Effect of slow release urea in sheep feed on nitrogen balance

Abstract

The aim of this study was to evaluate the effect of inclusion of 0.0%, 0.4%, 0.8%, and 1.2% slow release urea (SRU) in sheep feed on nitrogen balance (intake, fecal and urinary excretion, nitrogen absorbed and retained and/or nitrogen balance). Four sheep with an average body weight (BW) of 30.8 ± 1.7 kg were distributed using a Latin square experimental design. Sheep were allocated in metabolic cages and received two meals a day. The data were subjected to analysis of variance and differences were tested using a regression equation with a 5% probability. The inclusion of 0.0%, 0.4%, 0.8%, and 1.2% SRU in sheep diets did not change (p > 0.05) nitrogen intake (NI), with an average value of 20.49 g animal day , and % of NI. The minimum values calculated with the equations for UN were 0.86 g animal day -1 , 0.06 g (kg 0.75 ) -1 , and 0.28% NI for SRU inclusion levels of 0.79%, 0.76%, and 0.71%, respectively. The inclusion of 0.0%, 0.4%, 0.8%, and 1.2% SRU in sheep diets did not change (p > 0.05) the NB expressed as g animal day -1 (10.86) and g (kg 0.75 ) -1 (0.82). However, the NB expressed as % NI or in relation to the NI responded in a quadratic manner (p < 0.05) to the inclusion of different levels of SRU in sheep food. The maximum value for NB was 59.68% NI and it was obtained at 0.68% SRU. Thus, the inclusion of 0.6% to 0.8% slow release urea in sheep diets provides the lowest fecal and urinary nitrogen losses. In addition, these levels provide the best NB values, expressed as a percentage of NI. Key words: Excretion. Faces. Intake. Non-protein nitrogen. Urine. ResumoObjetivou-se avaliar a inclusão de 0,0%; 0,4%; 0,8% e 1,2% de ureia de liberação lenta (ULL) na ) -1 (0,82). Entretanto, o BN expresso em %NC ou em relação ao NC apresentou um comportamento quadrático (p<0,05) com a inclusão dos diferentes níveis de ULL nas rações de ovinos. O valor máximo do BN de 59,68% NC foi obtido para o nível de 0,68% de ULL. Assim, a inclusão de 0,6% a 0,8% de ureia de liberação lenta na alimentação de ovinos propicia as menores perdas do nitrogênio fecal e urinário, além de proporcionar os melhores valores de balaço de nitrogênio expresso em percentagem do nitrogênio consumido. Palavras-chave: Consumo. Excreção. Fezes. Nitrogênio não proteico. Urina.

Effect of Using Slow-Release Urea on Food Compound Digestion Coefficient and some Rumen and Blood Fluid Traits in Awassi Lambs

“…Table (2) shows a significant increase (A<0.05) in the rate of lambs' consumption of feed significantly for the third and fourth treatment over the second. This finding agreed with those of [8][9][10]. In contrast [11] reported that the addition of 1.8 g/kg DM SRU improves DMI and digestion.…”

Dynamics of biochemical parameters in lambs during the first four months of life

“…In fact, serum urea concentration is proportional to the ammonia levels produced in the rumen (Karimizadeh et al, 2017). Most of the protein ingested is degraded by ruminal microorganisms, releasing ammonia, which is used for microbial protein synthesis (Geron et al, 2018). However, when large amounts of protein are fermented in combination with low availability of energy from carbohydrate degradation, a high rumen ammonia concentration is generated.…”

“…However, when large amounts of protein are fermented in combination with low availability of energy from carbohydrate degradation, a high rumen ammonia concentration is generated. The capacity of ammonia utilization by ruminal microorganisms is exceeded, so the excess is absorbed into the enterohepatic circulation, and in the liver is converted into urea, which, added to urea from amino acid metabolism, constitutes the major portion of plasma urea (Fernandes et al, 2012;Karimizadeh et al, 2017;Geron et al, 2018). However, it can be observed that the energy requirement for the lambs in this study was practically met (Table 3), with only a small deficit in its balance at 91-120 days, while the protein deficit was much higher (not being the protein requirement fully met).…”

Effect of Slow-Release Urea Administration on Production Performance, Health Status, Diet Digestibility, and Environmental Sustainability in Lactating Dairy Cows

“…These findings can be partially explained by an increased abundance and activity of fibrolytic bacteria in the rumen, such as Ruminococcaceae, which uses ammonia as its main nitrogen source due to both a higher level of NH 3 availability and better synchrony between nitrogen and carbohydrates in the rumen, when SRU is used as a partial substitution for SBM [ 38 , 39 ]. Furthermore, Geron et al (2016) found a better in vivo digestibility of crude protein in sheep fed with SRU as a partial replacement for SBM [ 40 ].…”

“…The partial replacement of SBM with SRU decreased the CFP of the treatment diet, expressed per 1 kilogram of diet (−10.98%; 449.91 vs. 505.41 g CO 2 -eq/kg diet) compared to the control diet due to the lower global warming potential (GWP) of SRU than SBM [ 24 ]. The highest GWP of soybean meal is mainly due to large transport distances and emissions related to land-use change (LUC), such as deforestation, which can lead to heavier emissions of greenhouse gases [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ]. These results agree with the findings of Salami et al (2021), who showed a 12% reduction in CFP (g CO 2 -eq/kg diet) when SBM and other plant-protein sources were replaced by SRU [ 8 ].…”