RESUMO
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.
Assuntos
Lactobacillales/isolamento & purificação , Valor Nutritivo , Silagem/microbiologia , Silagem/normas , Animais , Bioprospecção , Fermentação , Lactobacillales/classificação , Lactobacillales/metabolismoRESUMO
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 ß-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 + ß-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.
Assuntos
Ração Animal/microbiologia , Bacillus subtilis/metabolismo , Silagem/microbiologia , Silagem/normas , Zea mays/microbiologia , Ração Animal/análise , Ração Animal/normas , Fibras na Dieta/metabolismo , Fungos/isolamento & purificação , Lactobacillus/metabolismo , Leveduras/isolamento & purificaçãoRESUMO
Advances in micro-organism identification techniques have resulted in increased knowledge of the diversity of prokaryotes and eukaryotes in silage. Such knowledge has enhanced the understanding of how fermentation occurs in forage crops with different characteristics and how the process can be improved to enhance silage quality. Undesirable micro-organisms can grow in silage when fermentation does not occur properly. Such micro-organisms may be pathogenic and/or produce toxic metabolic compounds; however, information on the consequences of these metabolites on the health of animals that consume silage is still lacking. The major challenge of ensilage is to produce high-quality feed that is nutritional, sanitary and stable, with a high dry matter recovery rate, in a process involving no interventions during fermentation and considerable variation in the characteristics of the substrates. It is important to note that each substrate has particularities and that we can only improve fermentation if we fully understand microbial diversity. This review is intended to update information related to the fermentation profile of silage, focusing on microbial diversity.
Assuntos
Microbiota , Silagem/microbiologia , Animais , Fermentação , Microbiota/genética , Silagem/análise , Silagem/normasRESUMO
AIM: To screen a lactic acid bacteria (LAB) strain for good adaption in alfalfa ensiling and to evaluate its effects on alfalfa ensiling. METHODS AND RESULTS: Lactobacillus plantarum (LP) strain ZZU203 was selected due to its superior ability to acidify structural carbohydrate metabolite and alfalfa powder. Alfalfa was ensiled with LP FG1 (from a commercial inoculant), LP ZZU203, or a no-additive control (CK) for 60 d. The two silages with LP additives significantly (P < 0·05) increased lactic acid (LA) and acetic acid (AA) concentrations compared to CK silage. The pH, ammonia nitrogen (NH3 -N) and cellulose concentrations, and the numbers of bacilli, coliform, aerobic bacteria and Clostridium decreased significantly (P < 0·05). The dry matter, LA, AA and water-soluble carbohydrate concentrations of ZZU203 silage were significantly (P < 0·05) higher, whereas the NH3 -N and the neutral detergent fibre concentrations, and the aerobic bacterial and Clostridium counts were significantly (P < 0·05) lower than in FG1 silage. CONCLUSION: ZZU203 obtained by the screening method of this study can improve the quality of alfalfa silage. SIGNIFICANCE AND IMPACT OF THE STUDY: The screening method designed for alfalfa silage conditions can effectively screen out LAB with potential application value in alfalfa silage.
Assuntos
Lactobacillus plantarum/metabolismo , Medicago sativa/microbiologia , Silagem/microbiologia , Adaptação Fisiológica , Amônia/análise , Bactérias/classificação , Bactérias/crescimento & desenvolvimento , Fibras na Dieta/análise , Fermentação , Concentração de Íons de Hidrogênio , Medicago sativa/química , Silagem/análise , Silagem/normasRESUMO
Protein degradation during ensiling is a major problem. Tannins are known to prevent or decelerate protein degradation in the rumen and may be able to do so in silages as well. Therefore, the present evaluation aimed to analyse the influence of tannins on silage quality. This was done by integrating from all suitable experiments found in literature on the topic in a meta-analysis approach. A total of 122 datasets originating from 28 experiments obtained from 16 published articles and one own unpublished experiment were included in the database. Tannins in the silages originated either from the plants ensiled or from supplementations of tanniferous plants or tannins extracted from such plants. Tannin concentrations ranged from 0 to 57.8 g/kg dry matter, and the ensiling period varied from 30 to 130 days. The analysis was based on the linear mixed model methodology in which the different studies were considered as random effects and tannin-related properties (either concentration or type of tannins) were treated as fixed effects. Results revealed that greater concentrations of tannins were associated with a decrease of butyrate concentration in the silages (p < 0.05). An increasing tannin concentration was also accompanied with smaller proportions of soluble N, free amino acid N, non-protein nitrogen and NH3 -N in total silage N (p < 0.05). The relationships between hydrolysable and condensed tannins and the decline in butyrate and NH3 -N concentrations in the silages were of different magnitude (p < 0.05). A higher tannin concentration was associated with a decline in in vitro dry matter digestibility. It was concluded that tannins apparently have the ability to limit extensive proteolysis which may occur during ensiling and thus may improve the fermentative quality of silages. A desired side effect seems to be given by the tannins' apparent property to limit the activity of the butyrate-producing microbes.
Assuntos
Análise de Alimentos , Plantas/química , Silagem/análise , Silagem/normas , Taninos/química , ProteóliseRESUMO
The commercialization of silage in many countries, including Brazil, has increased in recent years. Re-ensiling of previously ensiled forage occurs when silage is relocated from one farm to another, where it will be compacted and sealed again. During this process, silage is exposed to oxygen before being ensiled, which may affect its quality. We exposed sorghum silage to air during the anaerobic storage phase to simulate the transportation of silages between farms. Experimental treatments included silage exposed to air for 0 or 12 h, with or without the use of an inoculant containing a mixture of Lactobacillus plantarum and the propionic bacteria Propionibacterium acidipropionici (1 × 106 cfu/g of forage; Biomax corn, Lallemand, Saint-Simon, France), totaling 4 treatments: conventional silage, conventional silage with inoculant use, re-ensilage after exposure to air, and re-ensilage after exposure to air with use of an inoculant. The sorghum was stored in experimental silos containing about 9.0 kg of fresh forage per replicate. Treatments were tested in a factorial 2 × 2 design with 5 replicates each. Chemical composition, in vitro dry matter digestibility, fermentative characteristics, losses (due to gas, effluents, and total dry matter), microorganism counts, and aerobic stability of sorghum silage were evaluated. Dry matter content of sorghum before ensiling was 273.12 g/kg. The 12-h re-ensiling process increased the effluent loss of the silage when compared with conventional silage (456.42 vs. 201.19 g/kg of FM, respectively). In addition, re-ensiled silages presented lower concentrations of lactic acid and higher concentrations of propionic acid than the silages that had not been opened during storage. The aerobic stability of silage was not affected by the re-ensiling process and the use of inoculant. The use of inoculant increased the pH and loss of dry matter of the silages (4.23 vs. 3.98 and 14.05 vs. 7.82%, respectively) and therefore did not provide any benefits in this study.
Assuntos
Ração Animal/normas , Conservação de Alimentos/métodos , Silagem/normas , Sorghum , Aerobiose , Animais , Fermentação , Zea maysRESUMO
AIMS: To determine the suitability of diets containing either approximately 85% fodder beet (Beta vulgaris L.) with barley straw or 65% fodder beet with pasture silage when fed to non-lactating dairy cows, by measuring intakes, digestibility, rumen function including microbial growth, and N excretion. METHODS: Holstein-Friesian cows fitted with permanent rumen fistulae were fed either 65% fodder beet with pasture silage (Silage; n=8) or 85% fodder beet with barley (Hordeum vulgare L.) straw (Straw; n=8) in an indoor facility over a 9-day period, for measurement of intakes, digestibility, rumen function and urine production. The cows were adapted to the diets over 2 weeks before the indoor measurements. Feed was available for about 6 hours/day, as practiced commercially for wintering non-lactating cows. RESULTS: Five cows fed the Straw diet had to be removed from the trial because of acute acidosis; four on Day 1 of the measurement period and one on Day 7. One cow allocated to the Silage diet refused to eat fodder beet bulbs and was also removed from the trial. Two cows fed the Silage diet were also treated for acidosis. DM intakes were lower with the Straw than Silage diets (6.4 (SE 0.4) vs. 8.3 (SE 0.5) kg/day) and organic matter (OM) digestibility was lower with the Straw than Silage diets (77 (SE 1) vs. 83 (SE 1) g/100g). The N content of the two diets was 1.14 and 1.75â g/100â g DM and there was a net loss of N by cows fed the Straw diet (-22.7 (SE 7) g/day). Rumen microbial N production was much lower in cows fed the Straw than the Silage diet (6.6 (SE 1.3) vs. 15.8 (SE 0.7) g microbial N/kg digestible OM intake). Concentrations of ammonia in rumen liquid collected on Days 5-6 were below detection limits (<0.1â mmol/L) in 36/48 (75%) samples collected from cows fed the Straw diet and in 27/48 (56%) cows fed the Silage diet. Mean urinary N excretion was lower in cows fed the Straw than the Silage diet (52.0 (SE 5.8) vs. 87.7 (SE 5.9) g/day). CONCLUSION AND CLINICAL RELEVENCE: An over-wintering diet for dry cows comprising about 65% fodder beet with 35% pasture silage provided adequate nutrition, although there was some risk of acidosis. In contrast, the diet containing about 85% fodder beet with barley straw resulted in lower DM intakes, poor rumen function, negative N balance so that both nutrition and welfare were compromised.
Assuntos
Ração Animal/normas , Beta vulgaris/metabolismo , Bovinos/fisiologia , Hordeum/metabolismo , Silagem/normas , Acidose/etiologia , Acidose/veterinária , Amônia/análise , Análise de Variância , Ração Animal/análise , Animais , Ritmo Circadiano/fisiologia , Digestão/fisiologia , Ingestão de Líquidos/fisiologia , Ingestão de Alimentos/fisiologia , Fezes/química , Feminino , Concentração de Íons de Hidrogênio , Nitrogênio/metabolismo , Nitrogênio/urina , Rúmen/química , Rúmen/metabolismo , Rúmen/microbiologia , Ureia/sangue , Urina/químicaRESUMO
We assessed the impact of genetic divergence and the ability to combine corn hybrids used for the production of silage on the agronomic and bromatological traits of silage quality. We evaluated 18 corn hybrids used as genitors in a circulant diallel scheme in which each genitor hybrid participated in 9 hybrid combinations, and evaluated 100 treatments [18 genitor hybrids, 81 diallelic hybrids, and a commercial check hybrid (DKB330)] in a triple lattice 10 x 10 experimental design in two environments in Brazil. Genetic variability was adequate among the corn silage hybrids, and we can recommend the use of genitors 2B688 and P30B39 for the formation of a base population for intrapopulational breeding. The P30P34 hybrid is the best for intrapopulational breeding when aiming for silage with high protein content, low fiber content, and higher in vitro digestibility. Interpopulational breeding directed at improving silage digestibility can use a combination of genitors P30P34 and AS1572, but AS1572 and P30K64 are the most recommended. Hybrids 2B688, P30P34, and SG6015 are considered the most genetically distant of the others hybrids, and have desirable combining potential; therefore, they are important genitors for the formation of new segregated populations for improving corn silage.
Assuntos
Variação Genética , Hibridização Genética , Silagem/normas , Zea mays/genética , Melhoramento Vegetal/métodos , Característica Quantitativa HerdávelRESUMO
Nutrient composition of the feed and formulated ration often differ depending on uncertainties in DM content and nutrient composition of ingredients, as well as from feeder errors during loading. The objective of this study was to describe the deviation from target weight for the high-producing cow ration (HCR) and premix (HCP) on 26 California dairies ranging in size from 1,100 to 6,900 cows. Records from a consecutive 12-mo period were extracted from FeedWatch 7 (Valley Agricultural Software Inc., Tulare, CA), a feeding management software. Variables extracted and studied were date, recipe type, recipe number, ingredient, loading sequence, target weight, weight, and tolerance level (TL, deviation allowed per ingredient during loading). Based on the distribution of the deviation from target weight for the 8 most common ingredients, loading accuracy (quartile 1; small: |<10| kg; medium |10| to |20| kg; large |>20| kg), loading precision (interquartile range=quartile 3 to 1; small: <20kg; medium: 20 to 40kg; large >40kg), and extreme observations (quartile 3; small: |<25| kg; medium: |25| to |40| kg; large: |>40| kg) were described. Descriptive statistics were conducted with SAS 9.4 (SAS Institute Inc., Cary, NC). The median TL assigned to ingredients across dairies ranged from 0 to 90kg. At the ingredient level, the TL allowed a deviation from the median ingredient target weight of 0 to 2 (53.9%), >2 to 5 (25.5%), >5 to 10 (11.6%), or >10% (8.9%). A total of 2.5% of the loads did not reach the target weight set by the TL, ranging from 0.1 to 21.1% loads across dairies. Ingredient deviation from the formulated target weight across dairies was below target 49.1% of the time [<-10 (2.5%), -10 to <-5 (4.8%), -5 to <-2 (8.9%), -2 to <0% (32.8%)] or at or above target 50.9% of the time [0 (3.9%), >0 to 2 (36.7%), >2 to 5 (8.9%), >5 to 10 (1.2%), >10% (0.2%)]. Five dairies loaded ingredients with adequate accuracy (small to medium, quartile 1) and adequate precision (small to medium, interquartile range), but accuracy and precision were very poor on 3 dairies (large, quartile 1 and interquartile range). Rolled corn and almond hulls were loaded with adequate precision (small to medium, interquartile range) on a minimum of 64% of the dairies and adequate accuracy (small, quartile 1) on at least 68% of the dairies. In contrast, alfalfa hay, corn silage, and canola were loaded with poor precision (large, interquartile range) on a minimum of 60% of the dairies. There was a large variation within and across dairies on the deviation from target weight. Readjusting the TL settings might reduce the deviation from target weight. On 5 dairies, feeders were able to load ingredients with minimal deviation from target weight, setting achievable goals for the industry. Based on loading errors, opportunities exist to improve feeder performance on California dairies.
Assuntos
Ração Animal/análise , Ração Animal/normas , Indústria de Laticínios/estatística & dados numéricos , Indústria de Laticínios/normas , Silagem/análise , Ração Animal/estatística & dados numéricos , Animais , California , Bovinos , Dieta/veterinária , Silagem/normas , Silagem/estatística & dados numéricos , Zea maysRESUMO
Effects of nitrogen level and carbohydrate source on apparent ruminal synthesis (ARS) of thiamin, riboflavin, niacin, vitamin B6, folates, and vitamin B12 were evaluated using 4 lactating Holstein cows distributed in a 4 × 4 Latin square design with treatments following a 2 × 2 factorial arrangement. Cows were fitted with cannulas in the rumen and proximal duodenum. The treatments were 2 N levels and 2 carbohydrate sources. The diet with the high N level provided 14% crude protein, calculated to meet 110% of the protein requirements and an adequate supply in rumen-degradable protein, whereas the diet with the low N level contained 11% crude protein, calculated to meet 80% of the protein requirements with a shortage in rumen-degradable protein. Carbohydrate source treatments differed by their nature (i.e., high in starch from barley, corn, and wheat, or high in fiber from soybean hulls and dehydrated beet pulp). All 4 diets were isoenergetic, based on corn silage, and had the same forage-to-concentrate ratio (60:40, dry matter basis). Duodenal flow was determined using YbCl3 as a marker. Each B-vitamin ARS was calculated as duodenal flow minus daily intake. The intake of several B vitamins varied among treatments, but because the animals consumed a similar amount of feed every day (average of 20 kg of dry matter/d) the difference was mostly due to vitamin content of each ingredient and their relative proportion in the diets. Decreasing N concentration in the diet reduced vitamin B6 duodenal flow and increased its apparent ruminal degradation. It also decreased duodenal flow and ARS of folates. The high-starch diets increased duodenal flow and ruminal balance of riboflavin, vitamin B6, and folates, whereas the high-fiber diets increased vitamin B12 ARS and duodenal flow. These effects on apparent synthesis are possibly due to changes in ruminal fermentation.
Assuntos
Dieta/veterinária , Carboidratos da Dieta/metabolismo , Nitrogênio/metabolismo , Rúmen/metabolismo , Complexo Vitamínico B/biossíntese , Animais , Bovinos , Fibras na Dieta/metabolismo , Feminino , Fermentação , Hordeum/metabolismo , Lactação , Silagem/normas , Amido/metabolismo , Triticum/metabolismo , Vitamina B 12/farmacologia , Zea mays/metabolismoRESUMO
The research was aimed at studying whether the polyethylene (PE) film currently used to cover maize silage could be replaced with bio-based biodegradable films, and at determining the effects on the fermentative and microbiological quality of the resulting silages in laboratory silo conditions. Biodegradable plastic film made in 2 different formulations, MB1 and MB2, was compared with a conventional 120-µm-thick PE film. A whole maize crop was chopped; ensiled in MB1, MB2, and PE plastic bags, 12.5kg of fresh weight per bag; and opened after 170d of conservation. At silo opening, the microbial and fermentative quality of the silage was analyzed in the uppermost layer (0 to 50mm from the surface) and in the whole mass of the silo. All the silages were well fermented with little differences in fermentative quality between the treatments, although differences in the mold count and aerobic stability were observed in trial 1 for the MB1 silage. These results have shown the possibility of successfully developing a biodegradable cover for silage for up to 6mo after ensiling. The MB2 film allowed a good silage quality to be obtained even in the uppermost part of the silage close to the plastic film up to 170d of conservation, with similar results to those obtained with the PE film. The promising results of this experiment indicate that the development of new degradable materials to cover silage till 6mo after ensiling could be possible.
Assuntos
Plásticos Biodegradáveis , Polietileno , Silagem/normas , Zea mays/normas , Animais , Bovinos , Feminino , Fermentação , Fungos/crescimento & desenvolvimento , Projetos Piloto , Silagem/microbiologia , Zea mays/química , Zea mays/microbiologiaRESUMO
The objectives of this experiment were to determine the effects of corn silage particle size and supplemental hay on rumen pH and feed preference in lactating dairy cows experiencing a bout of subacute ruminal acidosis (SARA). In this study, 12 lactating (8 ruminally cannulated), multiparous Holstein cows averaging 91±40d in milk and weighing 695±95kg (mean ± SD) were randomly assigned to a replicated 4×4 Latin square. During each of the four 21-d periods, animals were offered 1 of 4 diets that were chemically similar but varied in corn silage particle size and supplemental second cutting orchardgrass hay: short corn silage total mixed ration (TMR; ST); short corn silage TMR with 5.6% supplemental hay (SH); long corn silage TMR (L); and long corn silage TMR with 5.6% supplemental hay (LH). Cows were allowed to adapt to this feeding scheme for 14d, and cannulated cows were then subjected to a rumen challenge to induce a bout of SARA by restricting feed before the challenge and providing 4kg of ground wheat via the rumen cannula. Although baseline pH was low, the SARA challenge lowered ruminal pH further for all cows regardless of diet. Daily average rumen pH decreased from 5.44 and 5.45 to 5.33 and 5.38 for ST and SH, respectively, and from 5.64 and 5.54 to 5.47 and 5.39 for L and LH, respectively, from baseline to challenge phase. Following the rumen challenge, rumen concentrations of acetate, propionate, butyrate, and valerate increased. Decreasing corn silage particle size significantly increased TMR and total DMI during all phases of the model. Feeding short corn silage TMR increased milk, protein, and lactose yields. Cows fed supplemental hay had increased fat yield and protein concentration in the milk and responded minimally to the effects of particle size selection when challenged with SARA. Cows consuming short corn silage TMR changed feed preference for longer forage particles during the course of the SARA challenge. During the recovery phase, however, cows refused an average of 13.5% of the offered TMR and 78.7% of the supplemental hay. These results indicate that cows did not prefer the supplemental hay regardless of corn silage particle size during a bout of SARA, which may have been due to the possible adaptation of a low ruminal pH throughout the study.
Assuntos
Bovinos/fisiologia , Carboidratos da Dieta/administração & dosagem , Preferências Alimentares , Rúmen/metabolismo , Silagem , Zea mays , Acidose/dietoterapia , Acidose/prevenção & controle , Acidose/veterinária , Animais , Indústria de Laticínios , Dieta/veterinária , Echinochloa , Feminino , Concentração de Íons de Hidrogênio , Lactação , Leite/metabolismo , Tamanho da Partícula , Silagem/análise , Silagem/normas , Amido/metabolismoRESUMO
BACKGROUND: Anaerobic spore-forming bacteria (ASFB) in milk derive from the farm environment, and the use of silages and management practices are the main responsible of milk ASFB contamination. The aim of this study was to evaluate the relationships between feeding, milking routine and cow hygiene and milk and Grana Padano cheese (produced with and without lysozyme) ASFB contamination. RESULTS: The study involved 23 dairy farms. ASFB in corn silage were on average 2.34 ± 0.87 log10 MPN g(-1). For grass, Italian ryegrass and alfalfa, ASFB (log10 MPN g(-1)) were numerically higher for silages (3.22) than hays (2.85). The use of corn silages of high quality (high lactic and acetic acids concentrations) decreased the milk ASFB contamination, whilst the use of herbage silages did not affect it. The presence (>40%) of cows with dirty udders increased the ASFB contamination of milk, while forestripping had a positive effect (-9% ASFB). Ripened Grana Padano had an ASFB count below the analytical limit; Clostridium tyrobutyricum DNA was found only in wheels produced without lysozyme, which also showed late blowing. CONCLUSION: The factors increasing milk spore contamination were corn silage quality, cow udder hygiene and inadequate milking routine. Late blowing was present only in cheeses without lysozyme.
Assuntos
Criação de Animais Domésticos/métodos , Bactérias , Indústria de Laticínios/métodos , Microbiologia de Alimentos , Leite/microbiologia , Silagem/microbiologia , Animais , Bovinos , Queijo/microbiologia , Clostridium , Feminino , Humanos , Higiene , Medicago sativa/microbiologia , Muramidase , Poaceae/microbiologia , Silagem/normas , Esporos Bacterianos , Zea mays/microbiologiaRESUMO
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.
Assuntos
Lactobacillus/metabolismo , Silagem/microbiologia , Aerobiose , Animais , Fermentação , Concentração de Íons de Hidrogênio , Silagem/normas , Zea maysRESUMO
The aim of this work was to characterize the fatty acid (FA) profile of milk from intensive dairy farming systems in the Po Plain (Italy) to estimate the costs of the adopted feeding strategies and to simulate the effect of supplementary premiums on the basis of milk FA composition on milk income. Twenty dairy farms with 5 different feeding strategies were studied: 3 corn silage-based systems in which cows were supplemented with a great proportion (CCH), a medium proportion (CCM), or without commercial concentrate mix (CC0), and 2 systems in which part of corn silage was replaced with grass or legume silage (HF) or with fresh herbage (G), cut and fed indoors. Bulk milk was sampled and lactating cow performance, feeding strategies and forage characteristics were recorded through a survey, 3 times during a year. The milk FA supplementary premium was calculated considering C18:3n-3 and saturated FA (SFA) concentrations, and ratio of total cis C18:1 isomers to C16:0. The CCH, CCM, and CC0 systems bought most of their dairy cow feeds off farm, which allowed them to increase milk production to 35,000 L/yr per hectare. Their low dry matter and crude protein self-sufficiency led to higher feeding costs per liter of milk (from 0.158 to 0.184), and highest income over feed cost was achieved only for milk yield performance greater than 10,000 kg/cow per year. The use of homegrown forages in HF and G increased dry matter and crude protein self-sufficiency and reduced the feeding costs per liter of milk from 9 to 22%, compared with the other studied systems, making HF and G feeding economically competitive, even for a lower milk yield per cow. The studied systems highlighted a remarkable variation in FA profiles. The concentrations of C16:0 and SFA were the highest in CCH (31.53 and 67.84 g/100g of FA) and G (31.23 and 68.45 g/100g of FA), because of the larger proportion of commercial concentrate mix in the cow diet. The concentrations of C16:0 and SFA were the lowest in CCM (27.86 and 63.10 g/100g of FA), because of low roughage-to-concentrate ratio in the cow diet, which is known to favor milk fat depression, affecting particularly these FA. The calculated supplementary premium was the highest in the CCM system, based on milk FA profiles from those herds. The HF diet was rich in forages and resulted in greater concentration of C18:3n-3 in milk (0.57 g/100g of FA) than the other systems and thus led to an increase in milk FA supplementary premium. Milk from G and HF milk had the lowest ratio of Σn-6:Σn-3 FA compared with milk from the systems based on higher corn silage proportion in the cow diet (3.71, and 3.25, respectively, vs. 4.58 to 4.78), with the lower ratios being closer to recommendation for human nutrition.
Assuntos
Indústria de Laticínios/métodos , Dieta/veterinária , Ácidos Graxos/análise , Métodos de Alimentação/veterinária , Leite/química , Animais , Bovinos , Ácidos Graxos/química , Ácidos Graxos/metabolismo , Feminino , Itália , Lactação/fisiologia , Poaceae/metabolismo , Silagem/normas , Zea mays/metabolismoRESUMO
This project aimed to evaluate the effects 8 additives on the fermentation, dry matter (DM) losses, nutritive value, and aerobic stability of corn silage. Corn forage harvested at 31% DM was chopped (10mm) and treated with (1) deionized water (control); (2) Buchneri 500 (BUC; 1×10(5) cfu/g of Pediococcus pentosaceus 12455 and 4×10(5) cfu/g of Lactobacillus buchneri 40788; Lallemand Animal Nutrition, Milwaukee, WI); (3) sodium benzoate (BEN; 0.1% of fresh forage); (4) Silage Savor acid mixture (SAV: 0.1% of fresh forage; Kemin Industries Inc., Des Moines, IA); (5) 1×10(6) cfu/g of Acetobacter pasteurianus-ATCC 9323; (6) 1×10(6) cfu/g of Gluconobacter oxydans-ATCC 621; (7) Ecosyl 200T (1×10(5) cfu/g of Lactobacillus plantarum MTD/1; Ecosyl Products Inc., Byron, IL); (8) Silo-King WS (1.5×10(5) cfu/g of L. plantarum, P. pentosaceus and Enterococcus faecium; Agri-King, Fulton, IL); and (9) Biomax 5 (BIO; 1×10(5) cfu/g of L. plantarum PA-28 and K-270; Chr. Hansen Animal Health and Nutrition, Milwaukee, WI). Treated forage was ensiled in quadruplicate in mini silos at a density of 172 kg of DM/m(3) for 3 and 120 d. After 3 d of ensiling, the pH of all silages was below 4 but ethanol concentrations were least in BEN silage (2.03 vs. 3.24% DM) and lactic acid was greatest in SAV silage (2.97 vs. 2.51% DM). Among 120-d silages, additives did not affect DM recovery (mean=89.8% ± 2.27) or in vitro DM digestibility (mean=71.5% ± 0.63). The SAV silage had greater ammonia-N (0.85 g/kg of DM) and butyric acid (0.22 vs. 0.0% DM) than other treatments. In contrast, BEN and Silo-King silages had the least ammonia-N concentration and had no butyric acid. The BEN and A. pasteurianus silages had the lowest pH (3.69) and BEN silage had the least ethanol (1.04% DM) and ammonia nitrogen (0.64 g/kg DM) concentrations, suggesting that fermentation was more extensive and protein degradation was less in BEN silages. The BUC and BIO silages had greater acetic acid concentrations than control silages (3.19 and 3.19 vs. 2.78% DM), but yeast counts did not differ. Aerobic stability was increased by 64% by BUC (44.30 h) and by 35% by BEN (36.49 h), but other silages had similar values (27.0±1.13 h).
Assuntos
Silagem/normas , Zea mays , Acetobacter/metabolismo , Amônia/análise , Indústria de Laticínios/métodos , Enterococcus faecium/metabolismo , Etanol/análise , Aditivos Alimentares/farmacologia , Gluconobacter oxydans/metabolismo , Concentração de Íons de Hidrogênio , Ácido Láctico/análise , Lactobacillus/metabolismo , Lactobacillus plantarum/metabolismo , Pediococcus/metabolismo , Silagem/análise , Silagem/microbiologiaRESUMO
The objective of this study was to evaluate the effect of hybrid, maturity at harvest [dry matter (DM) content], and length of storage on the composition and nutritive value of corn silage. The plants used in this study included a normal (NORM) and a brown midrib (BMR) hybrid, harvested at 32 or 41% DM and ensiled for various lengths of time (0 to 360 d) without inoculation. Measurements included nutrient analysis, fermentation end products, in vitro digestion of NDF (NDF-D, 30 h), and in vitro digestion of starch (7h). The concentration of acetic acid increased with length of storage for all treatments, specifically increasing as much as 140% between d 45 to 360 for 32% DM BMR silage. Small changes in lactic acid and ethanol were noted but varied by DM and hybrid. When averaged across maturities and length of storage, compared with NORM, BMR silage was lower in concentrations of lignin, crude protein, neutral detergent fiber, and acid detergent fiber, but higher in starch. On average, NDF-D of both hybrids was not affected by length of storage between 45 and 270 d. The NDF-D was markedly greater for BMR than NORM after all times of storage. Increasing maturity at harvest generally did not affect the NDF-D of NORM, with the exception that it was slightly lower for the more mature plants at 270 and 360 d. In contrast, the NDF-D of BMR was lower in more mature silage by approximately 5 percentage units from 45 to 360 d. The concentration of starch for 32% DM NORM was lower (21%) than other treatments (31±3%; mean±SD) at harvest. This finding was probably the cause for starch digestibility to be highest in 32% DM NORM samples atd 0 (about 80%) and lower (65 to 68%) for other treatments. Concentrations of soluble N and ammonia-N increased with length of storage, indicating that proteolytic mechanisms were active beyond 2 to 3 mo of storage. The in vitro digestion of starch generally increased with length of storage, probably as a result of proteolysis. Although active fermentation occurs for only a relatively short time in the silo, many metabolic processes remain active during long-term storage. Changes in the nutritive value of corn silage during storage should be accounted for during ration formulations.
Assuntos
Armazenamento de Alimentos , Valor Nutritivo , Silagem , Zea mays/metabolismo , Ácido Acético/análise , Animais , Bovinos , Etanol/análise , Ácido Láctico/análise , Silagem/análise , Silagem/normas , Amido/análise , Fatores de Tempo , Zea mays/químicaRESUMO
This study examined the effect of applying different bacterial inoculants on the fermentation and quality of corn silage. Corn plants were harvested at 35% DM, chopped, and ensiled in 20-L mini silos after application of (1) deionized water (CON) or inoculants containing (2) 1 × 10(5) cfu/g of Pediococcus pentosaceus 12455 and Propionibacteria freudenreichii (B2); (3) 4 × 10(5) cfu/g of Lactobacillus buchneri 40788 (BUC); or (4) 1 × 10(5) cfu/g of Pediococcus pentosaceus 12455 and 4 × 10(5) cfu/g of L. buchneri 40788 (B500). Four replicates of each treatment were weighed into polyethylene bags within 20-L mini silos. Silos were stored for 575 d at ambient temperature (25°C) in a covered barn. After silos were opened, aerobic stability, chemical composition, and yeast and mold counts were determined. The DNA in treated and untreated silages was extracted using lysozyme/sodium dodecyl sulfate lysis and phenol/chloroform and used as a template for a conventional PCR with primers designed on the 16S rRNA gene to detect the presence of L. buchneri in all silage samples. Acetic acid concentration was greater in B2 silages versus others (6.46 vs. 4.23% DM). Silages treated with BUC and B500 had lower pH and propionic acid concentration and greater lactic acid concentration than others. The B500 silage had the greatest lactic:acetic acid ratio (1.54 vs. 0.41), and only treatment with BUC reduced DM losses (5.0 vs. 14.3%). Yeast and mold counts were less than the threshold (10(5)) typically associated with silage spoilage and did not differ among treatments. Consequently, all silages were very stable (>250 h). Aerobic stability was not improved by any inoculant but was lower in B500 silages versus others (276 vs. 386 h). The conventional PCR confirmed the presence of similar populations of L. buchneri in all silages. This may have contributed to the prolonged aerobic stability of all silages.
Assuntos
Fermentação , Lactobacillus/metabolismo , Propionibacterium/metabolismo , Silagem/microbiologia , Zea mays/microbiologia , Aerobiose , Animais , Microbiologia de Alimentos , Silagem/normas , Zea mays/metabolismo , Zea mays/normasRESUMO
The objective of this study was to determine the effect of beet pulp (BP) and lactic acid bacteria (LAB) on silage fermentation quality and in vitro ruminal dry matter (DM) digestion of vegetable residues, including white cabbage, Chinese cabbage, red cabbage, and lettuce. Silage was prepared using a small-scale fermentation system, and treatments were designed as control silage without additive or with BP (30% fresh matter basis), LAB inoculant Chikuso-1 (Lactobacillus plantarum, 5mg/kg, fresh matter basis), and BP+LAB. In vitro incubation was performed using rumen fluid mixed with McDougall's artificial saliva (at a ratio of 1:4, vol/vol) at 39°C for 6h to determine the ruminal fermentability of the vegetable residue silages. These vegetable residues contained high levels of crude protein (20.6-22.8% of DM) and moderate levels of neutral detergent fiber (22.7-33.6% of DM). In all silages, the pH sharply decreased and lactic acid increased, and the growth of bacilli, coliform bacteria, molds, and yeasts was inhibited by the low pH at the early stage of ensiling. The silage treated with BP or LAB had a lower pH and a higher lactic acid content than the control silage. After 6h of incubation, all silages had relatively high DM digestibility (38.6-44.9%); in particular, the LAB-inoculated silage had the highest DM digestibility and the lowest methane production. The vegetable residues had high nutritional content and high in vitro DM digestibility. Also, both the addition of a LAB inoculant and moisture adjustment with BP improved the fermentation quality of the vegetable residue silages. In addition, LAB increased DM digestibility and decreased ruminal methane production.
Assuntos
Digestão/fisiologia , Lactobacillus plantarum/metabolismo , Silagem/microbiologia , Animais , Beta vulgaris , Bovinos/fisiologia , Fermentação/fisiologia , Silagem/normas , Fatores de Tempo , VerdurasRESUMO
A meta-analysis of quantitative trait loci (QTL) associated with plant digestibility and cell wall composition in maize was carried out using results from 11 different mapping experiments. Statistical methods implemented in "MetaQTL" software were used to build a consensus map, project QTL positions and perform meta-analysis. Fifty-nine QTL for traits associated with digestibility and 150 QTL for traits associated with cell wall composition were included in the analysis. We identified 26 and 42 metaQTL for digestibility and cell wall composition traits, respectively. Fifteen metaQTL with confidence interval (CI) smaller than 10 cM were identified. As expected from trait correlations, 42% of metaQTL for digestibility displayed overlapping CIs with metaQTL for cell wall composition traits. Coincidences were particularly strong on chromosomes 1 and 3. In a second step, 356 genes selected from the MAIZEWALL database as candidates for the cell wall biosynthesis pathway were positioned on our consensus map. Colocalizations between candidate genes and metaQTL positions appeared globally significant based on χ(2) tests. This study contributed in identifying key chromosomal regions involved in silage quality and potentially associated genes for most of these regions. These genes deserve further investigation, in particular through association mapping.