased linearly and serum glucose increased linearly with urea levels in the diet. The addition of 1.5% of urea to the diets did not change feed intake and efficiency or animal performance, and did not cause metabolic disorders in feedlot lambs in the finishing phase. Key words: Blood. Finishing. Glucose. Nitrogen. Sheep. ResumoAvaliou-se o consumo de alimento, o desempenho animal, a eficiência alimentar, e o metabolismo proteico e energético de cordeiros alimentados com rações contendo níveis crescentes de ureia (0,0; 0,5; 1,0; 1,5% da matéria seca -MS). O delineamento foi inteiramente casualizado com quatro tratamentos (níveis de inclusão de ureia) e seis repetições por tratamento. Os cordeiros foram alimentados à vontade por 56 dias até atingirem peso corporal (PC) médio de 35 kg. As rações foram compostas por 34% de feno de Tifton 85 (Cynodon spp.) e 66% de concentrado, com 17% de proteína bruta (PB) e 65% de nutrientes digestíveis totais (NDT), em média, com base na matéria seca (MS). O consumo de matéria seca (CMS) e de proteína bruta (CPB) não foram influenciados pelos níveis de inclusão de ureia na ração, apresentando valores médios de 1,175 e 0,206 kg animal -1 dia -1 . O ganho médio diário (GMD), a e 0,91 mg dL -1 . A ureia sérica apresentou resposta linear decrescente, enquanto a glicose sérica de apresentou resposta linear crescente ao aumento da inclusão de ureia. A inclusão de até 1,5% de ureia na MS em rações isoproteicas não afeta o consumo de alimento, o desempenho e a eficiência alimentar, e não causa prejuízos metabólicos em cordeiros confinados na fase de terminação. Palavras-chave: Glicose. Nitrogênio. Ovinos. Sangue. Terminação.

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“…However, both hepatic ureagenesis and gluconeogenesis are ATP consuming and integrated processes via the citric acid cycle (Nelson & Cox, ) and, in the present study, a clear and direct relationship between urea and glucose production by liver was observed. This is also supported by results of Noro, Bertinat, Yañez, Slebe, and Wittwer () who supplemented sheep with non‐protein nitrogen and observed an increment on liver phosphoenolpyruvate carboxykinase activity, which was associated to a metabolic adaptation with an increased gluconeogenic capacity. Milano and Lobley () reported that the conversion of excess of ammonia to urea during a short‐term hepatic ammonia overload (i.e., 1,100 μmol N/min in 31 min) required no additional contribution of aminoacids to ureagenesis.…”

Section: Discussionsupporting

confidence: 73%

“…Milano et al (2000) found that the liver O 2 consumption increased by 1.22 mmol/ TA B L E 1 Plasma concentration (mmol/L) of glucose, urea and ammonia N, and blood concentration of O 2 in artery, portal and hepatic veins of sheep infused into the mesenteric vein with physiological saline (Control) or with 375 μmol N/min of different N compounds (Nelson & Cox, 2017) and, in the present study, a clear and direct relationship between urea and glucose production by liver was observed. This is also supported by results of Noro, Bertinat, Yañez, Slebe, and Wittwer (2012) who supplemented sheep with non-protein nitrogen and observed an increment on liver phosphoenolpyruvate carboxykinase activity, which was associated to a metabolic adaptation with an increased gluconeogenic capacity. Milano and Lobley (2001) reported that the conversion of excess of TA B L E 2 Plasma flow in portal and hepatic veins, and net flux of metabolites across the portal-drained viscera (PDV), liver and total splanchnic tissues (ST) of sheep infused into the mesenteric vein with physiological saline (Control) or with 375 μmol N/min of different N compounds ammonia to urea during a short-term hepatic ammonia overload (i.e., 1,100 μmol N/min in 31 min) required no additional contribution of aminoacids to ureagenesis.…”

Section: Discussionsupporting

confidence: 68%

Oxygen uptake and net flux of metabolites by splanchnic tissues of sheep in response to short‐term mesenteric infusion of nitrogenous compounds

Stefanello

Mezzomo

Zeni

et al. 2018

Animal Physiology Nutrition

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This study was conducted in an attempt to quantify the impact of N load on splanchnic tissues metabolism of sheep. The trial was conducted with four male sheep (45 ± 2.5 kg body weight (BW)) surgically implanted with chronic indwelling catheters into the portal, hepatic and mesenteric veins. Blood flow and metabolic flux through portal-drained viscera (PDV), liver and total splanchnic tissues (ST) were measured daily following a 4 × 4 Latin Square experimental design, where sheep were continually infused into the mesenteric vein with a physiological saline (0.15 m NaCl) solution during 90 min followed by the infusion, during more 120 min, of either solution: physiological saline (control), 0.250 mNH HCO , 0.250 m L-alanine or 0.125 m L-arginine, all of them infused at a rate of 1.5 ml/min to provide 375 μmol N/min. During the treatment infusion period, the net removal of ammonia N and the net production of urea N by liver were higher (p < .05) in NH HCO infused sheep Based on oxygen consumption, and on average of all treatments, the heat produced by liver and ST was on average 6 and 14 kcal/kg BW representing 16% and 38% of the metabolizable energy intake respectively. Linear relationships between variables indicated that gluconeogenesis and ureagenesis occurred concomitantly and both processes accounted for approximately 50% of total liver energy expenditure, two-thirds of it associated with gluconeogenesis. The results of the current study did not present clear evidence of the expected energy costs associated with ammonia N, alanine or arginine metabolism by liver. However, they indicated that gluconeogenesis is on average a more energy expensive process than ureagenesis.

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Non-protein nitrogen supplementation increases gluconeogenic capacity in sheep

Cited by 10 publications

References 32 publications

Replacing Soybean Meal with Urea in Diets for Heavy Fattening Lambs: Effects on Growth, Metabolic Profile and Meat Quality

Replacing Soybean Meal with Urea in Diets for Heavy Fattening Lambs: Effects on Growth, Metabolic Profile and Meat Quality

Performance and serum chemistry profile of lambs fed on rations with increasing levels of urea

Oxygen uptake and net flux of metabolites by splanchnic tissues of sheep in response to short‐term mesenteric infusion of nitrogenous compounds

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