Morphogenesis of stockpiled Marandu, Piatã, Xaraés and Paiaguás brachiaria grass cultivars / [Morfogênese de cultivares de capins marandu piatã, xaraés e paiaguás diferidos]

The objective this study was to identify differences in the morphogenic patterns of four Urochloa brizantha cultivars (marandu, piatã, xaraés and paiaguás grasses) during the stockpiling period. A completely randomized design was used, with three replications, in experimental plots of 9m². The evaluations took place over 2 years. The grasses were stockpiled for 92 (Year 1) and 95 (Year 2) days. The leaf appearance rate of paiaguás grass was higher, compared to other grasses. In Year 1, the stem elongation rate of xaraés grass was higher than other grasses. At the end of stockpiling period of Year 1, the tiller population density (TPD) was higher in the paiaguás grass, intermediate in the xaraés and marandu grasses and lower in the piatã grass. At the end of the stockpiling period in Year 2, TPD was higher in the paiaguás grass canopy, intermediate in the marandu and piatã grasses canopies, and lower in the xaraés grass canopy. Paiaguás grass has greater leaf growth during the stockpiling period and is therefore suitable for use under stockpiled grazing. Xaraés grass has high stem elongation during the stockpiling period, which is why its use under stockpiled grazing must be accompanied by adjustments in pasture management.(AU)

O objetivo deste estudo foi identificar diferenças nos padrões morfogênicos de quatro cultivares de Urochloa brizantha (marandu, piatã, xaraés e paiaguás) durante o período de diferimento. Foi utilizado o delineamento inteiramente ao acaso, com três repetições, em parcelas experimentais de 9m². As avaliações ocorreram por dois anos. Os capins foram diferidos por 92 (Ano 1) e 95 (Ano 2) dias. A taxa de aparecimento foliar do capim-paiaguás foi maior, em comparação aos demais capins. No Ano 1, a taxa de alongamento do colmo do capim-xaraés foi superior aos demais capins. No final do diferimento do Ano 1, a densidade populacional de perfilho (DPP) foi maior no capim-paiaguás, intermediária nos capins xaraés e marandu e inferior no capim-piatã. No fim do período de diferimento do Ano 2, a DPP foi superior no dossel de capim-paiaguás, intermediária nos dosséis dos capins marandu e piatã, e menor no dossel de capim-xaraés. O capim-paiaguás tem maior crescimento foliar durante o período de diferimento, sendo, portanto, apropriado para uso sob pastejo diferido. O capim-xaraés apresenta elevado alongamento de colmo durante o período de diferimento, razão pela qual seu uso sob pastejo diferido deve vir acompanhado de ajustes no manejo da pastagem.(AU)

Morphological and structural characteristics of Urochloa decumbens Stapf. deferred pasture grazed by heifers under two periods of protein-energy supplementation

The aim of this study was to evaluate the morphological and structural characteristics of deferred Urochloa decumbens Stapf. ‘Basilisk grazed by Nellore heifers under two periods of protein and energy supplementation (PES). The experiment was carried out from Jun 21 to Nov 15, 2016, under a completely randomized design and two PES periods (55 [P55] and 147 [P147] days). Forage mass (FM), leaf blade dry mass (LBDM), stem dry mass (SDM), dead material dry mass (DMDM), canopy height (CH), and forage bulk density (FBD) were evaluated. Data were analyzed by the SAS® PROC MIXED procedure and treatment means were compared with the Student's t test (p < 0.05). LBDM was higher for P147 heifers after 21, 84, and 126 days of grazing, similar to those observed after 63 days, and was higher for P55 heifers at 42, 105, and 147 days of grazing. SDM was lower for P147 heifers after 21, 42, 105, and 126 days, and similar in the other grazing periods. Protein and energy supplementation for heifers over 147 days resulted in a lower stem mass of U. decumbens Stapf. ‘Basilisk deferred pastures.(AU)

Morphological and structural characteristics of Urochloa decumbens Stapf. deferred pasture grazed by heifers under two periods of protein-energy supplementation

The aim of this study was to evaluate the morphological and structural characteristics of deferred Urochloa decumbens Stapf. ‘Basilisk’ grazed by Nellore heifers under two periods of protein and energy supplementation (PES). The experiment was carried out from Jun 21 to Nov 15, 2016, under a completely randomized design and two PES periods (55 [P55] and 147 [P147] days). Forage mass (FM), leaf blade dry mass (LBDM), stem dry mass (SDM), dead material dry mass (DMDM), canopy height (CH), and forage bulk density (FBD) were evaluated. Data were analyzed by the SAS® PROC MIXED procedure and treatment means were compared with the Student's t test (p < 0.05). LBDM was higher for P147 heifers after 21, 84, and 126 days of grazing, similar to those observed after 63 days, and was higher for P55 heifers at 42, 105, and 147 days of grazing. SDM was lower for P147 heifers after 21, 42, 105, and 126 days, and similar in the other grazing periods. Protein and energy supplementation for heifers over 147 days resulted in a lower stem mass of U. decumbens Stapf. ‘Basilisk’ deferred pastures.

Avaliação da produção de forragem e desempenho de novilhas Nelore em diferentes métodos de pastejo e suplementação como estratégia para mitigar as emissões de metano

Brasil ocupa posição de destaque na pecuária, sendo considerado um dos mais importantes fornecedores de carne bovina do mundo. Para atender à demanda de uma população em crescimento, o setor pecuário precisa aumentar sua produção com eficiência, reduzindo o impacto ambiental, que tem recebido inúmeras críticas na produção animal. Para produzir com sustentabilidade, é necessário melhorar a produtividade, por meio do manejo adequado de pastagens e estratégias que reduzam o efeito sazonal da produção de forragem em determinadas épocas do ano. Uma das estratégias que podem ser adotadas para reduzir o efeito da baixa disponibilidade de forragem, devido à sazonalidade, são as pastagens diferidas associadas à suplementação nutricional, que visam melhorar a eficiência animal e reduzir as emissões de metano no meio ambiente. O objetivo deste estudo foi investigar, ao longo do ano, os efeitos dos métodos de pastejo (rotacionado e diferido) sobre o potencial de produção de forragem, valor nutricional da forragem e resposta animal de novilhas recebendo duas fontes de nitrogênio. O estudo foi conduzido em Pirassununga SP, Brasil. As unidades experimentais consistem em 8 módulos. Cada tratamento foi distribuído em 2 módulos, em delineamento de blocos casualizados. Foram utilizadas 24 novilhas Nelore (6 animais/tratamento). Os tratamentos consistiram em dois métodos de pastejo (diferido e rotacionado) e suplementos nitrogenados (urea e nitrato de amônio) em arranjo fatorial 2 x 2: 1) pastagem diferida com suplementação de ureia; 2) pastagem diferida com suplementação de nitrato de amônio; 3) pastagem rotacionada com suplementação de ureia e 4) pastagem rotacionada com suplementação de nitrato de amônio. O experimento durou um ano. Os dados foram analisados estatisticamente utilizando o SAS 9.3 (SAS Institute Inc., Cary, NC, EUA), considerando como efeitos significativos quando P 0,05. Houve diferenças na produção de forragem, componentes morfológicos e valor nutricional entre os métodos de pastejo nas estações. No entanto, essas diferenças não influenciaram na resposta final do desempenho das novilhas, sendo semelhantes entre os métodos de pastejo. A fonte de nitrogênio não impactou a produção de CH4.

Brazil occupies a prominent position in in livestock production, being considered one of the most important beef suppliers in the world. In order to meet the demand of a growing population, the livestock sector needs to increase its production efficiently, reducing the environmental impact, which has received numerous criticisms in animal production. In order to produce with sustainability, it is necessary to improve productivity, through adequate management of pastures and strategies that reduce the seasonal effect of forage production during certain seasons of the year. One of the strategies that can be adopted to reduce the effect of low forage availability due to seasonality is the deferred pastures associated with nutritional supplementation, which aims to improve animal efficiency and reduce the methane emission to the environmental. The objective of this study was to investigate, throughout the year, the effects of grazing methods (rotated and deferred) on the forage production potential, forage nutritional value and animal response of heifers receiving two sources of nitrogen. The study was conducted in Pirassununga - SP, Brazil. The experimental units consisted of 8 modules. Each treatment was allotted to 2 modules in a randomized block design. Twenty-four Nellore heifers (6 animals/treatment) were used. The treatments consisted of two grazing methods (deferred and rotate) and two nitrogen supplements (urea and ammonium nitrate) in a 2 x 2 factorial arrangement: 1) deferred grazing plus urea supplementation; 2) deferred grazing plus ammonium nitrate supplementation; 3) rotated grazing plus urea supplementation and 4) rotated grazing plus ammonium nitrate supplementation. The experiment lasted 1 year. The data were statistically analyzed using SAS 9.3 (SAS Institute Inc., Cary, NC, USA), considering as significant effects when P 0.05. However, these differences did not influence the final response of heifers' performance, being similar between grazing methods. The nitrogen source did not impact CH4 production.

Pasture stockpiling period of Brachiaria grass ( Brachiaria brizantha cv.Marandu) I. Dry matter yield and nutritive value / Épocas de vedação e de uso no capim Marandu I. Produção de matéria seca e valor nutritivo

The present experiment was carried out in Brotas, SP, with the objective of determining the most suitable time for shutting paddocks of Brachiaria grass up for accumulating herbage to be used for supplementation purposes during the dry season of the year. Treatments comprised a combination of three closure dates (March 10, March 24 and April 07) and four utilization dates (June 27, July 25, August 25 and September 22). The experiment was laid out on the field according to a complete randomized block design, replicated four times, with treatments assigned to experimental units according to a split- plot arrangement. Closure dates corresponded to the main plots and utilization dates to the subplots. The dry matter yields were different between the periods of stockpiling and increased with time. Herbage digestibility was strongly influenced by the lignin content. In order to obtain greater forage yields with better quality, it is suggested that stockpiling begin in March for utilization during the dry season of the year, to be used in July.

Utilizando-se de um delineamento em blocos completos ao acaso, com parcelas subdivididas, quatro repetições e 12 tratamentos, estudou-se os efeitos de três épocas de vedação e quatro épocas de uso na produção e valor nutritivo de Brachiaria brizantha cv. Marandu cultivada em Brotas-S.P. As épocas de vedação (10 de março, 24 de março e 07 de abril) representaram as parcelas principais e os períodos de utilização (27 de junho, 25 de julho, 25 de agosto e 22 de setembro) as subparcelas. Os resultados permitem afirmar-se que as produções de matéria seca para a Brachiaria brizantha cv. Marandu variaram com as épocas de vedação, aumentando com o tempo. A digestibilidade da forrageira foi afetada, principalmente pelos teores de lignina. Visando conciliar-se a produção de matéria seca e o valor nutritivo para a Brachiaria brizantha cv. Marandu, recomenda-se a vedação da pastagem no começo de março, para uso durante o período seco, preferencialmente em julho.

Pasture stockpiling period of Brachiaria grass ( Brachiaria brizantha cv.Marandu) I. Dry matter yield and nutritive value / Épocas de vedação e de uso no capim Marandu I. Produção de matéria seca e valor nutritivo

The present experiment was carried out in Brotas, SP, with the objective of determining the most suitable time for shutting paddocks of Brachiaria grass up for accumulating herbage to be used for supplementation purposes during the dry season of the year. Treatments comprised a combination of three closure dates (March 10, March 24 and April 07) and four utilization dates (June 27, July 25, August 25 and September 22). The experiment was laid out on the field according to a complete randomized block design, replicated four times, with treatments assigned to experimental units according to a split- plot arrangement. Closure dates corresponded to the main plots and utilization dates to the subplots. The dry matter yields were different between the periods of stockpiling and increased with time. Herbage digestibility was strongly influenced by the lignin content. In order to obtain greater forage yields with better quality, it is suggested that stockpiling begin in March for utilization during the dry season of the year, to be used in July.

Utilizando-se de um delineamento em blocos completos ao acaso, com parcelas subdivididas, quatro repetições e 12 tratamentos, estudou-se os efeitos de três épocas de vedação e quatro épocas de uso na produção e valor nutritivo de Brachiaria brizantha cv. Marandu cultivada em Brotas-S.P. As épocas de vedação (10 de março, 24 de março e 07 de abril) representaram as parcelas principais e os períodos de utilização (27 de junho, 25 de julho, 25 de agosto e 22 de setembro) as subparcelas. Os resultados permitem afirmar-se que as produções de matéria seca para a Brachiaria brizantha cv. Marandu variaram com as épocas de vedação, aumentando com o tempo. A digestibilidade da forrageira foi afetada, principalmente pelos teores de lignina. Visando conciliar-se a produção de matéria seca e o valor nutritivo para a Brachiaria brizantha cv. Marandu, recomenda-se a vedação da pastagem no começo de março, para uso durante o período seco, preferencialmente em julho.