Dry matter and crude protein degradability of Napier grass (Pennisetum purpureum) silage is affected by fertilization with cow-dung bio-digester slurry and fermentable carbohydrate additives at ensiling

Abstract

Dry seasons pose a major nutritional constraint on ruminant livestock production in tropical regions, which justifies forage conservation to meet the dry season feed requirement. Napier grass is a tropical forage that is used for silage in South Africa. The present objective was to determine the effects of Napier grass fertilization with bio-digester slurry (BDS) and the inclusion of fermentable carbohydrate additives at ensiling on the chemical composition and ruminal degradability of Napier grass silage. Napier grass was established in 5 x 4 metre plots, replicated three times in a completely randomized design, and irrigated weekly with either BDS or water. After 12 weeks, the Napier was cut and ensiled for 90 days in 1 liter glass jars in a 2 (BDS, Water) x 4 (no-additive, molasses, brown sugar, and maize meal) factorial arrangement replicated three times. The nutrient composition was determined using standard protocols. The ruminal degradability of dry matter (DM) and crude protein (CP) were determined using the nylon bag technique. Fertilization with BDS increased (p < 0.05) pH and CP and reduced (p < 0.05) fat content of fresh cut Napier. Additives increased (p < 0.01) silage DM content and reduced (p < 0.01) ADF, NDF content. The BDS fertilization with molasses inclusion increased (p < 0.05) silage DM relative to the no-additive and maize meal inclusion, and decreased (p < 0.05) fat content compared to the no-fertilizer, added maize meal silage.. Molasses increased silage WSC and decreased the NH3-N content (p < 0.05) compared to the no-additive and maize meal treatments. For DM, the BDS fertilized, no additive silage had the least “a” fraction (p<0.01), while the no BDS, no- additive silage had the least “b” fraction (p<0.01), with least (p<0.01) potential degradability observed for the no BDS, no-additive treatment. Fertilization increased (p<0.01) effective degradability of DM at outflow rates k = 0.02, 0.05, 0.08, with same effect for molasses and maize meal inclusion. Relative to the control, molasses inclusion increased (p<0.01) potential degradability of silage CP. In conclusion, our results suggested BDS fertilization of Napier grass ensiling with added readily fermentable carbohydrate substrate, particularly from molasses, induced changes in silage chemical and fermentation characteristics likely to promote better forage preservation and ruminal microbial function.

Mixed Leucaena and molasses can increase the nutritional quality and rumen degradation of corn stover silage

“…The dead bacteria will also be considered CP when analyzing the CP content of the silage. The current results are in contrast to those found by Rambau et al [ 21 ], who reported a substantial numerical reduction in CP silage in their study by adding fermentable carbohydrate additives. The highest CP content at 11.89% found in this experiment is enough to fulfill cattle needs for maintaining their life.…”

“…However, in our study, no investigation was carried out on the population and epiphytic diversity of LAB that grew during the ensiling process. The results study by Rambau et al [ 21 ] also showed an increase in DM silage due to the combined effect of bio slurry-digester with molasses. Silage with a high DM content shows that the nutrient contained also increases; for example, this study shows an increase in CP and energy silage.…”

Nutritive and Fermentative Traits of African Stargrass (Cynodon nlemfuensis Vanderyst) Forage Preserved for Silage and Haylage

“…Nevertheless, it is widely acknowledged that tropical grasses inherently possess lower levels of soluble carbohydrates; Kagan et al [44] reported 6.3% WSC in Bermudagrass and 4.3% in Tifton 85 Bermudagrass before preservation [36]. Values of 1.4, 1.25, and 1.63% WSC were obtained in silage of different tropical grasses [45][46][47], similar to WSC in haylage. Understanding the dynamics of WSC content during conservation is crucial for developing strategies to enhance fermentation efficiency and improve silage nutritive value.…”

“…The paddock was then fertilized at a rate of 200 kg N ha −1 year −1 (144 kg of urea [46% N].harvest −1 ) and harvested at 50 d of regrowth in late August 2021 with a FiMAKS model Double Chop 1550 forage harvester. The treatments consisted of silage or haylage preserved at four preservation periods (45,60,90, and 120 d) as factors, with 6 replicates per combination (n = 48 experimental units). The forage was filled and compacted in 50 kg plastic silage bags using a Silo Pack J-402 machine, with silage treatments prepared at harvest.…”

“…The experimental design was a randomized complete block design with a 2 × 4 factorial, with two treatments (silage and haylage) and four preservation periods (45,60,90, and 120 d) and six replications (n = 48). The data for nutritive and fermentative traits were analyzed using a generalized linear model (GLM) procedure in R-Studio [30], with mean separations by treatment or factor using the least significant difference (LSD) post hoc test.…”