RESUMO

Smallholder farmers who grow maize landraces face important challenges to preserve their seed biodiversity from one season to another. This study was carried out in the central highlands of Mexico to compare the effectiveness of two seed storage practices-specifically, polypropylene woven bags (farmers' conventional practice) vs. hermetic containers-for minimizing seed losses and maintaining germination. Four Mexican landraces were stored for three and six months. Data on moisture content and kernel damage were collected at the beginning and the end of the storage period. Pest-free samples collected were also analyzed for seed germination. Moisture content was below 13% overall and was not significantly affected by storage technology or storage time. Samples from the polypropylene woven bags suffered significant damage from Sitophilus zeamais and Prostephanus truncatus, with the percentages of insect damage and weight loss reaching 61.4% and 23.4%, respectively. Losses were minimal in seed stored in hermetic containers, with a maximum insect damage of 4.1% and weight loss of 2.2%. Overall, the germination rate of samples stored in these airtight containers was greater than 90%. This study provides additional evidence on the effectiveness of hermetic containers at maintaining Mexican landraces' seed quantity and quality during storage in smallholder conditions in central Mexico.

RESUMO

The ensilage of total mixed ration (TMR) is a technology designed to help farmers with limitations to provide a balanced diet for their herds. Our aim was to evaluate the conservation of TMR ensiled in round bales with or without holes in the wrapping plastic film. Eight round bales of a corn silage-based TMR of 1,000 kg (370 kg DM/m3) were prepared. Ten days (d) after ensiling, four bales were randomly punctured with two holes of 25 cm2 each in opposite sides of the bale. The temperature in the center of the bales was recorded during the storage using dataloggers. After 60 d of storage, bales were weighted to assess dry matter (DM) recovery. Silages were sampled for measuring DM content, chemical composition, pH, lactic acid, and microbial counts. The temperature of the sliced bale face was assessed by infrared thermography. The holes in the plastic affected the DM content, DM recovery, and pH, whereas lactic acid, microbial counts, and temperature were not affected by treatments. The holes in the sealing plastic film should be avoided. However, holes of 25 cm2 each were not capable of causing expressive losses in TMR silage stored in 1,000 kg bales.

RESUMO

O objetivo da pesquisa foi avaliar os efeitos da reidratação do grão de milho em dois diâmetros geométricos médios (DGM = 0,55 e 1,83 mm) sobre perfil fermentativo e composição química das silagens. O experimento foi conduzido em delineamento inteiramente casualizado sendo os tratamentos: silagem de milho finamente reidratado (SMFR) e silagem de milho moído e reidratado (SMMR), com seis repetições. Os materiais foram reidratados com água objetivando níveis de umidade próximos a 350 g kg-1. Em ambas as silagens foram verificadas uma recuperação da matéria seca superior a 97%; porém sem diferença entre ambas. Houve influência do tamanho de partícula sobre a porção fibrosa, com valores inferiores observados para a SMFR. A concentração de ácido acético e lático foi maior para a SMFR, porém sem promover alterações significativas no pH da silagem. O pH foi diferente apenas na fase de exposição ao oxigênio, com valores de 4,25 e 4,38 para a SMFR e SMMR, respectivamente. Após a abertura dos silos, ambas as silagens demonstraram alta estabilidade aeróbia, acima de 90 horas, evidenciando menor atividade de espoliação e menor perda de qualidade. Concluiu-se que o DGM dos grãos de milho afetou o perfil fermentativo e nutricional da silagem.(AU)

This study evaluated the effects of the rehydration and ensiling of corn grain with two geometric mean diameters (GMD) of 0.55 and 1.83 mm obtained by the diameter of the sieved used on the fermentation characteristics and chemical composition of the silage. The experimental design was completely randomized with two treatments and six replications, as follows: rehydrated fine-corn grain silage (RFS) and rehydrated coarse-corn grain silage (RCS). Ground corn was rehydrated with water to achieve moisture levels close to 350 g kg-1. There was no effect on the dry matter recovery, though the recovery rate was high, with values greater than 97% in both silages. The particle size influenced the fiber content, with lower values in the RFS. The acetic and lactic acid concentrations were higher in the RFS, but the pH of the silages did not change. Oxygen exposure changed the pH of silages to 4.25 and 4.38 for RFS and RCS, respectively. After opening the silos, the silages showed high aerobic stability after 90 hours, which resulted in lower deterioration and lesser loss of quality. The geometric mean diameter of corn grain affects the silage fermentative profile and nutritional value.(AU)

Assuntos

RESUMO

O objetivo da pesquisa foi avaliar os efeitos da reidratação do grão de milho em dois diâmetros geométricos médios (DGM = 0,55 e 1,83 mm) sobre perfil fermentativo e composição química das silagens. O experimento foi conduzido em delineamento inteiramente casualizado sendo os tratamentos: silagem de milho finamente reidratado (SMFR) e silagem de milho moído e reidratado (SMMR), com seis repetições. Os materiais foram reidratados com água objetivando níveis de umidade próximos a 350 g kg-1. Em ambas as silagens foram verificadas uma recuperação da matéria seca superior a 97%; porém sem diferença entre ambas. Houve influência do tamanho de partícula sobre a porção fibrosa, com valores inferiores observados para a SMFR. A concentração de ácido acético e lático foi maior para a SMFR, porém sem promover alterações significativas no pH da silagem. O pH foi diferente apenas na fase de exposição ao oxigênio, com valores de 4,25 e 4,38 para a SMFR e SMMR, respectivamente. Após a abertura dos silos, ambas as silagens demonstraram alta estabilidade aeróbia, acima de 90 horas, evidenciando menor atividade de espoliação e menor perda de qualidade. Concluiu-se que o DGM dos grãos de milho afetou o perfil fermentativo e nutricional da silagem.

This study evaluated the effects of the rehydration and ensiling of corn grain with two geometric mean diameters (GMD) of 0.55 and 1.83 mm obtained by the diameter of the sieved used on the fermentation characteristics and chemical composition of the silage. The experimental design was completely randomized with two treatments and six replications, as follows: rehydrated fine-corn grain silage (RFS) and rehydrated coarse-corn grain silage (RCS). Ground corn was rehydrated with water to achieve moisture levels close to 350 g kg-1. There was no effect on the dry matter recovery, though the recovery rate was high, with values greater than 97% in both silages. The particle size influenced the fiber content, with lower values in the RFS. The acetic and lactic acid concentrations were higher in the RFS, but the pH of the silages did not change. Oxygen exposure changed the pH of silages to 4.25 and 4.38 for RFS and RCS, respectively. After opening the silos, the silages showed high aerobic stability after 90 hours, which resulted in lower deterioration and lesser loss of quality. The geometric mean diameter of corn grain affects the silage fermentative profile and nutritional value.

Assuntos