J.A.S. Rodrigues

Potencial forrageiro de cultivares de girassol produzidos na safrinha para ensilagem

The objective of this study was to evaluate some important agronomic traits for silage production of 12 hybrids and a variety of sunflower (Helianthus annuus L.) participant of the national assay of sunflower, in the agricultural year of 1996/97. The experiment was conducted from February to June 1997. The experimental procedure followed a randomized block design and the means values were compared by Student-Newman-Keuls test. Significant differences among hybrids for fresh and dry matter productions, leaf, head and stem percentages, stems circumference close the head, broken plants percentage and height of the plants were observed. No significant differences among hybrids for stems circumference close the ground, diameter of the head and laying plants percentage were found. The agronomic traits indicated that some hybrids of sunflower present potential to be used for silage production in double-cropping system, or during the drought.

Potencial forrageiro de híbridos de sorgo com capim-sudão

The objective of this study was to evaluated the forage potential of 23 experimental genotypes and two check cultivars (AG2501C and BRS800) obtained by crossing sorghum (Sorghum bicolor cv. Bicolor) with sudangrass (Sorghum bicolor cv. Sudanense), managed in a cutting regime. The experimental procedure followed a completely randomized block design, including three replications per treatment and the mean values were compared by Scott-Knott test. Fifty seven days after sowing, the fresh matter production varied from 24.8 up to 37.8 t/ha, and dry matter production from 3.5 up to 5.8 t/ha, both results were not statistically different. It was observed great variation to leaf/stem ratio, and difference (P<0.05) among treatments. The height of the plants presented variation (P<0.05) among hybrids and was positively correlated (P<0.01) with the production characteristics. The productivity demonstrated the potential of these hybrids for forage production in central area of Brazil in the beginning of drought period. The significant difference in leaf/stem ratio could be used as a criterion for genotype selection.

Qualidade das silagens de três híbridos de sorgo ensilados em cinco diferentes estádios de maturação

Three hybrids of sorghum with medium height (BR700, BR701 e MASSA 03) for silage production were evaluated. Hybrids were harvest at five different maturation stages. Dry matter content, pH, ammonia nitrogen, crude protein, fibrous fractions, in vitro dry matter digestibility and organic acids were determined in silage. A completely randomized block design with three replicates was used. The treatments consisted in a factorial arrangement 5x3 (maturation stages x hybrids). The means were compared by SNK test (P<0.05). Dry matter content and pH values increased with the maturation stage; pH values were always lower than 4.09. No effects of maturation stage of the plant on ammonia nitrogen, fibrous fractions and in vitro dry matter digestibility were found. Organic acids contents suggested that the fermentation inside the silo was enough for preservation of the forage.

Composição bromatológica e cinética de fermentação ruminal de híbridos de sorgo com capim-sudão

The objective of this study was to evaluate the nutritional value of 23 experimental genotypes and two control cultivars (AG2501C and BRS800) obtained by crossing sorghum with sudangrass (Sorghum bicolor cv. Bicolor × Sorghum bicolor cv. Sudanense), managed in a cutting regime. The bromatological analysis was performed, and the kinetics parameters of dry matter fermentation was obtained by the semi-automated in vitro gas production technique. A completely randomized block design was used for total gas production in a split plot arrangement. For all other responses an entirely randomized design was applied. The mean values were compared by Scott-Knott test. The genotypes CMSXS212*CMSXS912 and ATF14*CMSXS912 showed the highest dry matter content and the genotypes (A3TX430*CMSXS225)*CMSXS912, (A3TX430*CMSXS227)*CMSXS912, (BR007*CMSXS217)*CMSXS912, CMSXS210*CMSXS912, CMSXS157*CMSXS912, CMSXS215*CMSXS912, ATF14*CMSXS912, CMSXS205*CMSXS912, CMSXS156*CMSXS912, CMSXS107*CMSXS912, CMSXS216*CMSXS912 showed the highest protein level. The cell wall contents, the kinetics parameters and the effective dry matter degradation for all the hybrids were not statistically different.

Qualidade das silagens de seis genótipos de sorgo (Sorghum bicolor (L. ) Moench) em diferentes estádios de maturaçäo

In order to evaluate the quality of sorghum silages, six genotypes of this crop were cultivated and ensiled at three different times of harvesting. The genotypes evaluated were BR 601, BR 303, BR 304, AG 2006, BR 700 and BRS 701. The sorghum hybrids were ensiled in laboratory silos made of PVC tubes. Eighteen treatments, six hybrids in three different times of harvesting, with four repetitions were analysed in a totally randomized design. The original material was analysed for dry matter. At the opening of the silos, pH and ammonia nitrogen were determined and the silages were analysed for dry matter, crude protein and fibrous fractions. In all treatments, differences between the dry matter content in periods 1 and 2 and periods 1 and 3 were observed. Differences between hybrids (P<0.05) for dry matter content in the same period were also found. The lowest value was BR 601, period 1 (20.8%), and the highest was BR 304, period 3 (49.1%). The pH values achieved were between 3.6 and 3.9. Significant differences (P<0.05) between treatments and periods of harvesting were observed. In all treatments, the silages presented good fermentation patterns based on ammonia nitrogen content. The BR 601 showed the lowest value of crude protein (5.6%) and the highest value was shown by BR 304 (8.4%). In all hybrids the silages showed good fermentation patterns and were considered of good quality. The fibrous fraction content did not change with the age of the plant. All hybrids must be ensiled at the early-dough stage, except for BR 601 that must be ensiled at the late-dough stage.

Consumo e digestibilidade aparente de silagens de sorgo em diferentes estádios de maturação

Avaliaram-se o consumo e a digestibilidade aparente, em ovinos, das silagens dos hibridos de sorgo BRS 610, BR 700 e BRS 655 colhidos em tres estadios de maturacao dos graos: leitoso, pastoso e farinaceo. Os valores de consumo da materia seca, em gramas por quilograma de unidade de tamanho metabolico (CMS-UTM), variaram de 45,90g/UTM/dia a 59,99g/UTM/dia e nao diferiram com o avanco do estadio de maturacao para todos os hibridos (P>0,05). No estadio pastoso, o BRS 655 apresentou menor CMS-UTM em relacao aos demais hibridos (P 0,05). Foi observado menor consumo de proteina digestivel para os hibridos com tanino, BR 700 e BRS 655, em relacao ao BRS 610 (P<0,05) nos estadios pastoso e farinaceo. Todos os tratamentos apresentaram balanco de nitrogenio levemente positivo, com valores entre 0,02g/UTM/dia e 0,20g/UTM/dia. Nao houve diferencas nos valores de digestibilidade da fibra entre os hibridos com tanino, BR 700 e BRS 655, e sem tanino, BRS 610. Recomenda-se a utilizacao da silagem do hibrido BRS 610, colhida no estadio pastoso. Os hibridos BRS 655 e BR 700 devem ser colhidos no estadio leitoso.

Porcentagem, perda e digestibilidade in vitro da matéria seca das silagens de 20 genótipos de sorgo

The objective of this experiment was to evaluate the nutritive value of 20 sorghum genotype silages. They were ensiled at 104 days of age in laboratory silos made of PVC tubes, which were 40cm in lenght and 10cm in diameter. The silos were opened 150 days after ensiling, and the following characteristics were evaluated: dry matter (DM), DM loss and in vitro dry matter digestibility (IVDMD) A completely randomized design was used, with three replications by treatment and the means were compared using SNK test. The silage DM contents ranged from 23.7 to 31.8% and all of them presented low DM losses. All 20 genotype silages were similar considering the evaluated characteristics, except for IVDMD. The hybrids C22 (62.8%) and CMSXS756 (63.0%) showed the highest values for IVDMD and 547 (54.1%) and C 11(55.5%) the lowest ones.

Padrão de fermentação da silagem de cinco genótipos de sorgo

Foram utilizados cinco genotipos de sorgo de colmo seco, sendo dois hibridos comerciais (Volumax e BR 700) e tres novos hibridos experimentais desenvolvidos pela Embrapa Milho e Sorgo (0249341, 0249317 e 0249339), com o objetivo de determinar, no material original e em sete tempos de abertura subsequentes a ensilagem (1, 3, 5, 7, 14, 28 e 56), as porcentagens de materia seca, proteina bruta, nitrogenio amoniacal em relacao ao nitrogenio total, pH e carboidratos soluveis em alcool. Os valores de materia seca dos materiais originais foram semelhantes aos das silagens em todos os dias de abertura. Os valores de materia seca das silagens variaram entre 26,03 e 41,13% com media 32,65%. Os valores de proteina bruta foram menores no 56° dia de abertura comparados aos dos materiais originais. A degradacao dos carboidratos soluveis foi intensa ate o quinto dia de fermentacao. Os valores de nitrogenio amoniacal foram baixos e estaveis ate o 28° dia pos-ensilagem, com pequeno aumento no 56° dia e a variacao neste ultimo periodo foi de 2,01 a 3,66%. Os valores de pH variaram de 3,69 a 4,52 e sua estabilizacao se deu no quinto dia pos-ensilagem. De maneira geral, os hibridos avaliados apresentaram potencial para serem utilizados na forma de silagem.

Avaliação de sete genótipos de sorgo (Sorghum bicolor (L.) Moench) para produção de silagem. II- Padrão de fermentação

Fermentation patterns in the silages of seven sorghum genotypes cut at 102 days, varying in height and stem moisture were studied. Laboratory silos were opened after 7, 14, 28 and 56 days from ensilage. Dry matter percentages varied among the different types of sorghum and they were associated to moistness and sugar contents in stem. The dry stem genotypes showed higher values than wet stem genotypes. Silages at 56 days fermentation showed dry matter content varying from 23.1 to 36.1%. pH from the seven sorghum silages were already stabilized within seven days of fermentation and oscillated from 3.5 to 4.3 at 56 days of fermentation. The high and wet stem sorghums showed the highest levels of soluble carbohydrates ranging from 4.0 to 17.2% in the original material. With 56 days the variation in lactic acid content was from 2.8 to 8.5%, and the medium height sorghums showed the lowest values. The ammonia nitrogen in relation to total nitrogen percentage ranged from 3.8 to 6.3% at 56 days of fermentation.

Avaliação de sete genótipos de sorgo (Sorghum bicolor (L.) Moench) para produção de silagem. I- Características agronômicas

Algumas caracteristicas agronomicas importantes para producao de silagens foram avaliadas em sete genotipos de sorgo de portes alto, medio e baixo. Determinaram-se as producoes de materia verde e materia seca em toneladas/hectare. Separaram-se folhas, colmo e panicula e determinaram-se as porcentagens de cada um desses componentes em relacao a planta inteira. A altura e a populacao de plantas, a porcentagem de folhas mortas e a porcentagem de acamamento foram avaliadas no momento do corte. As porcentagens de colmo, folhas e panicula variaram, respectivamente, de 45,5 a 83,8%, 6,8 a 32,6% e 9,3 a 35,1%. As folhas mortas oscilaram de 20,0 a 63,3%. A altura da planta apresentou correlacao significativa com a producao de materia seca, com a proporcao de colmo e com a porcentagem de acamamento. Foi observada correlacao positiva entre o numero de plantas/hectare e a producao de materia seca. Registrou-se grande variacao na producao de materia natural, e os sorgos de porte alto mostraram-se mais produtivos que os de porte medio e estes mais que o de porte baixo. Observou-se a mesma tendencia para o rendimento de materia seca/hectare, porem os genotipos de porte alto foram semelhantes a um sorgo de porte medio.