Effects of Bacillus subtilis and its metabolites on corn silage quality

Cellulolytic micro-organisms are potent silage inoculants that decrease the fibrous content in silage and increase the fibre digestibility and nutritional value of silage. This study aimed to evaluate the effects of Bacillus subtilis CCMA 0087 and its enzyme β-glucosidase on the nutritional value and aerobic stability of corn silage after 30 and 60 days of storage. We compared the results among silage without inoculant (SC) and silages inoculated with B. subtilis 8 log₁₀ CFU per kg forage (SB8), 9 log₁₀ CFU per kg forage (SB9) and 9·84 log₁₀ CFU per kg forage + β-glucosidase enzyme (SBE). No differences were observed in the levels of dry matter, crude protein and neutral detergent fibre due to the different treatments or storage times of the silos. Notably, the population of spore-forming bacteria increased in the SB9-treated silage. At 60 days of ensiling, the largest populations of lactic acid bacteria were found in silages treated with SB8 and SBE. Yeast populations were low for all silages, irrespective of the different treatments, and the presence of filamentous fungi was observed only in the SBE-treated silage. Among all silage treatments, SB9 treatment resulted in the highest aerobic stability.

Criteria for lactic acid bacteria screening to enhance silage quality

The main challenge of ensiling is conserving the feed through a fermentative process that results in high nutritional and microbiological quality while minimizing fermentative losses. This challenge is of growing interest to farmers, industry and research and involves the use of additives to improve the fermentation process and preserve the ensiled material. Most studies involved microbial additives; lactic acid bacteria (LAB) have been the focus of much research and have been widely used. Currently, LABs are used in modern and sustainable agriculture because of their considerable potential for enhancing human and animal health. Although the number of studies evaluating LABs in silages has increased, the potential use of these micro-organisms in association with silage has not been adequately studied. Fermentation processes using the same strain produce very different results depending on the unique characteristics of the substrate, so the choice of silage inoculant for different starting substrates is of extreme importance to maximize the nutritional quality of the final product. This review describes the current scenario of the bioprospecting and selection process for choosing the best LAB strain as an inoculant for ensiling. In addition, we analyse developments in the fermentation process and strategies and methods that will assist future studies on the selection of new strains of LAB as a starter culture or inoculant.

Productive performance of lambs fed with high-moisture triticale grain ensiled with different additives

This study aimed to evaluate the productive performance, nutrient intake, and ingestive behavior of lambs fed high-moisture triticale grain (HMTG) ensiled with different additives. Twenty-four intact male lambs with an initial body weight (BW) of 20.05 ± 2.88 kg were assigned to one of four dietary treatments: silage of HMTG, without additive; silage of HMTG ensiled with enzyme–bacterial additive; silage of HMTG ensiled with 0.5% urea; and silage of HMTG ensiled with 1.5% sodium benzoate. No difference (P > 0.05) was seen in the performance (with an average daily weight gain of 210 g d−1), nutrient intake, or ingestive behavior of the lambs. There was a significant difference in the intake of ether extract according to the additive used in the silage. The highest intake (in relation to metabolic BW) was found for HMTG ensiled with enzyme–bacterial additive: 1.49 g kg−1 BW0.75. The silage of HMTG can be used as a single source of concentrate, aiming at moderate weight gains for feedlot lambs, thus providing an alternative for the conservation of nutritional quality of ensiling without causing changes in the performance of the animals.

Fermentation Quality and Additives: A Case of Rice Straw Silage

Rice cultivation generates large amount of crop residues of which only 20% are utilized for industrial and domestic purposes. In most developing countries especially southeast Asia, rice straw is used as part of feeding ingredients for the ruminants. However, due to its low protein content and high level of lignin and silica, there is limitation to its digestibility and nutritional value. To utilize this crop residue judiciously, there is a need for improvement of its nutritive value to promote its utilization through ensiling. Understanding the fundamental principle of ensiling is a prerequisite for successful silage product. Prominent factors influencing quality of silage product include water soluble carbohydrates, natural microbial population, and harvesting conditions of the forage. Additives are used to control the fermentation processes to enhance nutrient recovery and improve silage stability. This review emphasizes some practical aspects of silage processing and the use of additives for improvement of fermentation quality of rice straw.

Chemical composition and in vitro ruminal degradation of hay and silage from tropical grasses

Arroquy, J. I., Cornacchione, M. V., Colombatto, D. and Kunst, Jr., C. 2014. Chemical composition and in vitro ruminal degradation of hay and silage from tropical grasses. Can. J. Anim. Sci. 94: 705–715. This study was conducted to evaluate the effects of preservation type on chemical composition and in vitro ruminal degradation of warm-season grasses (WSG). Treatments consisted of two factors (6×2): the first factor was tropical grasses: Cenchrus ciliaris (cv. Biloela, and cv. Molopo), Chloris gayana (cv. Callide and cv. Finecut), Panicum maximum, and Brachiaria bryzanta; and the second factor was preservation type (hay vs. silage). Cell wall, hemicellulose, cellulose, and water-soluble carbohydrate (P<0.05) concentrations were different among WSG. In general, hay or silage altered fiber content compared with fresh. For instance, hemicellulose and cellulose contents were lower in silage than in hay and fresh grass (P<0.05). Gas production rates were higher in silage from 0 to 24 h of fermentation, except at 4 h of incubation. After 24 h, gas production (GP) rate was similar for both preservation types, whilst potential GP was similar between preservation types. However, silage had decreased lag time compared with hay (P<0.01). Silage had greater dry matter disappearance than hay (P<0.05), and gas production yield was similar for grass species and preservation type. Our results indicate that WSG conserved as silage showed beneficial changes in chemical composition and dry matter degradation compared with hay.