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The effect of increasing the concentration of commercial pequi ( Caryocar brasiliense ) oil on fermentation characteristics and abundance of methanogens and fibrolityc bacteria was evaluated using the rumen simulation technique (Rusitec). In vitro incubation was performed over 15 days using a basal diet consisting of ryegrass, maize silage and concentrate in equal proportions. Treatments consisted of control diet (no pequi oil inclusion, 0 g/kg DM), pequi dose 1 (45 g/kg DM), and pequi dose 2 (91 g/kg DM). After a 7 day adaptation period, samples for fermentation parameters (total gas, methane, and VFA production) were taken on a daily basis. Quantitative real time PCR (q-PCR) was used to evaluate the abundance of the main rumen cellulolytic bacteria, as well as abundance of methanogens. Supplementation with pequi oil did not reduce overall methane production ( P = 0.97), however a tendency ( P = 0.06) to decrease proportion of methane in overall microbial gas was observed. Increasing addition of pequi oil was associated with a linear decrease ( P < 0.01) in dry matter disappearance of maize silage. The abundance of total methanogens was unchanged by the addition of pequi oil, but numbers of those belonging to Methanomassiliicoccaceae decreased in liquid-associated microbes (LAM) samples ( P < 0.01) and solid-associated microbes (SAM) samples ( P = 0.09) respectively, while Methanobrevibacter spp. increased ( P < 0.01) only in SAM samples. Fibrobacter succinogenes decreased ( P < 0.01) in both LAM and SAM samples when substrates were supplemented with pequi oil. In conclusion, pequi oil was ineffective in mitigating methane emissions and had some adverse effects on digestibility and selected fibrolytic bacteria. [ABSTRACT FROM AUTHOR]

The possibility of replacing net with film to tie large round bales for silage making was investigated. A specifically designed polyethylene film has been developed and used to replace the typical net wrapping. A film-tying device, which was already on the market, was fitted to a variable chamber round baler and used instead of the standard net-tying system. A total of 48 round bales, consisting of half Italian ryegrass and half lucerne were baled following a 2-day wilting period. Half of the bales were net-tied and the other half film-tied. The bales were wrapped with 4 or 6 layers of stretch film and stored outside, half on their ends and half on their curved surfaces, for 180 days. The mechanical, fermentative and microbiological aspects were investigated. The work rate was not affected by the tying method. No evident damage to the film used for tying was observed before or after ejection from the baler or after the mechanical handling using a typical bale squeeze. Plastic consumption for film-tying was slightly higher, but mould on the bale surface was reduced compared to the net-tying method. This study has shown that film-tying could represent an interesting alternative to net-tying when preparing round bales for making silage. [Copyright &y& Elsevier]

The efficacy of biological control agents is affected by numerous cultural conditions. This study was undertaken to determine how the efficacy of Dilophospora alopecuri inoculum was affected by various conditions, including length of fermentation, moisture content, and growth substrate. Dilophospora alopecuri (Fr.) Fr. provides biological control of the organisms (Rathayibacter toxicus and Anguina funesta) responsible for annual ryegrass toxicity. The effectiveness of D. alopecuri inoculum was evaluated under different conditions for establishment in ryegrass. Prolongation of incubation of the inoculum for 3–10 weeks had no significant effect on the inoculum as a biological control agent. The effect of inoculum moisture content was mixed. With wheat as the substrate, air-drying the inoculum had no apparent effect. However, with ryegrass as the substrate, air-drying the inoculum decreased the effectiveness of the inoculum in the field experiment but not in the pot experiment. The substrate itself also had a significant effect. In the pots, application of colonized ryegrass gave a mean of 56.9 infected inflorescences per pot compared to 30.4 for colonized wheat. In the field experiment, 87.5% of plots inoculated with colonized ryegrass had 25 or more infected inflorescences, twice that of plots treated with colonized wheat. [Copyright &y& Elsevier]