There is an increasing recognition throughout the world that many of the feeding problems of dairy herds are linked to the presence of aerobically deteriorated parts on a silo face, causing farmers ...to pose questions on what amount of silage should be removed daily to feed their animals. Since an adequate feed-out rate helps to prevent silage spoilage, a simple tool is needed to manage the aerobic deterioration of corn silages during feed-out. The aims of this study were to develop an unloading rate index, which we have called the mass feed-out rate (MFR), expressed in kilograms of fresh matter silage unloaded daily per square meter of silo face, to better predict the aerobic deterioration of silage and to offer management solutions to help prevent spoilage, through a survey on 97 commercial dairy farms in Italy and Brazil. Silages were sampled and analyzed for their main microbial, fermentative, and nutritional characteristics, whereas silage temperatures were measured in the core and peripheral areas of the silo working face. Moreover, a detailed questionnaire on silo management and silage utilization was administered to the farmers during each farm visit. The size and silage density of the silos presented a wide variability in the 2 countries, thus indicating that different management practices were adopted during corn harvesting, silo filling, and silage compaction. The differences between pH and temperature in the peripheral areas and in the core of the silage (dpH and dT, respectively) were tested as a single indicator to identify any aerobic deteriorated areas on the silo face, associated with the yeast and mold counts. Both indicators correctly identified aerobic deterioration in 86.6% and 93.8% of the studied silos, respectively. The lactic acid and ethanol increased as the MFR increased, whereas the starch, dT, and the yeast and mold counts decreased with increasing MFR. A daily removal rate of over 250 kg of silage/m2 markedly reduced the risk of spoilage in corn silages at a farm level in both temperate and tropical environments. The new MFR index can substitute for the commonly used linear feed-out rate as it includes the silage density and can be obtained from 1 single recording.
This study in dairy cow feeding explored the effects of growth stage and chop length for grass‐clover silage, and of concentrate protein level, including the interactions of these three factors. The ...experiment was conducted with 48 Norwegian Red cows according to a cyclic change‐over design with four 4‐week experimental periods and eight dietary treatments in a 2 × 2 × 2 factorial arrangement. Round bale silage from a mixed sward of timothy, meadow fescue, and red clover was harvested at two growth stages (H1, H2) and offered to dairy cows either unchopped with median particle length of 152 mm or chopped to 19 mm median particle length before feeding. A low protein (LP) concentrate containing 7% lignosulphonate treated soybean meal (SBM) and a high protein (HP) concentrate containing 12% solvent extracted SBM were compared. Silage was offered ad libitum and supplemented with 8 kg concentrate per day. Silage dry matter intake was 2.0 kg higher for H1 than H2 silage, which supported a higher yield of milk, energy‐corrected milk and the milk constituents, fat, protein, and lactose. All these measures of milk production, as well as feed energy efficiency and N use efficiency, increased when silage was fed chopped rather than unchopped. Lignosulphonate treated SBM spared N in the diet without milk yield reductions. For efficient milk production with high energy and N utilisation, we recommend chopping to 20 mm for timothy, meadow fescue, and clover silages harvested in late stem elongation or in reproductive growth stages.
We studied the effects of damaging ears of corn in the field prior to harvest and the use of various additives on the production of selected mycotoxins, silage fermentation, and aerobic stability of ...whole plant corn. In experiment 1, ears of corn were undamaged or were slashed with a knife 7 d before harvesting, exposing damaged kernels to the environment. Corn plants were harvested (about 35% DM) and treated in a 2×2 factorial arrangement of treatments. Treatments were undamaged or damaged plants, untreated or treated with Lactobacillus buchneri 40788 (400,000cfu/g of fresh forage) and Pediococcus pentosaceus (100,000cfu/g). Damaging ears prior to harvest increased the amount of fumonisin but decreased the amount of starch in harvested corn plants. After ensiling, corn silage made from plants damaged before harvest had lower starch but greater concentrations of deoxynivalenol and fumonisin than silage made from plants that were undamaged. Microbial inoculation resulted in fewer yeasts and lower concentrations of zearalenone in silage when compared to uninoculated silage. Inoculated silage also had more acetic acid and 1,2-propanediol than did uninoculated silage. In experiment 2, ears of corn were undamaged or were slashed with a knife 27 d or 9 d before harvesting for corn silage. Whole plants were harvested at about 36% DM in a 2×3 factorial arrangement of treatments. Factors were time of damaging the ears (27 d, 9 d, or no damage) relative to harvest and no additive or 0.1% (fresh weight) potassium sorbate. Damaging plants 9 d prior to harvest did not affect the concentrations of deoxynivalenol, fumonisin, and zearalenone in plants at harvest. However, concentrations of deoxynivalenol and fumonisin were increased in fresh forage that had ears damaged at 27 d when compared to corn plants that were undamaged. Corn plants damaged for 27 d prior to harvest also had a lower concentration of starch than corn damaged for 9 d but was higher in acid detergent fiber than other treatments. The addition of potassium sorbate at harvest had no effect on the concentrations of mycotoxins in the resulting silage, but concentrations of mycotoxins were still greatest in silage made from plants that were damaged the longest prior to harvest (27 d). Silages treated with potassium sorbate had fewer yeasts and molds than silages without the additive. Damaging ears of corn before harvest had no effects on the aerobic stability of silages in both experiments. In contrast, the addition of the inoculant and potassium sorbate improved aerobic stabilities of silages when compared to untreated silages. These studies showed that physical damage to ears of corn prior to harvest can result in the production of mycotoxins in the field. This finding suggests that producers should test corn silage for mycotoxins prior to feeding especially if the forage has been subjected to physical damage prior to ensiling.
The aim of this study was to evaluate the effect of two organic acids malic acid (MA) and citric acid (CA), Lactobacillus plantarum (LP) and their mixtures on the fermentation of alfalfa silage. The ...wilted and chopped alfalfa was ensiled in vacuum-sealed plastic bags (200-230 g per bag) with following additives: 0.5% distilled water (control), 0.5% DL-MA, 0.5% CA, LP (1 · 10
6
cfu/g), 0.5% DL-MA plus LP (MA+LP) or 0.5% CA plus LP (CA+LP) (application rates based on fresh weight). Each treatment had four replicates and was stored at room temperature. After 60 d of ensiling, decreases in pH, non-protein N (NPN) and increases in lactic acid were observed in all additive-treated silages (p < 0.01). Compared with treatment LP, higher pH and lower lactic acid concentrations were observed after MA or CA addition (p < 0.05) and further application of MA or CA together with LP did not promote lactic acid fermentation in ensiled alfalfa. Furthermore, additives decreased the proportion of saturated fatty acids and increased the proportion of polyunsaturated fatty acids in ensiled alfalfa, with the highest level in CA-treated silages (p < 0.05). Although MA and CA were not as effective as LP in improving silage fermentation quality, treatments MA+LP and CA+LP were more effective in decreasing silage NPN, and CA was most effective in inhibiting biohydrogenation of fatty acids in ensiled alfalfa.
The objective of this study was to select lactic acid bacteria (LAB) strains isolated from silage and assess their effect on the quality of maize silage. The LAB strains were inoculated into aqueous ...extract obtained from maize to evaluate their production of metabolites and pH reduction. The ability to inhibit the pathogenic and silage-spoilage microorganisms’ growth was evaluated. Nine LAB strains that showed the best results were assessed in polyvinyl chloride experimental silos. The inoculation of the LAB strains influenced the concentration of lactic and acetic acids and the diversity of Listeria. The inoculation of silages with Lactobacillus buchneri (UFLA SLM11 and UFLA SLM103 strains) resulted in silages with greater LAB populations and improvements after aerobic exposure. The UFLA SLM11 and SLM103 strains identified as L. buchneri showed to be promising in the treatment of maize silage.
Aims To describe, at high resolution, the bacterial population dynamics and chemical transformations during the ensiling of alfalfa and subsequent exposure to air. Methods and Results Samples of ...alfalfa, ensiled alfalfa and silage exposed to air were collected and their bacterial population structures compared using 16S rRNA gene libraries containing approximately 1900 sequences each. Cultural and chemical analyses were also performed to complement the 16S gene sequence data. Sequence analysis revealed significant differences (P < 0·05) in the bacterial populations at each time point. The alfalfa-derived library contained mostly sequences associated with the Gammaproteobacteria (including the genera: Enterobacter, Erwinia and Pantoea); the ensiled material contained mostly sequences associated with the lactic acid bacteria (LAB) (including the genera: Lactobacillus, Pediococcus and Lactococcus). Exposure to air resulted in even greater percentages of LAB, especially among the genus Lactobacillus, and a significant drop in bacterial diversity. Conclusions In-depth 16S rRNA gene sequence analysis revealed significant bacterial population structure changes during ensiling and again during exposure to air. Significance and Impact of the Study Significance and Impact of the Study: This in-depth description of the bacterial population dynamics that occurred during ensiling and simulated feed out expands our knowledge of these processes.
Abstract
Changing climatic conditions are imposing risks and diminishing yields in agriculture. Sorghum (Sorghum bicolor) silage is a feasible option for backgrounding beef cattle in terms of ...economic risk management and animal productivity when compared with corn (Zea mays) silage, due to its drought adaptability. Similarly, Brassica carinata meal has proven to be a viable alternative as a protein supplement in forage-based beef cattle systems, when included at 10% of the diet dry matter (DM). However, research is scarce regarding its inclusion in silage-based diets for backgrounding animals. The objective of this trial was to compare a processor-chopped sorghum silage (SS) against a typical corn silage (CS) in a digestibility and performance trial while supplementing two protein sources; one traditionally used like cottonseed meal (CSM) and one novel like B. carinata meal (BCM). A total of 84 Angus crossbred heifers (307 ± 33 kg BW) were evaluated in a randomized block design with a 2 × 2 factorial treatment arrangement with type of silage and protein source as factors. Diets were fed ad libitum, consisting of 89% silage source plus 10% protein source, and 1% mineral inclusion on DM basis. The experimental period consisted of 14 d of adaptation followed by 5 d of apparent total tract digestibility measurements and 56 d of animal performance and intake behavior measurements. Heifers fed SS showed greater number of daily meals but decreased meal sizes (P ≤ 0.05), not differing in meal length (P > 0.10) when compared with CS. Dry matter and organic matter (OM) digestibility showed a silage type × protein source interaction (P ≤ 0.01), where in CS diets, OM tended to be more digestible with CSM vs. BCM, and it did not differ between protein sources in SS based diets. There was an effect of protein (P ≤ 0.01) on ADF digestibility, where CSM was greater than BCM. No effect of treatment was observed (P ≥ 0.10) on DM intake. Average daily gain (ADG) and gain-to-feed ratio were greater for CS than SS (P ≤ 0.01) regardless of protein source. Although heifers fed CS had greater feed efficiency and digestibility, SS can still be considered a viable option for backgrounding beef heifers, obtaining adequate ADG rates of 0.945 kg/d. Lastly, BCM did not differ from CSM in terms of feed efficiency and animal performance, proving to be a viable alternative protein source in silage-based diets.
As climatic conditions are changing rapidly, certain areas of the United States, such as the southeast, are experiencing a negative impact in agricultural terms, as yields are decreasing, imposing a greater risk for farmers due to increased feed costs and decreased availability of feedstuffs. This study shows the viability of sorghum and carinata (and its meal byproduct) as alternative crops in the region. The study provides supports for future increments in the planted area of these alternative crops, with impact in beef cattle operations, increasing the resilience of beef production systems in the southeastern United States.
Lay Summary
Increased atmospheric CO2, rising temperatures, and altered patterns of precipitation can limit the production of certain crops commonly used in agriculture, increasing risk, cost, and availability of feedstuffs. The search for alternative plants that could thrive in these changing scenarios is necessary to provide producers with a broader array of options to feed cattle. In this study, sorghum silage was compared with corn silage as the main dietary ingredient, with either Brassica carinata (carinata) or cottonseed meal as the protein source for growing beef heifers. Variables assessed included intake behavior, digestibility, and performance of beef heifers. Heifers fed sorghum silage gained less than heifers fed corn silage, though they grew at an adequate rate for a replacement heifer. Carinata meal showed similar performance results compared with cottonseed meal, despite some of its fiber components being less digestible in the total tract. Therefore, sorghum silage has potential to be a viable feedstuff for growing beef heifers although it may result in decreased performance compared with corn silage. Alternatively, carinata meal can be a practical alternative to cottonseed meal as a protein source in terms of animal performance. This could translate in an increase in the planted area of both sorghum and carinata in Southern United States, as they are adapted to drought and high temperatures, enhancing the resilience of beef production systems in a context of increased climate variability.
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