Brachiaria Humidicola Cv Research Articles

Frequency of Endophytic Bacteria in Roots and Foliage of Brachiaria Humídicola Cv. Humidicola (Rendle) Schweick in Soil with Arsenic Presence

The objective of this study was to correlate the presence of arsenic in roots and stems of Brachiaria humidicola cv. humidicola (Rendle) Schweick grown in cattle areas of the San Jorge subregion and the population density of endophytic bacteria in roots and foliage with the presence of this metal. Samples of soil, roots and stems of B. humicola grass were collected and characterized for arsenic concentration in roots and foliage and the presence of endophytic bacteria (CFU/g tissue). The results show the presence of arsenic concentrations in roots and stems above the values established at national and international level. Likewise, the presence of endophytic bacteria was found in the roots and foliage of B. humidicola, which may be contributing to the remediation and reduction of arsenic concentration from the roots to the foliage. This is the first study correlating the presence of arsenic and endophytic bacteria on cattle farms with B. humicola and the possible role of these bacteria in contributing to bioremediation of this metal in the soil and within the tissues of the pasture species.

Evaluation of the Amount of Endophytic Bacteria Associated with Roots of Brachiaria Humidicola Cv. Humidicola (Rendle) Schweick in Relation to Ph Values, Organic Matter and Phosphorus Contents of Cattle Farm Soil

The objective of this study was to isolate endophytic bacteria from roots of Brachiaria humidicola cv. humidicola (Rendle) Schweick and to relate their presence to pH, organic matter and phosphorus contents of the soil of cattle farms located in the municipality of San Benito Abad. Soil sampling was carried out with roots of B. humicola for the isolation and counting of the population density of endophytic bacteria and soil samples were also collected for the determination of pH, organic matter and phosphorus parameters. The results found indicate that there is an amount of endophytic bacteria in roots of B. humidicola when the soil contains optimum pH values of (6.1 ± 6.98); low to moderate phosphorus content (10.8 ± 16.28 mg/kg) and low to moderate organic matter content (1.7 ± 2.31%). The presence of endophytic bacteria was observed in a range of 3.0 ± 8.0 X 106 CFU/g of roots. There is a worldwide need to establish a relationship between endophytic bacteria and soil physical-chemical quality indicator parameters to predict a change in functional diversity under physical, chemical and biological conditions of the soil ecosystem.

Analysis of the growth of Chetumal grass established in a tropical climate

Objective: To evaluate the growth of Chetumal grass (Urochloa humidicola CIAT 679), in order to determine the optimal moment for the first harvest.
 Design/Methodology/Approach: A completely randomized experimental block design, with measurements repeated over time, and three repetitions was used. Morphological composition (MC), growth rate (GR), plant height (PH), intercepted radiation (IR), leaf:stem ratio (L:S), leaf:no-leaf ratio (L:NL), and aerial biomass (AB) —as well as leaf biomass (LB), stem biomass (SB), dead material (DM), net growth (NG), and total biomass (TB)— were evaluated every fifteen days, except for the two first samplings, which were carried out on a monthly basis. Data were analyzed using the GLM procedure of the SAS software and Tukey’s mean comparison test (α£0.05).
 Results: The morphological composition (MC) of the Chetumal grass was statistically different (p<0.05), during the different growth ages. The maximum accumulation of total biomass (TB) (13,324 kg DM ha-1), leaf biomass (LB) (2,569 kg DM ha-1), and growth rate (GR) (99 kg DM ha-1 d-1) was reached at 135 DAS. On that day, the prairie reached a 68 cm plant height (PH) and 100% intercepted radiation (IR). The L:S ratio decreased from 1.62 to 0.31, while L:NL ratio changed from 1.62 to 0.22.
 Study Limitations/Implications: The Brachiaria humidicola cv. Chetumal grass reached its highest potential during the rainy season.
 Findings/Conclusions: The first cut of the Urochloa humidicola cv. Chetumal grass can be carried out at 135 DAS, when the highest accumulation of total biomass (TB), leaf biomass (LB), and growth rate (GR) is recorded.

Use of cashew and castor essential oils to improve fibre digestibility in high forage diets: digestibility, ruminal fermentation and microbial protein synthesis

High forage diets in the tropics are less efficient and more contaminating due to high energy losses as methane and the low digestibility of tropical forages. The objective of the study was to determine the effects of essential oils (EO) of Anacardium occidentale and Ricinus communis as additives in high forage diets on intake, digestibility, ruminal fermentation and synthesis of microbial protein. Four ‘Holstein’ steers fitted with ruminal cannula were used in a 4 × 4 Latin square design (21-day period). The treatments were 1, 2, 4 and 8 g day-1 EO per animal (essential oils, Oligobasics®). The diet was total mixed ration (TMR) of Brachiaria hay (Brachiaria humidicola cv. Lanero) and concentrate (ground corn, soybean meal, ammonium sulphate, urea and minerals) in an 80:20 ratio. Differences were observed in the digestibility of neutral detergent fibre (NDF) and total digestible nutrients (TDN) in levels above 2 g day -1 EO (P < 0.05). The VFA (volatile fatty acids) acetate and propionate were higher in diets with 2 g day -1 EO (P < 0.05), without affecting the acetate:propionate ratio. Levels above 2 g day -1 EO negatively affected the faecal N excretion (P < 0.05). The inclusions of A. occidentale and R. communis EOs at 2 g day-1 per day animal improved fibre digestion and decreased N excretion. These results indicate that this mixture of EOs may have strong antimicrobial activity at lower doses. The N losses, fibre digestion and digestibility could be improved with the use of cashew and castor essential oils in high forage diets.

Characterization of Brachiaria humidicola cv. BRS Tupi

This study aimed to carry out the morphogenic, structural, and bromatological characterization of Brachiaria humidicola cv. BRS Tupi. A completely randomized design was adopted. The treatments consisted of harvesting the forage at 14, 28, 42, and 56 days. Leaf appearance rate, leaf elongation rate, and phyllochron were similar among the treatments (P > 0.05). However, leaf life span varied among treatments (P < 0.05). Dry matter exhibited linear behavior (P < 0.05) whereas mineral matter, crude protein, neutral detergent fiber, acid detergent fiber, and lignin had quadratic behavior. Brachiaria humidicola cv. BRS Tupi exhibits the best forage potential for animal feed between 28 and 42 days of growth.

Characterization of Brachiaria humidicola cv. BRS Tupi

This study aimed to carry out the morphogenic, structural, and bromatological characterization of Brachiaria humidicola cv. BRS Tupi. A completely randomized design was adopted. The treatments consisted of harvesting the forage at 14, 28, 42, and 56 days. Leaf appearance rate, leaf elongation rate, and phyllochron were similar among the treatments (P > 0.05). However, leaf life span varied among treatments (P < 0.05). Dry matter exhibited linear behavior (P < 0.05) whereas mineral matter, crude protein, neutral detergent fiber, acid detergent fiber, and lignin had quadratic behavior. Brachiaria humidicola cv. BRS Tupi exhibits the best forage potential for animal feed between 28 and 42 days of growth.

Nitrogen requirement of Brachiaria hybrid cv. Ipyporã

Ipyporàgrass, a Brachiaria interspecific hybrid was developed by crossing a genotype of Brachiaria ruziziensis (syn. Urochloa ruziziensis) and an access of Brachiaria brizantha (syn. Urochloa brizantha), which have different nitrogen requirements. Therefore, the objective with work was to verify the nitrogen requirement of the interspecific hybrid of Brachiaria hybrid cv. Ipyporã. Experiment was carried out in a greenhouse in a randomized block design, with twelve treatments and four replications. Treatments consisted of a 4 x 3 factorial arrangement, with four nitrogen doses (0; 100; 200 and 300 mg dm3) and three forages (Brachiaria hybrid cv. BRS Ipyporã, Brachiaria humidicola cv. Llanero and Panicum maximum cv. Zuri). Each experimental plot consisted of a 3 dm³ pot with three plants. Three evaluation harvest were done . B. hybrid had greater response to nitrogen fertilization for number of tillers and leaves than the other forages. However, for the total dry mass, B. hybrid was less responsive to nitrogen than P. maximum grass (high demand) and more responsive than B. humidicola (low demand), which shows that this hybrid has medium nitrogen requirement.

Herbage utilisation efficiency of continuously stocked pastures during periods of restricted pasture growth

ABSTRACTThe aim of this study was to evaluate the defoliation patterns of individual tillers, efficiency of herbage utilisation, and forage production in continuously stocked Brachiaria humidicola cv. Comum swards during periods of the year of restricted pasture growth. The experiment was conducted at the Embrapa, Campo Grande-MS, Brazil, from April to October 2012. Treatments consisted of two grazing management strategies, defined by two ranges of sward height (10–15 and 20–25 cm) managed under continuous and variable stocking rates. The experiment was conducted as a completely randomised block design with three replications. During periods of resource constraints, grazing management strategies based on ‘steady state’ sward heights did not alter defoliation patterns, herbage utilisation efficiency (HUE), and forage production in Brachiaria humidicola swards under a continuous stocking method. A direct implication of our results is that grazing management strategies during the driest and coldest periods of the year in the tropics should be developed based on the conditions most suitable for better promoting faster pasture recovery and a return to production in the following spring; it is unlikely that any grazing management strategy would be successful in increasing herbage production and/or HUE in periods of restricted pasture growth.

Nematodes Associated to Tropical Forages in Pasture Areas

The quantification of soil nematodes is of great importance for the management and evaluation of the efficiency of control methods, considering the damages caused in crops of economic interest. The present work aimed to quantify and identify plant parasitic nematodes in pasture areas in the municipality of Santo Antônio do Leverger, Mato Grosso state, Brazil. For that purpose, 25 soil and root samples were collected in four plots, consisting of the following forage grasses: Brachiaria humidicola cv. Common (Plot 1), Panicum maximum cv. Tanzania (Plot 2), Brachiaria brizantha cv. Marandu (Plot 3) and Panicum maximum cv. Massai (Plot 4). The nematode extraction from the soil and root samples was performed, followed by the quantification and identification of nematodes genera. The nematodes classified as free-living were observed in all plots, with population densities varying from 230 to 1180 specimens. The genus Pratylenchus presented the lowest population level, with 40 specimens, in the area where the Brachiaria humidicola cv. Common is cultivated. The following phytoparasitic nematodes genera were observed: Pratylenchus and Paratrichodorus associated to the Humidicola grass, and Heterodera and Criconemoides associated to the Tanzania grass.

RESPONS PERTUMBUHAN RUMPUT Brachiaria humidicola cv Tully DENGAN PEMBERIAN PUPUK ORGANIK BOKASHI KOTORAN AYAM PETELUR

GROWTH RESPONSE OF Brachiaria humidicola cv Tully grass WITH ORGANIC FERTILIZER BOKASHI LAYING CHICKEN. This study aims to determine the growth response i.e stolon length, number of nodes, number of phytomers, and number of tillers of Brachiaria humidicola cv Tully with bokashi organic laying hens fertilizer. The completely randomized design was applied using four treatments and five replications for each treatment. The treatments were assigned level of bokashi. The levels of bokashi that B0 = 0 tons/ha (control), B1 = 2 tons/ha (1.8 kg/plot), B2 = 4 tons/ha (3.6 kg/plot) and B3 = 6 tons/ha (5.4 kg/plot). The variables measured consisted of stolon length, number of nodes, number of phyitomers, number of tillers. The Results of analysis of variance showed that treatment very significantly different (P <0.01) on stolon length, number of phyitomers, number of tillers and significantly different (P <0.05) on the number of nodes. Test of Honest Significance Difference (HSD) showed that B1 (1.8 kg / plot), B2 (3.6 kg / plot), and B3 (5.4 kg / plot) have higher length of stolone, number of phyitomers and number of tillers than B0. B3 and B2 had higher numbers of nodes than B0. It was concluded that the level 1.8 kg/plot organic fertilizer bokashi chicken laying equivalent to 2 tons/ha gave highest B. humidicola cv Tully growth response. Keywords: growth, B. humidicola cv Tully, bokashi laying Chicken

Superação da dormência em sementes de Brachiaria humidicola cv. BRS Tupi pelo uso de ácido giberélico

This study aimed to evaluate the effects of gibberellic acid in different concentrations and periods of immersion acting as promoters of dormancy overcoming of Brachiaria humidicola cv. BRS Tupi of different lots and storage times before treatments. The experiments, in number of four, were carried out with different seed lots, in a factorial scheme in different post-harvest storage periods (6, 7, 8 and 9 months), in which the treatments consisted of immersion of the seeds in solutions with (0, 50, 150, 300 and 600 mg L-1) for three exposure periods (12, 24 and 48 h), compared to a control (without treatment) in a completely randomized design. The evaluations were: imbibition curve, germination, germination speed index, first germination count and viability by tetrazolium test. The seeds responded positively to all treatments after eight months of storage, while the controls remained dormant. None of the treatments provided a viability loss and they demonstrated the storage possibility. For periods above 24 h of imbibition there is a risk of root protrusion, which may lead to the death of the seed.

English

The objective of this work was to evaluate the use of ten types of grasses as base substrate for the cultivation of strain GLM-10/02 of Ganoderma lucidum, considering the chemical characterization of the substrates, the biological efficiency (BE), the quantification of fresh and dry basidiomata and the number of basidiomata as evaluation criteria. Ten treatments were outlined, made up with napier or elephant grass (Pennisetum purpureum), marandu grass (Brachiaria brizantha cv. Marandu), aruana grass (Panicum maximum cv. Aruana), massai grass (Panicum maximum cv. Massai), mombaca grass (Panicum maximum cv. Mombaca), brachiaria grass (Brachiaria decumbens cv. Basilisk), humidicola (Brachiaria humidicola cv. humidicola), xaraes grass (B. brizantha cv. Xaraes), tifton (Cynodon species cv. Tifton 85), piata grass (B. brizantha cv. BRS Piata) and a control treatment based on eucalyptus sawdust. All the treatments had 80% of grass, 18% of wheat bran and 2% of limestone, with humidity adjusted to 60%. The treatments based on B. brizantha cv. Aruana (aruana) and Cynodon spp. cv. Tifton 85 (tifton) showed the best results, with 22.9 and 25% of BE, respectively. These data showed that not all grasses used in the experiment have the same fungal biomass conversion and it was concluded that B. brizantha cv. Aruana (aruana) and Cynodon spp. cv. tifton 85 (tifton) were the most indicated grasses for the cultivation of G. lucidum. Key words: Productivity, biological efficiency, substrates, fungi.

Biological nitrification inhibition by Brachiaria grasses mitigates soil nitrous oxide emissions from bovine urine patches

High nitrogen (N) concentration in bovine urine, which generally exceeds plant N uptake rates, results in the formation of hotspots of N loss when bovine urine is deposited on grazed pasture soils. High spatial variability in the distribution of urine patches in grazed pastures poses a major challenge to mitigate N losses. Some exudates from the roots of several tropical forage grasses were shown to inhibit the activity of soil nitrifiers; a process known as biological nitrification inhibition (BNI). We hypothesized that nitrate (NO3−) production and nitrous oxide (N2O) emissions from urine patches deposited on soils under forage grasses with high BNI capacity are lower than those with forage grasses with low BNI capacity. This hypothesis was tested using field plots of two tropical forage grass cultivars, Brachiaria humidicola cv. Tully (BT) and interspecific Brachiaria hybrid cv. Mulato (BM) which, correspondingly, have high and low BNI capacity. Nitrification rates and amoA gene copy numbers of ammonia oxidizing archaea (AOA) and bacteria (AOB) in soils under the two forage grasses were quantified before and after urine and water (control) application, as well, an additional experiment was conducted to quantify denitrification potential. Moreover, soil N2O emissions from simulated urine (0.123 kg N m−2) and water patches were monitored over a 29-day period. Results showed a greater suppression of nitrification, denitrification and AOA abundance in soils under BT than those under BM. Positive relationships (p < 0.05) existed between AOA and AOB abundance and NO3− contents in soils under BM. Bovine urine resulted in higher cumulative N2O fluxes from soils under BM (80 mg N2O-N m−2) compared to those under BT (32 mg N2O-N m−2). Consequently, N2O emission factors were higher for soils under BM (0.07%) than under BT (0.00002%). We conclude that tropical forage grasses with high BNI capacity play a key role in mitigating N2O emissions from bovine urine patches in archaea-dominated soils. This suggests that wide-spread adoption of tropical forage grasses with high BNI capacity may have a great potential to tighten N cycling in grazed pastures.

Potassium nitrate on overcoming dormancy in Brachiaria humidicola ‘BRS Tupi’ seeds

ABSTRACT: In this study, the aim was to determine the influence of potassium nitrate, using different concentrations and immersion times on the dormancy of the seeds of Brachiaria humidicola cv. ‘BRS Tupi’. Four experiments were performed adopting a factorial scheme (5x3+1) in different seed lots, for different post-harvest storage durations, during which the seeds were immersed in potassium nitrate solutions of different specific concentrations (0, 0.1, 0.3, 0.5 and 1% KNO3), for three exposure periods (12, 24 and 48h), plus one control (untreated), in a completely randomized design. The characteristics assessed included the imbibition curve, germination, first count and germination rate, as well as viability confirmed by using tetrazolium test. From the findings it was evident that treatments involving 0.1; 0.3; 0.5 and 1% KNO3 or pure water, with a 12 hour-soaking period enabled the stored seeds to germinate well for a minimum of eight months post harvest. Root protrusion was observed 24 hours post seed imbibition, whereas for the untreated seeds, satisfactory germination was observed from at least 12 months post harvest and, in most of the lots, between 18 and 24 months.

THE CHEMICAL COMPOSITION AND NUTRITIVE VALUE OF Brachiaria GRASS CULTIVARS AT KATUMANI DRYLAND RESEARCH STATION IN SOUTH EASTERN KENYA

The study was conducted at Kenya Agricultural and Livestock Research Organisation, Katumani, Machakos to evaluate the herbage quality of Brachiaria grass cultivars in semi arid regions of Eastern Kenya. Brachiaria cultivars namely B. decumbens cv. Basilisk, Brachiaria hybrid Mulato II, four Brachiaria brizantha cultivars Marandu, Xaraes, Piata, MG4 and Brachiaria humidicola cv Llanero were assessed with reference to their chemical and nutritive composition at 22, 24 and 28 weeks post seedling emergence. Rhodes grass (Chloris gayana cv KATR3) and Napier grass (P. pupureum cv. Kakamega I) were included as controls. There were significant differences (p&lt;0.05) among the cultivars for crude protein, crude fibre (NDF, ADF and ADL) Ash, Calcium, Phosphorus, Dry Matter Digestibilty and Metabolisable energy during the the week 22 and 24 post seedling emergence harvest. At week 28 harvest interval, however, ADL values for all the cultivars were similar and only Marandu was significantly different (p&lt;0.05) in terms of metabolizable energy from the rest. The mean CP content of the grasses decreased from 11.1% at week 22 to 6.3% at harvest week 28 harvest intervals. MG4, Mulato II and Xaraes were the only grasses able to meet minimum CP (7.0%) requirement for rumen microbial function throughout the harvest period. Ash and phosphorus values decreased whereas Calcium content increased for all the cultivars during the harvest intervals, with Mulato II recording the highest ash (15%) content during this period. Chloris gayana KATR3 recorded highest average NDF (72.9%), ADF (48.1%) and ADL (6.1%) content during this period. Xaraes, Marandu and Mulato II were the only cultivars able to achieve the highest metabolizable energy of 7.0 MJ/kg DM recorded for the grass cultivars throughout the harvest intervals. These results indicate that Brachiaria grasses can be a good source of forage for livestock and a boost to the forage resource base in the semi arid regions of Kenya. Further research is needed to quantify their productivity in both dry and wet periods and to assess the effect of feeding on animal production performance.

PENGARUH PEMBERIAN PUPUK N-P-K TERHADAP HASIL BAHAN KERING DAN PROTEIN KASAR RUMPUT Brachiaria humidicola cv. Tully dan Pennisetum purpureum cv. Mott

THE EFFECT OF N-P-K FERTILIZER ON THE YIELD OF DRY MATTER AND CRUDE PROTEIN OF GRASS (Brachiaria humidicola cv. Tully and Pennisetum purpureum cv. Mott.). This research was done to evaluate the effect of macro elements N-P-K on the dry matter and crude protein yield of grass (Brachiaria humidicola cv. Tully and Pennisetum purpureum cv. Mott). The research used combination of N-P-K fertilizer. The treatments were arranged in factorial design based on the Completely Randomized Design with two factors, three treatments and four replications. The factor A was applied for testing different grass of Brachiaria humidicola cv. Tully (a1), and Pennisetum purpureum cv. Mott (a2). The factor B was fertilizer combination of N (b1), NP (b2), and NPK (b3). Variables observed were dry matter and crude protein. The results of variance analysis showed that treatment affected significantly (P &lt;0.05) dry matter and crude protein. Application of factor A indicated that both grasses had positively response to the application of N-P-K fertilizer measured on the yield of dry matter and crude protein. Keywords: N-P-K Fertilizer, Dry Matter, Protein, Brachiaria humidicola cv. Tully and Pennisetum purpureum cv. Mott.

PENGARUH LEVEL PUPUK N,P,K TERHADAP KOMPONEN TANAMAN BRACHIARIA HUMIDICOLA CV.TULLY DAN PENNISETUM PURPUREUM CV.MOTT DI AREAL PERTANAMAN KELAPA

EFFECT OF N,P,K FERTILIZER LEVELS ON PLANT COMPONENTS OF BRACHIARIA HUMIDICOLA CV.TULLY AND PENNISETUM PURPUREUM CV.MOTT IN COCONUT PLANTATIONS. In North Sulawesi there are vast grasslands as pastures so that breeders only utilize the existing land in the coconut plantations as cattle raising area. Existing land under the coconut plantation can be utilized or planted variety of agricultural commodities, including forage, where feed was instrumental in the success of animal farm. In increasing the productivity of forage among others, animal grass needs to be supported by the physical environment, ideal soil and climate. The problem in this research was the area under coconut cultivation had low soil fertility (marginal), so one alternative was given by way of fertilization. Therefore the NPK fertilization is one of the most alternative method to overcome the low soil fertility. The objective of this study was to determine the effect of the combination of NPK fertilizer levels on plant components of Brachiaria humidicola cv. Tully and Pennisetum purpureum cv.mott in coconut plantations. This research was conducted in the western districts of Malalayang 1, Manado city from October 2013 – February 2014. Factorial design method was performed on the basis of completely randomized design with 4 replications. The result in this study showed that the influence of fertilization was demonstrated for the macro elements NPK fertilization required to increase the component of leaves. These elements were met the needs of forage for ruminants. Otherwise the rod components of both grass types were decreased by more complete combination of macro elements of NPK fertilization. In term of different types of grass, the statistical analysis showed that the leaves of the grass component of Pennisetum purpureum were 153.87 g/plot, significantly higher (P&lt;0.05) than Brachiaria humidicola. The stem components were not significantly different for both types of grass. Therefore, the results of this study showed that both types of grass treatment elements required the complete NPK macro to get result with higher leaf components. Keywords: Land, Forage, NPK Fertilizer, coconut plantation area

Espécies forrageiras para produção de leite em solos de várzea

Objetivou-se com este trabalho avaliar a disponibilidade de forragem, a composição morfológica e química do pasto, a capacidade de suporte do pasto e a produção de leite de vacas em três gramíneas forrageiras sob lotação contínua e taxa variável em solo de várzea. O delineamento experimental foi inteiramente casualizado com três tratamentos e três repetições. Os tratamentos constituíram-se das gramíneas Paspalum atratum cv. Pojuca, Brachiaria humidicola cv. Llanero e capim-tangola, híbrido natural de Brachiaria arrecta e Brachiaria mutica. A taxa de lotação foi ajustada para manter a forragem disponível entre 2.000 e 3.000 kg de massa seca por hectare. O período avaliado foi de novembro de 2003 a maio 2004. Não houve diferença significativa entre as espécies quanto à disponibilidade de massa seca de forragem verde, com valor médio de 2.902 kg/ha. O capim-pojuca apresentou 62% de lâminas foliares e 38% de colmo + bainha na massa seca de forragem verde, seguido pelo capim-humidícola com 49 e 51% e o capim-tangola com 18 e 82%, respectivamente. O capim-tangola apresentou teor mais alto de proteína bruta na lâmina foliar (15,41%) que os capins humidícola (9,98%) e pojuca (8,74%) e menores de fibra (FDN e FDA). A produção individual das vacas refletiu o melhor valor alimentício do capim-tangola, cuja média diária (10,27 kg/vaca) foi maior que no capim-pojuca (7,80 kg/vaca) e semelhante ao obtido com capim-humidícola (9,16 kg/vaca). A produção de leite por área não foi afetada pela gramínea forrageira, com média de 27,8 kg/ha × dia-1, uma vez que a taxa de lotação um pouco mais alta no capim-pojuca, apesar de não apresentar diferença significativa, compensou a menor produção individual das vacas.

Produção de forragem, composição química e morfogênese de Brachiaria humidicola cv. Tupi em diferentes idades de corte

The effects of plant age (14, 21, 28, 35 and 42 days) on dry matter (DM) yield, chemical composition and morphogenetic and structural characteristics of Brachiaria humidicola cv. Tupi, was evaluated under greenhouse with natural conditions of light and temperature. DM yields and regrowth, leaf blade lenght, and lifespan rate increased consistently with growth stage, however the nitrogen, phosphorus, magnesium, and potassium contents decreased as plant age, while calcium contents were not affected by plant age. For all plant ages, nitrogen contents were lower than its critic level. Maximum leaf appearance and elongation rates, and blade lenght were obtained with cutting at 41.1; 31.3 and 38.9 days, respectively. These data suggest that cutting at 28 to 42 days were optimal for obtain maximum yields and regrowth of rich forage and pasture persistence.

Effects of ruminal infusion of a slow-release polymer-coated urea or conventional urea on apparent nutrient digestibility, in situ degradability, and rumen parameters in cattle fed low-quality hay

Four ruminally cannulated beef steers were used in a 4 × 4 Latin square design experiment conducted to compare ruminal infusion effects of different sources of non-protein nitrogen (NPN) on intake; digestibility; ruminal dry matter (DM) and neutral detergent fiber (NDF) degradability; ruminal pH; and ammonia nitrogen (N-NH 3) of beef cattle fed Brachiaria humidicola cv. Llanero hay [CP = 24.9 g/kg DM; ash-free NDF corrected for contamination of CP (NDFom,cp) = 782.4 g/kg DM]. Treatments were: Control (hay only); U [hay + conventional urea (204.2 g/d)]; SRU [hay + slow-release polymer-coated urea (297.5 g/d)]; U + SRU [hay + a combination of 1:1 by weight of both urea types (130.4 g/d U + 130.4 g/d SRU)]. Supplements were infused into the rumen through the rumen cannula. Treatments SRU and U + SRU had an increasing of hay dry matter intake (DMI) (9.44 and 9.02 kg/d, respectively; P<0.01, compared with 7.62 kg/d for the control), as well as total NDF (P<0.01) and crude protein (CP, P<0.01). The CP digestibility was higher (P<0.01) for all treatments with NPN when compared to control. There were differences on DM and NDF degradability curves (P<0.05) between rumen exposure times, in which the disappearance was increased up to 120 h after incubation. On the first day of collections, the lowest pH values (6.89 and 6.91) were observed on SRU and U + SRU 6 h after the afternoon infusion, and the highest pH was observed immediately after the afternoon infusion of U (7.39). High levels of ammonia-N were kept for 8 h after the last infusion daily of SRU, which resulted in the most constant values of NH 3-N in the rumen. In general, our data suggested that SRU had a more adequate concentration of N during the fermentation of low-quality hay, and also had a proper pH for rumen activity.