Printer Friendly

Nutritional diversity of Brachiaria ruziziensis clones/Divergencia nutricional de clones de Brachiaria ruziziensis.

INTRODUCTION

In Brazil, beef and dairy cattle production is based primarily on grass-feeding systems (around 90%), making pasture grasses the main source of animal feed. With growth in the livestock sector, the search for foods that combine high production and high-quality has been increasing. However, only a few varieties meet the requirements, demonstrating the importance of the introduction of genetically improved cultivars.

Although, the number of forage species available in Brazil is high, Brachiaria and Panicum occupy the largest area. Among the Brachiaria species cultivated in Brazil, Brachiaria ruziziensis is not widely used in the country despite showing promise for breeding programs with high nutritional quality, good adaptation in crop-livestock-forest integration system (CLFIS), suitable ground cover with direct planting, and as the only diploid sexual species, which allows variability between generations for selection of superior genotypes. However, this forage species also has some unfavorable characteristics, such as susceptibility to be attacked by spittlebug, with low productivity, and reduced adaptation to less fertile and acidic soils (DIAS et al., 2013).

Multivariate analysis has been used to evaluate nutritional diversity in forage species (AZEVEDO et al., 2003; FREITAS et al., 2006), helping to identify genotypes with genetic differences that produce progeny with greater heterogeneity, thus increasing the likelihood of obtaining superior individuals in segregating generations (CRUZ et al., 2012; SHIMOYA et al., 2002).

Selecting for good performance and high nutritional value improves efficiency of a breeding program (CRUZ et al., 2012). In this context, the objective was to evaluate the nutritional diversity of 23 Brachiaria ruziziensis clones in the breeding program at EMBRAPA.

MATERIALS AND METHODS

The experiment was performed at the Experimental Complex Multiuser of Bioefficacy and Sustainability of Livestock and at the experimental farm of Jose Henrique Bruschi of EMBRAPA Dairy Cattle in Coronel Pacheco-MG, Brazil (23[degrees]35'16" S, 43[degrees]15'56" W, altitude of 426m). The climate corresponds to the Cwa type (mesothermal) in the Koppen classification and the soil of the experimental area is classified as Red-Yellow Alic Argisol (SANTOS et al., 2006).

The experimental design used randomized blocks with 26 treatments (genotypes) and three replications. Treatments consisted of 23 clones of Brachiaria ruziziensis, from the forage breeding program of EMBRAPA, represented by IDs: 15, 16, 46, 174, 411, 590, 651, 670, 768, 776, 844, 859, 950, 965, 970, 975, 1067, 1093, 1296, 1765, 1806, 1894 and 1972. Brachiaria ruziziensis cv. 'Kennedy', Brachiaria brizantha cv. 'Marandu' and Brachiaria decumbens cv. 'Basilisk' were used as a control.

Plants in each plot were cut within 27 days of growth, at an average height of 10cm with the aid of motorized costal mower. After collection, samples were weighed fresh and drying ovens with forced air circulation at 65[degrees]C for 72 hours. They were ground in a Wiley mill with 1 mm sieve and stored in polyethylene bottles for later composition analyses.

The contents of dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, and in vitro dry matter digestibility (IVDMD), were determined by near infra-red spectroscopy (NIRS) in the ruminant nutrition laboratory at the Animal Science section of EMBRAPA Dairy Cattle, Juiz de Fora, MG, Brazil.

The in vitro rumen fermentation kinetics was performed by the semiautomatic gas production technique following the procedures described in MAURICIO et al. (1999). For this evaluation, 50mL glass flasks were utilized and 0.32g of the substrate to be tested were incubated in filter bags F57 (Ankon[R]). Twenty-eight mL of buffered culture medium and rumen fluid, prepared the previous day (MENKE & SEINGASS, 1987) and kept pressurized under C[O.sub.2], were added. Flasks were sealed with a silicone stopper to avoid contamination and fermentation and refrigerated at 4[degrees]C. Five hours before inoculation with rumen fluid, the bottles were placed in a room at 39[degrees]C.

The rumen inoculate was collected from three fistulated Holstein x Gyr dry cows with 500 [+ or -] 15kg average body weight. Diet comprised of pasture (Brachiaria decumbens) supplemented with 15kg/day of corn silage and 2.0kg of concentrate a day. Rumen fluid was collected in the morning before feeding through the ruminal cannula and then filtered through double layers of cheesecloth and maintained at 39[degrees]C. Inoculum of three cows was pooled.

Three milliliters of rumen fluid was added to the flasks containing samples and buffered culture medium. Finally, flasks were sealed with a silicone stopper and aluminum washers to avoid gases escaping. Triplicates of each sample were incubated and kept heated at 39[degrees]C room. Flasks containing only inoculum and culture medium were used as a blank.

Pressure readings were taken using a pressure transducer (DPI 705 - GE) at 2, 4, 6, 8, 10, 12, 14, 17, 20, 24, 28, 34, 48, 72 and 96 hours after inoculation. The PSI values were converted to volume according to the equation: Volume = -0.0125[x.sup.2]+3.6015x - 0.1118; [R.sup.2]=0.9874, established from the laboratory conditions. Production volumes were adjusted to g of substrate (based on DM) incubated and the values obtained were corrected for blanks (flasks without substrate at each incubation time).

A mathematical description of rumen fermentation kinetics was estimated using in vitro gas production. The bi-compartmental model was used and fitted to the curve of cumulative gas production (SCHOFIELD et al., 1994) as described below: V (t) = VFNFC/(1+exp (2-4*kdNFC*(T-L)))+VFFC/ (1+exp (2-4*kdFC*(T-L)))

Where: V (t) = total gas accumulated at time t; VFNFC is equivalent to the maximum volume of gases from the NFC fraction (mL); VFFC is the maximum volume of the gases from the FC fraction (mL); kdNFC is the degradation rate (% h) of NFC; kdFC is the degradation rate (% h) of FC; and T and L are the incubation (hours) and lag (hours) times, respectively.

The data of bromatological composition were submitted to the univariate analysis through the Minitab 16 program and the averages compared by the Tukey test at 5% of probability. Principal components analyses and agglomerative hierarchical clustering (complete linkage) were conducted in Minitab 16 to evaluate the nutritional divergence between genotypes. Euclidean distance using standardized mean was used as a basic measure of similarity.

RESULTS AND DISCUSSION

The dry matter (DM), in vitro dry matter digestibility (IVDMD), and crude protein (CP) variables had a significant effect among the evaluated clones (P<0.05; Table 1). The DM content ranged from 202.6 to 147.0g/kg DM, with the highest DM content observed for clone 859, with a mean of 202.6g/ kg DM, whereas the clone presented lower IVDMD, with a mean of 577.5g/kg DM (P<0.05). The highest values of IVDMD were observed for clones 16, 46, 768, 970 and 1067, with a mean of 679.7 to 692.1g/ kg DM (P<0.05). Clones showed high protein content (range 164.9 to 130.4g/kg DM) and clone 15 had the highest value of protein.

No difference (P>0.05) was observed in neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin (Lig). The mean value of Lig was 45.5g/kg DM. For the NDF and ADF, the variations were 643.1 to 580.4 and 358.9 to 288.5g/kg of DM, respectively. According to VAN SOEST (1994), the NDF content influences the consumption of bulky foods and all clones presented values higher than 550g/kg, considered by this author as a limit to influence the consumption of forage.

LOPES et al. (2010) evaluated the nutritional quality of four Brachiaria species (B. brizantha, B. humidicula, B. decumbens and B. ruziziensis) at 56 days of growth and reported mean values of DM, NDF and ADF higher than those observed in the present study, 20.55, 68.44 and 36.53%, respectively, while mean values of CP, IVDMD and Lig were lower (6.9, 61.6 and 3.3%, respectively). Higher values of NDF and ADF and lower values of IVDMD and CP were also observed by SOUZA SOBRINHO et al. (2011) (NDF, ADF, IVDMD and CP of 78.0, 43.1, 55.2 and 6.3%, respectively) were evaluated for the forage quality of different species of Brachiaria, cut at 57 days of regrowth. Difference observed between the studies can be attributed to the stage of forage maturity, since digestibility and CP tend to decrease with the advancement of plant maturity and increase of the NDF and ADF fraction.

Table 2 shows the parameters of ruminal fermentation kinetics of B. ruziziensis clones and controls. Cumulative gas production rate for the fermentation of fibrous and non-fibrous carbohydrates (VFFC and VFNFC) ranged from 60.9 to 170.2mL/g and from 42.8 to 125.4mL/g, respectively. Volume of gas produced depends on the composition of the food and, the larger the amount of fiber, the greater the gas production (NOGUEIRA et al., 2006). This allowed that genotypes that presented superior VFFC are more digestible compared to the fibrous fraction. Structural carbohydrates have slower degradability and for this reason, the fibrous carbohydrate degradation rate (KdFC) is lower than the non-fibrous carbohydrate degradation rate (KdNFC), 0.019 and 0.052DM/h, respectively.

The estimated colonization time (L) presented an average value of 6h. This parameter indicated the time involved between the beginning of the incubation and the start of microbial action on the sample. Thus, the greater amount of readily fermentable substances and the physical and chemical characteristics of the sample's cell wall, which facilitated microbial colonization, represented lower time of colonization (MAGALHAES et al., 2006).

Assessing the kinetic parameters of ruminal degradation of the fibrous and non-fibrous carbohydrate fractions of Brachiaria brizantha cv. 'Marandu' at three ages of cuts (28, 35 and 54 days) by the in vitro technique of gas production, SA et al. (2011), reported mean values for VFNFC and KdNFC at 28 days of age of 93.51mL/g of DM and 0.05[h.sup.-1], respectively, values similar to those reported in the present study. However, the mean values observed for VFFC and KdFC (83.25mL/g DM and 0.01DM/[h.sup.-1]) were lower than those observed in the present study.

The evaluation of the nutritional divergence of Brachiaria genotypes (Table 3), was based on a principal component analysis (PC) where the cumulative variance of the first two principal components (PC1: 70.16% and PC2: 26.08%) explained 96.24% of variance between genotypes. Initially, we used all the variables of chemical and kinetic composition of fermentation, taken from minor models for discrimination of genotypes.

According to CRUZ et al. (2012), the relative importance of the main components decreases from the first to the last; the last component is responsible for explaining a tiny fraction of the total variance available. Thus, it was reported that the variables of lesser interest were KdNFC and KdFC once had a higher weighting in the smallest eigenvalue component (Table 3).

From the eigenvectors associated with the main components, we obtained the scores of the 26 Brachiaria genotypes. Graphical dispersion of the scores of the two main components can be reported in figure 1, where the distance of these points is proportional to the degree of dissimilarity between populations. Genotype grouping was observed in four sets. The first with clones 46, 768, 965, 970 and 106, the second one with clones 15, 16 and 950, the third one with clones 670, 844 and 859 and finally the fourth set with clones 174, 411, 590, 651, 776, 975, 1093, 1296, 1765, 1806, 1894, 1972 and the Brizantha, Decumbens and Ruziziensis controls. Clones 15, 16, 670, 844, 859 and 950 showed the highest dispersion of scores in the first two main components and were considered the most dissimilar.

For the hierarchical clustering analysis by full connection method, based on Euclidean distance average, we used six variables selected from the PC analysis (IVDMD, NDF, lignin, CP, KdNFC and KdFC) and obtained five distinct groups (Table 4). Group V, formed by clones 46, 768 and 1067, showed better results in relation to the others, with a higher average of IVDMD (686.3g/kg), which was the main discriminating factor. Group IV constituted by clones 15, 16 and 950 is distinguished by the low NDF, high CP contents and high degradation rate of the fibrous fraction.

Group V clones have IVDMD values higher than Group I and II that include traditional cultivars already consolidated in the domestic market, indicating the potential of the nutritional value of the members of this group for the breeding program. Group I introduced many clones and also included B. decumbens and B. ruziziensis (Kennedy). Group II, consisting of clones 670, 844, 859, 1093 and B. brizantha, showed the lowest IVDMD (612.8g/kg) and higher lignin content (49.7g/kg). Clones of this group have similar features to B. brizantha, a species of great importance in Brazilian livestock rearing.

CONCLUSION

B. ruziziensis clones showed nutritional divergence and clones 46, 768 and 1067 were distinguished clones of high nutritional value. Clones 15, 16 and 950 are distinguished by the lower values of NDF and high protein levels. The divergent nutritional characteristics can guide new crosses in the breeding program complementing the agronomic parameters for the generation of superior genotypes.

http://dx.doi.org/ 10.1590/0103-8478cr20160855

ACKNOWLEDGEMENTS

The authors acknowledge the Embrapa Gado de Leite, Fundacao de Amparo a Pesquisa do Estado de Minas Gerais (FAPEMIG), Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq--Edital Repensa--Projeto PECUS-RumenGases) for the financial support and to Fundacao de Amparo a Pesquisa do Estado da Bahia (FAPESB) for the granting scholarship.

BIOETHICS AND BIOSSECURITY COMMITTEE APPROVAL

All the management procedures of the animals were conducted according to ethical principles of animal experimentation, established by the Brazilian College of Animal Experimentation and the current legislation was approved by the Ethics Committee for Animal Use of EMBRAPA Dairy Cattle (No. 03/2014).

REFERENCES

AZEVEDO, J. A. G. et al. Evaluation of the Nutritional Divergence of the Sugarcane (Saccharum spp.) Varieties. Revista Brasileira de Zootecnia, v. 32, n. 6, p. 1431-1442, 2003. Available from: <http:// dx.doi.org/10.1590/S1516-35982003000600018>. Accessed: June 12, 2016. doi: 10.1590/S1516-35982003000600018.

CRUZ, C. D. et al. (2012) Biometric Models Applied to Genetic Improvement. 4th Edition, UFV, Vicosa.

DIAS, K. O. DAS G. et al. Plot size and border effect on breeding of Urochloa ruziziensis. Pesquisa Agropecuaria Brasileira, v. 48, n. 11, p. 1426-1431, 2013. Available from: <http://dx.doi. org/10.1590/S0100-204X2013001100002>. Accessed: June 21, 2016. doi: 10.1590/S0100-204X2013001100002.

FREITAS, W. P. et al. Evaluation of the nutritional divergence of sugarcane (Saccharum spp.) genotypes. Revista Brasileira de Zootecnia, v. 35, n. 1, p. 229-236, 2006. Available from: <http:// dx.doi.org/10.1590/S1516-35982006000100029>. Accessed: June 12, 2016. doi: 10.1590/S1516-35982006000100029.

LOPES, F. C. et al. Chemical composition and in situ ruminal degradability of four Brachiaria species. Arquivo Brasileiro de Medicina Veterinaria e Zootecnia, v. 62, n. 4, p. 883-888, 2010. Available from: <http://www.scielo.br/scielo.php?script=sci_artte xt&pid=S0102-09352010000400018>. Accessed: June 12, 2016. doi: 10.1590/ S0102-09352010000400018.

MAGALHAES, R. T. et al. Evaluation of four sorghum genotypes using the semi automated in vitro gas production. Revista Brasileira Milho e Sorgo, v. 5, n. 1, p.101-111, 2006. Available from: <http:// dx.doi.org/10.18512/1980-6477/rbms.v5n1.p101-111>. Accessed: June 21, 2016. doi: 10.18512/1980-6477/rbms.v5n1.p101-111.

MAURICIO, R. M. et al. A semi-automated in vitro gas production technique for ruminants feedstuff evaluation. Animal Feed Science and Technology, v. 79, n. 4, p. 321-330, 1999. Available from: <https://doi.org/10.1016/S0377-8401(99)00033-4>. Accessed: Jan. 21, 2016. doi: 10.1016/S0377-8401(99)00033-4.

MENKE, H. H.; STEINGASS, H. Estimation of the energetic feed value obtained from chemical analysis and in vitro gas production using rumen fluid. Animal Research and Development, 28, 7-55, 1988.

NOGUEIRA, U.T. et al. Comparison among substrates with different soluble carbohydrates concentration using the in vitro semi-automatic gas production technique. Arquivo Brasileiro de Medicina Veterinaria e Zootecnia, v. 58, n. 4, p. 633641, 2006. Available from: <http://dx.doi.org/10.1590/S010209352006000400027>. Accessed: July 15, 2016. doi: 10.1590/ S0102-09352006000400027.

SA, J. F. DE et al. In vitro ruminal fermentation kinetics of 'Marandu' grass at different harvest ages. Acta Scientiarum Animal Sciences, v. 33, n. 3, 2011. Available from: <http://dx.doi. org/10.4025/actascianimsci.v33i3.9462>. Accessed: July 19, 2016. doi: 10.4025/actascianimsci.v33i3.9462.

SANTOS, H. G. dos et al. (2006) Brazilian system of soil classification. 2th Edition. Rio de Janeiro: Embrapa Solos.

SCHOFIELD, P. et al. Kinetics of fiber digestion from in vitro gas production. Journal Animal Science. v. 72, n. 11, p. 2980-2991, 1994. Available from: <https://www.animalsciencepublications. org/publications/jas/articles/72/11/2980>. Accessed: July 25, 2016. doi: 10.2527 / 1994.72112980x.

SHIMOYA, A. et al. Genetic divergence among accessions of a germplasm bank of elephant grass. Pesquisa Agropecuaria Brasileira, Brasilia, v. 37, n. 7, p. 971-980, 2002. Available from: <http://dx.doi.org/10.1590/S0100-204X2002000700011>. Accessed: July 25, 2016. doi: 10.1590/S0100-204X2002000700011.

SOUZA SOBRINHO, F. DE et al. Productivity and quality of Brachiaria fodder in the Northern Region of Fluminense. Applied Research & Agrotechnology, v. 2, n. 3, p. 7-20, 2009. Available from: <http://200.201.10.18/index.php/repaa/article/view/1502>. Accessed: July 25, 2016.

VAN SOEST, P.J. Nutritional ecology of the ruminant. Ithaca, NY (USA): Cornell University Press, 1994.

Ellen de Almeida Moreira (1) Shirley Motta de Souza (2) Alexandre Lima Ferreira (3) Thierry Ribeiro Tomich (2) Jose Augusto Gomes Azevedo (1) Fausto de Souza Sobrinho (2) Flavio Rodrigo Gandolfi Benites (2) Fernanda Samarini Machado (2) Mariana Magalhaes Campos (2) Luiz Gustavo Ribeiro Pereira (2) *

(1) Universidade Estadual de Santa Cruz (UESC), Ilheus, BA, Brasil.

(2) Embrapa Gado de Leite, 36038-330, Juiz de Fora, MG, Brasil. E-mail: luiz.gustavo@embrapa.br. * Corresponding author.

(3) Universidade Federal de Sao Joao del Rei (UFSJ), Sao Joao del Rei, MG, Brasil.

Caption: Figure 1--Dispersion diagram of Brachiaria clones obtained by principal component analysis.
Table 1--Chemical compositions (g/kg DM) of the 23 clones and
Brachiaria ruziziensis cv. 'Kennedy', Brachiaria brizantha cv.
 'Marandu ' and Brachiaria decumbens cv. 'Basilisk'.

Clones             DM         SD      IVDMD      SD      NDF
                 (g/kg)              (g/kg)             (g/kg)

15              162.4abc     7.1     661.5ab    7.0     602.8a
16              160.8abc     15.0    692.1a     29.4    580.4a
46              186.8abc     16.7    685.0a     36.1    611.4a
174              147.9C      34.3   637.7abc    16.8    630.0a
411             159.8abc     12.6   655.7abc    34.4    639.5a
590             159.0abc     21.1   629.6abc    27.0    643.1a
651            1 67.1 abc    7.2    652.8abc    14.7    617.1a
670             165.6abc     11,6   626.0abc    31.0    609.0a
768             151.7abc     7.5     690.2a     40.2    605.3a
776             151.4abc     3.3    647.9abc    28.8    617.9a
844             173.5abc     13.0    593.3bc    17.7    616.8a
859              202.6a      31.4    577.5c     15.8    608.2a
950             206.3ab      8.9    638.7abc    7.0     590.2a
965             172.7abc     3.7     667.1ab    15.3    616.0a
970             180.7abc     1.9     679.7a     31.9    602.1a
975             148.2bc      7.7    640.2abc    18.5    635.3a
1067            184.1abc     27.3    683.7a     68.3    623.7a
1093            166.2abc     8.8    638.2abc    15.9    630.9a
1296            148.4bc      21.9   640.8abc    29.0    637.1a
1765            163.3abc     6.3    647.5abc    43.7    631.9a
1806             147.0c      10.5   637.8abc    16.4    618.5a
1894            172.2abc     24.7   65 1.6abc   36.6    624.7a
1972            160.2abc     21.7   644.9abc    12.1    628.9a
Ruziziensis    151.1 abc     6.9    633.9abc    24.8    618.9a
Brizantha       173.7abc     14.5   629.2abc    19.0    631.6a
Decumbens       187.9abc     17.5   649.8abc    14.0    628.7a
Average          166.9                646.9             620.1
SD                20.7                35.1               25.8
P-value          0.001                0.000             0.110

Clones          SD       ADF       SD    Lignin     SD         CP
                        (g/kg)           (g/kg)              (g/kg)

15             13.3     306.9a    10.3   44.7a     4.1       164.9a
16             6.9      288.5a    4.1    43.0a     1.0       173.5ab
46             18.5     319.8a    26.4   45.4a     6.3      158.6abc
174            11.1     337.8a    3.3    46.4a     1.4      151.4abcd
411            27.9     339.3a    25.0   40.6a     2.3      136.8bcd
590            30.9     358.9a    29.4   44.2a     1.1       130.4d
651            28.8     332.2a    38.7   46.7a     2.1      140.8abcd
670            33.3     342.4a    23.7   53.5a     7.0      156.6abcd
768            14.2     311.7a    12.5   42.9a     1.9      148.7abcd
776            13.6     346.3a    16.8   45.2a     3.1      144.0abcd
844            15.9     324.7a    10.9   47.6a     5.0      149.4abcd
859            46.9     329.8a    19.8   47.3a     5.0      153.7abcd
950            12.6     300.0a    1.8    49.0a     13.8     168.3abcd
965            8.0      319.3a    14.3   39.0a     2.5      148.1abcd
970            18.7     313.4a    13.7   46.1a     0.5      155.4abcd
975            28.6     336.7a    28.3   42.1a     7.8      138.8abcd
1067           51.1     331.2a    58.8   43.6a     5.1      145.8abcd
1093           27.6     340.9a    24.4   52.0a     3.3       160.4ab
1296           33.2     354.6a    27.9   45.2a     3.5      143.3abcd
1765           39.0     334.1a    31.4   45.1a     1.8      149.5abcd
1806           24.0     320.4a    24.5   47.7a     4.6      154.5abcd
1894           21.5     331.5a    28.1   42.2a     7.6      141.4abcd
1972           23.5     347.8a    25.1   48.9a     0.1       132.4cd
Ruziziensis    20.4     343.6a    23.7   44.1a     5.7      141.8abcd
Brizantha      13.1     342.8a    21.1   48.2a     2.9      150.4abcd
Decumbens      28.9     334.8a    21.4   42.7a     3.7      137.7bcd
Average                 331.3             45.5                148.5
SD                       25.8             5.0                 18.8
P-value                 0.016            0.123                0.000

Clones         SD

15            19.2
16            18.0
46            20.8
174           5.8
411           21.2
590           11.8
651           18.5
670           23.8
768           5.9
776           26.1
844           17.1
859           22.7
950           19.3
965           14.6
970           12.4
975           7.8
1067          29.7
1093          23.4
1296          27.4
1765          22.5
1806          14.3
1894          25.3
1972          17.4
Ruziziensis   26.0
Brizantha     12.8
Decumbens     10.1
Average
SD
P-value

SD = Standard deviation of the mean; Means followed by the same
letter within Column, do not differ by Tukey test (P<0.05).

Table 2--Average of the adjusted parameters in relation to the in
vitro fermentation kinetics of the fibrous carbohydrates (FC) and
non-fibrous carbohydrates (NFC) in relation to the Brachiaria
ruziziensis progenies and the Brachiaria ruziziensis cv. 'Basilisk'.

                                    Variables

                       VFNFC                  KdNFC
Clones            (ml/[g.sup.-1])    SE    ([h.sup.-1])    SE

15                     57.8         18.6      0.068       0.02
16                     62.3         23.2      0.059       0.01
46                     92.8         28.3      0.051       0.01
174                    118.7        19.9      0.042       0.00
411                    85.2         22.8      0.053       0.01
590                    92.7         24.4      0.048       0.01
651                    49.7         18.8      0.063       0.02
670                    73.6         22.5      0.054       0.01
768                    86.9         20.6      0.053       0.01
776                    11.9         19.4      0.040       0.00
844                    85.6         26.9      0.037       0.01
859                    93.7         17.3      0.049       0.01
950                    61.7         15.7      0.064       0.01
965                    49.4         13.1      0.088       0.02
970                    42.8         11.5      0.091       0.02
975                    101.5        29.4      0.041       0.01
1067                   88.4         36.9      0.043       0.01
1093                   79.0         21.4      0.042       0.01
1296                   122.9        28.9      0.036       0.00
1765                   111.2        37.8      0.036       0.01
1806                   60.1         16.4      0.074       0.02
1894                   83.5         21.0      0.050       0.01
1972                   125.4        21.5      0.038       0.00
B. ruziziensis         91.3         32.7      0.044       0.01
B. brizantha           91.9         22.2      0.046       0.01
B. decumbens           87.4         21.8      0.048       0.01
Average                85.0                   0.052

                               Variables

                     L                 VFFC
Clones            (h:min)   SE    (ml/[g.sup.-1])    SE

15                 0.225    0.6        134.8        17.8
16                 5:30     0.6        133.0        22.2
46                 4:47     0.7        123.7        26.9
174                8:12     0.5        79.3         17.6
411                6:07     0.1        126.8        21.6
590                6:28     0.5        115.4        23.2
651                5:33     0.7        142.0        17.8
670                5:15     0.7        114.9        21.4
768                6:12     0.5        98.5         19.7
776                9:04     0.4        66.1         17.1
844                8:33     0.6        69.3         24.3
859                6:10     0.4        80.3         16.3
950                3:55     0.6        125.9        15.0
965                4:58     0.7        170.2        12.6
970                5:35     0.7        165.9        11.1
975                6:06     0.5        87.8         27.7
1067               6:44     0.8        75.5         34.9
1093               6:18     0.6        74.7         19.7
1296               6:27     0.6        60.9         25.4
1765               6:15     0.7        75.7         34.6
1806               5:08     0.6        135.2        15.7
1894               4:25     0.6        119.4        19.8
1972               5:47     0.5        60.7         19.1
B. ruziziensis     5:56     0.7        108.2        31.0
B. brizantha       5:39     0.6        95.4         20.6
B. decumbens       6:55     0.6        105.4        20.3
Average            6:03                105.6

                       Variables

                      KdFC
Clones            ([h.sup.-1])    SE

15                   0.025       0.00
16                   0.023       0.00
46                   0.020       0.00
174                  0.015       0.00
411                  0.020       0.00
590                  0.020       0.00
651                  0.022       0.00
670                  0.021       0.00
768                  0.021       0.00
776                  0.015       0.00
844                  0.015       0.00
859                  0.019       0.00
950                  0.023       0.00
965                  0.025       0.00
970                  0.025       0.00
975                  0.018       0.00
1067                 0.018       0.01
1093                 0.017       0.00
1296                 0.014       0.01
1765                 0.016       0.01
1806                 0.025       0.00
1894                 0.019       0.00
1972                 0.015       0.00
B. ruziziensis       0.019       0.00
B. brizantha         0.018       0.00
B. decumbens         0.018       0.00
Average              0.019

VFNFC = equivalent to the maximum volume of gases from the NFC
fraction (ml-[g.sup.-1]); kdNFC = the degradation rate ([h.sup.-1])
of NFC; VFFC = maximum volume of the gases from the FC fraction (ml-
[g.sup.-1]); kdFC = degradation rate ([h.sup.-1]) of FC; L = lag time
(hours:minutes); V(t) = total gas accumulated at time t and SE =
Standard error.

Table 3--Estimates of the eigenvalues of the cumulative variance and
weighting of variables of the characters in the principal components
obtained based on six variables in 26 genotypes of Brachiaria.

                            Weighting of variable

Principal     Variance       Percentage       Variance
Component   (eigen value)     of Total     Cumulative (%)     DIVDM
                            Variance (%)

1              7.5142          70.16           70.16         0.9620
2              2.7933          26.08           96.24         0.2627
3              0.3389           3.16           99.40         0.0446
4              0.0641           0.60           100.00        0.0598
5              0.0002           0.00           100.00        -0.0009
6              0.0000           0.00           100.00        0.0000

                        Weighting of variable

Principal
Component      NDF       Lignin        CP        KdNFC     KdFC

1            -0.2400     -0.0476     0.1213     0.0023    0.0006
2            0.7973      -0.0802     -0.5375    -0.0031   -0.0009
3            0.5514      0.1883      0.8115     -0.0037   -0.0008
4            -0.0525     0.9776      -0.1945    -0.0068   -0.0019
5            0.0048      0.0074      -0.0003    0.9822    0.1874
6            0.0003      0.0006      -0.0002    -0.1874   0.9823

IVDMD = in vitro dry matter digestibility; NDF = neutral detergent
fiber; CP = crude protein; kdNFC = degradation rate ([h.sup.-1]) of
NFC and kdFC = degradation rate ([h.sup.-1]) of FC.

Table 4--Groups of genotypes of Brachiaria and average variables in
each group formed by the hierarchical agglomerative clustering method
of Complete Linkage, based on standardized average Euclidean
distance.

Items                                  Group

                            I               II          III
Clones
                           174              670         651
                           411              844         965
                           590              859         970
                           776             1093        1806
                           975         B. brizantha
                     B. ruziziensis
                          1296
                          1765
                          1894
                          1972
                      B. decumbens
DIVDM (%DM)               643.6            612.8       659.4
NDF (%DM)                 630.5            619.3       613.4
Lignin (% DM)             44.2             49.7        44.9
CP (%DM)                  140.7            154.1       149.7
KdNFC ([h.sup.-1])        0.043            0.045       0.079
KdFC ([h.sup.-1])         0.017            0.018       0.024

Items                     Group

                      IV       V
Clones
                      15      46
                      16      768
                      950    1067

DIVDM (%DM)          664.1   686.3
NDF (%DM)            591.1   613.5
Lignin (% DM)        45.5    44.0
CP (%DM)             168.9   151.0
KdNFC ([h.sup.-1])   0.063   0.049
KdFC ([h.sup.-1])    0.024   0.020

IVDMD = in vitro dry matter digestibility; NDF = neutral detergent
fiber; CP = crude protein; KdNFC = degradation rate ([h.sup.-1]) of
NFC and KdFC = degradation rate ([h.sup.-1]) of FC.
COPYRIGHT 2018 Universidade Federal de Santa Maria
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2018 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Moreira, Ellen de Almeida; de Souza, Shirley Motta; Ferreira, Alexandre Lima; Tomich, Thierry Ribeir
Publication:Ciencia Rural
Date:Feb 1, 2018
Words:4982
Previous Article:Brazilian ground beef authentication by multiplex polymerase chain reaction/ Autenticacao de carne moida brasileira atraves de uma reacao em cadeia...
Next Article:Detection of Campylobacter spp. in chilled and frozen broiler carcasses comparing immunoassay, PCR and real time PCR methods/Deteccao de...
Topics:

Terms of use | Privacy policy | Copyright © 2021 Farlex, Inc. | Feedback | For webmasters