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.

J.P. Ames, M.A. Neres, D.D. Castagnara, L.M. Mufatto, C. Ducati, C.C. Jobim, and T.T. Tres. 2014. Dry matter production, chemical composition, dry matter digestibility and occurrence of fungi in Bermuda grass hay (Cynodon dactylon) under different fertilization systems or associated with pea plantings in winter. Cien. Inv. Agr. 41(2): 163-174. This study aimed to evaluate the structural characteristics, dehydration curve, DM production, chemical composition, in vitro dry matter digestibility and occurrence of fungi in Bermuda grass hay (Cynodon dactylon cv. 'Bermuda grass', Tifton 85) produced in winter under different forms of fertilization or in association with a winter annual legume. The experimental design used was a randomized block with split plots in time and with four treatments: Bermuda grass without fertilization or intercropping, Bermuda grass with nitrogen (N) chemical fertilizer (100 kg N ha-'year-1), Bermuda grass oversown with forage pea (Pisum arvense cv. 'Iapar 83'), and Bermuda grass with the addition of 70 m³ ha-1 swine slurry. Three evaluation periods (cutting, baling and 30 days of storage) and five replicates were used. The DM yield of Bermuda grass without N was 2607 kg ha-1. The use of swine slurry increased the DM yield of Bermuda grass more than the use of the N chemical fertilizer (4864 and 3551 kg ha-1, respectively). In association with forage pea, a high total DM yield was obtained: 4261 kg ha-1 of pea and 2171 kg ha-1 of Bermuda grass. The dehydration time and final crude protein content of the Bermuda grass were higher in association with the legume. The levels of acid detergent-insoluble protein increased with storage. The in vitro DM digestibility reduced the cut to 30 days of storage in treatments with Bermuda grass without association with the legume. A higher occurrence of fungi occurred after 30 days of storage, with Penicillium generally predominant; however, Phoma was predominant in the hay produced from Bermuda grass grown with no N supplementation.

J.P. Ames, M.A. Neres, D.D. Castagnara, L.M. Mufatto, C. Ducati, C.C. Jobim y T.T. Tres. 2014. Producción de materia seca, composición química, digestibilidad de la materia seca y la aparición de hongos en heno de pasto Bermuda (Cynodon dactylon) bajo diferentes sistemas de fertilización o asociado con leguminosa anual de invierno. Cien. Inv. Agr. 41(2): 163-174. Este estudio tuvo como objetivo la evaluación de la curva de características estructurales, la deshidratación, la materia seca (MS), la composición química, digestibilidad in vitro de la MS y la aparición de hongos en heno de pasto Bermuda (Cynodon dactylon, cv. 'Tifton 85'), producido en invierno, bajo diferentes formas de fertilización o en asociación con una leguminosa anual de invierno. El diseño experimental utilizado fue de bloques al azar con parcelas divididas en el tiempo con cuatro tratamientos: Pasto Bermuda sin fertilización o consorcio, pasto Bermuda con fertilizante químico de nitrógeno (100 kg N ha- ¹ año -1), pasto Bermuda en asociación con el legume (Pisium avarse 'Iapar 83'), y pasto Bermuda con la adición de 70 m³ de purines ha-1 durante tres periodos de evaluación (de corte, de balas y 30 días de almacenamiento), con cinco repeticiones. El rendimiento de MS de pasto Bermuda sin nitrógeno fue 2.607 kg ha-1. El uso de purines porcinos aumentó el rendimiento de MS de pasto Bermuda más que el uso del nitrógeno fertilizante químico (4864 y 3551 kg ha-1, respectivamente). Su asociación con la leguminosa, de alto rendimiento de MS total, obtuvo: 4.261 kg ha-1 de guisantes y 2.171 kg ha-1 de pasto Bermuda. El tiempo de deshidratación y de proteína cruda total del heno de pasto Bermuda fueron más altos en asociación con leguminosas. Los niveles de la proteína insoluble en detergente ácido aumentaron con el almacenamiento y la digestibilidad de la MS in vitro, reduciendo el corte a los 30 días de almacenamiento en los tratamientos con pasto Bermuda y sin asociación con leguminosas. La mayor incidencia de los hongos se produjo después de 30 días de almacenamiento, con un predominio de Penicillium, excepto en el heno de pasto Bermuda, en ausencia de nitrógeno, donde el género predominante fue Phoma.

The experiment was carried out to evaluate the structural characteristics, biomass accumulation, chemical composition and in vitro digestibility of dry matter and crude protein of white oat (Avena sativa L. IPR 126) under different management systems. Grazing, cut at two heights (15 and 20 cm) and free growth were all evaluated in three periods (July, August and September) with a 28-day average interval between evaluations. In the free growth system, samples at 15 and 20 cm were also taken at the intervals chosen for cutting and grazing. The experimental design was in randomized blocks with three replications, arranged in a 3 × 2 factorial split plot design over time; systems of management and heights were the factors of plots, and time was taken as subplot. There was higher straw production under free growth, but, with decreased chemical quality from the first to the second period and from the second to the third one, with 236.4, 172.5, and 91.4 g/kg crude protein values, respectively. Regarding cutting and grazing systems, they showed structural changes in tillering, which was favored by the cut, but with some reduction in the periods. Nutritional quality values were close to cutting and grazing with high crude protein content (216.6 g/kg), adequate neutral detergent fiber (535.4 g/kg) content and high in vitro digestibility of dry matter (826.3 g/kg). Management heights promoted few changes in the characteristics evaluated. After the third period, cutting and grazing systems showed no suitable residual straw for ground covering and set a summer crop under no-tillage system, with 738.39 kg/ha of residual dry matter on average.