Characteristics and in situ degradability of whole crop faba bean, pea, and soybean silages

Abstract

P. 2003. Characteristics and in situ degradability of whole crop faba bean, pea, and soybean silages. Can. J. Anim. Sci. 83: 793-799. The objective of this study was to determine the ensiling characteristics and ruminal nutrient degradabilities of faba bean (FS, Vicia faba L.), soybean (SS, Glycine max (L.) Merr.) and pea (PS, Pisum sativum L.) silages. Forages were harvested between the beginning-and full-seed stages and ensiled in mini-silos for 0, 2, 4, 16, and 45 d. Two lactating Holstein cows fitted with ruminal fistulae were used to determine ruminal nutrient degradabilities. Results showed that all silages went through a rapid fermentation as indicated by rapid decline in pH and sharp increase in lactic acid concentration within the first 2 d of ensiling. Extensive proteolysis took place between day 0 and day 4 post-ensiling as indicated by a significant reduction in true protein (TP) and a significant increase in non-protein nitrogen (NPN). During the 45 d of ensiling, TP decreased (P < 0.05) by 26, 31, and 45% while NPN increased (P < 0.05) by 82, 54, and 47% for FS, SS, and PS, respectively. Chemical analysis showed that the three 45-d silages contained a similar level of neutral detergent fiber (NDF, average 421 g kg -1 ). Crude protein (CP) was highest (P < 0.05) for FS, intermediate for SS, and lowest for PS. Distribution of protein fractions showed that soluble protein and NPN were highest (P < 0.05) for PS, intermediate for SS, and lowest for FS. Neutral (NDICP) and acid (ADICP) detergent insoluble protein levels followed an opposite order to that observed for soluble crude protein (SCP) and NPN. Results of the in situ study showed that SS and PS had a similar ruminal degradability of dry matter (average 68.8%) and CP (82.9%), which were higher (P < 0.05) than those of FS (66.2 and 79.4%, respectively). However, no differences in ruminal degradability of NDF (average 34.7%) were observed between the three legume silages. . Les fourrages ont été récoltés du début à la fin de la production des graines puis stockés dans des silos miniatures pendant 0, 2, 4, 16 et 45 jours. Les chercheurs ont ensuite utilisé deux vaches Holstein en lactation pourvues d'une fistule au rumen pour vérifier la dégradation des éléments nutritifs. Les ensilages connaissent une fermentation rapide, comme le révèle la brusque chute du pH et la forte hausse de la concentration d'acide lactique au cours des deux premiers jours. Une forte protéolyse survient entre le jour 0 et le jour 4, ainsi qu'en témoignent la réduction appré-ciable de la concentration de vraies protéines (VP) et la hausse sensible de la teneur en azote non protéique (ANP). Pendant les 45 jours d'ensilage, la concentration de VP de l'EF, de l'ES et de l'EP baisse (P < 0,05) respectivement de 26, de 31 et de 45 % alors que celle d'ANP augmente (P < 0,05) de 82, de 54 et de 47 %. L'analyse chimique révèle que les trois ensilages contiennent une concentration analogue de fibres au détergent neutre après 45 jours d'ensilage (421 g par kilo, en moyenne). C'est l'...

Effects of bacterial inoculation on the fermentation characteristics and aerobic stability of ensiled whole plant soybeans (<i>Glycine max</i> (L.) Merr.)

“…This is agreement with Coffey et al (1995), who reported differences in DM content between Bay soybean forage and Stafford soybean forage at pre-ensiling. Mustafa & Seguin (2003) reported 264 g DM/kg in wilted forage soybean before ensiling, comparable with Link forage soybean before ensiling in the current study. However, the DM in forage soybean cultivars before ensiling was higher than 248 g DM/kg reported by Tobia et al (2008) in unwilted forage soybean at ensiling.…”

“…However, the present study agrees with that of Zhang et al (2013), who reported reduced CP content with LD inoculation in Urtica cannabina silage. Other studies (Mustafa & Seguin, 2003;Lima et al, 2013;Touno et al, 2014) have recorded CP values in soybean silage that are higher than in the soybean silage of the present study, which might be attributed to the different soybean forage cultivars used amongst these studies. Inoculation did not affect EE contents in soybean silages of the present study (Table 3).…”

“…The soybean cultivars had WSC content within this range (Table 1), with highest recorded in the Pannar cultivar (70 g WSC/kg DM). The WSC in forage soybean cultivars before ensiling was higher than 30 and 35 g WSC/kg DM recorded in other studies (Mustafa & Seguin, 2003;Mustafa et al, 2007). It has been reported that the initial WSC concentration in forages varies widely with genotype, maturity at harvest and climatic conditions such as crop heat units and frost (Addah et al, 2011), which might explain differences in WSC content in the soybean cultivars in this study compared with those recorded in the literature.…”

“…However, the pH was not low enough for efficient preservation, because it should range between 3.8 and 4.2 for well-preserved silage (Kung & Shaver, 2001), but was typical of that of soybean silage reported in the literature (e.g. Coffey et al, 1995, Nayigihugu et al, 2002, Mustafa & Seguin, 2003. The LD inoculation increased (P <0.05) silage pH compared with the control.…”

“…To have enough feed to sustain ruminant production during winter months or drought, forage soybeans could be ensiled for this purpose. Mustafa & Seguin (2003) reported that well-preserved silages can be produced from forage-typed soybean cultivars, but this forage has its own limitations for ensiling. These include its WSC content, relatively high buffering capacity and moisture which make it difficult to ensile it successfully without additives.…”