Abstracts
This study aimed to assess the fermentation profile, losses and chemical composition of the silages of five sorghum cultivars. A completely randomized design with five replicates was used. The experimental treatments were represented by five sorghum cultivars (Sorghum bicolor (L). Moench): 'BRS Ponta Negra' , 'BRS 610', 'BRS 655', 'BRS 800' and 'BRS 810'. There was variation (P<0.05) for the pH in the cultivars studied, with highest result of pH by 'BRS 610'. The average percentages of lactic acid, acetic acid and propionic acid, differed (P<0.05) among the cultivars, ranging from 32.9 to 59.5, 19.8 to 39.8, and 0.0 to 1.3g kg-1, respectively. The dry matter recovery varied among cultivars (P<0.05), allowing the identification of BRS Ponta Negra, and 'BRS 810' silages, as those which recovered the lowest dry matter, with values of 757.1 and 776.1g kg-1, respectively. There were differences (P<0.05) for dry matter, crude protein, ether extract, neutral detergent fiber, non-fibrous carbohydrates and total carbohydrates contents among the cultivars. It was concluded that, despite the morphological and chemical differences among cultivars, the resulting silages had good fermentation profile.
Objetivou-se com este estudo avaliar o perfil fermentativo, perdas e a composição bromatológica de silagens de cinco cultivares de sorgo. Foi utilizado um delineamento experimental inteiramente casualizado com cinco repetições. Os tratamentos experimentais foram representados por cinco cultivares de sorgo (Sorghum bicolor (L). Moench): 'BRS Ponta Negra', 'BRS 610', 'BRS 655', 'BRS 800' e 'BRS 810'. Houve variação (P<0,05) para o pH nos genótipos estudados, com maior resultado para o genótipo 'BRS 610'. Os valores médios de ácido lático, ácido acético e ácido propiônico, diferiram entre as cultivares (P<0,05), variando de 32,9 a 59,5; 19,8 a 39,8; e 0,0 a 1.3g kg-1, respectivamente. A recuperação de matéria seca variou entre as cultivares (P<0,05), em que as silagens dos cultivares 'BRS Ponta Negra' e 'BRS 810', é que tiveram menor recuperação de matéria seca, com valores de 757,1 e 776,1g kg-1, respectivamente. Houve diferença (P<0,05) para teores de matéria seca, proteína bruta, extrato etéreo, fibra em detergente neutro, carboidratos não-fibrosos e carboidratos totais entre as cultivares. Conclui-se que, apesar das diferenças morfológicas e químicas entre as cultivares, as silagens resultantes tinham adequado padrão de fermentação.
conservação; ensilagem; qualidade; Sorghum bicolor.
INTRODUCTION:
Among the advantages of using sorghum, these are highlighted: high dry matter yield in relation to other grasses and the possibility of use regrowth. Moreover, sorghum can be considered as a plant with xerophilous characteristics, low soil fertility requirements and resistant/tolerant to drought and salinity.
Choosing the most appropriate genotype is fundamental in establishing a more efficient production system. The efficiency in selecting genetic material can be enhanced by observing a set of information for the crop within each region. Among the features to be evaluated, the characteristics of silages produced from plants of different cultivars are very important, since the efficiency of the fermentation during ensiling determines the percentage of dry matter recovered and the nutritional value of the produced silage. Therefore, the evaluation of sorghum cultivars is especially important in the Brazilian northeast, where half of the region, classified as semiarid, is under the influence of adverse factors, some of which the sorghum is adapted to.
Based on the above, studies to evaluate the adaptability of sorghum cultivars, as well as the conservation potential in silage form, should be done in order to determine the genotypes that can be cultivated in production systems in the semiarid region.
Forage sorghum has more sugar content than other purpose sorghum owing to higher stem
than other parts of plant (SILVA et al., 2011aSILVA, T.C. et al. Agronomic divergence of Sorghum hybrids for silage
yield in the semiarid region of Paraiba. Revista Brasileira de Zootecnia, v.40, n.9,
p.1886-1893, 2011a. Available from:
<http://www.scielo.br/pdf/rbz/v40n9/a07v40n9.pdf>. Accessed: Jan. 08,
2013.
http://www.scielo.br/pdf/rbz/v40n9/a07v4...
).
In spite of being more productive, when ensiled losses may occur, since yeast can
develop into the silo. Thus, it is very important to evaluate not so agronomic
characteristics but also losses and fermentation profile of silages, to indicate the
more appropriate purpose sorghum for a given production system.
Thus, the objective was to evaluate losses, fermentation profile and chemical composition of silages of five sorghum cultivars of different purpose.
MATERIAL AND METHODS:
The soil in the experimental area had the following chemical attributes (profile from 0-20cm): pH: 6.94; P: 70.38; K+: 82 (mg dm-3), Na+: 0.37; H+ + Al+3: 2.06; Al+3: 0.0; Ca+2: 7.45; Mg+2: 2.40 (cmolc dm-3); base saturation: 83.51% and organic matter: 10.55g kg-1. Fertilization was conducted with 50kg ha-1 of nitrogen, in the form of ammonium sulfate, 15 days after emergence (DAE).
The experimental area measured 0.5ha, totaling 0.1ha for each variety of sorghum, distributed in a completely randomized block, with four blocks. The spacing of 0.7m between rows was used and a seeding rate of 12 seeds per meter. A completely randomized design with five replicates was used for silages evaluation, once material of all blocks of each treatment was mixed, thus silos were considered the replicates. The experimental treatments were represented by five sorghum cultivars (Sorghum bicolor (L). Moench): 'BRS Ponta Negra', 'BRS 610', 'BRS 655', 'BRS 800', 'BRS 810', with seeds provided by the Empresa Brasileira de Pesquisa Agropecuária - Embrapa Milho e Sorgo.
The cultivars 'BRS 810' and 'BRS Ponta Negra' have more forage characteristics; the cultivar 'BRS 610' has dual purpose characteristics; and the cultivars 'BRS 655' and 'BRS 800' have grain sorghum characteristics (Table 1).
: Dry matter yield, morphological components and leaf/stem ratio of forage crops harvested at the time of ensiling, based on dry matter.
The harvest was done manually, and the material was transported in oxcart, when the grains were in milky: pasty stage. For ensiling, plastic buckets of 15L were used - equipped with Bunsen valves for gas exhausting with 4kg of sand at the bottom to catch the effluent. The compression was performed by treading. After 40 days of ensiling, the silos were opened, and the upper and lower portions (5cm) were discarded; of the rest, 300g was taken for laboratory tests together with a composite sample of plants, obtained after chopping.
The agronomic characterization of the sorghum cultivars was conducted through sampling a linear meter at five different spots in the experimental area of each cultivar evaluated, totaling five repetitions. The plants of each linear meter were weighed to determine the yield per linear meter. This weight was multiplied by the total linear meters in a hectare, to determine green matter yield per hectare. Two plants per linear meter were randomly selected for separation into components: leaf, stem, panicle and dead material. The remaining plants were chopped in a stationary machine and, together with samples of plant components, were pre-dried in a forced ventilation oven at 65oC until they reached constant weight, later to determine the dry matter content. The green matter yield was converted into dry matter yield, and the percentage of the plant components were expressed, based on the dry matter of each component. The results are shown in table 1.
The chemical components evaluated were: dry matter (DM), crude protein (CP), ether
extract (EE), organic matter (OM), mineral matter (MM), according to SILVA & QUEIROZ (2002)SILVA, D.J., QUEIROZ, A.C. Análise de alimentos: métodos químicos e
biológicos. Viçosa: Universidade Federal de Viçosa, 2002. 165p. and FDNcp through the
method of VAN SOEST et al. (1991)VAN SOEST, P.J. et al. Symposium: carbohydrate methodology, metabolism,
and nutritional implications in dairy cattle. Journal of Dairy Science, v.74,
p.3583-3597, 1991. Available from:
<http://webpages.icav.up.pt/ptdc/CVT/098487/2008/Van%20Soest,%201991.pdf>.
Accessed: Feb. 14, 2013.
http://webpages.icav.up.pt/ptdc/CVT/0984...
with
adjustments proposed by the Ankon manual (Ankon(r) Technology Corp.).
A central portion was homogenized in order to proceed to withdraw a sample of about 200g
to determine pH and ammonium nitrogen, according to BOLSEN et al. (1992)BOLSEN, K.K. et al. Effect of silage additives on the microbial
succession and fermentation process of alfalfa and corn silages. Journal of Dairy
Science, v.75, p.3066-3083, 1992. Available from:
<http://www.sciencedirect.com/science/article/pii/S0022030292780709>. Accessed:
Jun. 18, 2013.
http://www.sciencedirect.com/science/art...
. For the analysis of organic acids, 10g of sample were
mixed on an industrial blender with 90ml of distilled water and filtered on a Whatman
filter paper type (KUNG & RANJIT JR., 2001KUNG JR. L., RANJIT, N.K. The effect of Lactobacillus buchneri and other
additives on the fermentation and aerobic stability of barley silage. Journal of
Dairy Science, v.84, n.5, p.1149-1155, 2001. Available from:
<www.agroteam.it/index.aspx?m=81&f=3&idf=118>. Accessed: May 13,
2013.
www.agroteam.it/index.aspx?m=81&f=3&idf=...
).
Losses by gases and effluents and dry matter recovery (DMR) were calculated through
equations described by SANTOS et al. (2008)SANTOS, E.M. et al. Composição bromatológica, perdas e perfil
fermentativo de silagens de capim-elefante com níveis de inclusão de jaca. Revista
Brasileira de Saúde e Produção Animal, v.9, n.1, p.64-73, 2008. Available from:
<http://revistas.ufba.br/index.php/rbspa/article/view/872/562>. Accessed: Jun.
13, 2013.
http://revistas.ufba.br/index.php/rbspa/...
.
The data were submitted to analysis of variance and the averages were compared by the Scott-Knott test at 0.05 level of probability, using the Statistical Analysis System SAS (SAS INSTITUTE, 2000STATISTICAL ANALYSES SYSTEM - SAS. SAS/STAT User's guide. Cary: 2000. 1028p.).
RESULTS AND DISCUSSION:
There was variation (P<0.05) for the pH in the cultivars studied (Table 2). Values were generally below the values recommended by McDONALD et al. (1991) McDONALD, P. et al. The bochemistry of silage. 2.ed. Marlow: Chalcombe, 1991. 340p, which is 4.0. This indicates that the fermentation was intense, probably due to high concentrations of water soluble carbohydrates (WSC) in the plants (Table 3).
The average percentages of lactic acid (LA) varied (P<0.05) among cultivars. 'BRS
Ponta Negra' silages had higher (P<0.05) content of lactic acid, 59.5g
kg-1, expected result, since this cultivar had higher WSC content (Table 3) and allowed greater fermentation by lactic
acid bacteria. On the other hand, 'BRS 655' and 'BRS 610' silages presented lower
(P<0.05) content of lactic acid, 43.8 and 43.7g kg-1, respectively. These
cultivars before ensiling had lower contents of WSC, 125.8 and 133.5g kg-1,
respectively, resulting in higher pH values. However, pH and amount of acid lactic are
influenced by the content of WSC sorghum. Soluble carbohydrates are major substrates for
lactic acid fermentation, who in turn allows pH drop. Due to the different
concentrations of WSC for the cultivars variation was observed in the fermentation
process (Table 3). Evaluating same cultivars
'BRS 610' and 'BRS 655' FILYA & KARABULUT
(2004)FILYA, I. Nutritive value and aerobic stability of whole crop maize
silage harvested at four stages of maturity. Animal Feed Science and Technology,
v.116, p.141-150, 2004. Available from:
<http://www.animalfeedscience.com/article/S0377-8401(04)00123-3/pdf>. Accessed:
Jun. 08, 2013.
http://www.animalfeedscience.com/article...
and FRANÇA et al. (2011)FRANÇA, A.F.S. et al. Características fermentativas da silagem de
híbridos de sorgo sob doses de nitrogênio. Ciência Animal Brasileira, v.12, n.3,
p.383-391, 2011. Available from:
<http://www.revistas.ufg.br/index.php/vet/article/view/540>. Accessed: Jan. 13,
2013.
http://www.revistas.ufg.br/index.php/vet...
found
values close, but lower than those found by MACHADO et
al. (2012)MACHADO, F.S. et al. Qualidade da silagem de híbridos de sorgo em
diferentes estádios de maturação. Medicina Veterinária e Zootecnia, v.64, n.3,
p.711-720, 2012. Available from: <http://www.scielo.br/pdf/abmvz/v64n3/24.pdf>.
Accessed: May 13, 2013.
http://www.scielo.br/pdf/abmvz/v64n3/24....
. In general the average observed among cultivars under study,
45.92g kg-1 of LA, are considered satisfactory according to McDONALD et al. (1991) McDONALD, P. et al. The bochemistry of silage. 2.ed. Marlow: Chalcombe,
1991. 340p, to ensure appropriate
fermentation.
For the average values of acetic acid (AA) there was difference (P<0.05) among the
cultivars. 'BRS 800' silage presented higher content, 39.8g kg-1 and 'BRS
Ponta Negra' lower content, 19.8g kg-1. According to McDONALD et al. (1991) McDONALD, P. et al. The bochemistry of silage. 2.ed. Marlow: Chalcombe,
1991. 340p, high acetic acid production is indicative of
enterobacteria action which occurs during to the initial phases of the silage
fermentation competing with lactic acid bacteria for nutrients. On the other hand, that
acetic acid production can be occur though heterofermentative acid lactic bacteria which
to the use pentoses as substrate produce one molecule of lactic acid and one molecule of
acetic acid, thus contributing to the fast acidification of the medium (ROTH & UNDERSANDER, 1995ROTH, G.; UNDERSANDER, D. Silage additives. In: Corn silage production
management and feeding. Madison: Madison American Society of Agronomy, 1995.
p.27-29.). Furthermore acetic
acid is highly effective antifungical agent that improve the aerobic stability of
silages (KUNG Jr. et al., 2003KUNG JR. L. et al. The effect of treating alfalfa with Lactobacillus
buchneri 40788 on silage fermentation, aerobic stability, and nutritive value for
lactating dairy cows. Journal of Dairy Science, v.86, n.1, p.336-343, 2003. Available
from: <http://www.sciencedirect.com/science/article/pii/S002203020373611X>.
Accessed: May 13, 2014.
http://www.sciencedirect.com/science/art...
).
There was no difference (P>0.05) among the cultivars for butiric acid, however there
effect (P<0.05) for propionic acid (Table 3).
The lower contents for these acids are associated with fast acidification of the medium
due to their susceptibility to low pH. Therefore in silages with good fermentation is
common to find minimum values for them, which was also observed by FRANÇA et al. (2011)FRANÇA, A.F.S. et al. Características fermentativas da silagem de
híbridos de sorgo sob doses de nitrogênio. Ciência Animal Brasileira, v.12, n.3,
p.383-391, 2011. Available from:
<http://www.revistas.ufg.br/index.php/vet/article/view/540>. Accessed: Jan. 13,
2013.
http://www.revistas.ufg.br/index.php/vet...
and MACHADO et
al. (2012)MACHADO, F.S. et al. Qualidade da silagem de híbridos de sorgo em
diferentes estádios de maturação. Medicina Veterinária e Zootecnia, v.64, n.3,
p.711-720, 2012. Available from: <http://www.scielo.br/pdf/abmvz/v64n3/24.pdf>.
Accessed: May 13, 2013.
http://www.scielo.br/pdf/abmvz/v64n3/24....
.
The DMR varied among cultivars (P<0.05), allowing the identification of silages of Ponta Negra and 'BRS 810' as those which recovered the lowest dry matter, 757.1 and 775.1g kg-1, respectively (Table 3). The other silages were similar to each other with higher values. These results are very important to be analyzed, because demonstrated that high amount of silage can be lost in forage purpose sorghum. In spite of 'BRS Ponta Negra' and 'BRS 810' being more productive, losses were very high, so that dry matter yield must be adjusted for these losses values. Although the dry matter contents of the silages were not high or lower than 300g kg-1 these not disfavored the fermentation process because the pH values of all silages were lower than 4.0.
On the other hand, when the content of WSC from the plant is high, which results in low
pH values, the development of yeasts during fermentation may occur, resulting in
production of ethanol or even bacteria which convert lactic acid into acetic acid (OUDE ELFERINK et al., 2001OUDE ELFERINK, S.J.W.H. et al. Anaerobic conversion of lactic acid to
acetic acid and 1,2- propanediol by Lactobacillus buchneri. Applied Environmental
Microbiology, v.67, p.125-132, 2001. Available from:
<http://aem.asm.org/content/67/1/125.short>. Accessed: Mar. 01,
2014.
http://aem.asm.org/content/67/1/125.shor...
). The alcoholic
fermentation leads to increased losses, because for each mole of fermented glucose, two
molecules of CO2 are formed and lost in gaseous form, besides the ethanol
which is a volatile organic compound.
Observing the values of residual soluble carbohydrates of the silages, it is noted that all silages had the same amount of residual sugar, so those with more sugars in the plant lost more sugars in the fermentation process, leading to losses of DM, probably for production of ethanol.
There were differences (P<0.05) among cultivars for the percentage of DM, which could
compromise the quality of silage, because values below 210g kg-1 present a
higher probability of undesirable secondary fermentations, damaging the quality of
silage. However, for the studied cultivars, the pH values were all low, which leads to
very acid silages, suggesting that the percentage of dry matter did not favor the
development of clostridia and enterobacteria, which require mediums with high water
activity (McDONALD et al., 1991 McDONALD, P. et al. The bochemistry of silage. 2.ed. Marlow: Chalcombe,
1991. 340p) and pH above
5.0, respectively (SANTOS et al., 2013SANTOS, E.M. et al. Lactic acid bacteria in tropical grass silages,
lactic acid bacteria - R & D for food, health and livestock purposes, Dr. J.
Marcelino Kongo (Ed.). ISBN: 978-953-51-0955-6, In Tech. Available from:
<http://cdn.intechopen.com/pdfs/42321
/InTech_Lactic_acid_bacteria_in_tropical_grass_silages.pdf>. Accessed: Jun. 17,
2013. doi: 10.5772/50703.
http://cdn.intechopen.com/pdfs/42321
...
). This
proves that there is a relationship between the percentage of dry matter to be ensiled
and the amount of soluble carbohydrates, as demonstrated by SILVA et al. (2011b)SILVA, T.C. et al. Populações microbianas, perfil fermentativo e
composição de silagens de capim-elefante com jaca. Archivos de Zootecnia, v.60,
n.230, p.253, 2011b. Available from:
<http://scielo.isciii.es/pdf/azoo/v60n230/art9.pdf>. Accessed: Jul. 30,
2013.
http://scielo.isciii.es/pdf/azoo/v60n230...
. Otherwise, that low dry matter content had
promoted development of undesirable microorganisms the use of moisture absorbents
additives would be indicated for to control secondary fermentations.
The crude protein contents (Table 4) differed
(P<0.05), approaching the minimum values of 49.1 and 69.4g kg-1 of the
rate considered adequate for the functioning of ruminal microbiota (VAN SOEST, 1994VAN SOEST, P.J. Nutritional ecology of the ruminant. 2.ed. Ithaca:
Cornell University, 1994. 476p. Available from:
<http://www.cornellpress.cornell.edu/book/?GCOI=80140100037050>. Accessed: Jul.
30, 2013.
http://www.cornellpress.cornell.edu/book...
), confirmed in tropical conditions
by LAZZARINI et al. (2009)LAZZARINI, I. et al. Intake and digestibility in cattle fed low-quality
tropical forage and supplemented with nitrogenous compounds. Revista Brasileira de
Zootecnia, v.38, n.10, p.2021-2030, 2009 Available from:
<http://www.scielo.br/pdf/rbz/v38n10/24.pdf>. Accessed: Aug. 03,
2013.
http://www.scielo.br/pdf/rbz/v38n10/24.p...
. Anyway, crude protein
in sorghum silages is below of value cited above, since sorghum is forage. 'BRS Ponta
Negra' silage presented lower crude protein content, 49.1g kg-1. This
cultivar was more productive (Table 1), however,
result in silages with lower crude protein content and high losses. This information
must be concern to decide about its use for silage, once costs with protein concentrate
will be elevated as compared to the other cultivars.
The levels of EE and NDF differed (P<0.05) among 'BRS Ponta Negra', 'BRS 610' and 'BRS 655', with higher percentages of NDF, and between 'BRS 800' and 'BRS 810' with lower values, which may contribute to the increased dry matter consumption. The increased levels of fiber for the first three cultivars can be explained from the fact that they have forage characteristics. For EE, the opposite occurred: the cultivars that had lower NDF contents, consequently showed higher levels of EE.
It was noted that the chemical compositions of sorghum silages follow their morphological characteristics, that is, the taller and more fodder plant allows for a silage with more fiber content, lower ether extract, less protein, but higher amount of carbohydrates than the less fodder plants which, on the other hand, because they contain more panicles, have higher levels of protein and ether extract.
CONCLUSION:
It is concluded that, despite the morphological and chemical differences among cultivars, the resulting silages had high lactic fermentation. The cultivars 'BRS 810', 'BRS Ponta Negra' and 'BRS 610' stood out in relation to the others. Nevertheless, more studies are needed to understand better the fermentation process of forage sorghum silages with higher concentration of sugars and to develop techniques for control of DM losses, to allow farms to explore their higher productive potential.
- BOLSEN, K.K. et al. Effect of silage additives on the microbial succession and fermentation process of alfalfa and corn silages. Journal of Dairy Science, v.75, p.3066-3083, 1992. Available from: <http://www.sciencedirect.com/science/article/pii/S0022030292780709>. Accessed: Jun. 18, 2013.
» http://www.sciencedirect.com/science/article/pii/S0022030292780709 - FILYA, I. Nutritive value and aerobic stability of whole crop maize silage harvested at four stages of maturity. Animal Feed Science and Technology, v.116, p.141-150, 2004. Available from: <http://www.animalfeedscience.com/article/S0377-8401(04)00123-3/pdf>. Accessed: Jun. 08, 2013.
» http://www.animalfeedscience.com/article/S0377-8401(04)00123-3/pdf - FRANÇA, A.F.S. et al. Características fermentativas da silagem de híbridos de sorgo sob doses de nitrogênio. Ciência Animal Brasileira, v.12, n.3, p.383-391, 2011. Available from: <http://www.revistas.ufg.br/index.php/vet/article/view/540>. Accessed: Jan. 13, 2013.
» http://www.revistas.ufg.br/index.php/vet/article/view/540 - KUNG JR. L., RANJIT, N.K. The effect of Lactobacillus buchneri and other additives on the fermentation and aerobic stability of barley silage. Journal of Dairy Science, v.84, n.5, p.1149-1155, 2001. Available from: <www.agroteam.it/index.aspx?m=81&f=3&idf=118>. Accessed: May 13, 2013.
» www.agroteam.it/index.aspx?m=81&f=3&idf=118 - KUNG JR. L. et al. The effect of treating alfalfa with Lactobacillus buchneri 40788 on silage fermentation, aerobic stability, and nutritive value for lactating dairy cows. Journal of Dairy Science, v.86, n.1, p.336-343, 2003. Available from: <http://www.sciencedirect.com/science/article/pii/S002203020373611X>. Accessed: May 13, 2014.
» http://www.sciencedirect.com/science/article/pii/S002203020373611X - LAZZARINI, I. et al. Intake and digestibility in cattle fed low-quality tropical forage and supplemented with nitrogenous compounds. Revista Brasileira de Zootecnia, v.38, n.10, p.2021-2030, 2009 Available from: <http://www.scielo.br/pdf/rbz/v38n10/24.pdf>. Accessed: Aug. 03, 2013.
» http://www.scielo.br/pdf/rbz/v38n10/24.pdf - MACHADO, F.S. et al. Qualidade da silagem de híbridos de sorgo em diferentes estádios de maturação. Medicina Veterinária e Zootecnia, v.64, n.3, p.711-720, 2012. Available from: <http://www.scielo.br/pdf/abmvz/v64n3/24.pdf>. Accessed: May 13, 2013.
» http://www.scielo.br/pdf/abmvz/v64n3/24.pdf - McDONALD, P. et al. The bochemistry of silage. 2.ed. Marlow: Chalcombe, 1991. 340p
- OUDE ELFERINK, S.J.W.H. et al. Anaerobic conversion of lactic acid to acetic acid and 1,2- propanediol by Lactobacillus buchneri. Applied Environmental Microbiology, v.67, p.125-132, 2001. Available from: <http://aem.asm.org/content/67/1/125.short>. Accessed: Mar. 01, 2014.
» http://aem.asm.org/content/67/1/125.short - ROTH, G.; UNDERSANDER, D. Silage additives. In: Corn silage production management and feeding. Madison: Madison American Society of Agronomy, 1995. p.27-29.
- SANTOS, E.M. et al. Composição bromatológica, perdas e perfil fermentativo de silagens de capim-elefante com níveis de inclusão de jaca. Revista Brasileira de Saúde e Produção Animal, v.9, n.1, p.64-73, 2008. Available from: <http://revistas.ufba.br/index.php/rbspa/article/view/872/562>. Accessed: Jun. 13, 2013.
» http://revistas.ufba.br/index.php/rbspa/article/view/872/562 - SANTOS, E.M. et al. Lactic acid bacteria in tropical grass silages, lactic acid bacteria - R & D for food, health and livestock purposes, Dr. J. Marcelino Kongo (Ed.). ISBN: 978-953-51-0955-6, In Tech. Available from: <http://cdn.intechopen.com/pdfs/42321 /InTech_Lactic_acid_bacteria_in_tropical_grass_silages.pdf>. Accessed: Jun. 17, 2013. doi: 10.5772/50703.
» https://doi.org/10.5772/50703» http://cdn.intechopen.com/pdfs/42321 /InTech_Lactic_acid_bacteria_in_tropical_grass_silages.pdf - SILVA, D.J., QUEIROZ, A.C. Análise de alimentos: métodos químicos e biológicos. Viçosa: Universidade Federal de Viçosa, 2002. 165p.
- SILVA, T.C. et al. Agronomic divergence of Sorghum hybrids for silage yield in the semiarid region of Paraiba. Revista Brasileira de Zootecnia, v.40, n.9, p.1886-1893, 2011a. Available from: <http://www.scielo.br/pdf/rbz/v40n9/a07v40n9.pdf>. Accessed: Jan. 08, 2013.
» http://www.scielo.br/pdf/rbz/v40n9/a07v40n9.pdf - SILVA, T.C. et al. Populações microbianas, perfil fermentativo e composição de silagens de capim-elefante com jaca. Archivos de Zootecnia, v.60, n.230, p.253, 2011b. Available from: <http://scielo.isciii.es/pdf/azoo/v60n230/art9.pdf>. Accessed: Jul. 30, 2013.
» http://scielo.isciii.es/pdf/azoo/v60n230/art9.pdf - STATISTICAL ANALYSES SYSTEM - SAS. SAS/STAT User's guide. Cary: 2000. 1028p.
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Publication Dates
-
Publication in this collection
Feb 2015
History
-
Received
15 Nov 2013 -
Accepted
29 May 2014