Urea in sugarcane-based diets for dairy cows

Abstract

-We evaluated the effect of adding four levels (0, 4, 8 and 12 g/kg, as fed) of a mixture (9:1) of urea and ammonium sulfate (UAs) to sugarcane on feed intake and digestibility, productive performance and metabolism of nitrogen compounds of dairy cows. Twelve multiparous Holstein cows (12.6±0.5 kg/d of milk, 225±90 days in milk) were distributed in three 4 × 4 Latin squares, receiving diets with the same amount of nitrogen (125 g crude protein/kg of dry matter). Concentrate feed was supplied at a ratio of 1 kg for each 3 kg of milk produced. The sugarcane presented 21.9 ºBrix. The level of UAs did not affect intake, total digestibility of diet components, milk production or milk components. Increasing UAs level linearly increased concentration of plasma urea nitrogen (PUN), urinary excretion of nitrogen and contribution of non-urea nitrogen in the urinary excretion and linearly reduced milk production/urinary excretion of nitrogen ratio. In spite of the linear increase of PUN with increased urea, the maximum value observed (14.31 mg/dL) was below the threshold value of 20 mg/dL, above which reproductive function may be compromised. In diets with sugarcane for dairy cows with production below 15 kg/day, the UAs level may be raised from 0 to 12 g/kg natural matter without impairing performance.

Post‐ruminal non‐protein nitrogen supplementation as a strategy to improve fibre digestion and N efficiency in the ruminant

“…The response at the high dose was not completely unexpected because the rumen has limited capacity to effectively capture large doses of urea N, as demonstrated in practical urea feeding experiments in ruminants (Souza et al, 2013;Zinn, Barrajas, Montano, & Ware, 2003). The response at the high dose was not completely unexpected because the rumen has limited capacity to effectively capture large doses of urea N, as demonstrated in practical urea feeding experiments in ruminants (Souza et al, 2013;Zinn, Barrajas, Montano, & Ware, 2003).…”

“…The corresponding increase in rumen ammonia and rumen pH indicates that fibre digestibility was compromised and excess ammonia was absorbed through the rumen wall and excreted as urea via the urine. The response at the high dose was not completely unexpected because the rumen has limited capacity to effectively capture large doses of urea N, as demonstrated in practical urea feeding experiments in ruminants (Souza et al, 2013;Zinn, Barrajas, Montano, & Ware, 2003). a UR50 = 50 g of urea into the rumen; UR150 = 150 g of urea into the rumen; UA150 = 150 g of urea into the abomasum; URA150 = 50 g of urea into the rumen and 100 g of urea into the abomasum.…”

Effect of pearl millet silage ammoniated with urea on lamb production and metabolic performance

“…In studies investigating the addition of urea to sugarcane and sorghum silages (Fernandes et al, 2009;Lopes & Evangelista, 2010), the applied urea levels contributed to increasing average pH levels, ammonia/total nitrogen content (N-NH 3 /TN), and crude protein content of silages. Urea can also be used as an alternative to reduce costs, as its cost per nitrogen unit is lower compared with that of other vegetable protein sources (Santiago et al, 2013). In this way, ammoniation performed during the ensiling process may increase weight gain in animals and improve silage use efficiency by reducing protein losses during fermentation and increasing the levels of non-protein nitrogen in the silage (Cardoso et al, 2004;Pires, Garcia, Cecon, Neiva, & Sarmento, 1999).…”

Uso de ferramentas de gestão na atividade leiteira: um estudo multicasos em Uberlândia, MG

“…Os autores não observaram efeito da suplementação dos teores de ureia sobre a produção e composição do leite, mas a eficiência alimentar foi melhor nas dietas em que se utilizou ureia. Santiago et al (2013) avaliaram o efeito da adição de 0, 4, 8 e 12 g kg -1 de cana de uma mistura de ureia e sulfato de amônio (9:1) Os autores concluíram que, em dietas com cana-deaçúcar para vacas leiteiras com produção abaixo de 15 kg leite por dia, as concentrações de ureia podem ser aumentadas de 0 a 12 g kg -1 de matéria natural sem prejudicar o desempenho, com diminuição da ingesta, melhorando, assim, seu desempenho.…”