The objective of this study was to select sorghum genotypes for silage production. The study was carried out at Embrapa Maize & Sorghum’s experimental field. Planting was performed in randomized blocks, with three replicates and the Scott-Knott test at a 5% probability level. The material was ensilaged in laboratory silos opened after 56 days for analysis concerning fermentation and bromatological composition. Only crude protein showed no significant difference (p > 0.05), with an overall mean of 8.88%. The other variables presented significant differences (p < 0.05): pH (3.34 to 3.94); Aw (0.93 to 0.98); N-NH 3/TN (1.61 to 6.56%); green matter yield (12.05 to 34.14 t ha-1); dry matter yield (6.19 to 11.42 t ha-1); dry matter (26.89 to 49.95%); ashes (4.08 to 6.88%); neutral detergent fiber corrected for ash and protein (47.67 to 65.79%); acid detergent fiber (16.62 to 35.89%); hemicellulose:cellulose (1.07 to 2.71%); lignin (2.03 to 6.52%), digestible dry matter yield (3.70 to 7.41 t ha-1) and dry matter digestibility (56.36 to 72.67%). Based on digestible dry matter yield, the genotypes: male 201191 and hybrids 2012F47484, 2012F47515 and 2012F47525 stood out in relation to the others for showing good yielding, adequate nutritional value, with low dry matter and NDF levels coupled with high digestibility values and good fermentation patterns of the silages.

The objective was to evaluate the productivity, chemical composition, ruminal degradability of dry matter and digestibility of BRS capiaçu grass (Pennisetum purpureum Schum.) managed at five regrowth ages. A completely randomized design with ten replications was used in the BRS capiaçu elephant grass subjected to five cutting intervals (30, 60, 90, 120 and 150 days) in the summer, making a total of 50 plots with a useful area of 4 x 2 m. There were daily increases in the dry matter production in the order of 382 kg ha-1, with 49,859 kg ha-1 being produced at 150 regrowth days. The dry matter content and organic matter linearly increased (P < 0.01) at different regrowth ages. The crude protein content, in vitro dry matter digestibility and in vitro digestibility of neutral detergent fiber linearly reduced (P < 0.01) 0.037%, 0.196% and 0.256% per day, respectively. Potential degradability of dry matter decreased from 68.9% at 30 days to 44.7% at 150 regrowth days (0.194 percentage units per day). The rate of degradation of fraction B 'c' was not modified (P = 0.94), averaging 1.46% hour-1. In the cultivation of BRS capiaçu elephant grass in the summer season, in the northern region of Minas Gerais, the age for harvesting between 90 and 120 days of regrowth is recommended.

The objective was to select from among 24 sorghum genotypes the superior ones for silage production. The study was conducted in the experimental field of Embrapa Maize & Sorghum, in the municipality of Sete Lagoas, Minas Gerais State. It used 24 forage sorghum genotypes, 21 being hybrids from the crossing of grain sorghum females and forage males (12F38019, 12F38006, 12F40006, 12F40005, 12F40019, 12F37016, 12F37005, 12F37043, 12F39006, 12F39005, 12F39019, 12F38005, 12F38007, 12F37007, 12F39007, 12F40007, 12F38014, 12F37014, 12F39014, 12F40014 e 12F38009) and three witnesses: BRS 610, BRS 655 and Volumax. It estimated productivity per area, in vitro dry matter digestibility, and assessed the bromatological and fermentation characteristics of sorghum silage. In vitro dry matter digestibility, unavailable protein in neutral detergent, neutral detergent fiber corrected for ashes and protein, acid detergent fiber, hemicellulose and lignin differed as to the genotypes tested. The pH and the ammoniacal nitrogen of the silage also showed differences between genotypes. Most of the genotypes tested are favorable for silage production, except the hybrid with higher lignin content 12F370014, and the hybrids 12F37007 and 12F370014, which showed the highest NDFap values.

The objective was to assess agronomic characteristics of sorghum genotypes and nutritional values of produced silage. A total of 15 sorghum genotypes were used. Planting was carried out through a randomized-block design with three replications per genotype, totaling forty-five (45) plots. Agronomic and nutritional characteristics, besides the quality of the silage, were assessed. There were differences between genotypes for all characteristics analyzed, with the exception of levels of acid detergent unavailable nitrogen (ADUN), acid detergent unavailable protein (ADUP) and water activity (aw). The assessment of the parameters, except for genotypes 1016013, 1016025, 1016037, 1016039, Volumax and BRS 610, which presented protein level below 7%, showed that the other genotypes can be used for silage production, since they have a good profile of fermentation and in vitro dry matter digestibility; however, genotype SF15 is the most favorable one for silage production due to its little participation in the neutral detergent fiber fraction.

The objective was to evaluate the effect of inclusion of acetic acid during the ensiling of sugarcane (Saccharum officinarum) on fermentation quality and nutritional value. The treatments consisted of sugarcane silages, variety (IAC 86-2480) additives with four inclusion levels of glacial acetic acid (1.5, 3.0, 4.5 and 6.0 % in natural matter) plus the control. A completely randomized design was used, being 5 treatments and 6 replicates. The glacial acetic acid showed a pH 2.9 (0,1M). There was a reduction of 0.07 units in the pH of the sugarcane silage for each 1% inclusion of acetic acid (P < 0.01). The N-NH3 concentration was not modified in the ensiled mass of the treatments, with a mean of 0.45% in dry matter (P =0.91). The averages of effluent losses were adjusted to the quadratic regression model with the application of acetic acid (P < 0.01). There was a reduction in the yeast population in the order of 0.44 log UFC/g of silage (P < 0.01). The addition of acetic acid in sugarcane silage reduces fermentative losses, the yeast population and improves the nutritional value in doses from 1.5% of natural matter.

The objective was to select sorghum genotypes for silage production using its chemical characteristics. The experiment was carried out in the facilities of Embrapa Maize and Sorghum in Sete Lagoas, state of Minas Gerais, to evaluate the agronomic characteristics, and nutritional quality of silage of twelve sorghum genotypes. We used a randomized block design with three replications. In relation to the production of green matter, the genotypes SF15 Volumax and BR610 stood out (52.07; 48.00 and 41.87 ton ha-1). Regarding pH, genotypes 1015339, 1015347, 1016007, SF15, BRS655, Volumax and BR610 averaged 3.68. All genotypes were similar considering the nutritional value, ammonia nitrogen and water activity. The genotypes SF15, Volumax and BRS610 showed the highest productivity per area, representing the best options for silage production.

ABSTRACT. This study evaluated the nutritional characteristics of hay of nineteen hybrids between sorghum and Sudan grass. The experimental design was a randomized block with nineteen treatments and three replications. The chemical characteristics of the respective hays were analyzed 52 days after sowing and 45 and 49 regrowth days. Data were analyzed by analysis of variance, and when the F test was significant, the treatment means were compared by the Scott and Knott test at 5%. Genotypes 1013026 and 1014020 showed similar dry matter content. As for ether extract content, the highest values ranged from 2.20 to 2.66%. Higher values of minerals were observed in hybrids 1013026 and 1011005. In relation to crude protein, higher content values were reported for hybrids 1013021 and 1013020 (14.59 and 15.47% CP). When evaluating the neutral detergent fiber content, lower values varied between 56.05 and 57.07% for hybrids 1013016 and 1011009. Considering the content of acid detergent fiber, values ranged from 32.70 to 35.78%. Values of dry matter digestibility were higher than 50%. All hybrids provide quality hay, however the hybrid 1014019 showed the best nutritional value.

ABSTRACT. This study aimed to evaluate the nutritional characteristics and quality of silages of five sorghum genotypes, namely: Volumax, AG2005E, Qualimax, BRS610 and AG2501. The study was conducted at the Experimental Farm Unimontes, in the municipality of Janaúba, state of Minas Gerais. The treatments were distributed in a randomized block design with four replicates. Data were tested by analysis of variance and means were compared by Scott-Knott test at a significance level of 5%. The pH values ranged from 3.93 and 4.10. Genotypes differed in all studied nutritional characteristics (p < 0.05). For the acid detergent fiber, differences were detected between the genotypes, AG2501 (35.66%), Volumax (34.89%), AG2005E (34.53%), Qualimax (32.39%) and BRS610 (33.60%). The high participation of lignin was verified in all genotypes except for Volumax (4.14%). All silages were within the recommended range 50-65% for in vitro dry matter digestibility and classified as having good quality, however only the AG2005E genotype met nitrogen requirements for microbial fermentation, with 7.06% crude protein.