Effects of extruded urea levels on the productive performance and carcass and meat characteristics of Nellore cattle.

Because the non-protein nitrogen sources can be an option for a ruminant diet to replace true-protein sources, we hypothesized that using extruded urea in increasing levels by reducing soybean meal in the diet can maintain or improve the productive performance of beef cattle in a feedlot. It was aimed to evaluate the effects of extruded urea levels on the productive performance and carcass and meat characteristics of Nellore steers in feedlot. Twenty-four Nellore steers, with an average age of 22 months and an average initial weight of 333.5 kg, were used. A completely randomized design was used with four treatments: 50, 60, 70, and 80 g/100 kg BW of extruded urea. There was no effect of extruded urea levels on nutrient intake. The final weight and average daily gain were adjusted by a quadratic equation, with maximum estimated values of 479.18 kg and 1.02 kg/day with the inclusion of 59.71, 54.14, and 54.16 g/100 kg BW of extruded urea, respectively. There was no effect (P > 0.05) of extruded urea levels on hot carcass weight (233.3 kg), carcass yield (53.2%), ribeye area (72.7 cm2), and subcutaneous fat thickness (5.3 mm). Likewise, there was no effect (P > 0.05) of extruded urea levels on meat chemical composition, shear force (8.9 KgF), cooking losses (28.2%), pH (5.6), and meat color parameters. We recommended the use of 70 g/100 kg BW of extruded urea in the diet for finishing Nellore steers in confinement.

Natural intoxication caused by protodioscin in lambs kept in Brachiaria pastures.

Protodioscin poisoning of Brachiaria spp. has been a serious problem for lambs in grazing systems. The defoliation process can stimulate the appearance of new leaves and, the younger leaves have a lower concentration of protodioscin. Thus, it was aimed to assess the effect of different leaf offerings on the protodioscin content in forage and if protodioscin can interfere with the dry matter intake (DMI) and on metabolic and productive parameters of lambs. Twelve tester lambs (average weight 17.5 ± 3.48 kg) were divided into four groups of different levels of dry leafy matter (60, 75, 90, or 105 g/kg body weight). In addition to these, 33 regulator lambs were used as needed to adjust the leaf offerings of pasture. The animals were divided and kept in 12 paddocks, each with a tester lamb. The DMI was estimated using chromic oxide as an external marker. In vitro digestibility and degradation kinetics and ruminal, blood, and urinary parameters were measured in the forage sampled by the hand plucking method. The protodioscin concentration in forage was determined by high-performance liquid chromatography. The DMI increased linearly as a result of the supply of leaves. However, the protodioscin content and its consumption showed a quadratic behavior. There was no effect of leaf supply on in vitro digestibility, in vitro degradation kinetics of forage, and on ruminal, blood, and urinary parameters of lambs. However, a negative correlation was observed between the DMI and the concentration of protodioscin at the highest level of leaf supply. This is due to the fact that in the most intense grazing, there is a stimulus for greater regrowth; therefore, there was an increase in the concentration of protodioscin in forages in older forages. Protodioscin poisoning was confirmed by urinary and blood parameters.

Biofuel by-product can replace partially corn in supplement for Angus × Nellore heifers: productive performance and meat characteristics.

The aim of this is study was to test the hypothesis that corn can be partially replaced by crude glycerin (at a level of 50%) without affecting performance, ingestive behavior, ruminal parameters, meat composition, and fatty acids profile on the meat of heifers. Sixty-four intact plus four rumen cannulated Angus × Nellore heifers (359.0 ± 12.15 kg BW) were used. The cannulated animals received the same diets as the intact ones to determine the ruminal N-NH3 concentration, pH, and chewing activity weekly. All heifers were maintained in Brachiaria brizantha pasture and supplemented with a concentrate containing corn, soybean meal, urea, premixed minerals, and glycerin partially replacing corn. A completely randomized experimental design was used, with two treatments (corn ground or glycerin + corn ground). The inclusion of crude glycerin (high fat) decreased nutrients intake and ruminal N-NH3 concentration in the rumen but increased lipid intake. Inclusion of glycerin had no effect (P > 0.05) on ruminal pH, daily gain, performance, time spent eating, rumination, idling, or water intake. The moisture, ash, and protein contents of meat were not affected (P > 0.05) by crude glycerin intake. Crude glycerin increased saturated fatty acids (C14:0, C16:0, and C18:0) and decreased unsaturated fatty acids (C18:2n6c and C20:1) in meat. Despite the reduction in nutrient intake, we recommend crude glycerin to replace corn in concentrate because glycerin did not impair the performance, meat composition, and ruminal pH. Therefore, crude glycerin is a by-product that can partially replace corn in diets efficiently.

Anti-nutritional potential of protodioscin and kinetics of degradation in Urochloa grasses / Potencial anti-nutricional da protodioscina e cinética de degradação de gramíneas do gênero Urochloa

This study aimed to evaluate the nutritional value of Urochloa exotic grasses to quantify aspects of anti-quality and to identify their correlation with quality grasses. We evaluated the grasses U. humidicola cv. Comum, U. humidicola cv. BRS Tupi, U. decumbens cv. Basilisk, D70 U. decumbens and U. ruziziensis ecotype R124, and we grouped them into summer, autumn, winter and spring. We determined the chemical composition, in vitro digestibility, levels of protodioscin and cumulative gas production from the leaves of grass materials in nature. Basilisk and D70 showed higher content protodioscin in all seasons, with the highest values (31.4 and 27.4 g kg-1, respectively) in spring. D70 had a crude protein content of 140.0 g kg-1 in summer and a better in vitro digestibility of dry matter (888.7 g kg-1). R124 had a higher cumulative gas production in the spring (16.44 mL gas 100 mg DM-1). U. humidicola (Comum and BRS Tupi) presented lower protodioscin concentrations (1.22 and 1.07 g kg DM-1, respectively), and U. decumbens (Basilisk and D70) presented higher concentrations (27.25 and 24.55 g kg DM-1, respectively). The presence of protodioscin interfered with in vitro digestibility results and cumulative gas production in vitro.

Objetivou-se avaliar o valor nutricional e quantificar os aspectos de anti-qualidade e suas correlações com a qualidade de gramíneas exóticas do gênero Urochloa. Foram avaliadas as gramíneas Urochloa. humidicola cv. Comum, Urochloa humidicola cv. BRS Tupi, Urochloa decumbens cv. Basilisk, Urochloa decumbens ecotipo D70 e Urochloa ruziziensis ecotipo R124 e agrupadas em épocas verão, outono, inverno e primavera. Foram determinados composição bromatológica, digestibilidade in vitro, teores de protodioscina e produção cumulativa de gáses das folhas das gramíneas material in natura. Basilisk e D70 apresentaram os maiores teores de protodioscina em todas as épocas do ano, com maior valor observado na primavera, 31,4 e 27,4 g kg-1, respectivamente. D70 apresentou maior teor de proteína bruta (140,0 g kg-1) no verão e maior digestibilidade in vitro da matéria seca (888,7 g kg- 1). R124 teve maior produção cumulativa de gás na primavera (16,44 mL de gás 100 mg de MS-1). U. humidicola (Comum e BRS Tupi) apresentaram os menores teores de protodioscina (1,22 e 1,07 g kg-1 MS, respectivamente). Houve correlação negativa entre o teor de protodioscina e a FDN, a fração C (Lag time) e a produção cumulativa de gás in vitro. A presença de protodioscina interfere nos resultados de digestibilidade in vitro e a produção cumulativa de gases in vitro.

Combinações de fontes de nitrogênio não proteico em suplementos para novilhos Nelore em pastejo

SUMMARY The objective of evaluating sources of non-protein nitrogen (NPN) combined for supplementation of Nelore steers in deferred pasture. After the deferral of four pickets of Brachiaria brizantha cv. MG4 (20 ha each) of 60 days, 80 Nellore steers, with average body weight 280.40 ± 19.59 kg, were evaluated for 120 days. The management adopted was rotational grazing, with pickets changes every 15 days. We evaluated four treatments with different combinations of NNP sources: Urea +Urea extruded + Urea coated; Urea + Urea coated; Urea + Urea extruded and Urea extruded. In all treatments were provided protein supplement-mineral energy ad libitum, with 30% of crude protein and 40% of total digestibility nutrient. When evaluated individually, the NPN sources presented different solubility in water and buffer, and lowest value observed for coated urea (P 0.05).The animals of the treatments Urea + Ureaextruded + Urea coated and Urea extruded showed average daily gain (0.4 kg/day; P 0.05) of animals treatments Urea + Urea extrudedthe animals(0.34 kg/day).The animals of the Urea extruded treatment higher carcass gain (1.71 @/animal) compared to other (P 0.05).The net margin of the Urea extruded treatment (R $ 158,20/animal) was superior in 10.8%, 8.2% and 35.8% to treatments Urea + Urea + Urea coated, Urea + Ureaextruded and Urea + Ureacoated, respectively. It is recommended to use extruded urea as source of non-protein nitrogen (NPN) in supplements of Nellore steers in deferred pasture.

RESUMO Objetivou-se avaliar fontes de nitrogênio não-proteico (NNP) combinadas para suplementação de novilhos Nelore na recria mantidos em pastagens diferidas. Após o deferimento de quatro piquetes de Brachiaria brizantha cv. MG4 por 60 dias (20 ha cada) 80 novilhos Nelore castrados, com peso corporal médio de 280,40±19,59kg, foram avaliados durante 120 dias. O manejo adotado foi pastejo rotacionado, com mudanças de piquetes a cada 15 dias. Foram avaliados quatro tratamentos com diferentes combinações de fontes de NNP: Ureia + Ureia extrusada + Ureia revestida; Ureia + Ureia revestida; Ureia + Ureia extrusada; Ureia extrusada. Em todos os tratamentos foram fornecidos suplemento proteico-energético-mineral ad libitum, com 30% de proteína bruta e 40% de nutrientes digestíveis totais.Quando avaliadas individualmente, as fontes de NNP apresentaram solubilidades distintas em água e solução tampão, sendo o menor valor observado para ureia revestida (P 0,05). Os animais dos tratamentos Ureia + Ureia extrusada + Ureia revestida e Ureia extrusa da apresentaram ganho médio diário superior (0,4kg/dia; P 0,05) aos animais dos tratamentos Ureia + Ureia extrusada (0,34kg/dia). Os animais do tratamento Ureia extrusada apresentaram maior ganho de carcaça (1,71 @/animal) em relação aos demais (P 0,05). A margem líquida do tratamento Ureia extrusada (R$ 158,20/animal) foi superior em 10,8%, 8,2% e 35,8% aos tratamentos Ureia + Ureia extrusada + Ureia revestida, Ureia + Ureia revestida e Ureia + Ureia extrusada, respectivamente. Recomenda-se a utilização de ureia extrusada como fonte de nitrogênio não proteico em suplementos para novilhos Nelore em pastagem diferida.

Anti-nutritional potential of protodioscin and kinetics of degradation in Urochloa grasses / Potencial anti-nutricional da protodioscina e cinética de degradação de gramíneas do gênero Urochloa

This study aimed to evaluate the nutritional value of Urochloa exotic grasses to quantify aspects of anti-quality and to identify their correlation with quality grasses. We evaluated the grasses U. humidicola cv. Comum, U. humidicola cv. BRS Tupi, U. decumbens cv. Basilisk, D70 U. decumbens and U. ruziziensis ecotype R124, and we grouped them into summer, autumn, winter and spring. We determined the chemical composition, in vitro digestibility, levels of protodioscin and cumulative gas production from the leaves of grass materials in nature. Basilisk and D70 showed higher content protodioscin in all seasons, with the highest values (31.4 and 27.4 g kg-1, respectively) in spring. D70 had a crude protein content of 140.0 g kg-1 in summer and a better in vitro digestibility of dry matter (888.7 g kg-1). R124 had a higher cumulative gas production in the spring (16.44 mL gas 100 mg DM-1). U. humidicola (Comum and BRS Tupi) presented lower protodioscin concentrations (1.22 and 1.07 g kg DM-1, respectively), and U. decumbens (Basilisk and D70) presented higher concentrations (27.25 and 24.55 g kg DM-1, respectively). The presence of protodioscin interfered with in vitro digestibility results and cumulative gas production in vitro.

Objetivou-se avaliar o valor nutricional e quantificar os aspectos de anti-qualidade e suas correlações com a qualidade de gramíneas exóticas do gênero Urochloa. Foram avaliadas as gramíneas Urochloa. humidicola cv. Comum, Urochloa humidicola cv. BRS Tupi, Urochloa decumbens cv. Basilisk, Urochloa decumbens ecotipo D70 e Urochloa ruziziensis ecotipo R124 e agrupadas em épocas verão, outono, inverno e primavera. Foram determinados composição bromatológica, digestibilidade in vitro, teores de protodioscina e produção cumulativa de gáses das folhas das gramíneas material in natura. Basilisk e D70 apresentaram os maiores teores de protodioscina em todas as épocas do ano, com maior valor observado na primavera, 31,4 e 27,4 g kg-1, respectivamente. D70 apresentou maior teor de proteína bruta (140,0 g kg-1) no verão e maior digestibilidade in vitro da matéria seca (888,7 g kg- 1). R124 teve maior produção cumulativa de gás na primavera (16,44 mL de gás 100 mg de MS-1). U. humidicola (Comum e BRS Tupi) apresentaram os menores teores de protodioscina (1,22 e 1,07 g kg-1 MS, respectivamente). Houve correlação negativa entre o teor de protodioscina e a FDN, a fração C (Lag time) e a produção cumulativa de gás in vitro. A presença de protodioscina interfere nos resultados de digestibilidade in vitro e a produção cumulativa de gases in vitro.