Abstract The objective of the present study was to evaluate the productive performance, the ingestive behavior, the apparent digestibility of the diet, and the carcass characteristics of beef steers finished in confinement under the effect of ammonium dipropionate in the diet, and the fractionation or not in the supply of the diet. The experimental design was completely randomized, in a 2 x 2 factorial scheme, totaling four treatments, as follows: Diet without ammonium dipropionate provided twice a day; Diet without ammonium dipropionate given once daily; Diet with ammonium dipropionate provided twice daily; Ammonium dipropionate diet provided once daily. Thirty-two ½ Angus ½ Nellore bulls were used, with an average age of 11 months. The use of ammonium dipropionate in the overall average increased average daily gain, dry matter intake, and carcass gain. The diet provided twice a day provided, on average, greater weight gain, greater carcass gain, and better feed conversion. When evaluating the association between treatments, the use of dipropionate plus the diet supplied twice a day showed greater daily carcass gain during the experimental period and higher hot carcass weight (1.251 kg, 111.4 kg, and 308.6 kg respectively), as well as ensuring better apparent digestibility of dry matter (74.57%). With the data obtained in the present study, it is possible to state that it is advisable to use ammonium dipropionate while maintaining the fractionation of the diet for beef steers in the finishing phase.

Resumo O objetivo do presente estudo foi avaliar o desempenho produtivo, o comportamento ingestivo, a digestibilidade aparente da dieta e as características de carcaça de novilhos de corte terminados em confinamento sob efeito do dipropionato de amônio na dieta, e do fracionamento ou não no fornecimento da dieta. O delineamento experimental foi inteiramente casualizado, em um esquema fatorial 2 x 2, totalizando quatro tratamentos, sendo: Dieta sem dipropionato de amônio fornecida duas vezes ao dia; Dieta sem dipropionato de amônio fornecida uma vez ao dia; Dieta com dipropionato de amônio fornecida duas vezes ao dia; Dieta com dipropionato de amônio fornecida uma vez ao dia. Utilizou-se 32 novilhos ½ sangue Angus ½ sangue Nelore, com idade média de 11 meses. O uso do dipropionato de amônio na média geral aumentou o ganho médio diário, a ingestão de matéria seca, e o ganho de carcaça. A dieta fornecida duas vezes ao dia proporcionou na média geral, maior ganho de peso, maior ganho de carcaça e melhor conversão alimentar. Ao avaliar a associação entre os tratamentos, o uso de dipropionato mais a dieta fornecida duas vezes ao dia mostrou maior ganho de carcaça diário, durante o período experimental e maior peso de carcaça quente (1,251 kg, 111,4 kg e 308,6 kg respectivamente), assim como garantiu melhor digestibilidade aparente da matéria seca (74,57%). Com os dados obtidos no presente estudo é possível afirmar que é recomendável utilizar o dipropionato de amônio mantendo o fracionamento da dieta para novilhos de corte em fase de terminação.

ABSTRACT The objective of this study was to evaluate the effect of harvesting corn at different maturity stages for silage production combined with four storage periods, considering nutrient loss and the chemical composition of silage of the whole plant and also of grainless plants. The experiment was performed in a completely randomized design with a factorial arrangement of six maturity stages of corn [reproductive (R); R1 to R6] and four periods of silage storage (30, 60, 90, and 120 days). At stages R1 and R2, losses by effluents occurred more intensely when compared with the more advanced stages, whereas losses by gases showed the opposite behavior, with stage R6 responsible for the greatest losses. Stage R4 showed a stable dry matter (DM) content during the storage period, 42.08%, and had the lowest levels of neutral detergent fiber (NDF), acid detergent fiber (ADF), and acid detergent lignin (ADL) for the whole plant silage. The ADL in the silage of grainless plant of stage R4 was not the lowest, but it was close to the first reproductive stages, being an important point, since the first reproductive stages can present a vegetative fraction of better quality. The highest DM volumes produced by area occurred in the most advanced stages; however, R5 obtained a greater reduction in volume over the days of storage (20.66 kg day −1 ). The production cost was lower at the advanced stages (R4, R5, and R6) when compared with the first reproductive stages (R1, R2, and R3), and in general, during the storage period the costs did not have great variations. Based on the chemical composition of the silages, DM losses during the storage period, the stability in the costs of DM ton over the days of storage, the R4 stage was the most suitable for silage production.

Resumo O objetivo deste trabalho foi avaliar a qualidade químico-fermentativa da silagem de dois híbridos de sorgo nos diferentes estratos da face do silo e a interferência do tempo de exposição aeróbia da face do silo estruturada e/ou desestruturada (após desensilagem). A silagem do híbrido AG-2005E apresentou maior teor de proteína bruta e pH mais elevado em comparação à do híbrido AG-60298 (6,33% e 4,0 contra 6,06% e 3,8, respectivamente). As silagens do estrato de 0 a 20 cm tinham o menor teor de matéria seca e o maior teor de proteína bruta (38% e 6,35%, respectivamente). O pH não diferiu entre os estratos e o teor de NH3 foi maior no estrato de 60 a 80 cm (4,5%). Com o avanço das 72 horas de exposição aeróbia, a silagem desestruturada apresentou maior incremento de temperatura em relação à silagem da face estruturada, mas esse tempo não foi suficiente para mostrar diferenças entre os teores de matéria seca, matéria mineral, NH3 e pH. O híbrido de sorgo e o estrato do silo interferem diretamente na qualidade químico-fermentativa da silagem. Após a exposição aeróbia, a silagem do painel do silo estruturado parece sofrer menor interferência em relação à silagem após ser desensilada.

Abstract This study aimed to evaluate the chemical and fermentation quality of silage from two sorghum hybrids in different layers of the silo feed-out face, as well as the interference of the aerobic exposure time of structured and/or unstructured silo face (after feed-out). The AG-2005E hybrid silage presented higher crude protein content and higher pH compared to hybrid AG-60298 (6.33% and 4.0 versus 6.06% and 3.8, respectively). Silages from stratum 0 to 20cm had the lowest dry matter content and the highest crude protein content (38% and 6.35%, respectively). The pH did not differ between layers, and the NH3 content was higher in the stratum 60 to 80cm (4.5%). During 72 hours of aerobic exposure, the unstructured silage presented a higher increase in temperature than the silage from the structured face, but this period was not enough to result in differences in dry matter, mineral matter, NH3, and pH. The chemical and fermentation quality of the silage was directly influenced by hybrid and silo stratum. After aerobic exposure, silage from the structured face seems to suffer less interference compared to the silo feed-out face.

ABSTRACT. The objective of this work was to evaluate the chemical composition and rumen disappearance rate of dry matter of corn silages with inoculants combining L. buchneri strain LN40177 in different strata of the silo. The experimental design was a 3x2 randomized complete block design, with three treatments: Control: corn silage without inoculant; 11CFT: corn silage with inoculant which combines L. buchneri strain LN40177 (1.1 x 1011 CFU g-1) with L. casei (1.1 x 1011 CFU g-1); and 11C33: corn silage with inoculant which combines L. buchneri strain LN40177 (1.1 x 1011 CFU g-1) with L. plantarum (1.1 x 1011 CFU g-1) and Enterococcus faecium (1 x 1010 CFU g-1), associated with two strata of the silo (lower and upper). The silage inoculated with 11C33 presented higher contents of crude protein and NDF and lower hemicellulose content in relation to the control treatment and 11CFT. The use of both inoculants resulted in silages with higher concentrations of soluble nutrients. Lower stratum silage had a higher rumen disappearance rate of dry matter compared to the upper stratum. In general, the combinations of L. buchneri promoted nutritional improvements in corn silage, but in presence of L. casei, there were more outstanding improvements.