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