The effect of Lactobacillus buchneri and L. plantarum, applied at ensiling, on the ensiling fermentation and aerobic stability of wheat and sorghum silages

The effect of applying Lactobacillus buchneri (LB), alone or in combinations with L. plantarum (LP) and yeasts at ensiling, on the ensiling fermentation and aerobic stability of wheat and sorghum silages was studied under laboratory conditions. Treatments comprised LB, LP, yeasts, LB + yeasts, LP + yeasts, LB + LP and B-589 (a lactic acid bacterial strain isolated from wheat silage in Israel) alone. The treatments were also applied to sterilized aqueous extracts of wheat which were incubated at 30°C for 10 days. The pH of all treatments was below 4.0 already on day 4 of the experiment. Silages treated with LB had higher acetic acid concentrations than those treated with LP: 32–34 vs 16–18, and 28–34 vs 4–7 g kg⁻¹ in the experiments with wheat and sorghum, respectively. Similar results were obtained in wheat extracts. In the aqueous phase, marked differences in pH decrease were noticed among the treatments: 4.4 in LB, 6.0 in the yeast, and 3.7 in LP and B-589 (from day 3 and onwards). In both crops LB resulted in aerobically stable silages when applied alone or with LP and yeasts, whereas LP resulted in unstable silages upon aerobic exposure; the stability of the LB-treated silages is attributed to the higher acetic acid concentrations. The isolated strain (B-589) did not exhibit any advantage with regard to aerobic stability. Received 26 April 1999/ Accepted in revised form 05 July 1999     

Fermentation patterns of forage sorghum ensiled under different environmental conditions

The effects of temperature, aerobic and anaerobic conditions in the silo and plant characteristics [water-soluble carbohydrate (WSC) contents, growing season] on the fermentation characteristics of a tropical forage species, Sorghum bicolor cv. sugar-drip, were investigated. Silages fermented in oxygen-impermeable bags were well preserved and had low pH (3.7), high lactic acid [72 g kg^–1 dry matter (DM) 80% of total acids], and low butyric acid (0.12 g kg^–1 DM) and ammonia nitrogen (NH₃–N) (57 g kg^–1 total nitrogen contents. Conversely, the use of oxygen-permeable bags as silos allowed aerobic decomposition of the ensiled forages. Increasing the incubation temperature lowered the population of lactic acid bacteria, reduced lactic acid production and caused the pH to rise. The heterofermentative Leuconostoc spp. predominated on fresh forages but homofermentative Lactobacillus plantarum began to dominate after 5 and 8 days of fermentation. Heterofermentative lactobacilli, notably Lactobacillus brevis, were dominant among the isolates obtained from 100-day silages. Varying the WSC contents, by crushing and/or chopping the forage, and growing season did not significantly affect the fermentation quality of the resulting silages. It was concluded that the maintenance of anaerobic conditions is essential if good quality silage is to be produced from tropical forage species.     

Effects of <Emphasis Type="Italic">Lactobacillus buchneri</Emphasis> and <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> on fermentation,aerobic stability,bacteria diversity and ruminal degradability of alfalfa silage

Silages are important feedstuffs. Homofermentative lactic acid bacterial inoculants are often used to control silage fermentation. However, some research pointed out those homofermentative lactic acid bacteria (LAB) impaired the aerobic stability of wheat, sorghum, and corn silages. Adding heterofermentative LAB can produce more acetic acid, thereby stabilizing silages during aerobic exposure. Alfalfa is difficult to ensile. The present work was to study the effects of L. buchneri (heterofermentative LAB), alone or in combination with L. plantarum (homofermentative LAB) on the fermentation, aerobic stability, bacteria diversity and ruminal degradability of alfalfa silage. After 90 days ensiling, the pH, NH₃-N/TN, butyric acid content and molds counts of control were the highest. The inoculated silages had more lactic acid, acetic acid content and more lactic acid bacteria than the control. Inoculating LAB inhibited harmful microorganisms, such as Enterobacterium and Klebsiella pneumoniae. The L. buchneri + L. plantarum-inoculated silage had more acetic acid and less yeasts than other three treatments (P < 0.05), and lower NH₃-N/TN than control (P < 0.05). The CO₂ production of L. buchneri + L. plantarum-inoculated silage was less than that of L. plantarum-inoculated silage (P < 0.05). Inoculating LAB in alfalfa silages can decrease pH, increase the production of lactic and acetic acids, reduce the number of yeasts and molds, and inhibit Enterobacterium and K. pneumoniae. Inoculating with L. buchneri or L. buchneri + L. plantarum can improve aerobic stability of alfalfa silages. A combination of L. buchneri and L. plantarum is preferable because it enhanced alfalfa silage quality and aerobic stability.     

Survival of <Emphasis Type="Italic">Listeria monocytogenes</Emphasis> in Wilted and Additive-Treated Grass Silage

Grass was field-dried to 3 different dry matter (DM) levels (200, 430 and 540 g/kg) and inoculated with 10⁶–10⁷ cfu/g of a Listeria monocytogenes strain sharing a phagovar occasionally involved in food-borne outbreaks of listeriosis. Formic acid (3 ml/kg) or lactic acid bacteria (8·10⁵/g) with cellulolytic enzymes were applied only to forages with low and intermediate DM levels. Forages were ensiled in laboratory silos (1700 ml) and were stored at 25°C for 30 or 90 days. After 90 days of storage, L. monocytogenes could not be detected in any silo, except one with the high dry matter grass without additive. After 30 days of storage, between 10² and 10⁶ cfu L. monocytogenes/g silage were isolated from the untreated silages. Increasing the DM content from 200 to 540 g/kg did not reduce listeria counts possibly because of the lower production of fermentation acids (higher pH). In silages treated with additives, counts of L. monocytogenes were always lower than in silages without additive. In wet silages (DM 200 g/kg) both additives were effective, but in the wilted silages (DM 430 g/kg) only the bacterial additive reduced listeria counts below detection level. Listeria counts were highly correlated to silage pH (r = 0.92), the concentration of lactic acid (r = -0.80) and the pooled amount of undissociated acids (r = -0.83).     

Temperate forages ensiled with molasses or fresh cheese whey: Effects on conservation quality, effluent losses and ruminal degradation

Effects of ensiling and adding molasses or increasing levels of fresh cheese whey on the conservation and rumen degradability of temperate pasture silages were evaluated. Forage from three paddocks of mixed grass and legume pastures was used to make 45 silages (15 silages per paddock) with 5 treatments, including silage without additives (control), silage with 15 g/kg dehydrated molasses and silage with 20, 50 and 100 g/kg fresh cheese whey. The chemical composition and fermentation quality (i.e., pH, ammonia N, loss of dry matter (DM) and neutral detergent fibre (NDF), effluent production) of the silages were determined. Fresh and ensiled materials were evaluated for in situ rumen degradability. Ensiling reduced DM and NDF rumen degradability (P<0.01). When additives were employed, the reduction of DM degradability of the silages decreased (P≤0.03). Addition of molasses led to the lowest pH (P<0.01) and DM losses (P<0.01), and highest DM degradability (P<0.01). The conservation and DM degradation results of dried molasses silage was superior to those of fresh whey silages. In general, an increase in the level of whey increased DM degradability (P≤0.03), but linearly increased effluent production (P<0.01) and losses (P<0.01).     

The effects of temperature on the aerobic stability of wheat and corn silages

The aim of this work was to study the effects of temperature on the aerobic stability of wheat and corn silages. Three silage samples from each crop were taken from the faces of six different commercial bunker silos immediately after unloading them. The samples were exposed to air for 3 or 6 days at 10, 20, 30 or 40°C. The most intensive deterioration occurred at 30°C. Samples incubated at 30°C had the highest yeast counts, most prolific CO₂ production and greatest increases in pH. Silage samples exposed to 10 or 40°C remained stable. The duration of exposure had a significant effect on aerobic stability, especially at 30°C. Temperature has a significant effect on silage aerobic stability. In a warm climate, special care should be taken during unloading of silage in order to prevent intensive aerobic deterioration. Journal of Industrial Microbiology & Biotechnology (2002) 28, 261–263 DOI: 10.1038/sj/jim/7000237 Received 12 June 2001/ Accepted in revised form 02 November 2001     

The effect of a propionic acid bacterial inoculant applied at ensiling on the aerobic stability of wheat and sorghum silages

The effect of a new strain ofPropionibacterium shermanii (PAB), applied at ensiling, on the aerobic stability of wheat and sorghum silages was studied in several experiments under laboratory conditions. In the one experiment with wheat and in those with sorghum a lactic acid bacteria (LAB) inoculant (Lactobacillus plantarum andPediococcus cerevisiae) was also included. After treatment, the chopped forages were ensiled in 1.5-L anaerobic jars which were sampled in triplicate on predetermined dates to follow fermentation dynamics. At the end of the experiments, the silages were subjected to an aerobic stability test. The PAB inoculant improved the aerobic stability only in one experiment with wheat, in which the decrease in pH was very slow; the final pH remained relatively high (4.5). The PAB-treated silages contained 19.5±2.0 g of propionic acid per kg of dry matter. In the experiments with sorghum, the control and PAB-inoculated silages were stable, whereas LAB-inoculated silages deteriorated. The results suggest that PAB can survive in and improve the aerobic stability of only slow-fermenting silages which are prone to aerobic deterioration.     

Bacterial and fungal communities of wilted Italian ryegrass silage inoculated with and without Lactobacillus rhamnosus or Lactobacillus buchneri

Aims: To understand the effects of lactic acid bacteria (LAB) inoculation on fermentation products, aerobic stability and microbial communities of silage. Methods and Results: Wilted Italian ryegrass was stored in laboratory silos with and without inoculation of Lactobacillus rhamnosus and Lactobacillus buchneri. The silos were opened after 14, 56 and 120 days and then subjected to aerobic deterioration for 7 days. Intensive alcoholic fermentation was found in untreated silage; the sum of ethanol and 2,3‐butanediol content at day 14 was about 7 times higher than that of lactic and volatile fatty acids. Alcoholic fermentation was suppressed by L. rhamnosus and L. buchneri inoculation and lactic acid and acetic acid became the dominant fermentation products, respectively. Silages were deteriorated in untreated and L. rhamnosus‐inoculated silages, whereas no spoilage was found in L. buchneri‐inoculated silage. Enterobacteria such as Erwinia persicina, Pantoea agglomerans and Rahnella aquatilis were detected in untreated silage, whereas some of these bacteria disappeared or became faint with L. rhamnosus treatment. When silage was deteriorated, Lactobacillus brevis and Bacillus pumilus were observed in untreated and L. rhamnosus‐inoculated communities, respectively. The inoculated LAB species was detectable in addition to untreated bacterial communities. Saccharomyces cerevisiae and Pichia anomala were the main fungi in untreated and L. rhamnosus‐inoculated silages; however, P. anomala was not visibly seen in L. buchneri‐inoculated silage either at silo opening or after exposure to air. Conclusion: Inoculation with L. rhamnosus can suppress alcoholic fermentation of wilted grass silage with elimination of enterobacteria at the beginning of fermentation. Addition of L. buchneri may improve aerobic stability, with distinct inhibitory effect observed on P. anomala after silo opening. Significance and Impact of the Study: Bacterial and fungal community analyses help us to understand how inoculated LAB can function to improve the fermentation and aerobic stability of silage.     

Intake, digestibility, rumen fermentation and performance of beef cattle fed diets based on whole-crop wheat or barley harvested at two cutting heights relative to maize silage or ad libitum concentrates

This experiment aimed to quantify the relative intake, digestibility, rumen fermentation, performance and carcass characteristics of beef cattle fed diets based on good quality whole-crop wheat and barley silages, each harvested at two cutting heights, and to rank these relative to good quality maize silage and an ad libitum concentrates-based diet. Ninety beef steers, initial live-weight 438 ± 31.0 kg, were allocated to one of the following dietary treatments in a randomised complete block design: maize silage (MS), whole-crop wheat harvested at a normal cutting height (WCW) (stubble height 0.12 m) or an elevated cutting height (HCW) (stubble height 0.29 m), whole-crop barley harvested at a normal cutting height (WCB) (stubble height 0.13 m) or an elevated cutting height (HCB) (stubble height 0.30 m), each being supplemented with 3 kg concentrates/head/day, and ad libitum concentrates (ALC) supplemented with 5 kg grass silage/head/day for the duration of the 160-day study. Mean dry matter (DM) of the maize silage, whole-crop wheat, head-cut wheat, whole-crop barley and head-cut barley was 301, 488, 520, 491 and 499 g/kg, respectively. There were no differences in total DM intake among treatments, or in rumen fermentation characteristics (except ammonia), or in DM digestibility among the forage-based treatments. Neutral detergent fibre digestibility was lower (P<0.05) for whole-crop wheat than head-cut barley, and starch digestibility was lower (P<0.05) for whole-crop barley and head-cut barley than maize silage. Steers fed ALC had a higher carcass gain (P<0.001) and carcass weight (P<0.05) than all other treatments, but there were no differences between any of the forage-based treatments. Steers fed MS had a better feed conversion efficiency (FCE) than those on WCW or WCB (P<0.05) but were similar to HCW and HCB. The FCE was better for ALC versus any of the other treatments, particularly compared to WCW or WCB (P<0.001). Subcutaneous fat from steers fed ALC was more yellow (P<0.01) than that from steers fed the other treatments. Neither intake nor performance were altered by raising the cutting height of cereals or by replacing whole-crop wheat by barley. However, head-cut cereals numerically favoured DM intake, carcass gain and feed conversion efficiency values nearer to that of maize than whole-crop cereal silages. Ad libitum concentrates supported superior levels of growth by steers compared to all other treatments.     

Chemical composition,digestibility and in situ degradability of dried and ensiled apple pomace and maize silage

The nutritive value of the dried and ensiled apple pomace (DAP and EAP), taken from two processing factories in Urmia city, was compared with maize silage (MS). For EAP, 1 tonnes of AP was mixed with 100 kg of wheat straw and 5 kg of urea (on fresh weight basis). The chemical composition of all feedstuffs was determined by laboratory analysis. Additionally, pH and the concentration of ammonia-N and volatile fatty acids (VFA) were measured in the EAP and MS silages. An in vivo digestibility study was undertaken with three Gezel wether sheep to determine the digestible organic matter content in the dry matter (DOMD) and to estimate the metabolisable energy (ME) content. The dry matter (DM) and protein effective degradabilities (ED) of the feedstuffs were assessed using a nylon bag method. The mean values of the DM, OM, CP, acid detergent fibre (ADF), neutral detergent fibre (NDF), lignin and acid detergent insoluble nitrogen (ADIN) were, respectively, 749 g/kg fresh weight, 929, 64, 405, 473, 10 and 5.6 g/kg DM for DAP, 284 g/kg fresh weight, 925, 72, 460, 567, 20 and 6.5 g/kg DM for EAP and 429 g/kg fresh weight, 936, 260, 463, 44 and 4.4 g/kg DM for MS. No butyric acid was found in EAP and MS, which indicate good preservation for these silages. However, ammonia-N was higher in MS than EAP. The DOMD values were 690, 654 and 580 g/kg DM for DAP, MS and EAP, respectively. The DOMD and ME values for DAP and MS were significantly higher than those of EAP. The dry matter ED of EAP was significantly lower than that of DAP and MS and there was a significant difference among all feedstuffs in the protein ED where MS was the highest and EAP the lowest. The nutritive value of AP was reduced by the addition of wheat straw. However, ensiling apple with straw is a practical method to preserve such high moisture by-product.     

The effect of Lactobacillus buchneri on the fermentation, aerobic stability and ruminal degradability of maize silage

AIMS: To evaluate the effect of Lactobacillus buchneri, heterofermentative lactic acid bacteria (LAB), on the fermentation, aerobic stability and ruminal degradability of whole-crop maize silages under laboratory conditions. Two homofermentative LAB were tested for the purpose of comparison. METHODS AND RESULTS: Maize was harvested at early dent [290 g kg(-1) dry matter (DM)] and one-half milk line (355 g kg(-1) DM) stages. Both homofermentative LAB were applied at 1 x 10(5) CFU g(-1) of fresh forage. Lactobacillus buchneri was applied at 1 x 10(5), 5 x 10(5) and 1 x 10(6) CFU g(-1) of fresh forage. Silages with no additives served as control. After treatment, the chopped forages were ensiled in 1.5-l anaerobic jars. Three jars per treatment were sampled on day 60. After 60 days of storage, silages were subjected to an aerobic stability test lasting for 5 days, in which CO(2) production, as well as chemical and microbiological parameters, was measured to determine the extent of aerobic deterioration. Both homofermentative LAB increased the concentration of lactic acid and the numbers of yeasts, and decreased the concentration of acetic acid and impaired the aerobic stability of silages. In contrast, applying L. buchneri decreased the concentration of lactic acid and increased the concentration of acetic acid of the silages. Under aerobic conditions, silages treated with 5 x 10(5) and 1 x 10(6) CFU g(-1) of L. buchneri, had lower pH, CO(2) production and the numbers of yeasts than the silages treated with 1 x 10(5) CFU g(-1) of L. buchneri (P < 0.05). However, all doses of L. buchneri and both homofermentative LAB did not affect in situ rumen DM, organic matter and neutral detergent fibre degradability of the silages. CONCLUSIONS: Lactobacillus buchneri was very effective in protecting maize silages exposed to air under laboratory conditions. All doses of L. buchneri, especially 5 x 10(5) CFU g(-1) or more, markedly decreased the numbers of yeasts and improved the aerobic stability of silages. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of L. buchneri, as a silage inoculant, can improve the aerobic stability of maize silages by inhibition of yeast activity.     

Effects of feeding level and NDF content of grass-clover silages on chewing activity,fecal particle size and NDF digestibility in dairy heifers

The objective of this study was to assess effects of feed intake and NDF content of highly digestible grass-clover silage on chewing behavior, fecal particle size distribution and apparent digestibility in restrictively fed heifers. Four grass-clover silages (Lolium perenne, Trifolium pratense and Trifolium repens) were harvested in 2009 at different regrowth stages, resulting in silages with NDF contents of 312, 360, 371 and 446 g/kg dry matter (DM), respectively. Four rumen-fistulated Jersey heifers (343±32 kg BW) were fed silage at 90% of ad libitum levels in a 4×4 Latin square design, replicated with further restricted feeding levels (50%, 60%, 70% or 80% of ad libitum) in a balanced 4×4×4 Greco-Latin square design. Eating activity was estimated from test meal observations, while rumination activity was estimated from jaw movements logged by a jaw recorder system. Total tract digestibility was estimated from chromic oxide marker and fecal spot sampling, and fecal particle size distribution in washed and freeze-dried particulate DM was determined by dry sieving (2.36, 1.0, 0.5, 0.212 and 0.106 mm, and bottom bowl). Higher NDF content of silage stimulated longer eating time per kg DM intake (P<0.001), while reduced feeding level caused a reduction in eating time per kg DM intake (P<0.001) and NDF (P<0.001). Rumination time per kg DM intake (P<0.01) increased with reduced feeding level, with less effect of feeding level at lower NDF contents (P<0.01) and more rumination with greater NDF content (P<0.01). Relative to NDF intake, rumination time increased with greater NDF content (P<0.01), at a higher rate with reduced feeding level (P<0.05). Digestibility of potentially digestible NDF (DNDF) decreased with greater NDF content (P<0.001) and increased with reduced feeding level (P<0.05). Increasing NDF content resulted in more particulate DM in feces (g/kg DM; P<0.05) and larger mean particle size (P<0.001). In conclusion, feeding heifers with grass-clover silages of decreasing NDF content increased chewing time relative to NDF intake, reduced mean fecal particle size, and increased DNDF digestibility. Restricting feeding level made heifers eat for a shorter time period while rumination and total chewing was increased, causing the ratio between eating and rumination time to decrease with lower intake of forage fiber. Particle size reduction and digestibility depended mostly on changes in NDF content, especially the indigestible NDF content.     

Characterizing the ensiling properties of sugarbeets with dry feedstuffs

A study was conducted to evaluate the ensiling characteristics of chopped sugarbeets with dry feedstuffs and the corresponding change in the nutritive composition of the silages with the addition of dry substrates. Pre-calculated amounts of each feedstuff were weighed individually to achieve desired proportions of each silage product and thoroughly mixed for 5 min. After mixing, the silage was distributed evenly into three 19-L buckets and sealed to provide an anaerobic environment. The treatments for this study were arranged in a 4 × 4 + 1 factorial design to determine the effects of DM level and source of dry feedstuff on the ensiling properties of sugarbeets following a 42-d fermentation period. Treatments were ensiled sugarbeets alone (250 g/kg) or based on (1) formulated silage DM concentrations of 275, 350, 425, and 500 g/kg and (2) the inclusion of dry feedstuffs (alfalfa hay, dry-rolled corn, wheat middlings, and wheat straw). Fermentation and nutritive characteristics of ensiled sugarbeets were influenced with the addition of dry substrates. A linear increase (P<0.001) in silage pH was observed with the addition of alfalfa, dry-rolled corn, wheat middlings, and wheat straw to ensiled sugarbeets. Lactic acid increased (P<0.001) with the addition of wheat middlings. Alfalfa addition to sugarbeet silage did not alter (P<0.001) lactate concentration. Concentration of lactate decreased (P=0.01) when corn was added, while wheat straw addition did not influence (P=0.37) lactate. A contrast was used to compare ensiling characteristics of sugarbeets alone (250 g/kg DM) to 350 g/kg DM (sugarbeets with dry substrates). Results indicated fermentative parameters were altered; pH increased (P<0.001) for all dry substrates while lactate was lower (P=0.003) for the sugarbeets ensiled with dry-rolled corn compared with sugarbeets ensiled alone. Alfalfa, wheat straw, and wheat middlings decreased (P<0.001) while dry-rolled corn did not affect (P=0.54) in vitro DM digestion. These results indicate the inclusion of dry feedstuffs with sugarbeets altered fermentation and with the exception of corn, decreased in vitro DM digestion. Nutrient composition and DM content of ensiled sugarbeets was altered with the addition of dry substrates.     

Effect of wilting and the additives,straw, molasses and urea on the fermentation pattern of maize silage

The process of ensiling was studied in fresh maize (15% dry matter (DM)), wilted maize (18 and 24% DM) and maize mixed with 5–20% of wheat straw (18, 25 and 29% DM). Silages with 24% DM were preserved better than those with lower dry matter content. There was a significant change, with time, in pH, titrable acidity, volatile fatty acids, lactic acid, number of lactic acid bacteria, volatile nitrogen and soluble sugars in all the treatments. There was a significant decline in volatile fatty acids (P<0.05) and ammonia (P<0.01) production, and a significant increase in soluble sugar (P<0.01) in silages made after wilting. A significant decline in titrable acidity (P<0.01), volatile fatty acid production (p<0.05) and ammonia nitrogen (P<0.01), and a significant increase in pH (P<0.01) were found in silages of maize mixed with wheat straw. The overall rate of fermentation decreased during the first few days of fermentation in wilted and wheat straw silages, but the final products had characteristics of a good silage. In the second experiment the effect of urea and molasses was studied on wheat straw plus maize (15:85) silage with an initial DM content of 31–34%. Three levels of molasses (0, 3 and 6% of fresh weight) and two levels of urea (0 and 0.5% of fresh weight) were studied. Urea treatment with 3% molasses was found to be the best on the basis of silage characteristics.     

The effect of Propionibacterium acidipropionici, with or without Lactobacillus plantarum, on the fermentation and aerobic stability of wheat, sorghum and maize silages

AIMS: To determine the effect of Propionibacterium acidipropionici, alone or in combination with Lactobacillus plantarum, on the fermentation and aerobic stability of wheat, sorghum and maize silages. METHODS AND RESULTS: The inoculants were applied at 1.0 x 10(6) CFU g(-1). Silages with no additives served as control. Fresh forages were sampled prior to ensiling. Three jars per treatment were sampled on days 2, 4, 8, 16 and 60 after ensiling, for chemical and microbiological analysis. At the end of the ensiling period, the silages were subjected to an aerobic stability test. The P. acidipropionici-inoculated silages had significantly higher levels of acetic and propionic acid than the L. plantarum or P. acidipropionici + L. plantarum-inoculated silages (P < 0.05). Therefore, yeast activity was impaired in the P. acidipropionici-inoculated silages. As a result, P. acidipropionici decreased CO(2) production and improved aerobic stability of wheat, sorghum and maize silages. However, the combination of P. acidipropionici + L. plantarum did not improve aerobic stability of the silages. CONCLUSIONS: The P. acidipropionici was very effective in protecting the wheat, sorghum and maize silages exposed to air under laboratory conditions, probably because the acidic environment under ensiling conditions is favourable for this micro-organism. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of P. acidipropionici, as a silage inoculant can improve the aerobic stability of silages by inhibition of yeast activity.     

Nutritive value and voluntary feed intake by goats of three browse fodder species in the Sahelian zone of West Africa

Browsing ruminants have access to different biomass, depending on how high they can reach. Foliage consisting of leaves and green pods from Acacia senegal, Pterocarpus lucens and Guiera senegalensis, was collected according to height above ground accessible to either sheep (0.90 m), goats (1.65 m) or cattle (1.50 m). There was a significant variation in the chemical composition of the biomass between species. The crude protein (CP) content was 114, 157 and 217 g/kg dry matter (DM) and the neutral detergent fiber (aNDF) content 604, 534 and 412 g/kg DM for G. senegalensis, P. lucens and A. senegal, respectively. There was no significant variation in chemical composition according to the height accessible by cattle, sheep or goats. The voluntary intake was studied using eight goats per diet. The six diets consisted of the three browse leaves and two pods (A. senegal and P. lucens) and a control. The leaves were fed combined with hay of Schoenefeldia gracilis (maximum 30%) and the control was pure hay. Apparent digestibilities of the same diets, with the exception of G. senegalensis, were measured using five goats per diet. All browse fodders used in the feeding and digestibility trials were high in CP (105–170 g/kg DM) and lignin (164–234 g/kg DM except A. senegal leaves) and low in fiber (322–590 g/kg DM of NDF) compared to the hay (31 g/kg DM of CP and 755 g/kg DM of NDF). The highest intake was of the P. lucens diet (864 g) and the lowest of the G. senegalensis diet (397 g). The intake of pods from A. senegal was higher (1033 g) than from P. lucens pods (691 g). The apparent digestibility of OM and CP in the browse leaves was 0.63 and 0.57 and 0.63 and 0.64 for A. senegal and P. lucens, respectively, higher than for the hay, which showed higher digestibility of NDF. A. senegal pods had higher digestibility for all nutrients than P. lucens pods. Based on the high CP content and the intake and digestibility characteristics, P. lucens leaves and A. senegal leaves and pods can be recommended as protein supplements to low quality diets.     

Characterization of protein fractions and amino acids in ensiled alfalfa treated with different chemical additives

Formic acid, formaldehyde, tannic acid or mixtures of two were studied on their effects on ensiled alfalfa (Medicago sativa L.) amino acids and N fractions by the Cornell Net Carbohydrate and Protein System (CNCPS). The alfalfa forage was a second cut and was wilted to a mean over-dry dry matter (DM) content of 330 g/kg. All silages were prepared as mini-silos using 100 ml polypropylene centrifuge tubes (50 g) on a small laboratory-scale, with the additives added in 20 ml aliquots/kg herbage fresh weight (FW). After 35 d of ensiling, most of forage true protein was converted to fraction A and all of the added additives reduced fraction A content in the ensiled forages (P<0.05). The content of fraction B₁ in all of the additive-treated silages was higher (P<0.05) than that in control silage. Large proportions of true protein in the tannic acid/formaldehyde- and formic acid/formaldehyde-treated silages were fractions B₂ and B₃, respectively. No difference was observed on fraction C content between the control silage and silages treated with additives except for the formaldehyde or tannic acid-treated silages. Amino acids were well preserved in additive-treated silages compared with the control silage. Concentration of total amino acid was higher in formic acid-treated silages than that in the control and the other additive-treated silages (P<0.05). The pattern of changes in individual amino acid in all of the silages indicated that branched chain amino acids and methionine were relatively well preserved during fermentation but the basic and acidic amino acids were not.     

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.     

The effect of calcium and sodium hydroxides and of sodium acrylate on the fermentation and digestibility in vitro of ensiled whole-crop wheat and barley harvested at different stages of maturity

Whole-crop wheat and barley were each harvested at the soft-, medium- and hard-dough stages of grain development. Material from each harvest was ensiled in polythene bag silos without additive or after the addition of calcium hydroxide, sodium hydroxide or sodium acrylate at 50, 50 and 12.5 g kg_?1 of the crop dry matter (DM), respectively. All silages were opened after 60 days.With advancing maturity there was an increase in the content of DM, starch and insoluble-nitrogen, but a reduction in water-soluble carbohydrates (WSC) and ash.When crops were ensiled without additives, only medium-dough barley fermented to give butyric acid. However, the addition of calcium hydroxide to crops of low DM (soft-dough) and medium DM (medium-dough) promoted the activity of clostridial bacteria giving rise to the production of butyric acid, but this did not occur with crops of high DM (hard-dough). Sodium hydroxide gave rise to butyric acid only at low DM, and to restricted fermentation at high DM content. Sodium acrylate restricted fermentation and prevented butyric acid production in all silages.Ensiling led to an average reduction of 5 percentage units in the digestible organic matter (DOM) of the control silages compared to that of the crops. Addition of calcium hydroxide and sodium acrylate gave values similar to the control silages. Only sodium hydroxide consistently increased DOM, the effect becoming more marked as the crops matured. The increases over the control silages were 10, 18 and 26 units for wheat and 15, 21 and 20 units for barley at low, medium and high DM, respectively.     

Effect of ruminally protected fat on in vitro fermentation and apparent nutrient digestibility in buffaloes (Bubalus bubalis)

Experiments were conducted to evaluate effects of supplementation of calcium salts of long chain fatty acids (Ca-LCFA) as a rumen inert fat (PF) on in vitro fermentation and apparent nutrient digestion in adult buffaloes fed wheat straw based diets. For the in vitro fermentation study, five total mixed rations (TMR) consisting of a concentrate mixture (CM), green Sorghum bicolor, WS and supplemented without (C) or with 30 g/kg dry matter (DM) rice bran fatty acid oil (RBO) (30 RBO) or 20 g/kg RBO + 10 g/kg PF (20 RBO/10 PF) or 10 g/kg RBO + 20 g/kg PF (10 RBO/20 PF) or 30 g/kg PF in the DM in the ratio of 340:50:580:30 were prepared. The in vitro DM degradability (IVDMD), TN, trichloro acetic acid precipitable N (TCA-N), non-protein N (NPN) and ammonia N (NH₃-N) were similar among groups. Within the fat supplemented groups, total volatile fatty acid (TVFA) concentration increased linearly (P=0.025) with PF supplementation. Apparent nutrient digestibility was determined on 20 adult buffaloes divided into five equal groups fed CM supplemented without (C) or with 300 g RBO (30 RBO) or 200 g RBO + 100 g PF (20 RBO/10 PF) or 100 g RBO + 200 g PF (10 RBO/20 PF) or 300 g PF (30 PF) along with limited green S. bicolor and WS maintaining forage: concentrate ratio of 650:350. Fat supplementation had no effect on the DM intake and apparent digestibilities of DM, organic matter (OM), crude protein (CP), total carbohydrate (TCHO) and neutral detergent fiber (aNDF). Within fat supplemented groups, inclusion of PF increased digestibilities of DM, OM, ether extract (EE), TCHO, aNDF and ADF. Supplemental fat also increased the digestible energy (DE) and metabolizable energy (ME) content of the diet, which also increased linearly with PF supplementation. All buffaloes were in positive N, Ca and P balances. We conclude that 200–300 g supplemental PF in the form of Ca-LCFA can be included in straw based diets fed to buffaloes to increase its energy density without adversely affecting DM intake and digestibility.