Effects of the harvest stage of maize hybrids on the chemical composition of plant fractions: an analysis of the different types of silage

14 páginas, 1 figura, 6 tablas.

The chemical composition of plant components of three maize hybrids harvested at thebeginning of six reproductive stages of maturity was compared. The hybrids evaluated includedMaximus VIP3, Defender VIP and Feroz VIP, which were evaluated at each of following stages: R1(grain formation), R2 (milky grain), R3 (pasty grain), R4 (floury grain), R5 (hard grain) and R6 (ripegrain). The advancement in maturation was linearly related to the crude protein (CP) content ofthe stem, whole plant, and leaves, and there was a difference among the hybrids. Between R4 andR5 stages, Maximus and Defender presented the highest CP contents for husk (6.58 and 5.42% forMaximus; 5.54 and 5.17% for Defender). The neutral detergent fiber (NDF) of the leaves showed aquadratic relationship with the advancement of maturation but did not differ among the hybrids.For all the hybrids, the NDF content in the husk and cobs increased linearly during the reproductivestages (>77 and 78%, respectively, for the three hybrids in R6). Defender had the lowest NDF contentof the cob in R3. The acid detergent lignin contents did not differ among stages in the stems, andshowed a linear decrease throughout the whole plant, though the contents did not differ amongthe hybrids. Due to the differences observed, recommendations for harvest based on the maturitystage for each hybrid should be taken into consideration. There seems to be no important distinctionamong hybrids for harvesting and use of straw. Despite the reduction in grain yield, an early harvestfor earlage or snaplage can provide lower lignin content in husk and cob, as well as higher proteincontent in the husk, favoring the nutritional value of the vegetative fraction (husk and/or cob)

Peer reviewed