Anti-nutritional potential of protodioscin and kinetics of degradation in Urochloa grasses

Abstract

This study aimed to evaluate the nutritional value of Urochloa exotic grasses to quantify aspects of antiquality 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. Key words: Fodder. Gas production. In vitro digestibility. ResumoObjetivou-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, 1 Projeto financiado pelo CNPq, (processo n° 563988/2010-0) e pela FUNDECT (processo 23/200.145/2011).

Characterization of Brachiaria humidicola cv. BRS Tupi

“…According to Van Soest (1994), that is explained by the decrease in cell content, whereas the high CP content at 14 days of age is related to the initial vegetative growth stage of the forage plant. The values found in the present study at 30 days (11.74 g/100 g) match those by Leal et al (2016), who assessed the nutritional value of BRS Tupi cut in 30-day intervals in summer, autumn, winter, and spring. Those authors reported CP contents of 8.79, 8.31, 8.71, and 10.6 g/100 g, respectively, i.e., higher age at cut led to lower CP contents.…”

“…NDF is a major parameter in defining forage quality and limits the intake capacity of animals (Costa et al, 2007). Hence, forage plants harvested at more advanced ages will be less consumed and digestible by animals (Jung & Allen, 1995;Leal et al, 2016). Age in days growth stage of the forage plant.…”

“…BRS Tupi.MM concentration decreased to the lowest level (5.12 g/100 g) at 50 days (Figure 2). The mineral composition of forage plants varies as a function of interdependent factors such as plant age, soil fertility (fertilizing), differences among species and varieties, and season, among others(Cezário, Ribeiro, Santos, Valadares, & Pereira, 2015;Leal et al, 2016).…”

Production and quality of Urochloa decumbens (stapf) r.d. webster forage co-related to the physical and chemical properties of the soil

“…In spite of low productivity rates, the Brazilian commercial cattle herd amounts to 209,541,109 units. It has been estimated that 89% are raised exclusively on pasture in native or cultivated pasturelands covering some 172 million ha and approximately 85% of this area is pasture of the genus Urochloa (Leal et al, 2016).…”

Production Potential and Quality of Panicum maximum Cultivars Established in a Semi-Arid Environment

“…The content of protodioscin-the main saponin associated with intoxication and used as an indicator of photosensitization in animals (Lelis et al, 2018)-in the cultivars was low when compared with those described in studies with cultivars of the genus Brachiaria (Faccin et al, 2014;Porto et al, 2013;Leal et al, 2016Leal et al, , 2020. In Brachiaria spp., Melo et al (2018) found that protodioscin levels between 3 and 13 g/kg DM caused intoxication in lactating lambs.…”