ABSTRACT. The experiment was carried out to evaluate total and partial digestibility of nutrients, the efficiency of microbial protein synthesis, in situ degradability and ruminal parameters in cattle fed diets with rehydrated corn grain silages, okara or soybean grain. Three Holstein steers were distributed in a 3 x 3 Latin square design. The treatments evaluated were: SO (corn grain silage + 30% okara), SSG (corn grain silage + 20% soybean grain) and CG (dry corn grains). The ruminal digestibility of non-fiber carbohydrates (NFC) increased in SO (88.34%) and SSG treatments (87.87%), compared to the CG treatment (63.48%). The minimum ruminal pH value was 6.01, observed 4.13 hours after feeding a diet with SO. The highest ammonia-N contents were 15.25 and 15.07 mg dL-1 observed in SSG and SO, respectively, 2.45 and 2.61 hours after feeding. Treatments SO and SSG showed higher fraction A content (readily degradable fraction) and C (constant rate of degradability of fraction B). The effective degradability (ED) of dry matter (DM) was higher for the diets SO and DE of CP was higher for treatments SO and SSG. SSG and SO result in better utilization of nutrients by animals.

ABSTRACT We ensiled different levels of okara and ground corn to evaluate the effects on the fermentative pattern, aerobic stability, and chemical composition of resulting silages. The experimental design was completely randomized with four replicates per treatment. The okara levels were (dry matter basis): control (without okara) and 200, 300, 400, and 500 g kg−1 okara, with four replicates per treatment. Control silage did not contain okara, but water was added to adjust the moisture content (400 g kg−1 as fed). Mixtures were ensiled in lab-scale silos and stored for 150 days. Compared with the control silage, okara inclusion linearly increased crude protein (from 89.1 to 251 g kg−1 DM), ether extract (from 39.6 to 136 g kg−1 DM), neutral detergent fiber (from 79.9 to 174 g kg−1 DM), acid detergent fiber (from 22.4 to 119 g kg−1 DM), and ash (from 12.2 to 32.4 g kg−1 DM), whereas decreased dry matter content and in vitro dry matter digestibility (from 830 to 730 g kg−1 DM). The use of okara linearly increased lactic acid concentration but also intensified secondary fermentation. On the other hand, aerobic stability of silages increased due to okara inclusion because of the higher amount of short-chain fatty acids, such as butyric and acetic acids, which accumulated during fermentation. Okara inclusion in corn grain silage must be conditioned to the dry matter content at ensiling, but must not exceed 200 g kg−1 on dry matter basis.

ABSTRACT We aimed to evaluate the effects of glyphosate as a chemical desiccant on the nutritional quality, fermentation pattern, and aerobic stability of wilted black oat (Avena strigosa Schreb) silage. Black oat sowing occurred in the first fortnight of May 2013. Desiccant application took place when oat reached milky/dough grain stage (96 days after planting). Glyphosate dosages evaluated were 0, 500, 750, 1000, and 1250 mL ha−1. Three days after desiccation, all treatments were ensiled, and the silos were kept stored for 150 days. A completely randomized design was used, and all statistical procedures were performed by means of Bayesian Inference. Treating herbage prior to ensiling from 500 mL ha−1 glyphosate increased dry matter and organic matter contents compared with control. On the other hand, fiber content decreased linearly for desiccated silages, as shown by the negative slopes for neutral detergent fiber, acid detergent fiber, and cellulose. The highest concentrations of hemicellulose and neutral detergent insoluble nitrogen occurred for the dosages of 729.96 mL ha−1 and 759.52 mL ha−1 glyphosate, respectively. Wilted silage had less concentration of acetic acid and isovaleric acid and presented a higher amount of 2,3-butanediol. Due to the lack of beneficial short-chain fatty acids, treated silages had a higher organic matter loss (0.1 g mL−1) and reached a maximum pH (0.009 h mL−1) more quickly than control silage, after aerobic exposure. In this way, for wilted black oat silage production, harvested at milky/dough grain stage, the application of 500 mL ha−1 glyphosate is recommended.

ABSTRACTThe objective of this study was to evaluate the production practices and use of corn silage in dairy farms in Southern Brazil, and to evaluate their impact on the nutritional quality and occurrence of mycotoxins. The data were collected by application of questionnaires among the producers, and by analysis of silage samples. The variables were subjected to factorial analysis of data reduction through the principal components method, thus obtaining 84.12% of the variance associated with the location, corn hybrid, crop production management, and inoculant used, characterizing the farms into four distinct groups. In farms from Paraná, the silage production technologies were more associated with implantation and crop management processes, and investment in equipment related to ensilage/silo feed-out was less frequent. Farms of Rio Grande do Sul showed high adoption of outsourced services, self-propelled machines, bunker silos, double-sided plastic film, and inoculant to control aerobic deterioration, and the silages showed higher levels of propionic acid (7.95 g/kg DM), and lower concentrations of aflatoxins (7.7 ppb) and total mycotoxins (26.58 ppb). The farms evaluated in Southern Brazil have good production efficiency and corn silages with excellent quality, regardless of their production characteristics.

Objetivou-se avaliar o efeito do uso de aditivo microbiano e de uréia na composição química, digestibilidade in vitro, no desaparecimento ruminal, e na estabilidade aeróbia de silagens de grãos úmidos de milho com adição de soja crua. Um segundo ensaio foi conduzido com o objetivo de avaliar a substituição do concentrado comercial por silagem de grãos de milho com adição de 20% de soja crua na produção e composição do leite de vacas holandesas. Para a avaliação das silagens foram feitos mini silos de pvc arranjados em delineamento inteiramente casualizado com três tratamentos (silagem de grãos úmidos de milho + 20% de soja crua; silagem de grãos úmidos de milho + 20% de soja crua + inoculante microbiano e silagem de grãos úmidos de milho + 20% de soja crua + 1,4% de ureia) e quatro repetições. As silagens apresentaram-se estáveis no período de 96 horas, com perdas de matéria seca de 3,55, 3,32 e 4,39 para silagens sem aditivos, com a adição de inoculante microbiano e com uréia respectivamente. A adição de uréia diminuiu a taxa de degradação ruminal das silagens de grãos úmidos de milho com adição de soja. Para a avaliação da produção e composição do leite foram utilizadas 20 vacas leiteiras arranjadas em delineamento inteiramente casualizado, com dois tratamentos e dez repetições. Verificouse que a silagem de grãos de milho com adição de grãos de soja pode ser usada na alimentação de vacas em lactação sem impacto sobre a produção e composição química do leite, mantendo os níveis de produção.

This study aimed to evaluate the effect of using microbial additive and urea on in vitro digestibility, in ruminal disappearance, and aerobic stability of moisture corn silage with the addition of raw soybeans. The experiment was conducted in a completely randomized design with three treatments (moisture corn grain silage + 20% of raw soybeans, moisture corn silage + 20% of raw soybean + microbial inoculant and moisture corn silage + 20% of raw soybean + 1.4% of urea) and four replications. Silages showed good aerobic stability, within the period of 96 hours, with few losses of dry matter and no consistent variations in the chemical composition. The Urea addition decreased the rate of ruminal degradation of the moisture corn silage with the addition of soybean. A second trial was conducted to evaluate the replacement of commercial concentrate by moisture corn silage with the addition of 20% of crude soybean, 20 dairy cows were used and arranged in a completely randomized design with two treatments and ten replicates. It was found that the moisture corn silage with added soybeans can be used in diets for lactating cows, in replacement of the commercial concentrate, with no impact on the production and chemical composition of the milk, maintaining production levels.