A relação FDA/FDN poderia ser um indicador de resistência à moagem em leguminosas tropicais?

Abstract

Little is known about the physical analyzes of tropical legumes and whether there is a correlation between the physical and chemical characteristics of these forages. Therefore, the objective was to evaluate the chemical and physical composition of six species of tropical legumes used to feed ruminants and verify whether there is a correlation. between these characteristics. The legumes were collected at the Glória Experimental Farm and the physical and chemical analyzes were carried out at the Laboratory of Bromatology and Animal Nutrition (LABAN) of the Faculty of Veterinary Medicine of the Federal University of Uberlândia (UFU). In November 2023, three replications of each of the six legumes were collected: Forage Peanut, Cratília, Estilosantes cv. Mineirão, Feijão Guandu, Gliricidia and Leucena, totaling 18 samples. The samples were dried in a forced ventilation oven for 72 hours and divided into two samples, one intended for grinding resistance analysis, and then for chemical-bromatological analysis. The physical analysis (grinding resistance) and chemical analyzes (dry matter, mineral matter, crude protein, neutral detergent fiber, acid detergent fiber, lignin, iNDF and in vitro digestibility of dry matter) were compared using a mean test. 5% probability level for type I error. The experiment was conducted in a completely randomized design. All legumes had a crude protein content above 22%, with the exception of Estilosantes. Cratília had higher NDF and lignin content compared to other legumes (P<0.05), also numerically it had higher NDFi and hemicellulose and lower DIVMS. Guandu Beans had a higher FDA/NDF ratio and greater resistance to grinding (P<0.05), which also showed high levels of iNDF and lignin. There was a significant and positive correlation between the ADF/NDF ratio and grinding resistance (r=0.70; P<0.05), and between dry matter content and grinding resistance (r= 0.66; P<0 .05). A significant and positive correlation was also found between Lignin and NDF content (r=0.83; P<0.05), lignin and ADF (r=0.81; P<0.05), as well as lignin and ADF ratio /FDN (r=0.55; P<0.05). It was concluded that the legume Cratília has a higher NDF and lignin content. Guandu Beans have greater grinding resistance, consequently a high FDA/NDF ratio. And the FDA/NDF ratio positively correlates with grinding resistance. Consequently, this chemical analysis can be used as an indirect indicator of grinding resistance in tropical legumes.