F. H. S. Rabelo

What is the best additive to use at the ensiling of sugarcane SP81-3250?

Our objective was to determine the best additive to use for the ensiling of sugarcane SP81-3250 based on the nutritional properties and aerobic stability of the silages. The additives evaluated were (1) and (2): salt (NaCl) at rates of 1.0 or 2.0 kg/100 kg fresh sugarcane (as-is basis), respectively; (3) and (4): quicklime (CaO) at rates of 1.0 or 2.0 kg/100 kg fresh sugarcane, respectively; (5) and (6): commercial inoculants Silobac® and Maize All®; and a control treatment. The addition of quicklime reduced the NDF and ADF contents of the silages by 11% compared with the control treatment, but did not increase the digestibility. On the other hand, after 24 h of in vitro fermentation, the application of 1.0 and 2.0% salt reduced the gas production by 34.15 and 33.55 mL/g OM, respectively, and the IVOMD was reduced 5.74 and 5.90%, respectively, compared with the untreated silage. Moreover, the addition of quicklime elevated the pH of the sugarcane silages, with a trend towards an increase in the DM recovery. In contrast, the bacterial inoculants did not alter the pH values, but there was an upward trend for a DM recovery. After the silos were opened, the silages that were treated with salt (independent of the dose) and 1.0% quicklime exhibited greater stability. We recommend applying 1.0 kg of quicklime to each 100 kg of sugarcane at the time of ensiling to improve the nutritional characteristics of sugarcane silage variety SP81-3250.

Silagens de milho inoculadas microbiologicamente em diferentes estádios de maturidade: perdas fermentativas, composição bromatológica e digestibilidade in vitro

The aim of this study was to evaluate the fermentative losses, chemical composition and in vitro organic matter digestibility of corn silages produced in different maturity stages microbiologically inoculated. Two commercial inoculants were applied in the silages produced in stages SLL, 1/3 LL, 1/2 LL, 2/3 LL and CN, remaining an uninoculated treatment (control silage), illustrating a factorial scheme 3 x 5. The lactic acid bacteria (LAB) inoculation resulted in lower fermentative losses (P=0.0348), whereas silages produced with dried plants present lower DM losses (P<0.01). Because of inoculant application, there was higher concentrations of CP in the silages produced in stages SLL, 2/3 LL and CN (P=0.0033) and concentration lower of NDF (P=0.0140) in CN stage because of the Maize All® inoculant. This inoculant provided increase in the IVOMD coefficients when the plants were harvested with 2/3 LL and CN (P= 0.0006). Fermentative losses decreased because of the use of microbial inoculants, and this fact it is also observed in silages produced with dried plants. Application of lactic acid bacteria (Maize All® inoculant) in corn silages produced with plants harvested in more advanced stages of maturity improve the chemical composition and in vitro digestibility.

Características agronômicas e bromatolôgicas do milho submetido a adubações com potássio na produção de silagem

Objetivou-se avaliar doses e formas de aplicacao do potassio nas caracteristicas agronomicas e bromatologicas na cultura do milho para ensilagem. O experimento foi conduzido na UNIFENAS durante o ano agricola de 2008/2009. A adubacao de plantio e a semeadura foram realizadas manualmente, utilizando-se 120 kg ha-1 de P2O5, 30 kg ha-1 de N, o potassio foi aplicado de acordo com os tratamentos. O delineamento experimental utilizado foi em blocos casualizados, em arranjo fatorial 4x2, com quatro repeticoes, fazendo-se uso de quatro doses (0; 60; 90 e 120 kg ha-1) e duas formas de aplicacao do K (100% no plantio e 50% no plantio + 50% em cobertura). A interacao entre os fatores doses e forma de aplicacao do potassio nao foi significativa (p>0,05) para as variaveis estudadas, passando-se a estudar o efeito principal de cada fator. Nao houve efeito (p>0,05) das doses de K sobre as porcentagens de MS e plantas acamadas, produtividade de MS e graos e participacao de graos na massa. A maior produtividade de graos foi obtida empregando-se o K totalmente no plantio (p<0,05). Elevadas doses de potassio nao proporcionaram mudancas para MS, porcentagem de plantas acamadas, produtividade de MS, produtividade de graos e porcentagem de graos na planta. As diferentes doses e formas de aplicacao de potassio nao alteram as caracteristicas bromatologicas da silagem de milho.