Alexandre Fernandes Perazzo

Agronomic divergence of sorghum hybrids for silage yield in the semiarid region of Paraiba

The objective of this study was to evaluate the agronomic divergence of 25 sorghum hybrids (Sorghum bicolor L. Moench) in the semiarid region of Paraiba. A randomized block design with three replications was used for evaluation of plant height (PH), total natural matter production (TNMP) and total dry matter production (TDMP) and the percentage of components of DM (panicle, leaf blade, stem and dead matter) of the following hybrids: 866005, 866019, 866033, 866034, 866035, 866036, 866037, 866040, 866041, 866042, 866043, 866044, 870025, 870031, 870035, 870041, 870051, 870067, 870081, 870085, 870095, 1F305, BRS 610, Volumax, and XBS60329. Hybrid 1F305, followed by hybrid 866034, presented the highest average PH. There was a range from 7.679 to 20.948 kg/ha (average of 13,799 kg/ha) for TDMP. Hybrids 1F305, BRS 610 and Volumax presented less potential, and hybrids 866,041 and 866,042 were the most productive. Based on cluster analysis and subjective cut in 50% of dissimilarity, it was possible to establish four hierarchical groups, from which two stood out concerning productive characteristics. The group formed by hybrids Volumax, BRS 610, and XBS60329 presented lower averages for yield and lower percentage of panicle. Hybrids 866041 and 866042 show a higher total dry matter production, with values around 20,000 kg/ha.

Morfogênese e estrutura de Brachiaria decumbens em resposta ao corte e adubação nitrogenada

Objetivou-se avaliar as caracteristicas morfogenicas e estruturais do pasto de Brachiaria decumbens, submetido a intensidades, fre- quencias de corte e adubacao nitrogenada. O delineamento experimental foi em blocos casualizados em esquema de parcelas subdividi- das, tendo na parcela o arranjo fatorial 2 x 2 referente a combinacoes entre duas alturas de corte (40 e 50 cm) e duas alturas de residuo (15 e 25 cm) e nas sub-parcelas a adubacao nitrogenada (com ou sem nitrogenio), com quatro repeticoes. As variaveis analisadas para as ca- racteristicas morfogenicas foram: taxa de alongamento foliar (TAlF); taxa de alongamento de colmo (TAlC); taxa de aparecimento foliar (TApF); taxa de senescencia foliar (TSF) e filocrono; e para as caracteristicas estruturais foram: numero de perfilhos basais (NPB); numero de folhas totais (NFT); numero de folhas aparecidas (NFAp); nu- mero de folhas mortas (NFM); numero de folhas vivas (NFV) e comprimento final da folha (CFF). A utilizacao de 100 kg/ha de N permitiu aumento (p<0,10) na TAlF de 31,58% e 126,32%, respec- tivamente para os residuos de 15 e 25 cm. O NPB em comparacao as alturas de corte (40 e 50 cm) foi afetado (p<0,10) apenas com a utilizacao da adubacao nitrogenada, observando-se media de 145,62 perfilhos/m 2 para a altura de corte 50 cm. A altura de residuo 25 cm combinada com a altura de corte 40 cm, junto a aplicacao de 100 kg/ha de N, promovem maior producao de materia seca total em menor espaco de tempo (28 dias), permitindo maiores taxas de lotacao e facilitando o manejo no sistema de lotacao rotacionada.

Cinética de fermentação ruminal in vitro de silagens de híbridos de sorgo

The aim of this research was to evaluate the silage of 23 sorghum hybrids using the in vitro semi-automatic gas production technique. A completely randomized design with 23 treatments was used, with three replications, and treatments were the sorghum-hybrids silages. Hybrids were grown at the experimental station of the Instituto Nacional do Semiarido (INSA), in Campina Grande - PB. The gas production was estimated using the bicompartimental logistic model, adjusted to the curves of cumulative gas production. A significant effect (P<0.05) was observed for final gas of fibrous carbohydrates (VfCF), which results ranged from 105.99 to 144.53mL/g of DM. Degradation rate of fibrous carbohydrates (KdCF) values ranged (P<0.05) for the hybrid 866041, which showed the highest result 0.015h-1. Final total volume (VFT) was affected by hybrid (P<0.05), in which hybrids 870085, Volumax and XBS60329 had the highest (P<0.05) values compared to other hybrids. By multivariate analysis were formed six distinct groups. Group 2, consisting of hybrids 22 (Volumax) and 23 (XBS60329) showed the highest average values for gas volumes, both for fibrous carbohydrates and for the non-fibrous. Group 4, comprising the hybrid 1 (866005), had the lowest gas volume produced means and a highest lag time (3.15 hours). All hybrids studied have potential to silage, according to the ruminal fermentation kinetics.

Importance of the Fermentation to Produce High-Quality Silage

The objective of this chapter was to discuss the importance of the fermentation processes for silage making and how it affects the final quality of the silage. The preservation of the forage crops as silage is based on a fermentation process that lows the pH and preserves the nutritive value of the fresh crop. The main principle is the production of lactic acid by the lactic acid bacteria from the metabolism of the water-soluble carbohydrates in the fresh crop. However, different fermentations may occur into the silo environment and it depends on the availability of substrate, the microbial populations, the moisture content, and the buffering capacity of the crop at the ensiling. The fermentation is quite important in the ensiling process because it affects the nutritional quality of the silage and the animal performance. If the fermentation does not occur as recommended and the undesirable fermentations will take place, which will result in a total spoiled feed that is potentially risky for animals and human’s health. Well-fermented silage can be used in diets for ruminant animals without any risk for their health and without compromise the productive performance.

Perfil Fermentativo de Silagens de Capim Tanzânia Contendo Diferentes Concentrações de Farelo de Algaroba

Objetivou-se com este estudo a avaliacao do perfil fermentativo de silagens de capim Tanzânia contendo diferentes concentracoes de algaroba. Os teores de acido latico, acetico, propionico e butirico aumentaram (P<0,05) quadraticamente com os niveis do farelo de algaroba, havendo um decrescimo a partir do tratamento com 20% de inclusao do farelo de algaroba. Os valores para pH diminuiram com a inclusao do farelo de algaroba, chegando a valores abaixo do normal. Foi encontrado valores medios satisfatorios para acido latico apenas para os niveis com 10 e 20%, com 3,81 e 3,32, respectivamente. Mesmo com a diminuicao do pH e provavel diminuicao da materia seca com aumentos dos niveis concentracao de algaroba houve alta incidencia do acido butirico e propionico. O farelo de algaroba nao foi eficiente em melhorar os parâmetros fermentativos da silagem de capim Tanzânia. DOI:10.15528/2176-4158/rcpa.v14n1p39-42