Herbage accumulation and grazing losses on Mulato grass subjected to strategies of rotational stocking management

Grazing management strategies affect not only herbage accumulation but also the efficiency of grazing. This study aimed to evaluate herbage accumulation (leaf, stem and dead material), grazing efficiency and losses of mulato grass (a Brachiaria ruziziensis × Brachiaria brizantha cv. Marandu hybrid) subjected to strategies of rotational stocking management. Treatments consisted of combinations between two post-grazing heights (15 and 20 cm) and two pre-grazing conditions (95 % and maximum canopy light interception (LI)) assigned to experimental units (1200-m² paddocks) according to a 2 × 2 factorial arrangement and a randomized complete block design, with four replications. The experiment was carried out from Jan 2008 to Mar 2009. Season of the year influenced almost all studied variables, resulting in a common pattern of response that was determined by pre- and post-grazing management targets. Herbage accumulation was greater on swards managed at 95 %, with higher accumulation of leaves and lower accumulation of stem and dead material in relation to those managed at maximum LI (99 %) during the entire experimental period. On the other hand, herbage removal by grazing was larger on swards managed at 99 % LI, which was compensated for by the smaller number of grazing cycles and larger losses due to grazing under those circumstances. Under rotational stocking, the pre-grazing LI of 95 % and post-grazing height of 20 cm resulted in efficient grazing and high producing leafy pastures, highlighting the potential of Mulato grass pastures for animal production.

Herbage accumulation and grazing losses on Mulato grass subjected to strategies of rotational stocking management

Grazing management strategies affect not only herbage accumulation but also the efficiency of grazing. This study aimed to evaluate herbage accumulation (leaf, stem and dead material), grazing efficiency and losses of mulato grass (a Brachiaria ruziziensis × Brachiaria brizantha cv. Marandu hybrid) subjected to strategies of rotational stocking management. Treatments consisted of combinations between two post-grazing heights (15 and 20 cm) and two pre-grazing conditions (95 % and maximum canopy light interception (LI)) assigned to experimental units (1200-m² paddocks) according to a 2 × 2 factorial arrangement and a randomized complete block design, with four replications. The experiment was carried out from Jan 2008 to Mar 2009. Season of the year influenced almost all studied variables, resulting in a common pattern of response that was determined by pre- and post-grazing management targets. Herbage accumulation was greater on swards managed at 95 %, with higher accumulation of leaves and lower accumulation of stem and dead material in relation to those managed at maximum LI (99 %) during the entire experimental period. On the other hand, herbage removal by grazing was larger on swards managed at 99 % LI, which was compensated for by the smaller number of grazing cycles and larger losses due to grazing under those circumstances. Under rotational stocking, the pre-grazing LI of 95 % and post-grazing height of 20 cm resulted in efficient grazing and high producing leafy pastures, highlighting the potential of Mulato grass pastures for animal production.

Morphogenetic and structural comparative characterization of tropical forage grass cultivars under free growth

Understanding of the morphogenetic characteristics allows comprehension of aspects related to the form and function of forage plants, providing opportunities to identify potentially high productive plants and distinct defoliation management requirements. The objective of this experiment was to carry out a comparative study of ten tropical forage grasses using morphogenetic and structural variables. Treatments corresponded to grasses of the Panicum genus (P. maximum cultivars Tanzânia and Mombaça) and the Brachiaria genus (B. brizantha cultivars Piatã, Marandu, Xaraés, Capiporã and Arapoty; B. decumbens cultivar Basilisk; B. humidicola cultivars Comum and Tupi), evaluated under free growth conditions.. Response variables were leaf appearance and elongation rates, phyllochron, stem elongation rate, final leaf length, number of live leaves per tiller, leaf life span and tiller appearance, death and survival rates. There was difference between cultivars for these variables, indicating a large variability within plants. Considering the morphogenetic and structural variables of leaves and tillers, B. brizantha had a similar pattern of variation to those of P. maximum, and B. Decumbens, similar to those of B. humidicola. Tiller appearance was large at the onset of the experiment and second and third generations comprised the large majority of tiller population for the cultivars Mombaça, Tanzânia, Xaraés and Capiporã. Group analysis based on plant morphogenetic and structural characteristics of leaves and tillers was an interesting way of grouping cultivars, indicating the importance and the potential of using morphogenesis in plant selection and evaluation programmes.

O estudo das características morfogênicas permite compreender aspectos relativos à forma e função das plantas forrageiras além de possibilitar identificar plantas com potenciais produtivos e exigências de manejo diferentes. O objetivo deste trabalho foi avaliar, comparativamente, dez plantas forrageiras tropicais por meio de variáveis morfogênicas e estruturais. Os tratamentos corresponderam a cultivares pertencentes ao gênero Panicum (P. maximum cvs. Tanzânia e Mombaça) e ao gênero Brachiaria (B. brizantha cvs. Piatã, Marandu, Xaraés, Capiporã, e Arapoty; B. decumbens cv. Basilisk; B. humidicola cvs. Comum e Tupi), avaliados sob condições de crescimento livre. Foram avaliadas a taxa de aparecimento e alongamento de folhas, filocrono, taxa de alongamento de colmos, comprimento final da lâmina foliar, número de folhas vivas por perfilho, duração de vida das folhas e padrão demográfico de perfilhamento. Houve diferença entre cultivares para as variáveis, indicando grande variabilidade no material estudado. Considerando as características morfogênicas e estruturais de folhas e perfilhos, as B. brizantha apresentaram comportamento parecido com os P. maximum, e B. decumbens mais próximo das B. humidicola. Verificou-se que o aparecimento de perfilhos foi inicialmente elevado e que a segunda e, ou, terceira gerações contribuíram de forma significativa para o número total de perfilhos dos cultivares Mombaça, Tanzânia, Xaraés e Capiporã. A análise de agrupamento baseada nas características morfogênicas e estruturais de folhas e perfilhos foi um método interessante para agrupar cultivares, demonstrando a importância e o potencial de uso da morfogênese em trabalhos de seleção e avaliação de plantas forrageiras.

Morphogenetic and structural comparative characterization of tropical forage grass cultivars under free growth

Understanding of the morphogenetic characteristics allows comprehension of aspects related to the form and function of forage plants, providing opportunities to identify potentially high productive plants and distinct defoliation management requirements. The objective of this experiment was to carry out a comparative study of ten tropical forage grasses using morphogenetic and structural variables. Treatments corresponded to grasses of the Panicum genus (P. maximum cultivars Tanzânia and Mombaça) and the Brachiaria genus (B. brizantha cultivars Piatã, Marandu, Xaraés, Capiporã and Arapoty; B. decumbens cultivar Basilisk; B. humidicola cultivars Comum and Tupi), evaluated under free growth conditions.. Response variables were leaf appearance and elongation rates, phyllochron, stem elongation rate, final leaf length, number of live leaves per tiller, leaf life span and tiller appearance, death and survival rates. There was difference between cultivars for these variables, indicating a large variability within plants. Considering the morphogenetic and structural variables of leaves and tillers, B. brizantha had a similar pattern of variation to those of P. maximum, and B. Decumbens, similar to those of B. humidicola. Tiller appearance was large at the onset of the experiment and second and third generations comprised the large majority of tiller population for the cultivars Mombaça, Tanzânia, Xaraés and Capiporã. Group analysis based on plant morphogenetic and structural characteristics of leaves and tillers was an interesting way of grouping cultivars, indicating the importance and the potential of using morphogenesis in plant selection and evaluation programmes.

O estudo das características morfogênicas permite compreender aspectos relativos à forma e função das plantas forrageiras além de possibilitar identificar plantas com potenciais produtivos e exigências de manejo diferentes. O objetivo deste trabalho foi avaliar, comparativamente, dez plantas forrageiras tropicais por meio de variáveis morfogênicas e estruturais. Os tratamentos corresponderam a cultivares pertencentes ao gênero Panicum (P. maximum cvs. Tanzânia e Mombaça) e ao gênero Brachiaria (B. brizantha cvs. Piatã, Marandu, Xaraés, Capiporã, e Arapoty; B. decumbens cv. Basilisk; B. humidicola cvs. Comum e Tupi), avaliados sob condições de crescimento livre. Foram avaliadas a taxa de aparecimento e alongamento de folhas, filocrono, taxa de alongamento de colmos, comprimento final da lâmina foliar, número de folhas vivas por perfilho, duração de vida das folhas e padrão demográfico de perfilhamento. Houve diferença entre cultivares para as variáveis, indicando grande variabilidade no material estudado. Considerando as características morfogênicas e estruturais de folhas e perfilhos, as B. brizantha apresentaram comportamento parecido com os P. maximum, e B. decumbens mais próximo das B. humidicola. Verificou-se que o aparecimento de perfilhos foi inicialmente elevado e que a segunda e, ou, terceira gerações contribuíram de forma significativa para o número total de perfilhos dos cultivares Mombaça, Tanzânia, Xaraés e Capiporã. A análise de agrupamento baseada nas características morfogênicas e estruturais de folhas e perfilhos foi um método interessante para agrupar cultivares, demonstrando a importância e o potencial de uso da morfogênese em trabalhos de seleção e avaliação de plantas forrageiras.

Carbohydrate and protein fractions of mesquite ("Prosopis juliflora" (Sswartz) D. C.) pods meal and its different component parts / Fracionamento dos carboidratos e componentes nitrogenados do farelo e diferentes partes integrantes da vagem de algaroba ("Prosopis juliflora" (Swartz ) d. c.)

The objective of this study was evaluate the chemical analyses, in vitro dry matter true digestibility (IVTDMD) and carbohydrate and protein fractions of mesquite pods meal treated (80C/10 - 12 h) or without heat treatment (FVACTT e FVASTT, respectively), and from the component parts of the pods. The treatments were: exocarp (EXVA), mesocarp and endocarp (EMVA), seeds (SVA) and the pod meals submitted or not to heating. Nitrogenous fractions were divided into fractions: A (non protein nitrogen; NPN), B1 + B2 (true protein fractions with fast and intermediate enzymatic degradations), B3 (true protein fraction with enzymatic degradation) and C (indigestible protein). Total carbohydrates were estimated as follows: TC = 100 (crude protein + ether extract + ash). Carbohydrate fractions were: A + B1 (sugars and organic acids plus starch and pectin, respectively), B2 (available fiber) and C (indigestible fiber). Crude protein values were: FVASTT 8.89%, FVACTT 8.72%, SVA 44.22%, EMVA 9.69%, EXVA 8.45%. Structural carbohydrate values were: FVASTT: 28.34% for NDF and 17.74% for ADF and for FVACTT: 31.52% NDF and 18.46% ADF. IVTDMD result for FVASTT was 73.04%, while for FVACTT was 69.21%. Nitrogenous fractions in mesquite pods meal indicated higher contribution of fractions A, B1 and B2. Heat treatment of mesquite pods meal raised the cellular wall component va

O objetivo deste trabalho foi realizar análises químicas, a digestibilidade verdadeira in vitro da matéria seca (DVIVMS) e a separação das frações de carboidratos e compostos nitrogenados, no farelo de vagem de algaroba com (80C/10 12 h) ou sem tratamento térmico (FVACTT e FVASTT, respectivamente) e das partes que compõem a vagem, como se segue: exocarpo (EXVA), endocarpo e mesocarpo (EMVA), as sementes da vagem de algaroba (SVA). Os compostos nitrogenados foram fracionados em: A (nitrogênio não protéico), B1 + B2 (proteína verdadeira de degradação enzimática rápida e intermediária, respectivamente), B3 (proteína verdadeira que apresenta degradação enzimática lenta) e C (proteína indigestível). As frações que compõem os carboidratos totais (CT) foram estimadas como: CT = 100 (PB + EE + MM). Os carboidratos foram fracionados em: carboidratos não-fibrosos (CNF), que correspondem às frações A + B1 (açúcares solúveis, ácidos orgânicos somados ao amido e a pectina, respectivamente), B2 (fibra disponível) e C (fibra indigerível). Para a proteína bruta (PB), obteve-se: FVASTT 8,89%, FVACTT 8,72%, SVA 44,22%, EMVA 9,69%, EXVA 8,45%. Encontrou-se no FVASTT 28,34% de FDN e 17,74% de FDA e no FVACTT, 31,52% de FDN e 18,46% de FDA. A DVIVMS do FVASTT foi igual a 73,04% e a do FVACTT igual a 69,21%. O fracionamento dos compostos nitrogenados apresentou maior participação

Carbohydrate and protein fractions of mesquite ("Prosopis juliflora" (Sswartz) D. C.) pods meal and its different component parts / Fracionamento dos carboidratos e componentes nitrogenados do farelo e diferentes partes integrantes da vagem de algaroba ("Prosopis juliflora" (Swartz ) d. c.)

The objective of this study was evaluate the chemical analyses, in vitro dry matter true digestibility (IVTDMD) and carbohydrate and protein fractions of mesquite pods meal treated (80C/10 - 12 h) or without heat treatment (FVACTT e FVASTT, respectively), and from the component parts of the pods. The treatments were: exocarp (EXVA), mesocarp and endocarp (EMVA), seeds (SVA) and the pod meals submitted or not to heating. Nitrogenous fractions were divided into fractions: A (non protein nitrogen; NPN), B1 + B2 (true protein fractions with fast and intermediate enzymatic degradations), B3 (true protein fraction with enzymatic degradation) and C (indigestible protein). Total carbohydrates were estimated as follows: TC = 100 (crude protein + ether extract + ash). Carbohydrate fractions were: A + B1 (sugars and organic acids plus starch and pectin, respectively), B2 (available fiber) and C (indigestible fiber). Crude protein values were: FVASTT 8.89%, FVACTT 8.72%, SVA 44.22%, EMVA 9.69%, EXVA 8.45%. Structural carbohydrate values were: FVASTT: 28.34% for NDF and 17.74% for ADF and for FVACTT: 31.52% NDF and 18.46% ADF. IVTDMD result for FVASTT was 73.04%, while for FVACTT was 69.21%. Nitrogenous fractions in mesquite pods meal indicated higher contribution of fractions A, B1 and B2. Heat treatment of mesquite pods meal raised the cellular wall component va

O objetivo deste trabalho foi realizar análises químicas, a digestibilidade verdadeira in vitro da matéria seca (DVIVMS) e a separação das frações de carboidratos e compostos nitrogenados, no farelo de vagem de algaroba com (80C/10 12 h) ou sem tratamento térmico (FVACTT e FVASTT, respectivamente) e das partes que compõem a vagem, como se segue: exocarpo (EXVA), endocarpo e mesocarpo (EMVA), as sementes da vagem de algaroba (SVA). Os compostos nitrogenados foram fracionados em: A (nitrogênio não protéico), B1 + B2 (proteína verdadeira de degradação enzimática rápida e intermediária, respectivamente), B3 (proteína verdadeira que apresenta degradação enzimática lenta) e C (proteína indigestível). As frações que compõem os carboidratos totais (CT) foram estimadas como: CT = 100 (PB + EE + MM). Os carboidratos foram fracionados em: carboidratos não-fibrosos (CNF), que correspondem às frações A + B1 (açúcares solúveis, ácidos orgânicos somados ao amido e a pectina, respectivamente), B2 (fibra disponível) e C (fibra indigerível). Para a proteína bruta (PB), obteve-se: FVASTT 8,89%, FVACTT 8,72%, SVA 44,22%, EMVA 9,69%, EXVA 8,45%. Encontrou-se no FVASTT 28,34% de FDN e 17,74% de FDA e no FVACTT, 31,52% de FDN e 18,46% de FDA. A DVIVMS do FVASTT foi igual a 73,04% e a do FVACTT igual a 69,21%. O fracionamento dos compostos nitrogenados apresentou maior participação