Fermentation and Utilization of Grass Silage

Abstract

The decision to utilize particular forages in support of dairy production should be based on a number of key factors, such as available land base, type of manure management, soil type and topography, climate, and availability of purchased forages and feeds. Because of the complexity and environmental concerns existing in the dairy industry today, decisions about forage and manure management should include whole farm analysis with the aid of computer software. The chemical composition and digestibility of grass are affected more by stage of maturity than by other management factors, such as species, DM, or type of harvest system. The decline in digestibility of nutrients in first growth forage is approximately .55 to .68%/d and is dependent on the method of estimation. The decline in digestible DMI in first growth is .3 to .5%/d. The use of silage additives has become an integral part of forage management, and improvements in DMI and milk production are documented. Particle size and type of harvest equipment significantly affect eating behavior and efficiency of milk production. Wilting of silage results in an increase in DMI and efficiency of microbial protein production.

Effects of restriction of silage fermentation with formic acid on milk production

“…The responses are in line with observations in experiments where restrictively fermented FA silage has been compared with more extensively fermented inoculated silages (Heikkilä et al 1998, Shingfield et al 2002a. In a literature review by Harrison et al (1994), FA treatment increased intake of direct-cut silage by 2.3 to 15.2% and that of wilted material by 0.4% to 9.6% as compared with untreated silage.…”

“…The effect of FA on silage intake and animal performance is positive especially when compared to relatively poorly preserved untreated silage (Harrison et al 1994, Kung et al 2003. The effect of FA treatment on silage intake is mediated through effects on silage fermentation as silage intake is greatly influenced by the fermentation quality of silage (Huhtanen et al 2002).…”

The effect of high polyphenol oxidase grass silage on metabolism of polyunsaturated fatty acids and nitrogen across the rumen of beef steers1

“…The relatively high level of WSC in PR was related to the high-sugar grass selected (cv. AberStar) and the use of bacterial inoculant, which also resulted in relatively high levels of WSC in RC (Harrison et al, 1994;Merry et al, 2006). The chemical composition of CO was typical of that previously reported with low WSC and high NDF (Aufrère et al, 2003;Kammes and Allen, 2012).…”

“…As only PR falls within this range, it would appear that the DM content of RC was underestimated during feeding, resulting in more RC being offered than the 16 g DM/kg BW daily allowance, whereas CO intake was affected due to the low palatability of the high-fiber silage, as animals did not consume all silage offered. Palatability/maturity of silage has been reported to significantly affect intake in grass silages to a greater extent than legume silages (Harrison et al, 1994;Kuoppala et al, 2009). Ruminal pH mean values were typically greater than those previously reported for animals offered a sole forage diet (Lee et al, 2002;Merry et al, 2006) and may relate to the high DM and fiber content of the experimental silages.…”

"Efeitos da inoculação microbiana da silagem pré-secada de alfafa sobre a fermentação no silo, digestibilidade e desempenho produtivo de vacas leiteiras"

“…Os resultados obtidos com o uso dos vários aditivos existentes no mercado, quanto à preservação e fermentação da silagem, além de respostas no desempenho animal, vêm sendo extensivamente estudados ao longo da sua produção e utilização em todo o mundo (HARRISON et al, 1994 (BARRY et al, 1980;HENDERSON e McDONALD, 1984e HAIGH e PARKER, 1985. A adição de ácido fórmico restringe a fermentação dos açúcares liberados pela degradação da parede celular e dos açúcares já presentes na forragem, e estes efeitos são maiores na fermentação dos produtos da alfafa (NADEAU et al, 2000).…”