Impact of Harvest Time on the Dry Matter Content, and Nutritional Parameters Related to Forage Quality of Maralfalfa (Cenchrus purpureus (Schumach.) Morrone, Poaceae) under Mediterranean Climate

Abstract

Maralfalfa (Cenchrus purpureus (Schumach.) Morrone) is a productive fodder crop in tropical regions that has been evaluated for forage nutritional value in a Mediterranean climate. To assess the nutritional value, parameters including dry matter content (DM), ash, ether extract (EE), protein (CP), fiber contents (NDF and ADF), and the amino acids profile were determined at eight harvest times (HTs) in a non-fertilized and non-irrigated crop based in Silla (Valencia, Spain). The results showed significant differences in most of the parameters studied. While CP and ash significantly decreased over the eight HTs, NDF and ADF increased. In contrast, EE and the ratio of essential amino acids/total amino acids remained constant. Values of CP remained higher than 15% during the first two HTs (16 and 28 days). According to the analyses performed, the optimum HT can be stated at 28 days as it combines high levels of CP (including an optimal combination of essential amino acids) with low levels of fibers (NDF = 57.13%; ADF = 34.76%) and a considerable amount of dry matter (15.40%). Among the essential amino acids (EA) determined, lysine and histidine showed similar values (Lys ≈ 6%, His ≈ 1.70%) when comparing the composition of these EA to other forage species and cultivars studied, whereas methionine showed lower values. This work establishes the basis for the appropriate HT of maralfalfa according to the nutritional parameters measured. Further studies could be aimed to optimize the nutritional and phytogenic properties of maralfalfa to improve its value as a fodder crop, and to finally introduce it for sustainable livestock production in Mediterranean countries.